三江并流区金沙江流域不同海拔云南核桃群体遗传多样性及分布特征

Genetic Diversity and Distribution Characteristic of Walnut Populations in Different Altitude along Jingsha River in Three Parallel Rivers Belt of Yunnan

采用微卫星(SSR)分子标记技术对三江并流区金沙江流域153份3个不同海拔的云南核桃群体遗传多样性及分布特征进行研究。结果表明:19对SSR引物共检测到130个等位序列,各序列在153份样本中的出现频率各不相同,其中A 122出现的频率最高,达到0.830 1;有14个频率仅为0.003 3的稀有序列;3个群体等位序列数量占总数的比例为80.00%~86.92%,Nei’遗传多样性指数(H)平均为0.636 2,Shannon信息指数(I)平均为1.291 1,期望杂合度(H e)平均为0.638 4,遗传多样性属于中等水平;3个群体遗传多样性的分布由高至低依次为2 000 m≤h(海拔)<2 400 m群体、h<2 000 m群体、h≥2 400 m群体。其中值得关注的是h≥2 400 m群体,高频率等位序列A 122的频率为0.852 3,尤其是稀有等位序列数量有8个,占稀有等位序列总数的57.14%。

SSR technology was used to analyze genetic diversity and its distribution characteristic of walnut populations in different altitude along Jingsha River in Three Parallel Rivers Belt of Yunnan. The 130 allelic sequences were detected by 19 pairs of primers. The frequency of each sequence in 153 samples was different, among which A122 showed the highest frequency with 0.830 1, while there were 14 sequences (rare sequence) showed the lowest frequency with only 0.003 3. The sequence percentage of three populations was from 80.00% to 86.92%. The average expected heterozygosity was 0.638 4. Nei’s gene diversity was 0.636 2 and Shannon’s information index was 1.291 1. The data suggested a medium genetic diversity. The descending order of genetic diversity was 2 000-2 400 m altitude population,<2 000 m altitude population, and >2 400 m altitude population. It was worth noticing that ≥2 400 m altitude population, of which high frequency sequence A 122 reached 85.23%, and there were eight rare sequences, of which the frequency accounted for 57.14% of all rare sequences.