谷子黄叶色突变体光合特性研究

为解析谷子黄叶色突变体高光合特性机理,以野生型豫谷1号为对照,分析了谷子全生育期黄叶色突变体ylm-1和ylm-2的光合色素、光合速率、气孔特性、荧光参数、光合关键酶活性和产量性状。结果表明,突变体光合色素含量为野生型豫谷1号的50%~60%,强光下突变体光合速率(Pn)较野生型显著提高,且无明显的“午休睡眠现象”;ylm-1和ylm-2气孔导度(Gs)显著增加。荧光参数结果显示,与野生型相比,突变体的光能利用效率和转化效率明显增加,光合关键酶1,5二磷酸核酮糖羧化酶(Rubisco)活性明显降低,而ylm-1和ylm-2磷酸烯醇式丙酮酸羧化酶(PEPCase)和苹果酸酶(NADP-ME)活性分别增加了23.3%、24.4%和12.9%、15.5%。产量相关性状分析表明,突变体单穗质量、穗粒质量及千粒质量较野生型显著增加。本研究结果为谷子高光效及分子标记辅助选择育种提供了重要的理论依据。

Study on Photosynthetic Characteristics of Foxtail Millet Mutant With Yellow Leaf Colour

To explore the mechanism of high photosynthesis efficiency of millet mutant with yellow leaf colour. The photosynthetic pigment, photosynthetic rate, stomatal traits, fluorescence parameters,activity of key photosynthetic enzymes and yield characteristics of two yellow leaf colour mutant lines ylm-1 and ylm-2 were studied, the wild type of “Yugu 1” was used as the control. The results suggested that the contents of photosynthetic pigment in mutants were 50%~60% of that in Yugu1. The photosynthetic rates of mutants were higher than that of the control under high light intensity and had no obvious “Midday depression phenomenon”. The stomatal conductance of ylm-1 and ylm-2 were increased significantly. The fluorescence parameters suggested that light energy efficiency and conversion efficiency of mutants were obviously higher than that of the wild type. The activity of key photosynthetic enzyme ribulose-1,5-bisphosphate carboxylase (Rubisco) in mutants were significantly lower than that in control, but the activities of phosphoenolpyruvate carboxylase (PEPCase) and NADP-malic enzyme (NADP-ME) were 23.3%, 24.4% and 12.9%,15.5% higher than those of the control, respectively. The results of yield characteristics showed that the weight per spike, seed weight per spike and thousand grain weight were increased significantly compared with control. These results provide an important theoretical basis for high light efficiency and molecular marker assisted selection breeding in millet.