The pepper is a widely cultivated vegetable and its domestication and dissemination history have received significant attention from the academic community. This article summarizes the pathways of pepper’s dissemination worldwide. The wild pepper species originated in the northwestern part of the Andes Mountains in South America and expanded, spread, and evolved in South and Central America. The Capsicum cultivars migrated outward from Mexico and underwent parallel domestication in multiple regions. After Christopher Columbus brought peppers back to Spain from South America, they began to spread to other European countries and eventually spread throughout Central Europe by the mid-16th century. Simultaneously, a large number of pepper varieties introduced into Asia, Africa, and Eastern Europe via the “Eurasian Trade Route” and the “Galleon Trade Route”. The prevalent slave trade in the 17th century further facilitated the comprehensive dissemination of peppers in Africa and North America. With the development of global trade, the Capsicum cultivars from different regions were exchanged more extensively. Among them, C. annuum spread to Asia, Africa, North America, Oceania, and Eastern Europe, becoming the most widely cultivated peppers worldwide. C. frutescens and C. chinense were introduced to Eastern Europe, tropical regions of Africa, and Asia, while C. baccatum and C. pubescens are mainly grown in Central and South America, Indonesia, and South Africa. Genomic research results have provided important genetic evidence for the global dissemination history of pepper, while also offering a new perspective for the study of pepper evolution.
Self-incompatibility is a genetic mechanism to prevent self-fertilization and the consequent inbreeding and fitness decay in plant populations. In the gametophyte self-incompatibility mechanism represented by Solanaceae, Rosaceae and Plantaginaceae, the self/non-self recognition between pollen and pistil is determined by the polymorphic S locus. SLF (S-locus F-box)/SFB (S-haplotype-specific F-box) gene is the pollen S determinant of gametophyte self-incompatibility. In this study, 21 SLF/SFB family genes were screened and identified based on the genome-wide of the pineapple. Each AcSLF gene had an F-box conserved domain at the N-terminal. There were great differences in amino acid length, theoretical isoelectric point and molecular weight. The size range of the encoded amino acid sequence was 242-612 aa, and the molecular weight was 27.778-69.070 kDa. The isoelectric point ranged from 5.70 to 9.57. 18 AcSLF proteins were alkaline and most proteins were unstability, only AcSLF19, AcSLF21 were stability. It was predicted that 18 AcSLF proteins were located in the nucleus, one AcSLF protein in chloroplast, two AcSLF protein in both chloroplast and nucleus, and more than 60% of the secondary structure of the protein was composed of alpha helix and random coil. Bioinformatics analysis showed that the pineapple SLF/SFB family genes, which were unevenly distributed on 14 chromosomes, and the chromosome location of AcSLF21 was undetermined. Furthermore, AcSLF4, AcSLF5, AcSLF6, AcSLF8, AcSLF14 and AcSLF15 were linked with RNase T2 family genes, this was one of the main characteristics of pollen SLF gene. AcSLF genes contained different numbers of introns, most of which contained 1~2 introns, and AcSLF3 contained 4 introns. Based on the above analysis results, it showed that AcSLF proteins had different characteristics. Phylogenetic analysis indicated that the evolutionary relationship of AcSLFs in pineapple was far away from the SLF/SFB in Rosaceae, Plantaginaceae and Solanaceae, the degree of clustering was low on the branches of evolutionary tree. The expression levels of the AcSLF genes in pistil, stamen, leaf, sarcocarp, stem and root were analyzed by qRT-PCR. The results showed that AcSLFs had obvious expression differences in different tissues of pineapple. AcSLF1, AcSLF2, AcSLF4, AcSLF9, AcSLF10, AcSLF11, AcSLF15, AcSLF19, AcSLF20 and AcSLF21 genes were highly expressed in pineapple stamens. The expression of AcSLF3 and AcSLF7 in sarcocarp was higher than that of other tissue, and AcSLF5, AcSLF12, AcSLF18 were higher expression in root than other tissues. In general, most pineapple AcSLF genes are mainly expressed in pineapple stamens or leaves. It was found that the expression of AcSLF1, AcSLF2, AcSLF15 genes in pollinated pistil were significantly up-regulated than that in non-pollinated pistil. Especially at 6 h after cross-pollination, the expression level was significantly higher than that of non-pollinated pistils. With the extension of the pollen tube in the pistil, the expression level decreased, but it still had a high expression at 24 h after pollination. And the expression trend of AcSLF1, AcSLF2 and AcSLF15 in cross-pollination was consistent with the growth of pollen tube in the pistil. Therefore, it is speculated that AcSLF1, AcSLF2 and AcSLF15 play an important role in pineapple self-incompatibility. This is the first time to analyze the expression pattern of SLF/SFB family genes in pineapple. This study would provide a reference for the cloning of pineapple SLF/SFB family genes, and basis for the study of pineapple self-incompatibility mechanism.
