玉米自交系性状的遗传差异与杂种优势及特殊配合力的关系

以9个玉米自交系和完全双列杂交设计配制的72个单交种(包括反交)为材料,测定了株高、果穗长等13个植株和穗部性状,用主成份法测定了遗传距离D~2,模拟了遗传距离D~2与杂种优势和特殊配合力的关系,但相关不显著。而用了13个性状差异(两亲本同一性状之差的绝对值)与杂种优势和特殊配合力的相关比较表明:杂种优势与两亲本风干穗重、单穗粒重差异呈极显著负相关,相关值为—0.730,—0.770,与其余性状的差异相关不显著。特殊配合力与两亲本的风干穗重、单穗粒重呈显著负相关,相关值为—0.386,—0.404,与其余性状差异亦不显著。因此,本研究认为选配亲本时应考虑双亲单穗粒重高,且差异小,易奏效。

Corelations of Genetic Difference of Self Line, Hybrid Vigor of Grain Yield and Special Combining Ability in Zea Maize

Seventy two hybrids were obtained by using 9×9 complete diallel crossing design with 9 self lines in Zea maize. Plant height, ear length and other 13 characters of these hybrids were measured and their genetic distance (D) were obtained through main composition analysis. The corelations of genetic distance, hybrid vigor and special combining ability were simulated, but the corelations were not significant. Meanwhile the corelations of the difference in thirteen characters (difference between two parents in same character), the characters of their hybrid and their special combining ability were also studied. The negative corelations of hybrid vigor, parent dry ear weight and grain weight per ear were significant(the coefficience was —0.730 and —0.770, respectively), but other corelations were not significant. The corelations of special combining ability, dry ear weight and ear weight per ear of parent were negative (the coefficience was —0.386,—0.404 respectively). It is suggested that the ear weight per ear and small differences between parent characters should be considered when hybrid combines are chosen.