【作者】 王丽霞；

【导师】 魏建民； 王立新；

【作者基本信息】 内蒙古农业大学 ， 生物化学与分子生物学， 2009， 硕士

【摘要】 我国植物新品种保护条例规定授予新品种权的品种必须具备特异性、一致性和稳定性,品种稳定性和一致性主要受品种DNA位点纯合率和环境的影响。小麦品种纯合DNA位点是杂合体通过自交而形成,随着自交世代的增加,DNA位点纯和率将不断提高,其后代群体的稳定性和一致性也将随之提高。我国小麦品种育种年限多为5年以上,但有些育种者认为可以忽略F₄代株系个体之间的差异,而用F₄代株系作为品种加以繁殖、进行品比,甚至参加国家或省市级区域试验。针对目前小麦F₄代株系能否作为品种的争议,本研究以10个小麦杂交组合F₄代株系及其亲本为试验材料,对不同株系及其亲本的DNA位点纯合率和重要农艺性状稳定性进行了研究。取得了如下结果:1、10个F₄代株系的DNA位点纯合率为83.0～94.8 %,平均值为90.0%,其4个亲本北农6号,复壮30,农大015的DNA位点纯合率分别为98.5%、98.2%、97.9%、95.3%,平均值为97.5%。亲本的DNA位点纯合率均高于95 %。2、以DNA位点纯合率≥95 %的品种为对照,10个F₄代株系中仅BF-2003-82-17的农艺性状变异幅度在对照品种的变异范围之内,其DNA位点纯合率为94.2 %,接近95%。其余9个F₄代株系均有变异幅度大于对照品种或仍在分离的农艺性状,证明大多数F₄代株系的一致性和稳定性尚不符合要求,只有极少数株系具备了一致性和稳定性。因此认为通过检测DNA位点纯合率来确定DNA位点纯合率较高的F₄代株系,再经过田间鉴定考察农艺性状的一致性和稳定性,可以从中选择具备一致性和稳定性的优良株系,达到缩短育种年限的目的。更多还原

【Abstract】 New varieties must have the distinctness, uniformity and stability, the stability and uniformity affected by the homozygous DNA locus ratio and the environment. The homozygous DNA locus was formed through the heterozygotes self-crosslinking, the homozygous DNA locus ratio will continue to increase with the generation increasing, and the stability and uniformity of their future generations will also improve. In China, years of wheat breeding for more than 5 years, in order to shorten breeding time, some wheat breeders used F₄ lines as cultivars to carry out comparison tests and submit them to wheat cultivar regional tests. Therefore ten of F₄ lines were employed to detect the homozygous DNA locus ratio and the uniformity as well as the stability of main agronomic traits in this study. The main results are as follows:1. The homozygous DNA locus ratio of 10 of F₄ lines were 83.0– 94.8 %, the average was 90.0%. The ratios of their four parents were 98.5%, 98.2%, 97.9%, 95.3%, the average was 97.5%, the ratios higher than 95 %.2. The variation range of agronomic traits of F₄ line BF-2003-82-17 were within the scope of the control cultivars by comparing with the control cultivars which the homozygous DNA locus ratio were higher than 95 %. The homozygous DNA locus ratio of BF2003-82-17 was 94.2%. It closed to 95%. Some agronomic traits of the other nine lines presented higher variation coefficient than that of the control cultivars, and some agronomic traits were still separating. It proves that the uniformity and stability of the most of F₄ lines do not accord with the requirements yet. Only a few lines possess the uniformity and stability.So, it is possible to choose F₄ lines with the uniformity and stability by detecting the homozygous DNA locus ratio and identifying the uniformity and stability of agronomic traits in the field, and to reach the purpose of reducing the breeding years.更多还原