Abstract:

Through the analysis of photosynthetic physiology and hybrid heritability of alfalfa male sterile lines, their hybrids and their correlation with heterosis, the results showed that the net photosynthetic rate (Pn) and transpiration rate (Tr) of hybrid hybrids showed a "single peak" curve. When the consumption of the same amount of water was consumed, there was more synthesis dry matter, that is, high-water use efficiency (WUE) associates with significant hererosis. The results showed that the water use efficiency was the main photosynthetic index of heterosis, and the transpiration rate had little effect on the heterosis formation of yield traits. The variation range of heterosis in hybrid combinationsranged from 0 to 1, among which hybrid combination 2×Ⅱ has the highest heritability (0.6129), and the heterotic effect is the highest (52.10%). There was a significant positive correlation between hybrid heritability and heterosis effect in hybrid combinations, so the hybrid heritability could have a direct effect on heterosis.

Key words: Alfalfa male sterile lines, Hybrid Heritability, Net photosynthetic rate(Pn), Transpiration rate(Tr), Water use efficiency(WUE)

摘要：

通过对苜蓿（Medicago sativa）雄性不育系及其杂交组合的光合生理特性和杂种遗传力测定，以及与杂种优势间的相关性分析，结果表明：杂交组合净光合速率（Pn）和蒸腾速率（Tr）日变化均呈现“单峰”曲线。在消耗等量的水分条件时，合成的自身干物质较多，即水分利用效率（WUE）高则其杂种优势明显。表明水分利用效率是杂种优势形成的主要光合生理指标，而蒸腾速率对产量性状杂种优势形成影响不大；杂交组合的杂种遗传力值的变异范围均在0~1之间，其中杂交组合2×Ⅱ的杂种遗传力最高（0.6129），同时其杂种优势效应值也最高（52.10%）；杂交组合的杂种遗传力与杂种优势效应间存在极显著正相关，因此杂种遗传力可对杂种优势效应有直接影响。

关键词: 苜蓿雄性不育系, 杂种遗传力, 净光合速率(Pn), 蒸腾速率(Tr), 水分利用效率(WUE)