Abstract:

37 rubber tree cultivars were used as the materials to establish DNA fingerprints and to analyze the genetic relationship with SSR fluorescence labeling technology. A total of 34 pairs of SSR primers were screened and determined as the core primers for the construction of rubber tree variety DNA fingerprint library. Of which 30 pairs of SSR primers could be used for variety identification and 4 pairs of SSR primers could be used as alternative primers for the identification of subsequent newly selected varieties. The core SSR primers screened and determined showed high polymorphism information content (PIC value). Among them, the number of primers with PIC value higher than 0.5 was 97%, the number of primers with PIC value greater than 0.7 was 12, and the number of primers with PIC value greater than 0.8 was 2. Primer rbm28 had the highest polymorphism and could be used as the best primer to identify the genetic diversity of the main strains of rubber tree in China. The other four primers HESR025, HESR163, H-084 and H-122 had high heterozygosity and polymorphism at the same time, so they could be considered as alternative primers. A total of 161 alleles were detected by 34 pairs of core SSR primers in 37 rubber tree varieties, with an average of 5.4 alleles per pair of primers and an average polymorphism information content (PIC) value of 0.65. 30 pairs of core SSR primers were used to amplify 37 rubber tree strains to obtain the accurate SSR site information of related varieties. The standard DNA fingerprint library of 37 rubber tree varieties was constructed, of which 33 rubber tree varieties had unique DNA characteristic fingerprints, which could be used as the specific fingerprints of each variety, so as to provide a basis for rubber tree variety identification and breeding practice.

Key words: Hevea brasiliensis, hybrid identification, SSR fluorescent marker, DNA fingerprint