轮回选择对玉米沈综(C_0、FC_2)群体的产量组成性状的遗传改良效果研究

对玉米(ZeamaysL.)沈综基础群体和FC2 实施了轮回选择遗传改良 ,第一轮以半姊妹选择方案完成 ,获得了沈综(330)C1 群体 ,而后对它进行两轮全姊妹轮回选择改良 ,选择性状主要以籽粒产量为主 ,兼顾抗病性和部分植株性状 ,然后将得到的FC2、FC3 群体和C0、CK置于同一环境种植 ,根据调查和考种结果对各群体产量性状进行分析。结果表明 :群体产量获得了7.5 %的遗传增益。穗行数、行粒数、百粒重和单穗粒重得到明显的改良。群体中优良个体频率增加 ,与产量相关性状的变异系数下降。相关分析和通径分析表明 :不同群体的农艺性状与单株产量的相关程度有差异 ,群体产量的提高是由于农艺性状得到了改善和性状之间的关系得到了协调发展的结果

Study on the Genetic Improvement Effects in Yield Traits of Shenzong(C0/FC2) Populations by Means of Recurrent Selections

Recurrent seletion for genetic improvement was implemented on maize (Zea may L.) Shenzong basic population and FC2. Firstly, Shenzong(330)C1 was obtained by means of half-sib recurrent selection and then it was improved by two cycles of full-sib recurrent selection, grain yield was principally considered while other traits such as disease resistance and plant traits were paid attention also. The populations FC2/FC3/C0/CK were planted in same environment. The yield and agronomic traits were analyzed on the basis of the results of traits investigation. The results show that the genetic gain of population yield is 7.5%. The yield traits such as row number/per row grain no.100_kernel weight and single ear grain weight were significantly improved. With the frequency of elite individuals grew, the coefficient of variability related to grain yield decreased slightly. Correlation analysis and path analysis indicated that the correlations were different between agronomic traits and plant yield among different populations. The reasons for yield enhancement are that the traits affecting plant yield are reasonably ameliorated and the relationships among them are coordinately developed.