Abstract: In order to screen out the key metabolites that control the fragrance of areca nut, enhance the fragrance of areca nut, attract more pollinators, and then increase the yield of areca nut. In this study, Headspace Solid Phase Microextraction Gas Chromatography-Mass Spectrometry Combined Analysis Technology was used for non-targeted metabolomic detection of areca nut flowers in different periods. 236 metabolites were detected in the study. 75 differential metabolites were screened by combining VIP value and differential fold. Main metabolites were terpenes, ketones, alcohols. Among them, the volatile compounds of female flowers of Areca accumulated a lot from the female flower unopened stage to the initial blooming stage, and decreased slightly in the full bloom stage, so the initial blooming stage of female flowers of Areca may be the key period for the formation of female flower fragrance. The volatile compounds in the male flowers of Areca accumulated a lot from the initial blooming stage to the blooming stage, so the blooming stage of male flowers may be the key period for the formation of flower fragrance of male flowers of Areca. KEGG database was used to analyze the metabolic pathways of differential metabolites. The fatty acid biosynthesis was the metabolic pathway that was significantly enriched in the female flowers of areca nut and related to flower aroma synthesis, and the substance enriched in this pathway was capric acid. Capric acid is a fatty acid, which is mostly used in plant physiology and signal transmission and other functions. The capric acid content in the female flowers of betel nut increased from the unopened stage to the early flowering stage, and the release of floral fragrance also increased correspondingly. This may be because areca nut starts pollination at the beginning of female flower, and more chemical signals are needed to be transmitted to attract pollinators. So capric acid may be a chemical signal released by betel nut female flowers for pollination. Metabolic pathways significantly enriched in male areca nut flowers and related to flower aroma synthesis are diterpenoid biosynthesis and fatty acid degradation. Palmitaldehyde and (4aR,6aS,9R,11aR,11bR)-4,4,11b- trimethyl-8-methylene tetrahydro-6a and 9-methylcycloheptyl [a] naphthalene were enriched in two pathways. (4aR, 6aS,9R,11aR,11bR)-4,4,11b-trimethyl-8-methylenetetrahydro-6a,9-methylcyclohept[a]naphthalene is a terpenoid. Its enantiomer, ent-kaurene, is synthesized by ring-opening of trans-geranylgeranyl pyrophosphate with the use of kaurine synthase and is a precursor ofgibberellin. The content of this substance was down-regulated from the early flowering period to the full bloom period of male flowers, which may be due to the decrease of the required gibberellin content in male flowers during the full bloom period. Palmitaldehyde is an aldehyde substance, which is a metabolite released by the biodegradation of fatty acids. The release of the fragrance of areca nut male flowers increased from the early blooming stage to the blooming stage, and the content of palmitaldehyde also increased. There is a positive correlation between these two situations. In conclusion, the above three metabolites may be the key metabolites that affect the fragrance of areca nut.
Cellulose is one of the main components of plant roots, and plays a key role in lodging resistance. CesA7 is for cellulose synthesis, but its function is unknown in sugarcane. Rice OsCesA7 gene was used as the reference sequence to conduct homology analysis and functional prediction in the genomes of Sacchrum spontaneum, S. hybrid and S. officinarum. Phylogenetic analysis showed that CesA7 in S. hybrid was closer to that in S. officinarum, and grasses were clustered together, but herbs and woody plants could not be separated clearly. The promoter region of the sugarcane CesA7 genes had abundant light-responsive elements and methyl jasmonate element, indicating that the gene may be involved in the photomorphogenesis and the stress resistance response in sugarcane. Interaction prediction of the protein and analysis of the promoter indicated that CesA7 had interaction with MYB transcription factor, suggesting that CesA7 played a role in crop growth and development and stress response. In addition, functional predictions of CesA proteins in rice and sorghum showed involvement in regulating cellulose synthesis and lignin degradation processes. Transcriptomic analysis of roots and leaves of seven representative species of sugarcane at seedling stage revealed that CesA7 expression level in roots was much higher than that in leaves, suggesting that CesA7 might regulate sugarcane root development. The SNP variation of the gene was detected in the germplasm of sugarcane, and the nucleotide diversity was the highest in S. spontaneum. The nucleotide diversity in the exon region was significantly higher than that in the intron region, and the highest diversity was found in the region of exon 4 (about 2000 bp) of the gene. It is speculated that the functional differentiation of different alleles are caused by the balancing selection of this locus. After multiple sequence alignment combined with resequencing data analysis, two potential molecular markers were identified, which could distinguish S. spontaneum and S. officinarum samples. The study would provide theoretical guidance for subsequent research and use of CesA7 gene to improve sugarcane variety.
Noni fruit is a characteristic fruit of Hainan with a variety of medicinal effects, but there are few studies on its plant proteins. In the present study, two-dimensional gel electrophoresis (2-DE gel) technology based on the BPP+phenol extraction method was used to extract and separate the proteins of noni fruits at different ripening stages including bud stage, half ripe stage, and mature stage by optimizing the experimental conditions to obtain the fingerprint of plant proteins. The gel images were analyzed by Image Master 5.0 software and some proteins with high expression were screened out. The enzymatic hydrolysates of the proteins were further identified by using MALDI-TOF-MS technology. The functional analysis of the highly expressed proteins of three kinds of noni fruits were preliminarily carried out by bioinformatics methods. The results indicated that there were respectively forty four, forty nine, and forty highly expressed proteins at three maturites noni fruits. Among the proteins, there were respectively thirty three, twenty two and thirty nine proteins by mass spectrum identification, which subordinated to various types of protein with different plant functions. Moreover, significant difference existed in the highly expressed proteins of different maturity stages, which involved in a variety of proteins such as chloroplastic ligase, cysteine proteinase, protein kinase, ubiquitin ligase, and auxin response factors. It could provided a scientific and reasonable theoretical guidance for the further development and utilization of the plant protein of noni fruits.
