我国北回归线区域普通野生稻遗传多样性和遗传结构研究

选择分布于水稻染色体组的26对SSR引物,对集中分布于广西来宾市北回归线附近的13个普通野生稻居群的342份材料进行遗传多样性和遗传结构研究。结果表明,该地区的野生稻无论在种内(A=9.154,Ae=4.446,I=1.547,He=0.671)还是居群水平上(P=95%,A=4.219,Ae=2.394,I=0.905,He=0.476)遗传多样性都十分丰富,高于同类研究水平。供试居群的遗传分化系数Gst为0.30,表明30%的遗传变异存在于居群间,大部分遗传变异存在于居群内。居群间的遗传一致度变化范围为0.332~0.903,且居群间地理距离越近,遗传一致度越高,说明北回归线附近的普通野生稻居群符合"隔离-距离"模型。综合上述研究结果和我国野生稻保护现状,建议对居群G13和G06实施优先保护。

Studies on Genetic Diversity and Population Structure of Oryza rufipogon near the Tropic of Cancer in China

The Tropic of Cancer in China has been recognized as the center of Oryza rufipogon with abundant superior genes such as resistance to diseases and pests.To provide information for the conservation of O.rufipogon in this area,342 individuals from 13 populations near the Tropic of Cancer in Laibin City,Guangxi Autonomous Region,were collected and studied for the genetic diversity and population structure with 26 SSR primer pairs which were distributed among the genome of rice.The results indicated that:(i) Relatively high level of genetic variation was detected both at species(A=9.154,Ae=4.446,I=1.547,He=0.671) and population levels(P=95%,A=4.219,Ae=2.394,I=0.905,He=0.476) comparing to previous studies on O.rufipogon.(ii) The genetic differentiation(Gst=0.30) suggested that 30% genetic variation existed among populations,meaning that most variation happened among the individuals within populations.(iii) The cluster analysis showed that genetic identity among populations was negatively correlated with geographical distance,consistent with the isolation by distance model for the isolation populations.Based on the above results and the conservation actuality of O.rufipogon in China, it could be concluded that population G13 and G06 should be given priority for in-situ conservation.