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对我国小麦育成品种初选核心种质(1680份)的78个微卫星标记(SSR)位点进行了扫描,并就此对50年来育成品种的遗传多样性进行了评价和分析,得到以下结果和结论:(ⅰ)74对SSR荧光引物共检测到1336个等位变异,其中1253个等位变异可以定位在71个位点上.这71个位点上检测到的每个位点等位变异数为4~44个,平均17.6个;多态性信息指数(PIC)为0.19~0.89,平均为0.69.(ⅱ)三个基因组的平均等位变异丰富度为B>A>D,遗传多样性指数为B>D>A.(ⅲ)7个部分同源群的平均等位变异丰富度为2=7>3>4>6>5>1,遗传多样性指数为7>3>2>4>6>5>1.结合两个指标分析,第7部分同源群具有最高的多样性,而1,5群多样性最低.(ⅳ)21条染色体中,7A,3B和2D三条染色体遗传多样性较高,而2A,1B,4D,5D和1D的遗传多样性偏低.(ⅴ)育成品种遗传多样性指数以50年代的最高,以后越来越低,但年代间变化较平缓;品种间平均遗传距离以50年代最高(0.731),以后逐渐减小,各年代依次为0.711,0.706,0.696和0.695.品种遗传基础狭窄化问题日趋突出,应引起有关部门和育种家的关注.
A total of 78 microsatellite markers (SSR) loci of 1680 wheat germplasms were screened and the genetic diversity of cultivated varieties in the past 50 years was evaluated and analyzed. The following results were obtained: Conclusions: (i) A total of 1336 alleles were detected by 74 pairs of SSR primers, of which 1253 alleles were located at 71 loci.All alleles detected at these 71 loci The average number of polymorphic information index (PIC) ranged from 0.19 to 0.89 with an average of 0.69. (Ii) The average allelic diversity of the three genotypes was B> A> D, with genetic diversity The index of sexuality was B> D> A. (iii) The average allelic diversity of 7 homoeologous groups was 2 = 7> 3> 4> 6> 5> 1, and the genetic diversity index was 7> 3> 2 > 4> 6> 5> 1.According to the analysis of two indicators, the homology group has the highest diversity in part 7, while the lowest in groups 1 and 5. (ⅳ) Among the 21 chromosomes, there are three lines 7A, 3B and 2D The genetic diversity of chromosomes was higher, while the genetic diversity of 2A, 1B, 4D, 5D and 1D was lower. (Ⅴ) The genetic diversity index of breeding varieties was the highest in the 1950s and then lower and lower, Gentle; the average genetic distance between varieties to 50 years (0.731), and then gradually decreased, followed by the years were 0.711, 0.706, 0.696 and 0.695. The narrow genetic base of cultivars has become increasingly prominent, which should arouse the concern of relevant departments and breeders.