Dendrobium sinense is a tropical plant endemic to Hainan Island with great ornamental and medicinal values. However, unascertained reference genes restrict the quantitative analysis of gene expression in the species. In this study, using our previous transcriptome data of D. sinense, the 164 candidate genes were identified with low variance (CV≤0.2) and moderate expressions (TPM between 10-300). By GO clustering, 24 candidate genes were selected from different functional groups to avoid the effect of co-expression on further stability analysis. In order to avoid the false positive of genomic DNA that may remain in the template during RT-qPCR amplification, primers across introns were designed in this study, and amplification primers that met the requirements of 15 candidate reference genes were screened by electrophoresis. To ensure the specificity of RT-qPCR amplification, LightCycler 96 was used for melting curve analysis. According to the RT-qPCR data of 15 candidate genes, four tools were used to evaluate the expression stability. The results of multiple algorithm analysis showed that CLP1 & SEC23, SEC23 & CPY71, CLP1 & SEC23 and RNG1L & PECT were the best reference genes under drought stress. After comprehensive sorting, SEC23 and CLP1 were selected as the most stable reference genes under drought stress. In different tissues of D.sinense, ADF11 & IBR5, PRP19 & CLP1, ADF11 & CLP1, ACBP2 & IBR5 were identified as the best reference genes, respectively. After comprehensive analysis, ADF11 and ACBP2 were identified as the most stable reference genes in different tissues. Combined with the above drought stress and different tissue analysis data, IBR5 and CPY71 were finally determined as stable reference genes under comprehensive conditions. The validation of internal reference genes showed that compared with the traditional Actin internal reference, the internal reference genes screened in this study could obtain more accurate RT-qPCR calibration results, indicating that the generated internal reference genes had extremely high stability. In summary, this study provides ideas for identifying stable reference genes using transcriptome data. For the first time, stable reference genes were identified in the whole genome of D.sinense, which laid a foundation for further study of gene expression and function.
Starch branching enzyme (SBE) play a key role in amylopectin biosynthesis and directly influence the content and structure of starch. Taro is a major tuber crop, widely cultivated in tropical and subtropical regions of the world. At present, there are few studies on SBE in taro, and the number, molecular structural characteristics and expression patterns of SBE genes in taro are not clear. In this study, a comprehensive analysis of taro SBE genes was conducted for the first time, and three SBE genes (CeSBE1, CeSBE2 and CeSBE3) were identified. The amino acid numbers of CeSBE1, CeSBE2 and CeSBE3 proteins was 828, 845 and 598, respectively, with molecular mass of 92 956.71 Da, 95 625.13 Da and 69 169.16 Da, and isoelectric point of 5.22, 5.41 and 7.36, respectively. Phylogenetic analysis showed that the three CeSBE proteins were divided into three different subgroups. Gene structure analysis showed that the number of CeSBE1, CeSBE2 and CeSBE3 exons was 16, 22 and 10, respectively. Conservative structural domain analysis showed that both CeSBE1 and CeSBE2 proteins had α-amylase_C and α-amylase structural domains and 7 motifs, while CeSBE3 protein had α-amylase and CBM_48 structural domains and 3 motifs. Analysis of cis-acting elements in the promoter region of CeSBE gene showed that a total of 55 cis-acting elements were predicted, 29 of which were functionally annotated, involving elements related to light response, hormone response, plant growth and development, and environmental stress. The three CeSBE genes were expressed in all tissues, with CeSBE2 being significantly expressed in corms and leaves (P<0.05). At different developmental stages of the corm, CeSBE2 had high expression at all developmental stages, showing a trend of increasing and then decreasing expression, with peak expression at 120 d of corm development. The increase in total starch and amylopectin content at different developmental stages of the corm was consistent with the trend of CeSBE2 expression, suggesting that CeSBE2 may be a key gene for amylopectin biosynthesis in taro. The study would enhance the understanding of CeSBE gene family members and provide the basis for genetic improvement of yield, quality and nutritional traits in taro.
Breadfruit is considered as the most potential food crop to solve tropical famine with high economic value. Breadfruit was introduced from several countries, and there are no research on the systematic taxonomic and genetic diversity analysis about it. The objective of this study was to specify the genetic distance and relationship among breadfruit and its closest wild relatives. For genetic diversity analysis, 33 pairs of SSR primers with clear amplified bands, high polymorphism and good stability were selected from 75 pairs of SSR primers. PCR amplification was performed, and the products were detected by 8% denaturing polyacrylamide gel. Genetic diversity correlation analysis was performed by NTSYS software. The results showed that the polymorphism ratio of amplified bands of the 33 SSR markers was 94.57%. 199 number of polymorphic sites were detected, with an average of 6.030 per marker. The PIC values of the SSR markers ranged from 0.623 to 0.940, with an average of 0.865. The genetic similarity coefficients among the breadfruit resources ranged from 0.517 to 0.951, with an average genetic similarity coefficient of 0.685. Furthermore, germplasm ZZP possessed the greatest variation among individuals, with an average genetic similarity coefficient of 0.626. Germplasm XYS1-3 possessed the least variation among individuals, with an average genetic similarity coefficient of 0.723. At the genetic similarity coefficient of 0.713, the 30 breadfruit resources were clustered into five groups, with XBL and breadnut type I (ZZP, LX, STH, HJ5) which used for landscaping clustered into one group, breadfruit SLLK, XYS2, XYS3, XYS5, XYS6 and YN clustered into one group, breadnut type Ⅱ SLM2, YDNXY1, G1 and G2 clustered into one group, breadnut type Ⅱ W1, W3, SMY, 8-4, 8-3, 5-5 and 5-6 clustered into one group. The three-dimensional diagram could better distinguish XBL and breadnut type I ZZP, LX, STH, HJ5 from the breadfruit and breadnut type Ⅱ resource with edible value. Based on the cluster analysis, we speculated that XYS2, XYS3, XYS5 and XYS6 might be introduced from Vietnam, XYS1-3, YBG and XYS1 might be introduced from Indonesia. Furthermore, FJ was regarded as a breadfruit germplasm. The present study reported the genetic diversity of breadfruit resources in China firstly, and elucidated the genetic relationship among breadfruit resources. In addition, the results could provide theoretical basis for variety breeding and identification of breadfruit complex.
