Abstract:
Objective Clarifying the population structure and genetic diversity of rare and endangered plant Bretschneidera sinensis, so as to provide scientific basis for the formulation of effective conservation measures and management strategies.
Method According to the comprehensive investigation data of wild B. sinensis in Xianxialing Nature Reserve, the diameter class structure of B. sinensis was analyzed by static life table and survival curve. Sixteen samples were sequenced by gene recombination, and the nucleotide polymorphism, Tajima’S D value, observed heterozygosity and expected heterozygosity of Xianxialing population were calculated based on SNP markers.
Result (1) According to the data of each tree scale, the population of B. sinensis is divided into diameter class, the number of trees in diameter class Ⅰ is the most, and the population structure is generally increasing, (2) The nucleotide diversity of Xianxialing population is 0.000 155 ± 0.000 112, the average observed heterozygosity is 0.125 021, and the average expected heterozygosity is 0.251 483, which was lower than that of populations in other areas, and the genetic diversity within the population is at a low level. (3) There is no significant correlation between the population structure of growth type and genetic diversity.
Conclusion The diameter class structure of B. sinensis population in Xianxialing Nature Reserve is complete, and the number of B. sinensis population is increasing under the background of climate change in the future, but the level of genetic diversity is low. In the future, in the protection of rare and endangered species, we will actively carry out germplasm resources conservation to avoid population decline caused by the loss of genetic diversity.