【作者】 廖惠红；

【导师】 李杨瑞； 李容柏；

【作者基本信息】 广西大学 ， 作物栽培学与耕作学， 2004， 硕士

【摘要】 水稻杂种优势利用是提高粮食产量的有效途径，但是目前育成的新组合的产量水平处于徘徊状态。分子标记辅助育种可以更有效地利用资源的遗传多样性，在分子水平上更精确地进行选择，从而培育出更高产的杂交水稻品种。本研究通过对杂交稻亲本进行分子标记，试图找出杂种优势与亲本遗传差异的相关性，为水稻杂种优势的分子标记选择提供有效的参考。 本研究采用12个水稻亲本(其中3个母本和9个父本)按NCⅡ设计配组27个杂种，以特优63为对照，研究与产量密切相关的农艺经济性状，对这些性状的杂种表现及竞争优势进行偏相关分析，找出对产量影响较大的因子，对这些因子进行通径分析，判断出这些因子对产量的贡献程度。并以12个亲本为DNA样品来源，通过RAPD和SSR两种标记技术对亲本间的遗传差异进行标记。最后将杂种优势中对产量影响最大的因子分别与RAPD及SSR标记的亲本间遗传距离进行偏相关分析。本实验所得结果如下：在影响杂交水稻产量的主要因素中，每穗实粒数的影响最大，有效穗数次之，千粒重和穗长影响较小；每穗实粒数与RAPD标记的亲本间遗传距离相关性不显著，而与SSR标记的亲本间遗传距离相关性达到极显著水平，与RAPD-SSR标记的亲本间遗传距离相关性亦达到极显著水平。竞争优势与亲本的遗传距离关系分析表明，增产杂交组合的亲本SSR标记遗传距离在0.50-0.83之间，RAPD-SSR标记遗传距离在0.59-0.81之间。本实验结果表明：在水稻杂种优势的分子标记选择方面，SSR标记技术优于RAPD技术，而将两种技术结合起来分析效果更好。研究结果为分子标记辅助选择杂交水稻亲本提供了依据。更多还原

【Abstract】 The utility of heterosis is an efficient way to improve yield in rice. At present, however, the yield potential of rice new hybrid combinations is stagnant. The molecular marker-assisted breeding is an efficient way for making full use of genetic diversity, fine selection at molecular level and therefore, lead to higher yield potential of rice hybrids. The present research attempts to find out the relationship between parental genetic difference and heterosis of hybrids through molecular marker techniques, which provides help to molecular marker-assisted selection for rice heterosis.In this research, 12 indica rice parents were crossed by use of NCII design and 27 F1 hybrids were obtained, and Teyou 63, a most popular indica rice hybrid, was used as the control variety. Agricultural economic characters closely related with yield were recorded and analysed for their relationships with yields, and main factors contributing to yields were further analysed by partial correlation analysis and path coefficients analysis of hybrid performance and standard heterosis. The genetic differences among the parents were studied by RAPD and SSR molecular marker techniques. And the relationship between the closest factor related to yield and genetic distance was evaluated by partial correlation analysis. Results from the study showed filled seeds per panicle to be the most important factor among the major characters contributing to yield, followed by effect panicle number, and then the 1000-seed weight and panicle length. The correlation between filled seeds per panicle and RAPD marker genetic distance was not significant, while that between filled seeds per panicle and SSR marker genetic distance and that between filled seeds per panicle and RAPD-SSR genetic distance were very significant. The analysis of relationship between standard heterosis and parental genetic distance indicated the hybrids indicated positive increase of yield with parental genetic distances from 0.50 to 0.83 of SSRs or from 0.59 to 0.81 of RAPD-SSRs. These results showed that SSR molecular marker technique is superior to RAPD in parent selection for rice heterosis, and it is better to combine both RAPD and SSR molecular markers for the marker-assisted selection. The study results would provide valuable help to selection of hybrid parents by molecular marker-assisted selection in rice.更多还原