The study of the leaf anatomical structure of macadamia germplasm resources and its drought resistance was aimed to provide theoretical basis for macadamia seed breeding, introduction and cultivation. 11 leaf anatomical parameters of 20 macadamia germplasm resources were analyzed and compared using paraffin section technique. The drought resistance of different germplasm resources was comprehensively evaluated by the principal component analysis, membership function method and systematic clustering method. The results showed that macadamia leaves were typical leaves with different faces, and there were significant differences among the anatomical structure indexes of different germplasm resources (P<0.01). Principal component analysis showed that the order of the eleven indexes reflecting the drought resistance of macadamia was thickness of palisade parenchyma thickness>leaf thickness>cell tense ratio>palisade/spongy tissue>sponge ratio>upper cuticle thickness>lower epidermis thickness>upper epidermis thickness>lower cuticle thickness>midrib thickness>spongy parenchyma thickness. According to the membership function method and the weight of each index, the order of drought resistance of the 20 macadamia germplasm resources was as follows: No. 1>No. 19>No. 5>No. 10>No. 14>No. 11>No. 16>No. 7>No. 2>No. 20>No. 8>No. 13>No. 18>No. 15>No. 9>No. 3>No. 6>No. 4>No. 17>No. 12. After “Z-score” standardization, the 20 germplasm resources were classified into 3 groups at 15 genetic distances. No. 1, No. 5, No. 10, No. 11, No. 14, No. 16 and No. 19 had thicker leaves, developed palisade tissue, higher palisade/spongy tissue and cell tense ratio than other germplasms, and had higher water retention and photosynthetic capacity, so they were high drought-resistant groups. The leaves, epidermis and cuticle of No. 3, No. 4, No. 6, No. 9, No. 12, No. 15 and No. 17 were thin, and the leaves were relatively loose, showing low drought resistance, so they were low drought resistance groups. The drought resistance of other germplasms was in the middle.
Based on specimen diagnostics and literature studies, six new records of Angiosperm in Guizhou Province were reported, namely Lepidium didymum L. (Brassicaceae), Lactuca serriola L. (Asteraceae), Dactylicapnos lichiangensis (Fedde) Hand.-Mazz. (Papaveraceae), Dinetus duclouxii (Gagnep. & Courch.) Staples (Convolvulaceae), Zingiber atrorubens Gagnep. (Zingiberaceae), Carex phyllocephala T. Koyama (Cyperaceae). Main morphological identification characteristics, distribution descriptions, voucher specimens and photographs were provided for all species, and the systematic position changes of some species were also discussed. The voucher specimens were deposited in the Herbarium of the Natural Museum of Guizhou University (GACP).
Leaf anatomy, plant growth traits and leaf ecological stoichiometry were analyzed in 8 pineapple cultivars (Gold diamond, Red skin, Red fragrant, Hand torn, Gold, Bali, Watermelon, and Mango) in a common garden in Jiangmen, Guangdong, China. The purpose was to explore the differentiation of functional traits between different pineapple cultivars, and the relationships between leaf ecological stoichiometry and plant growth as well as the plant nutrient limitation. The results showed that leaf stomatal density was the highest in the middle of leaves in most pineapple cultivars, and leaf thickness increased from the upper position to the lower position. There were significant differences in stomatal density, guard cell length, leaf thickness and anatomical proportion in different leaf positions within the same cultivar or in the same leaf position between different pineapple cultivars. Different pineapple cultivars differed in the leaf C, N, P and K content. Pineapple plants required large amount of K, as leaf K content was much higher than N and P content. Leaf N and P content in pineapples were lower than those in grassland plants in China. The leaf content of N and P of pineapple was higher than that of the plants in grasslands and in farmland ecosystems in China, while the leaf content of C, C:N and C:P were higher than those of the plants in grasslands and in farmland ecosystems in China, indicating that pineapple plant is reducing the dependence on nutrients through special leaf morphological or histological structure, agreement with the “Demand reduction strategy”. Moreover, leaf C content, C:P and N:P were significantly negatively correlated with total leaf biomass, which was consistent with the growth rate hypothesis. Ranging from 6.40 to 19.07 across all pineapple cultivars, leaf N:P values indicated that plant growth of Golden and Mango pineapples were limited by P; Golden diamond, Red skin, Hand torn and Watermelon pineapples were restricted by N, while Red fragrant and Bali pineapples were co-limited by N and P. This study twould provides a theoretical foundation for the cultivar selection and the agricultural management of pineapples.
To study the physiological characteristics of high light efficiency in cassava cultivar Ku50, W14, a wild type, wild relatives of A4047 and cultivated species of Ku50 were used as the materials to investigate the character of photosynthetic physiology during different varieties of cassava by measuring the photosynthetic pigment content on functional leaves, net photosynthetic rate (including the photosynthetic rate curve under different light intensity and photosynthetic daily variation) and chlorophyll fluorescence parameters (including mainly the actual photosynthetic efficiency of PSⅡ-Y(Ⅱ), and non-photochemical quenching-NPQ). The result showed that the content of various photosynthetic pigments in Ku50 was significantly higher than that in W14, but no significant difference with that in A4047, suggesting that Ku50 and A4047 may have higher photosynthetic carbon fixation capacity. The net photosynthetic rate of Ku50 was slightly higher than that of A4047 and much higher than that of W14 on the photosynthetic daily variation and Ku50 and A4047 had no obvious midday photoinhibition phenomenon while W14 had, suggesting that Ku50 and A4047 may have higher light conversion efficiency and stronger resistance to high light. The photosynthetic rate curve under different light intensity showed that three varieties of cassava all did not arrive the light saturation point up to the maximum light intensity of 2500 μmol/(m2·s), and the net photosynthetic rate also showed Ku50>A4047>W14. Among them, Ku50 was about 40 μmol/(m2·s), A4047 was about 34 μmol/(m2·s), but W14 was only about 15 μmol/(m2·s). This result was consistent with photosynthetic daily variation and also suggested that Ku50 had stronger resistance to high light and higher light energy conversion efficiency. In addition, the chlorophyll fluorescence parameters were measured to analyze the absorption, distribution and utilization of light energy in different varieties cassava. The result showed that under high light the Y(II) of Ku50 was significantly higher than that of W14, but slightly higher than that of A4047 which had no significant difference (P>0.05). And the NPQ of Ku50 was significantly lower than those of W14 and A4047, indicating that the light energy dissipated into heat on Ku50 was lower than those of W14 and A4047, which in turn proved that the light energy conversion efficiency of Ku50 was higher than those of W14 and A4047, and which was consistent with the results of photosynthetic pigments content and net photosynthetic rate. In conclusion, this research proved that high light efficiency in cassava cultivar Ku50 was induced by high light, and had higher tolerance and utilization rate to high light than wild type of W14 and wild relatives of A4047.
