玉米株型、果穗性状的遗传和相关性分析

本试验以14个玉米自交系及由其组成的9个杂交组合以及相应的F2代为材料，系统地研究了自交系与杂交种之间及杂交种性状与性状之间的关系，探讨了玉米杂交种自交衰退的数量指标．研究结果表明，(1)玉米穗长，行粒数和百粒重在母本与F₁之间呈极显著正相关；穗位高、穗直径和单穗粒重在父本与F₁之间呈显著正相关，株高在父母本与F₁之间均为显著正相关．(2) F₁单穗粒重与株高、穗长、行粒数、穗粒数和百粒重之间存在显著的正相关．(3) F₁性状优势越强，F₂衰退越重(r＝0.8830)．单穗粒重优势分别与行粒数和穗粒数优势呈极显著正相关(r＝0.8618和r＝0.8441)．(4) 单穗粒重的衰退主要是由穗粒数衰退所致(r＝0.7473)．穗行数，植株叶片数和叶向值的衰退值较小或为负值。

Genetic and Correlation Analysis of Plant Type and Ear Characters in Maize

The relationships between the inbred lines and F1 and among the characters of F1 in maize were studied with 14 inbred lines and 9 crosses (F1,F2), and the inbreeding depression was also studied. There are positive and significant correlations at the 0.01 probability level between female parent and F1 in the characters of the ear length, kernels per row and 100 kernel weight. Meanwhile the correlations between male parent and F1 are positive and significant at the 0.01 probability level in the ear height,ear diameter and kernel weight per ear. F1 has a positive and significant relationship at the 0.05 probability level with male or female parent in the plant height. The kernel weight per ear is positively and significantly correlated with the plant height, ear length.kernels, per row, kernels per ear and 100 kernel weight in F1 reopectively. It is shown that the more the heterosis expxesses in F1, the more. the inbreeding depression occures in F2. The heterosis of kernels weight per ear showed highly positiive correlation (P<0.01) with the kernels per row and kernels per ear. The inbreeding depression of the kernel weight per ear is mainly caused by the inbreeding depression of the kernels per ear. There is little depression of inbreeding in rows per ear, leaves per plant and leaf orientation.