期 刊 ：植物遗传资源学报 2014年 15卷 3期
Keywords:Ningxia, rice varieties, different period, SSR makers, genetic diversity,
摘 要 ：对宁夏不同年代推广种植的主栽水稻品种(系）的主要农艺性状比较表明，第1阶段（1950～1962年）宁夏地方品种与其它阶段第2阶段（1978～1989年）、第3阶段（1990～1999年）、第4阶段（2000～2005年）、第5阶段（2006～2012年）第6阶段（2010～2013年）育成品种（系）的农艺性状差异显著，说明通过育种手段宁夏水稻品种的主要农艺性状得到了改良;从第2阶段到第6阶段年的性状改良趋势为生育天数变长，有效穗数减少，穗长、穗粒数、单株粒重、穗粒重、生物学产量、经济系数、单产等性状增加，说明产量性状的育种改良从穗数型向穗粒兼顾型或穗重型发展。利用48对SSR引物对76份宁夏不同年代水稻品种（系）进行遗传多样性分析表明，共检测出290个等位基因，每个位点等位基因变幅为3～15个，平均为6.04个；稀有等位基因有109个，占等位基因总数的37.59%；多态信息含量PIC值变异范围为0.1423～0.8783，平均为0.5512；Nei’s基因多样性指数（He）的变幅为0.1492～0.8945，平均为0.6032。RM333、RM297、RM249、RM501和RM206引物表现为较高的等位基因数和稀有等位基因数，认为较适合应用于宁夏水稻品种的遗传多样性检测。分子方差分析(AMOVA)结果表明，6个不同阶段间遗传变异仅占总体变异的19.27%，而各阶段内品种间的遗传变异占总体变异的80.73%。76个宁夏水稻UPGMA聚类分析结果表明，在遗传相似系数(GS)为0.805处可将76个宁夏水稻其区分为5大类群，12个地方品种都被聚为第Ⅰ类群，具有外来引进血缘的8个常规粳稻品种被聚为第Ⅱ类群，5个优质常规粳稻被聚为第Ⅲ类群，第Ⅴ类群包括2个大穗高产品种，49个宁夏常规粳稻选育品种被聚为第Ⅳ类，说明大多数宁夏水稻品种的亲缘关系较近。6个不同阶段主栽水稻品种UPGMA聚类分析结果表明，第1阶段（地方品种）独聚一类，与其它阶段品种亲缘关系远；第2、第3、第4阶段与第5、第6阶段育成品种亲缘关系相对较远。不同年代宁夏水稻遗传多样性分析表明，其遗传多样性有较大差异，2005年后宁夏水稻品种的遗传多样性趋于变小。今后宁夏水稻育种中应加强国外及外省种质资源的引进和利用，深入挖掘宁夏稻区地方品种和杂草稻资源的有利基因，拓宽宁夏水稻品种的遗传基础，以促进宁夏水稻育种的快速发展。
Abstract:The comparision of main agronomic traits of different period rice varieties（strains） commercially grown in Ningxia showed the significant difference of agronomic characters between the first stage (1950 ~ 1962) and the second(1978～1989 year), the third (1990～1999 year),the forth(2000～2005 year), the fifth(2006～2012 year),the six(2010～2013 year) stage. This means that, the agronomic traits of rice varieties in Ningxia was improved by breeding techniques. There was a decreasing trend of effective panicle and a increasing trend of days of growth period, panicle length, spikelets per panicle, weight per panicle, weight per plant, and grain yield per unit area from the second stage to the sixth stage were found. The pattern of breeding of grain yield traits become to panicle weight type or both of panicle and spikelet type from panicle number type. The analysis of the genetic diversity of 76 rice varieties bred in different period of Ningxia was analysedby using 48 polymorphic simple sequence repeats (SSR) markers shows that there was total of 290 alleles were detected, and the number of alleles per pair of primers ranged from 3 to 15 with a mean value of 6.04. Among which, 109 alleles (37.59%) were minor alleles. RM333、RM297、RM249、RM501 and RM206 showed higher score of alleles and minor alleles, which were suitable to assess the genetic diversity of rice varieties from Ningxia. Polymorphic information content (PIC) was ranged from 0.1423 to 0.8783 with a mean value of 0.5512. The Nei’s genetic diversity index (He) was ranged from 0.1492 to 0.8945 with a mean value of 0.6032. The results of analysis of molecular variance (AMOVA) indicated that the genetic variation among the six decades stages was just only accounted for 19.27% of the total genetic variation, but which the genetic variation among the variety varieties within during every decade stage was accounted for 80.73%. The UPGMA cluster analysis of 76 rice varieties in Ningxia showed that there were five categories were clustered in the 0.805 level of genetic similarity coefficient. Twelve rice landraces were clustered into the Ⅰ group; the Ⅱ group included eight conventional japonica rice varieties, which had blood relationship with foreign varieties; the Ⅲ group included five high quality rice improved varieties; the Ⅴ group included two large-panicle and high-grain yielding improved cultivars. 49 conventional japonica rice varieties were clustered in the Ⅳ group, it showed that majority rice varieties in Ningxia had a closer genetic relationship. The UPGMA cluster analysis of six stages of rice varieties in Ningxia showed that , the first stage (Landrace) was clustered into a separate category , it has a relatively low genomic affinity to others. The relationship was relatively distant between the second, the third, the forth stage and the fifth, the six stage. The results of genetic diversity analysis of different period rice varieties in Ningxia showed that there was greater differences of genetic diversity betweenamong the six different periods, and the genetic diversity decreased after 2005. In order to accelerate the rice breeding process in Ningxia, we should strengthen the introduction and use of rice germplasm resources from other provinces and abroad, and to explore the favorable genes from rice landrace and weedy rice in Ningxia, to and broaden the genetic basis of in order to improved the rapid development of rice breedingcultivars in Ningxia.