Trichoderma spp. is an important biocontrol microorganism in the fungal disease prevention and control of green agriculture. Which is widely developed as Trichoderma agent for biological control, biofertilizer and soil amendment. The development of traditional Trichoderma fungicide is limited to the screening of Trichoderma strains and the optimization of fermentation conditions. Therefore, it is necessary to explore a new application mode of Trichoderma. Due to intolerance to storage and high costs of transportation and development, coconut water is often directly discarded as waste in the production of coconut industry. In this study, coconut water was compounded with Trichoderma spores and medium elements as water-soluble fertilizers to explore the effects on seed germination and seedling physiological indexes of cucumber. The results showed that adding medium element to coconut water and adjusting pH to 7 had the best effect on the production of Trichoderma spore, and the sporulation reached 2.32×107 CFU/mL. The treatment group A of water-soluble fertilizer compounded with medium element in Trichoderma spp. and coconut water and treatment group B of water-soluble fertilizer compounded with Trichoderma spp. and coconut water significantly promoted the germination of cucumber seeds, and the germination rates of cucumber seeds was 94.44% and 87.50%, respectively, compared with sterile water (CK), which increased by 28.30% and 18.87%, respectively. Pot experiment showed that the plant height and root length of treatment group A was 24.01 cm and 27.76 cm, respectively, which was 48.03% and 47.27% higher than those of CK, which significantly promoted the growth of cucumber seedlings. At the same time, the fresh weight and dry weight of stem and root of cucumber seedlings in treatment group A were also significantly higher than those of CK. Further, we determined the content of total chlorophyll, reducing sugar and soluble protein, the activity of peroxidase (POD) and catalase (CAT) of cucumber seedlings in treatment group A, compared with CK, which increased by 97.46%, 66.32%, 58.85%, 32.67%, and 40.31%, respectively; and the content of malondialdehyde (MDA) was significantly decreased, which was 79.96% lower than that of CK. In summary, the treatment group of water-soluble fertilizer compounded with medium element in Trichoderma spp. and coconut water could significantly promote cucumber seed germination and seedling growth, improve the contents of total chlorophyll, reducing sugar, soluble protein, POD and CAT activity, decrease MDA content of seedlings, and enhance the ability of cucumber to resist stress.
The harvested Newhall navel orange fruits are easy to quality deterioration and spoilage, which seriously affecting the commodity value and shelf-life. Kadozan, a novel commercial liquid chitosan formulation, can be conveniently used for fresh produce postharvest treatment by diluting Kadozan to the required concentration with water. The influences of Kadozan with dilution of 1:800 (VKadozan:VKadozan+water) on the storage quality and storability of Newhall navel orange fruit were investigated.Postharvest Newhall navel oranges were immersed with distilled water (the control) and chitosan for 5 min, respectively, and then stored at (18±1)℃ and 80% relative humidity. During the storage, the samples were taken every 30 days to determine the rate of commercially acceptable fruit, the percentage of weight loss, respiration rate, fruit appearance color characteristics, the contents of chlorophyll and carotenoid in pericarp, and the contents of pulp nutrients. Compared with the control fruits, during storage, chitosan (Kadozan) treatment could reduce fruit weight loss, fruit respiration rate, retain higher rate of commercial acceptable fruit, higher contents of pericarp chlorophyll and carotenoid, higher values of pericarp L*, b* and h°, but lower values of pericarp a* and citrus color index (CCI). In addition, Kadozan treatment could maintain higher contents of soluble solids (TSS), titratable acid (TA), soluble total sugar, sucrose, vitamin C, carotenoids, flavonoids and total phenol in the pulp of Newhall navel orange during storage. When stored for 120 d, the rate of commercially acceptable fruit and the percentage of weight loss in Kadozan-treated oranges was 95.56% and 4.39%, respectively. From the above data, it is concluded that the treatment of chitosan (Kadozan) can improve the storability and maintain the better quality of postharvest Newhall navel orange fruit, indicating the dilution of 1:800 (VKadozan: VKadozan+Water) could be a safe and facile approach to maintain the quality and extend the shelf life of Newhall navel orange after harvest.
