CAJ | 학술논문

由稻瘟病菌(Magnaporthe oryzae )侵染引起的稻瘟病是全球水稻生产上最严重的病害之一.利用6对 SSR 荧光标记对采自四川绵阳、营山、雅安、北川和武胜地区的5个稻瘟病菌群体的遗传结构进行分析.结果表明,在124个稻瘟病菌中检测出43个等位基因,平均每个位点的观测等位基因数为7．2,有效等位基因数为3．1,所有位点均显著偏离 Hardy-Weinberg平衡.5个群体的平均观测杂合度(0．374)低于期望杂合度(0．502),暗示群体内存在因近交而导致的杂合子缺失. AMOVA 分析显示,绝大多数遗传变异(81．17％)存在于群体内个体间,仅有18．83％的变异来自于群体间的差异.5个地理群体间呈现高水平的遗传分化(遗传分化系数为0．057~0．528).Mantel 检验表明,群体间的遗传距离与地理距离相关未达显著水平,说明稻瘟病菌的遗传变异呈现随机分布的空间模式.群体遗传学数据分析表明5个群体间存在不同程度的基因流(基因流水平为0．472~4．347),基于贝叶斯聚类法的 Structure 分析也证实了这一结果.
유도온병균(Magnaporthe oryzae )침염인기적도온병시전구수도생산상최엄중적병해지일.이용6대 SSR 형광표기대채자사천면양、영산、아안、북천화무성지구적5개도온병균군체적유전결구진행분석.결과표명,재124개도온병균중검측출43개등위기인,평균매개위점적관측등위기인수위7．2,유효등위기인수위3．1,소유위점균현저편리 Hardy-Weinberg평형.5개군체적평균관측잡합도(0．374)저우기망잡합도(0．502),암시군체내존재인근교이도치적잡합자결실. AMOVA 분석현시,절대다수유전변이(81．17％)존재우군체내개체간,부유18．83％적변이래자우군체간적차이.5개지리군체간정현고수평적유전분화(유전분화계수위0．057~0．528).Mantel 검험표명,군체간적유전거리여지리거리상관미체현저수평,설명도온병균적유전변이정현수궤분포적공간모식.군체유전학수거분석표명5개군체간존재불동정도적기인류(기인류수평위0．472~4．347),기우패협사취류법적 Structure 분석야증실료저일결과.
Rice blast,caused by Magnaporthe oryzae ,is one of the most destructive disease worldwide.The genetic structure of five populations of M .oryzae ,collected from Mianyang,Yingshan,Ya’an,Beichuan and Wusheng of Sichuan Province,were analyzed using six fluorescent labeled SSR markers.A total of 43 polymorphic alleles were produced in 124 isolates of M .oryzae .The mean number of observed alleles (Na )and effective alleles (Ne )per locus were 7.2 and 3.1 ,respectively,and all loci exhibited significant deviations from Hardy-Weinberg equilibrium.The mean observed heterozygosity (Ho = 0.374 )was lower than expected (He = 0.502 ),indicating the deficit of heterozygotes resulting from the accumulation of inbreeding within populations.Analysis of molecular variance showed that the majority (81 .1 7%)of genetic variation was attributed to the differences among isolates within population,with only 18.83% of the variation resulting from differences among populations.High levels of genetic differentiation (Fst , 0.057-0.528)existed among all five geographical populations.Mantel test revealed no significant correlation between the genetic and geographical distances for all populations (r = - 0.201 ,P = 0.587 ),indicating that the genetic variation of M .oryzae populations was randomly distributed in geographic space.Different levels of gene flow (Nm , 0.472 - 4.347),occurred between populations,were also verified by Bayesian-based clustering algorithm analysis by Structure.