不同基因型玉米株型性状的杂种优势分析

为了提高玉米产量,培育适宜高密度种植和适宜机械化收获的株型,已成为当前玉米育种的需求。本研究以4个玉米杂交种及其亲本为材料,以‘郑单958’为对照。通过测量株高、穗位高、基部第三节间茎粗、雄穗长度、雄穗分枝数、叶夹角,计算叶向值和叶面积,计算中亲优势和超亲优势。结果表明,与双亲相比,‘新单61’、‘新单68’、‘新单65’和‘新单58’的叶夹角均变小,植株的抗倒性增强。对5个杂交种叶形结构相关性状间的相关性分析表明,叶长和叶宽与叶面积间均呈极显著正相关,叶夹角和叶面积与叶向值均呈显著或极显著负相关。‘新单61’的株高、穗位高、穗三叶叶面积,‘新单68’的雄穗长度,‘新单65’的基部第三节间茎粗和‘新单58’的叶向值均具有较大的杂种优势。因此,要加大这些株型性状的选择压力,才能组配出株高和穗位高适中、株型较紧凑的强优势杂交组合。

Plant Type Characters of Maize with Different Genotypes: Heterosis Analysis

In order to increase maize yield, suitable high-density planting variety has become the demand of maize breeding, and it plays an important role in improving the plant type characters of maize. Four maize hybrids and their parents were used as materials and ‘Zhengdan 958’ was used as the control. Plant type characters were investigated including plant height, ear height, stem diameter of the third internode, tassel length, tassel branching number, and leaf angle. LOV (leaf orientation value) and leaf area were measured, and the mid-parent heterosis value and heterobeltiosis value were calculated. The results showed that the leaf angle of ‘Xindan 61’, ‘Xindan 68’, ‘Xindan 65’ and ‘Xindan 58’ were smaller than that of their parents, and the lodging resistance of plants increased. The correlation of leaf shape and structure related characters of the five hybrids were analyzed, the results showed that the leaf length and leaf width were significantly and positively correlated with leaf area, and the leaf angle and leaf area were significantly and negatively or highly significantly and negatively correlated with leaf direction. There was heterosis in plant height, ear height and leaf area of ‘Xindan 61’, tassel length of ‘Xindan 68’, stem diameter of the third internode of ‘Xindan 65’and LOV of ‘Xindan 58’. Therefore, to form a strong dominant hybrid combination with suitable plant height and ear height and compact plant type, it is necessary to increase the selection pressure on these plant type characters.