Welcome to Chinese Journal of Tropical Crops,

Chinese Journal of Tropical Crops ›› 2021, Vol. 42 ›› Issue (10): 2915-2923.DOI: 10.3969/j.issn.1000-2561.2021.10.023

• Plant Cultivation, Physiology & Biochemistry • Previous Articles     Next Articles

Effects of Phosphorus Application on the Establishment of Source-sink Balance at the Initial Stage of Sweetpotato Root Development

LINAG Qinggan, CHEN Yanli, LIU Yonghua, WANG Jianwei, WANG Ning, ZENG Liping, ZHU Guopeng*(), SI Chengcheng*()   

  1. Horticulture College of Hainan University / Key Laboratory for Quality Regulation of Tropical Horticultural Crops of Hainan Province, Haikou, Hainan 570228, China
  • Received:2020-12-28 Revised:2021-02-24 Online:2021-10-25 Published:2021-11-25
  • Contact: ZHU Guopeng,SI Chengcheng

Abstract:

A two-year pot-sand-culture experiment was conducted to investigate the root activity, root morphology, fresh weight and diameter of potential storage root, storage root numbers, single storage root fresh weight, root biomass, leaves area, stem-leaves biomass and both root and top dry matter allocation rate as well as root-top ratio (R/T) under phosphorus application P0.04 (P2O5 0.04 g/kg) on two sweetpotato varieties ‘Yanshu 25’ and ‘Pushu 32’. Compared with P0 (P2O5 0 g/kg), the total roots number, total roots fresh weight, length, surface area, mean diameter, volum and tips as well as root activity and the fresh weight and diameter of potential storage root at the early growth stage (0-30 days after planting) were significantly increased under proper phosphorus application (P0.04). Further more, sweetpotato leaf area index, fresh leaf weight, fresh stem weight, above-part fresh weight and dry weight accumulation of root, above-part and whole plant as well as dry matter to root partition ratio and root-top ratio were also increased at significant level under proper phosphorus application (P0.04). However, excessive P0.08 (P2O5 0.08 g/kg) inhibited the distribution of dry matter in roots, resulting in the decrease of root-top ratio, which was not conducive to the formation of storage root. At closure stage (40 days after planting), compared with P0, appropriate amount of phosphorus P0.04 (P2O5 0.04 g/kg) significantly increased the number of single plant storage root number (the number of storage root with diameter more than 5 mm was increased) and single storage root fresh weight, thus increased the weight of single plant. If the amount of phosphorus continued to increase, the number storage root number and single storage root fresh weight decreased significantly. Appropriate phosphorus application is of great significance to sweetpotato storage root formation. It would be beneficial to the formation of adventitious root, the growth and development of stem and leaf, and the dry matter synthesis of stem and leaf, thus laying a good material foundation for the formation of storage root, it could promote the distribution of dry matter to the root, increase the ratio of root to top, and promote the harmonious growth of plant, beneficial to storage root formation and the increase of storage root number.

Key words: sweetpotato, phosphorus, source-sink relationship, storage root forming characteristics

CLC Number: