[Genetic diversity of SP1 population of space mutagenized Pueraria montana].

To explore the mutagenic effect of the space environment on Pueraria montana and select the elite germplasm with good growth conditions and high isoflavone content, this study observed the agronomic traits, determined the flower isoflavone content, and labeled amplified fragment length polymorphism(AFLP) fluorescent molecular markers of 79 P. montana plants exposed to space mutagenesis(SP1 group) and 10 control plants of P. montana(CK group). Excel 2019, SPSS 25.0, NTSYSpc-2.11F, and Popgen 32 were employed to analyze the genetic diversity and perform the cluster analysis. The results showed that the SP1 group presented changed leaf hairy attitude and flower structure and higher CV and H' of quantitative traits than the CK group. The cluster analysis screened out five plants in the SP1 group. Ten P. montana plants in the SP1 group had higher content of 6″-O-xylosyl-tectoridin and tectoridin in the flowers than the control group, with the total content of both exceeding 11%. After clustering, 9 plants in the SP1 group were separated. Nine pairs of polymorphic primers were screened out frrom 64 pairs of primers. A total of 1 620 polymorphic loci were detected, with the average percentage of polymorphic loci(PPL) of 83.33%. The average Nei's gene diversity index(H) and Shannon's information index(I) were 0.192 2 and 0.305 2, respectively. After clustering, 4 plants in the SP1 group were screened out. According to the above results, plants No. 30, No. 66, and No. 89 in the SP1 group were subjected to greater mutagenic effect by the space environment and presented better growth and higher flower isoflavone content. Moreover, plant No. 30 showed the flower structure variation and flower weight two times of that in the CK group. These plants can be used as key materials for the subsequent experiments.