The Genetic Diversity Analysis and Evaluation of Sun-cured Tobacco Landraces Germplasm Resources

PurposeTo better collect, identify and preserve local sun-cured tobacco varieties, and efficiently use local sun-cured tobacco germplasm to select and breed tobacco varieties.

MethodUsing DNA of 67 local sun-cured tobacco varieties as template, 25 pairs of SSR primers obtained by screening were used for PCR amplification. The results of PCR amplification were recorded by binary system. NTSY 2.1 software was used for cluster analysis and POPGENE 32.0 software was used for genetic diversity analysis.

Result(1) A total of 83 polymorphic loci were detected by 25 pairs of SSR primers. The variation range of genetic similarity coefficient among varieties was 0.60-0.84. (2) When the genetic similarity coefficient was 0.62, 67 sun-cured tobacco varieties could be divided into three groups. The first group included 49 sun-cured tobacco varieties, the second group included 13 sun-cured tobacco varieties, and the third group included 5 sun-cured tobacco varieties. (3) The average number of observed alleles, effective alleles, observed heterozygosity and expected heterozygosity were 3.44, 2.762, 0.168 and 0.597, respectively. The average Nei’s gene diversity index (H) was 0.593, and the average Shannon’s index (I) was 1.013. The average expected heterozygosity was more than 0.5.

ConclusionThere were rich genetic diversity in sun-cured tobacco germplasm resources used in this study. There was no obvious correlation between genetic relationship and geographical origin of tobacco varieties.