Potato is the fourth largest food crop in the world, but little research has been done on this crop about rice husk mulching and copper (Cu). Rice husk is a by-product of rice processing and has great potential to reduce environmental pollution. Plastic film mulching gives us a non-negligible problem of environmental pollution, and even crop yields will be affected. Compared with black film, it has the advantages of wide source, lower cost and no need for recycling, which can basically be used locally. Previous studies have shown that the photosynthetic pigment content, photosynthetic rate, nutrient content, plant height, stem thickness, tuber number, above ground dry weight and yield of potato plants were enhanced by both Cu solution dip treatment and foliar spray of Cu. In this experiment, the accumulation and distribution of Cu in potato plants under different mulching patterns were investigated by using potato “Favorita” as the material and three mulching patterns: bare ground (CK), rice husk (6 000 kg/hm2) mulching (DK) and black film mulching (HM) for winter cultivation in the field. The results showed that the accumulation of Cu in stems and leaves showed a trend of increasing and then decreasing under different mulching patterns, while the accumulation in tubers and whole plants showed a trend of gradually increasing. The accumulation of Cu in stems and leaves ranged from 13.45%~17.70% and 82.30%~86.55% of the whole plant 10 d after full seedling emergence to 2.99%~3.53% and 8.40%~10.56% 58 d after full seedling emergence, respectively. The accumulation of tubers increased from 26.76%~29.60% 22 d after full seedling emergence to 85.91%~88.68% 58 d after full seedling emergence. The Cu accumulation of plants under DK treatment was generally higher than that of LD and HM treatments in the whole growth period. The Cu accumulation of plants under DK treatment was 38.01%, 80.92%, 40.24%, 72.45% more than that of CK treatment in stem, leaf, tuber and whole plant respectively, and 92.21%, 47.22%, 48.12%, 45.16% higher than than that of the HM treatment, respectively. The accumulation of Cu in potato plants 10 d after full seedling emergence was positively correlated with the accumulation of Cu at the later stage, and the accumulation of Cu in stems and leaves was also positively correlated with the yield until 58 d after full seedling emergence. The difference in accumulation by site is due to the fact that in the early growth period, when potato plant is still in the seedling stage, stems and leaves are the sites of Cu accumulation. As the plant grows, tubers are gradually formed. About 31 days after full seedling emergence, the growth of stems and leaves gradually slow down, while the tubers are in the growth phase. At this time, the accumulation center shifts to the tuber, from stems and leaves, which shows that the accumulation of stem and leaves gradually decreases, while the accumulation of tuber continues to increase. The reasons for the higher accumulation of DK than CK and HM may be as follows. First, rice husk, on the other hand, can not only act as a thermal insulation layer to isolate strong external heat, but also improve soil water storage efficiency, increase soil water content, and have significant effects in reducing soil temperature. Second, rice husk can increase soil organic carbon content after being degraded as exogenous organic matter, and the study found that the soil available Cu content was significantly and positively correlated with soil organic carbon content. The experiment showed that under the test conditions, the accumulation of Cu by potato plants could be effectively increased under rice husk mulching at 6000 kg/hm2 level.
In this experiment, seven different camellia plants were used as rootstocks and four different camellia scions to form 28 combinations, to screen the stocks-scion combination and study the grafting affinity, and to measure and analyze grafting experiment indicator that is the survival rate, preservation rate and growth traits of grafted seedlings, to investigate the growth status of grafted seedlings after 18 months. The relationship between grafting anvil, soluble sugar content and graft compatibility was evaluated. The result showed that the grafted survival rate and preservation rate of Camellia gigantocarpa Hu grafted with C. rosmannii and C. achrysantha scion were more than 90%, and the grafting survival rate and survival rate of scions reached more than 80% when C. gigantocarpa Hu grafted with C. chrysantha,, it is proved that C. gigantocarpa Hu is the best rootstock for grafting affinity. The grafting seedlings of C. japonica Heimudan and C. rosmannii had a preservation rate was 6.67%, the preservation rate of C. japonica Heimudan and other 3 kinds of scion was 0, it is proved that C. japonica Heimudan had the worst affinity as rootstock. The scions of C. achrysantha and C. rosmannii had better affinity with different rootstocks. The grafting survival reached more than 90% when C. achrysantha was grafted with C. semiserrata, C. hirsuta, C. japonica Heimudan, C. gigantocarpa. The grafting survival reached more than 90% when C. rosmannii grafted with C. gigantocarpa and C. amplexicaulis. The grafting survival reached more than 80% when C. rosmannii grafted with C. semiserrata and C. polyodonta. Grafting affinity is related to the soluble sugar content of stocks-scion. Closer sugar content of stocks-scion leads to the ratio is closer 1 and the higher grafting survival rate will be. C. gigantocarpa/C. achrysantha, C. hirsuta/C. achrysantha, C. amplexicaulis/C. rosmannii, C. gigantocarpa/C. rosmannii, C. gigantocarpa/C. chrysantha were found to be the excellent combinations by principal component analysis.
Mango is known as the “king of tropical fruits” for its unique flavor and rich nutrition. However, mango is extremely perishable during postharvest ripening, and the decay loss caused by anthracnose is the most serious. Therefore, how to prevent and control mango anthracnose after harvest has become a bottleneck problem restricting the healthy development of mango industry. In this paper, Tainong No.1 mango was used as the experimental material, and the green cinnamon essential oil composite chitosan lotion was used as the treatment means to study its control effect and mechanism on postharvest mango anthracnose, which would provide theoretical basis and practical reference for the development of postharvest mango storage, transportation and preservation industry in China. The results showed that the treatment of 0.5% cinnamon essential oil+0.3% chitosan had the best control effect on mango anthracnose, the treatment of 0.03% cinnamon essential oil could completely inhibit the growth and spore production of mango anthracnose in vitro, and the treatment of 0.01% and 0.02% cinnamon essential oil had obvious destructive effect on mango anthracnose mycelium. The complex treatment significantly inhibited the expansion of mango anthracnose disease spot, increased the content of disease resistance related substances lignin, total phenol (TP) and hydrogen peroxide (H2O2), and increased the content of disease resistance related enzymes phenylalanine ammonia lyase (PAL), peroxidase (POD), β-1,3 glucanase (β-1,3-GA) and chitinase (CHI). It can be seen that cinnamon essential oil composite chitosan lotion has a good control effect on mango anthracnose by inhibiting or destroying the growth and spore production of mango anthracnose mycelium, and inducing mango fruit to improve disease resistance. Therefore, the proper concentration of cinnamon essential oil combined with chitosan lotion treatment would provide a new green way to control mango anthracnose after harvest.
