广适高产玉米杂交种金玉506穗部性状改良效应

摘要

[Objective] The ear strait is the main yield component.The ear trait of parents of hybrid maize combinations can be improved and the genetic effect of hybrid maize combinations is analyzed to provide a theoretical support for improvement of hybrid maize.[Method] Excellent hybrid maize lines of Eyu 10,Qianxing 201,Yayu 889 and Shundan 6 and Ph6wc inbred line are respectively introduced into QB506 by the genetic selection method and 15 excellent improved lines are selected from 485 improved lines of QB506.Excellent inbred lines of T32,QB572,QB576 and QB48 are introduced into QR273 separately and 27 improved inbred lines are selected from 367 improved inbred lines of QR273.The phenotype of 100 hybrid combinations is identified at three test sites (Dejiang,Guiyang and Luoping) to investigate 8 ear straits.[Result] The combining variance analysis shows that the variance between bocks in test sites reaches a significance or very significant level and the variance between combinations reaches a very significant level.There is a significant difference in ear phenotype trait among 27 improved line of QR273.The variable coefficient shows that the phenotype variable coefficient of the same trait among different donors presents an irregular fluctuation pattern and the variation range of phenotype variable coefficient of most straits among different donors is small.PH6WC has a higher improvement effect on ear strait compared with other four donors in QB506 improved lines but the variation range of the variable coefficient is big.Therefore,the correct donor selection is very important to genetic characteristics of the improved inbred lines (receptor).The average yield of 26 combinations at three test sites is 10 ％ higher than CK and their parents all include QB576 and T32 (donors of QR273,female parent of Jinyu 506) and PH6wc,Qianxing 201 and Eyu 10 (donors of QB506,male parent of Jinyu 506).[Conclusion] The correct donor selection can effectively rejet the disavantage of receptor and maintain excellent genetic characteristics of inbred lines (receptors) under the suitable selection intensity based on maize inbred line improvement of groups in heterotic population.%[目的]穗部性状是产量的主要构成因子,以玉米杂交种的双亲为“中心”,分别对其穗部表型性状不足进行改良,并解析玉米杂交种遗传改良效应;为玉米杂交种的改良提供理论支撑.[方法]利用配子选择法将优良玉米杂交种鄂玉10号、黔兴201、雅玉889、顺单6号和自交系Ph6wc分别导入QB506得458份改良系,从中选择15份;同时,将优良自交系T32、QB572、QB576和QB48分别导入QR273得367份改良系,从中选择27份;2014年,在3个地点(德江、贵阳和罗平)对100个杂交组合进行表型鉴定,调查8个穗部性状.[结果]联合方差分析表明:试点内区组间的方差均达显著或极显著水平.组合间的方差在P=0.01水平均达极显著.玉米QR273改良系的果穗表型性状差异显著性、变异系数分析表明:不同供体间的同一性状的表型变异系数呈不规则波动式变化;不同供体大多数性状的表型变异系数变化幅度小;同时,在QB506改良系上:PH6WC比其他4个供体在穗部性状改良效果明显,变异系数变化幅度大;正确的供体选择对改良优良自交系(受体)的遗传特性十分重要.3点平均产量超过对照10％以上的有26个组合,均由QR273(金玉506母本)的供体QB576与T32,(父本)QB506的供体PH6WC、黔兴201与鄂玉10号提供.[结论]基于杂种优势群内组群的玉米自交系改良,适宜地选择强度下,正确的选择供体能较好地剔除受体的缺点,同时,保持自交系(受体)的遗传特性的优点.