优良玉米杂交种植株性状杂种优势及其与亲本自交系的相关分析

以7个优良玉米杂交种及其亲本自交系为材料,研究了株高、穗位高、顶高、顶高/株高、穗上叶片数、雄穗长、雄穗分枝数、叶夹角、叶向值、叶面积、气生根层数、气生根数目、茎粗13个植株性状的表现、杂种优势及杂交种与双亲的相关性。结果表明:杂交种和自交系间各性状均存在显著差异;不同杂交种及不同性状的中亲优势(MH)和超高亲优势(HH)均存在差异,株高、穗位高、顶高、叶面积、雄穗长、茎粗、夹角、穗上叶片数、雄穗分枝数等杂种优势较大,顶高/株高、叶向值、气生根层数、气生根数等杂种优势较小;顶高、顶高/株高和穗上叶片数表现为杂交种与父本呈显著或极显著正相关;雄穗长和叶面积表现为杂交种与母本呈显著正相关;顶高、雄穗分枝数、叶夹角和叶面积表现为杂交种与中亲值呈显著或极显著正相关。

Heterosis of Plant Characters for Elite Maize Hybrids and Their Correlations with Parent Lines

In this study,seven excellent maize hybrids and their 13 parent lines were studied for 13 plant traits,including plant height,ear height,top height,top height/plant height,tassel length,tassel branch number,leaves above ear,leaf angle,leaf orientation value,leaf area,aerial root layers,first layer aerial roots and stem diameter.The mid-parent heterosis(MH),over-high parent heterosis(HH) of all hybrids,and the correlations of hybrid with its two parent lines were analyzed for all traits.The results showed that great differences existed among hybrids and parent lines for all traits.MH and HH were greatly different among different hybrids for the same trait and among different traits for the same hybrid.The heteroses of plant height,ear height,top height,tassel length,tassel branch number,the leaves above ear,leaf angle,leaf area and stem diameter were high,but the heteroses of top height/plant height,leaf orientation value,aerial roots layers,first layer aerial roots were low.Significant positive correlations were found between hybrid and its male parent line for top height,top height/plant height,leaves above ear,between hybrid and its female parent line for tassel length and leaf area,and between hybrid and mid-parent value for top height,tassel branches,leaf angle,and leaf area.This result could provide useful information for cross-making in the improvement of plant traits in maize breeding.