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【目的】通过群体的创建和改良,扩大玉米种质基础,为广西玉米杂交育种提供新的优良种质。【方法】根据配合力测定和自交系的系谱分析结果和育种目标要求,分别应用37、26个优良自交系创建两个玉米基础群体GZPA和GZPB,应用经简化后的改良HS相互轮回选择法对两个群体进行遗传改良,并对其农艺性状进行测定和遗传增益分析。【结果】经改良后,两群体杂交组合4个试点的平均产量增益为7.70%,其吐丝天数、开花间隙天数、穗长、穗粗、穗行数、行粒数、出籽率、千粒重均获得一定程度的有利增益。GZPA和GZPB平均产量增益分别为5.37%和4.85%;群体GZPA的吐丝天数、开花间隙天数、出籽率为负增益,其他性状为正增益,且株高、穗粗、穗行数的增益达显著水平;群体GZPB的吐丝天数、开花间隙天数、穗长、穗粗、穗行数、行粒数为正增益,其他性状为负增益。两个群体改良前后性状变异系数变化较小。【结论】简化后的改良HS相互轮回选择法对两个群体的改良效果明显,两个群体内仍有较大的遗传变异,可作进一步改良。
【Objective】 The objective of this study was to expand the base of maize germplasm by creating and improving groups and to provide new excellent germplasm for Guangxi maize hybrid breeding. 【Method】 According to the determination of combining ability and the pedigree analysis results and breeding target requirements, two maize basic populations GZPA and GZPB were established respectively by 37,26 elite inbred lines. After the modified HS was simplified and reincarnated The two groups were genetically modified, and their agronomic traits and genetic gain were analyzed. 【Result】 The results showed that the average yield gain of the four experimental crosses was 7.70%. The number of silking days, days of flowering gap, ear length, ear diameter, ear number, row grain number, seed yield, Have gained a certain degree of beneficial gains. The average yield gains of GZPA and GZPB were 5.37% and 4.85%, respectively. The numbers of silking days, flowering days and yield of GZPA were negative and the others were positive, and the gains of plant height, ear diameter and ear number Reaching the significant level. The number of silking days, the number of flowering gaps, the spike length, the ear diameter, the number of ear rows and the grain number of the population GZPB were positive gains, and the other traits were negative gains. The coefficient of variation of the two groups changed little before and after the improvement. 【Conclusion】 The improved HS cross-recycle selection method has obvious improvement effect on two groups. There is still a large genetic variation in both groups, which can be further improved.