【作者】 赵庆勇；

【导师】 王才林；

【作者基本信息】 南京农业大学 ， 遗传学， 2008， 硕士

【摘要】 本研究利用部分粳稻品种和新品系回交转育的一批BT型粳稻新不育系和生产上广为利用的恢复系,采用NCⅡ设计配制组合,对F₁主要农艺性状和品质性状的配合力和杂种优势进行了研究,其结果如下:（1）以12个新育成的BT型粳稻不育系和8个恢复系为亲本,采用NCⅡ设计,对其F₁代13个农艺性状的配合力和杂种优势进行分析的结果表明,除单株穗数的特殊配合力方差不显著外,所有性状的一般配合力方差和特殊配合力方差均达到极显著水平。所测性状主要受亲本一般配合力的影响,主穗实粒数、结实率、单株产量和收获指数受组合特殊配合力的作用较突出。穗长、穗颈长、结实率和收获指数受不育系的影响稍大,其余性状均受恢复系的影响较大。亲本一般配合力和组合特殊配合力是相互独立的。杂交粳稻普遍存在较强的平均优势,但大多数性状的超亲优势不强,竞争优势较弱。一般配合力和特殊配合力与杂种优势呈极显著正相关。不育系以六盐A、丹阳941A、98G26A、99-9A、香粳8016A和95122A较好,有较大的应用潜力。恢复系以C418、J16、晚161和C76较好。（2）以9个新育成的BT型粳稻不育系和5个恢复系为亲本,采用NCⅡ设计研究12个品质性状的配合力和杂种优势。结果表明:各性状的亲本一般配合力方差均达显著或极显著水平,特殊配合力方差除精米长和长宽比外也均达到显著或极显著水平。精米率、整精米率、食味值、直链淀粉含量和蛋白质含量同时受加性和非加性效应的作用,糙米率、垩白率、垩白度、精米长、精米宽、长宽比和精米厚等性状则主要受加性效应的影响。粒型和食味品质性状同时受不育系和恢复系的影响,碾米品质和外观品质性状则受恢复系的影响较大。除精米率、整精米率和食味值有一定程度的超高亲优势外,其他性状多介于双亲之间。杂种优势同时受亲本一般配合力和组合特殊配合力的影响,且多数性状都达到显著或极显著水平。在优质育种中,不育系以95122A最好,香粳8016A次之;恢复系以J16最好,R187次之,用上述亲本选配的杂交组合米质较好。（3）通过观察7个新育成的BT型粳稻不育系的开花习性发现,各不育系花时均比恢复系C418迟;开颖角度较小;除95122A和99-12A有较低的柱头外露率外,其余不育系柱头均不外露;异交结实率大小依次为六盐A＞99-12A＞香粳8016A＞95122A＞丹阳941A＞99-9A＞98G26A。（4）利用SSR分子标记对20个粳稻不育系和10个恢复系进行遗传多样性分析,继而研究分子标记遗传距离与按照NCⅡ设计获得的200个杂交组合主要产量性状杂种优势的相关性,探讨分子标记遗传距离预测杂种优势的可行性。结果表明,64对SSR引物共检测到185个多态性片段,平均每对引物为2.9条,每个SSR位点的PIC值变化范围为0.064～0.844,平均为0.380。以SSR标记遗传相似系数为原始数据,按UPGMA方法将30个亲本材料划分为7大类群,分类结果与系谱关系基本相符。分子标记遗传距离与杂种平均值的相关除总粒数外均达到显著或极显著水平,与杂种优势的相关均达到极显著水平,相关系数介于-0.361～0.359之间,说明分子标记可用于研究杂种优势群的划分和遗传多样性分析,但相关程度还不足以预测杂种优势。更多还原

【Abstract】 The combining ability and heterosis for the major agronomic and quality characters were studied with the BT-type CMS lines newly bred and restorer lines widely used by the NCⅡdesign. The main results were summerized as below.1. The combining ability for 13 agronomic characters was studied with 12 new BT-type japonica sterile lines and 8 restorer lines by NCⅡ4 design. Both general combining ability （GCA） and specific combining ability （SCA） of all the characters were significant at 1% level except for the number of panicles per plant in which the SCA was insignificant. The GCA was more important than SCA in most characters. The SCA for number of filled grains of main panicle, seed setting rate, grain weight per plant and harvest index was greater compared to other characters. The other characters were influenced more greatly by restorer lines than by sterile lines, except panicle length, panicle neck length, seed setting rate and harvest index. GCA and SCA effects were independent each other. Hybrid japonica rice had stronger heterosis over mid-parent, but heterosis over parent and competitive heterosis of most characters were not strong. There was a significant positive relationship between the combining ability and heterosis. Based on the GCA and SCA of the parents, sterile lines Liuyan A, Danyang 941A, 98G26A, 99-9A, Xiangjing 8016A, 95122A and restorer lines C418, J16, Wan 161, C76 were recommendable.2. The combining ability and heterosis for 12 quality characters were studied with 9 new BT-type japonica sterile lines and 5 restorer lines by NCⅡdesign. General combining ability （GCA） variance of all characters was significant or highly significant. Except milled rice length and length/width ratio, specific combining ability （SCA） variance was significant or highly significant for other characters. Milled rice ratio, head rice ratio, tasted value and amylose content were controlled by both additive and non-additive effect, other characters were mainly controlled by additive effect. Grain shape and tasted quality characters were influenced by sterile lines and restorer lines, while milling quality and appearance quality characters were mainly influenced by restorer lines. Most quality characters of hybrids rice showed the measurements between their parents except milled rice ratio, head rice ratio and tasted value showed heterosis over parent. There was a significant or highly significant positive relationship between the combining ability and heterosis for most characters. Based on the GCA effect and SCA variances of the parents, sterile lines 95122A and Xiangjing 8016A and restorer lines J16 and R187 were recommendable and can be widely used for high quality breeding for japonica hybrid rice.3. The flowering habits of 7 BT-type CMS lines newly bred were studied. The results showed that the flourishing flowering of all sterile lines was later than that of C418. The opening angles of spikelets of all sterile lines were smaller. The stigmas could not exsert except 95122A and 99-12A with low stigma exsertion rate. The order of outcross seed setting percentage from big to small is Liuyan A, 99-12 A, Xiangjing 8016A, 95122A, Danyang 941 A, 99-9A, 98G26A.4. Genetic diversity among 30 Japonica rice was studied using the SSR molecular marker, and relationship between genetic distance based on SSR markers and yield heterosis was discussed. The materials consisted of 30 parents and 200 F₁ hybrids with a diallel crossing design. The results indicated that 64 SSR markers detected 185 alleles among 30 parents with 2.9 on the average. Polymorphic index content （PIC） values varied from 0.064 to 0.844 with an average of 0.380. Cluster analysis by UPGMA classified 30 parents in seven groups based on genetic similarity corresponding to the heterotic groups determined by their pedigree analysis. The correlations between the genetic distance and yield heterosis and hybrid performance were significant except total spikelets per panicle, but the values were too small（-0.361⁰.359） to predict heterosis. The research indicated that molecular markers could be used as a useful tool for assigning heterotic group and measuring genetic diversity. .更多还原