Banana (Musa spp.) is one of the most popular fruits in the world and is widely loved for its sweet taste and nutritious value, it is usually eaten after ripened. Bananas are rich in more than 90% resistant starch before they are unripe, and the effective use of resistant starch in green bananas can significantly increase the added value of the banana planting industry. In addition, green bananas are prone to producing a large number of defective fruits during the harvesting process, resulting in a serious waste of starch resources. In order to study the effect of autoclaving treatment on the digestion and structure properties of flour, three different banana cultivars: Dajiao, Fenjiao, and Gongjiao were chosen. By using scanning electron microscopy, dynamic light scattering, rapid paste viscometer, differential scanning calorimetry, Fourier transform near infrared spectroscopy, and X-ray diffraction analysis. To investigate the relationship between the structural changes and digestion properties of the three green banana flours before and after an autoclaving treatment was applied to them. The content of resistant starch in green banana flour decreased from 91.50%-93.33% (RS2 type) to 39.17%-44.63% (RS3 type) after autoclaving treatment. The scanning electron microscope results showed that powder granules were completely pasted and disintegrated, with variable particle size distribution and irregular shape. The amylose starch content increased from 23.3%-28.3% to 32.7%-37.0%, so that the thermal stability and gel enthalpy of green banana flour were significantly decreased (P<0.05) while the peak viscosity and breakdown was increased. The relative crystallinity of the green banana flour decreased from 28.98%-32.56% to 20.66%-22.26% after the autoclaving treatment. Despite this, the B-type crystalline structure was still preserved after the treatment. The new chemical bonds or functional groups were not found after the autoclaving treatment compared with green banana flour, and the short-range order R1047/1022 was decreased from 1.031-1.166 to 1.016-1.122. The findings revealed that although the content of the resistant starch was reduced after autoclaving treatment, the type of resistant starch was changed from RS2 to RS3. This suggests that the stability of the resistant starch is greatly enhanced after autoclaving treatment. This research could offer a theoretical foundation for the production of heat-stable banana resistant starch, support the development of naturally starch-based materials, and is crucial for resolving the disparity between banana industry production and sales.
Carica papaya L. belongs to Caricaceae, Brassicales, which is widely distributed in tropical and subtropical areas. In our previous study, the major constituent of C. papaya seeds essential oil was benzyl isothiocyanate (BITC) with a content of up to 99%. It had many advantages such as natural, non-pollution, high purity and strong antifungal activity against Candida strain. However, the application of BITC in pharmaceuticals, food industry and other fields is limited due to its poor aqueous solubility, volatility and easily degradation. In this study, in order to increase the stability and anti-Candida efficacy of BITC, nanostructured lipid carrier loaded with benzyl isothiocyanate from C. papaya seeds (BITC-NLC) was prepared by the melting emulsification ultrasonic method. The physicochemical properties such as morphology, particle size, Zeta potential, encapsulation efficiency, drug loading, etc. were evaluated and its anti-Candida activity was investigated. On the basis of single factor influence test, the orthogonal design was adopted to choose the preparation process of nanostructured lipid carrier (NLC) and formulation of BITC-NLC. The best preparation process was stirring for 20 minutes and ultrasonic dispersion for 15 minutes (amplitude 80%). The best prescription was composed of 50 mg monostearate, 50 mg octyl capric acid triglyceride, 400 mg poloxamer, 400 mg soybean lecithin, 100 mg BITC and 20 mL ultrapure water. The morphology was observed by a transmission electron microscope, the particle size and zeta potential were measured by Zetasizer Nano ZSE, and the encapsulation efficiency and drug loading were analyzed by high performance liquid chromatography. The final prepared BITC-NLC was quasi-spherical shapes and the average particle size, Zeta potential and encapsulation efficiency was 79.13 nm, -21.77 mV and 91.52%, respectively. The preliminary stability test results showed that BITC-NLC was stable for 30 d kept at 25 ℃. The minimal inhibitory concentrations (MICs) were determined using the broth dilution method. MICs of the BITC-NLC against all the selected Candida strains were 8-32 μg/mL, which were better than BITC. In addition, it could inhibit C. albicans and C. tropicalis that are resistant to the most commonly used antifungal drug - fluconazole. The new prepared formulation BITC-NLC from papaya seeds essential oil in this study has small particle size, good physical stability, high encapsulation efficiency and better antifungal effect on C. albicans and C. tropicalis. The results may provide theoretical and experimental basis for the application of papaya seeds which are abundant and typically discarded and the development of natural antifungal drugs.
