Acta Agriculturae Zhejiangensis ›› 2021, Vol. 33 ›› Issue (9): 1640-1649.DOI: 10.3969/j.issn.1004-1524.2021.09.08

• Horticultural Science • Previous Articles     Next Articles

Development of SSR markers based on transcriptome sequencing and genetic diversity analysis of Nainaiqingcai leaf mustard

MA Jie1,2(), QU Wen2, CHEN Chunyan1, WANG Lei2, MA Jun1, LIU Zhenshan2, MA Wei1, ZHOU Ping1, HE Yuankuan1, SUN Bo2,*()   

  1. 1. Bijie Institute of Agricultural Science, Bijie 551700, China
    2. College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China
  • Received:2020-11-05 Online:2021-09-25 Published:2021-10-09
  • Contact: SUN Bo

Abstract:

In order to explore the diversity level of leaf mustard Nainaiqingcai (Brassica juncea L.), this study investigated the characteristics of simple sequence repeat markers (EST-SSR) based on transcriptome, and screened suitable EST-SSR primers for Nainaiqingcai mustard, and then analyzed the genetic diversity of Nainaiqingcai mustard. The results showed that a total of 46 386 unigenes were obtained based on the transcriptome sequencing data of the leaf mustard Nainaiqingcai. It was found that 18 720 SSR loci were in 13 544 unigene sequences, the frequency of SSR was 29.20%, and the average distribution was 2.73 kb, and the average distribution frequency was 40.36%. Single nucleotide SSR was the abundant, which accounted for 49.39% of the total SSR, followed by tri-nucleotide and di-nucleotide, which accounted for 25.44% and 24.13%, respectively. A/T, AG/CT and AAG/CTT were the dominant repeat types in single nucleotide, di-nucleotide and tri-nucleotide, respectively. Thirty varieties of Nainaiqingcai mustard and five other Brassica vegetables were collected as materials, and 17 pairs of polymorphic primers were selected from a total of 37 primers. A total of 135 polymorphic bands were obtained, and the polymorphism rate was 88.2%. The genetic diversity analysis showed: average number of alleles (Na) was 5.705 9, average effective allele number (Ne) was 2.397 8, average diversity index (I) average was 1.036 1, average observed heterozygosity (Ho) was 0.312 1, average expected heterozygosity (He) was 0.530 0, and average Nei’s gene diversity was 0.521 9, indicating that the selected 17 pairs of SSR primers had good genetic diversity. Unweighted pair-group method with arithmetic means (UPGMA) cluster analysis showed that 30 varieties of Nainaiqingcai mustard could be divided into three groups at the genetic similarity coefficient of 0.677. In summary, the results provided primer supporting and technical reference for germplasm resource identification, genetic relationship analysis and molecular marker assisted breeding of leaf mustard Nainaiqingcai.

Key words: Nainaiqingcai mustard, molecular marker, transcriptome, genetic diversity

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