对玉米人工合成群体遗传性状改良效果的研究

The study on the improvement effects for genepical characters of artificical synthetical maice populations

为对玉米群体改良提供理论依据和实践经验,对其进行限制性选择的株型改良以及确定合理的选择指数是群体改良的一项重要内容。在选择强度、有效群体和环境条件均一致的条件下,对玉米(Zea mayL.)沈综基础群体和(S_1)C_1群体实施两种方案的轮回选择,得到半同胞家系HC_2群体和全同胞家系FC_3群体,同时对产量组成性状、植株性状及抗病性进行表型选择,结果表明:在HC_2群体中,穗长、穗粗、行粒数、穗行数、百粒重的通径系数总效应分别为:0.579、0.415、0.363、0.311、0.293,在FC_3群体中,分别为0.511、0.317、0.578、0.014、0.368。与产量相关农艺性状的变异系数有所下降。群体植株性状获得的遗传增益不尽相同,营养体的生长量有所增加。

Two kinds of recurrent selection were implemented on maize basic population and (S_1) C_1 for the acquirement of half-sib HC_2 population and full-sib FC_3 population,while carrying out phenotypic selection according to yield-composite traits,plant characters and disease resistance.The results show that the total efficacy of coefficients path for ear length,ear thickness,per row grain no.,row number, 100-kernel weight are 0.579,0.415,0.363,0.311,0.293 respectively in HC_2 and 0.511, 0.317,0.578,0.014,0.368 in FC_3.The variability coefficient of agronomic traits related to yield decreased slightly.The genetic gain for population plant characters are different and the growth of nutrient body increased,therefor the restriction selection and determination of rational selection index for plant type will play an important role in population improvement.