The biological activity of loquat exosomes and cytosol on human skin cells in vitro was explored to provide a scientific basis for the development of skin care products. The loquat exosomes and cytosol were obtained by ultra-high-speed centrifugation and mechanical disruption, respectively. Firstly, the effect of different concentrations of loquat leaf-derived exosomes (loquat leaf-exo), loquat cell suspension culture-derived exosomes (loquat suspension-exo) and loquat cell suspension culture-derived cytosol (loquat suspension-cytosol) on cell viability of human skin fibroblasts (HSF) was detected by the CCK8 method. And then, HSF cells were treated with LPS (lipopolysaccharide) for inflammation modeling, and the concentration that significantly promoted the cell survival rate was selected, followed by adding exosomes or cytosolic treatment to detect cell apoptosis and migration ability. Secondly, the melanoma cells (A375) were subsequently treated with exosomes or cytosol, and the melanin content and tyrosinase activity were detected. The concentration of exosomes per gram of loquat leaves was 8.54×109 particles, and the particle size was 86.78 nm; each milliliter (approximately equal to 1 g) of loquat suspension cells contained exosomes with a concentration of 8.67×108 particles, with a particle size of 80.39 nm. At the concentration level of 20 μg/mL, loquat leaf-exo, loquat suspension-exo, and loquat suspension-cytosol all significantly increased the survival rate of HSF cells in vitro (P<0.05). Compared with the positive control (LPS treatment group), loquat leaf-exo at 20 μg/mL, loquat suspension-exo at 20 μg/mL and loquat suspension-cytosol at 10 μg/mL significantly reduced the apoptosis induced by LPS treatment (P<0.01), both significantly promoted cell migration (P<0.05). 5 μg/mL loquat suspension-exo and loquat suspension-cytosol could significantly reduce the melanin content of A375 cells in vitro, and loquat suspension-cytosol could also significantly reduce the tyrosinase activity (P<0.05).
For the study of Hainan Island typical farmland soil fertility conditions, the forest land, cultivated land, garden land and grass land of Hainan, China under the type of soil pH, mechanical composition, organic matter, cation exchange capacity, total nitrogen, alkali solution nitrogen, total phosphorus, effective phosphorus, total potassium were determined and statistically analyzed. Based on “the second soil census nutrient classification standard”, the Nemerow Index Method was used to evaluate the comprehensive soil fertility of each land use type. The results showed that nitrogen content was deficient in different land use types. The phosphorus content was abundant or very abundant. Potassium content was abundant in woodland and cultivated land, moderate in garden land, and deficient in grassland. In the four types of farmland, and cation exchange capacity of soil organic matter, total nitrogen, hydrolyze nitrogen were significantly correlated (P<0.05) or extremely significant correlation (P<0.01), soil cation exchange capacity and total nitrogen and hydrolysis nitrogen showed strong correlation, and other soil nutrient showed virtually no correlation or weak correlation. The corresponding comprehensive soil fertility of the four land types was in the order of garden land (1.164)>forest land (1.058)>arable land (0.879)>grassland (0.784). The comprehensive soil fertility of garden land and forest land was average, while that of arable land and grassland was poor. Therefore, we should strengthen land management, rational use of land, improve soil nutrient structure, and finally improve land productivity.
Exploring the characteristics of dry-wet climate change and its impacts on crop yield can provide scientific basis for agricultural production planning and meteorological disaster prevention under climate change. Based on the daily ground observation data of meteorological stations in Zhanjiang area from 1960 to 2020 and the statistical data of rice, sugarcane and peanut yields from 1990 to 2020, the aridity index calculated by reference crop evapotranspiration (ET0) and precipitation were used as drought index to analyze the characteristics of dry-wet climate change, and the impact of dry-wet climate change on crop yield was analyzed. The results showed that the interannual variation of precipitation in Zhanjiang area fluctuated greatly, and the annual average precipitation was 1534.41 mm, showing an insignificant rising trend. The temperature rised significantly at the rate of 0.18 ℃/10 a, and the annual average ET0 and aridity index was 1242.72 mm/a and 0.87 respectively, showing an insignificant upward trend. According to the annual variation of the dryness index, from January to April and from October to December were the drought prone periods in Zhanjiang. The yield of rice, sugarcane and peanut showed a significant growth trend in the past 31 years, the increase of aridity index in April would reduce the yield of the three crops. The increase of aridity index in May would significantly increase the yield of peanut, but had no significant impact on the yield of the other two crops. The increase of temperature and the decrease of precipitation in June were conducive to the significant increase of rice and peanut yield. Sugarcane yield was not significantly affected by the change of temperature and precipitation, while the increase of dryness index in December significantly increased sugarcane yield. The results are of great significance for Zhanjiang and its surrounding areas agriculture to cope with climate change and improve the crop potential productivity.
In order to clarify the differences and similarities in climate conditions between major cigar producing areas in China and dominant cigar producing areas in foreign countries, this study selected 17 major cigar production areas in Hainan province, Yunnan province, Sichuan province and Hubei province of China, as well as the dominant major cigar production areas in foreign countries, including Pinar del Rio in Cuba, Santiago in Dominica, Jember in Indonesia and Bahia in Brazil. General statistical analysis and cluster analysis were used. The differences of six key meteorological factors including monthly average temperature, maximum temperature, minimum temperature, rainfall, relative humidity and difference in temperature in the field period, the drying period as well as the whole growing season of cigar production in the 17 production areas were studied. There was no significant difference in the overall climate conditions of the field period, drying period and the whole growing season between domestic and foreign major cigar producing areas, while the differences in the four meteorological factors of the maximum temperature, minimum temperature, rainfall and difference in temperature in the whole growing season between domestic and foreign major producing areas reached the significant level (P<0.05). Among them, the differences of the three meteorological factors of maximum temperature, minimum temperature and difference in temperature reached the level of extremely significant (P<0.01). Taking the Euclidean distance of 15 as the critical value, the 17 major cigar producing areas in the field period could cluster into four categories, the 17 major cigar producing areas in the drying period could cluster into three categories, and the 17 major cigar producing areas in the whole growing season could cluster into two categories. The results of this study would provide a scientific basis for major cigar producing areas in China to learn from dominant cigar producing areas in foreign countries in planting layout, variety selection and quality improvement, and also provide a data basis for climate assessment and variety optimization of cigar growing areas in China.
