改良HS相互轮回选择法对两个玉米群体的改良

Studies on the Application of Modified HS Reciprocal Recurrent Selection in Maize Population Improvement

对MZZ3(改良中综 3号 )、MZZS4 (经 4轮MS1改良的中综 4号群体 )完成了 2轮改良半同胞 (HS)相互轮回选择。结果表明 ,两群体以籽粒产量为主要选择目标 ,经两轮改良HS相互轮回选择 ,与各测验种间的测交组合产量、杂种优势都获得了逐轮提高。测交组合产量每轮增益 (ΔG)在 2 85kg hm2 (5 .5 % )到 6 88kg hm2 (13.0 % )之间。同时 ,两群体ΔG都以MZZS4C2×MZZ3Cn和MZZ3C2×MZZS4Cn最大 ,其次为掖 4 78×MZZ3Cn、P178×MZZ3Cn及黄早四×MZZS4Cn、丹 340×MZZS4Cn ;杂种优势每轮增益 (ΔG)在 193kg hm2 到 4 2 1kg hm2 之间。两群体一般配合力均得到了显著改良 ,MZZ3从C0的 - 5 17提高到C2的 5 10 ,MZZS4从C0的 - 5 0 9提高到C2的 4 94。同时 ,两群体间的特殊配合力也逐轮提高。不仅如此 ,还改良了群体与测交种 (含同类种质 )的特殊配合力。从特殊配合力的获得量看 ,MZZS4C2×MZZ3Cn、MZZ3C2×MZZS4Cn最大 ,其次为掖 4 78×MZZ3Cn、P178×MZZ3Cn及黄早四×MZZS4Cn、丹 340×MZZS4Cn。杂种优势、测交组合产量的变化与配合力完全一致。改良HS相互轮回选择可同时改良群体S1、S2后代的产量 ,MZZ3每轮群体S1后代获得 10 2 %的增益 ,S2后代获得 12 .7%的增益 ;MZZS4每轮群体S1后代获得 11.8%的增益 ,S2后代获得

Tow cycles of modified HS reciprocal recurrent selection aiming at improvement of grain yield in MZZ3 and MZZS4 maize ( Zea mays L.) populations was completed in northern China. The objective was to evaluate improvement effects for MZZ3 and MZZS4 via NCⅡ mating design at four locations in 2002. Analysis of variance indicated that significant progress( P <0.01)was available among populations for all traits. The GCA of grain yield were increased from -517 and -509 of C0 to 510 and 494 of C2 for MZZ3 and MZZS4 populations, respectively. There were the first response to SCA of grain yield in MZZS4C2×MZZ3Cn,MZZ3C2×MZZS4Cn,and the second one in 478×MZZ3Cn, P178×MZZ3Cn and Huangzao4×MZZS4Cn, Dan340×MZZS4Cn.There were similar results in the gains of heterosis and grain yield for testcrosses per cycle. The gains of heterosis were from 193 kg/ha to 421 kg/ha. The increment of grain yield for testcrosses was from 285 kg/ha (5.5%) to 688 kg/ha(13.0%). Just like the SCA , there were the maximum responses to heterosis and grain yield for testcrosses in MZZS4C2×MZZ3Cn, MZZ3C2×MZZS4Cn,and then in 478×MZZ3Cn, P178×MZZ3Cn and Huangzao 4×MZZS4Cn, Dan340×MZZS4Cn. The grain yields of S1 and S2 progenies in MZZ3 and MZZS4 populations at the cycle 2 were significantly( P <0.01)increased as compared with the original cycle(C0). The gains of grain yields per cycle were 10.2%, 12.7% and 11.8%, 17.8% for MZZ3 and MZZS4 populations, respectively.