速效氮对叶色突变体谷子苗期光合生理的影响

Effects of Available Nitrogen on Photosynthetic Physiological of Leaf Color Mutant Millet during Seedling Stage

叶色突变体具有易于辨识的表型,在理论研究和实际应用方面都具有重要价值。对EMS诱变的晋谷21号突变体库中筛选获得叶色突变体进行叶面喷施速效氮肥试验。结果表明,速效氮使叶色突变体谷子的净光合速率(Pn)增加了78.58%、水分利用率(WUE)增加了57.34%,但气孔导度(Gs)、蒸腾速率(Tr)、胞间CO2浓度(Ci)均没有显著变化;叶色突变体谷子叶片光系统II最大的(潜在)光化学量子效率(Fv/Fm)、叶片光系统II有效光化学量子效率(Fv′/Fm′)、光系统II实际光化学量子效率(ΦPSII)和电子传递速率(ETR)分别比对照增加了33.06%,28.89%,15.88%,15.88%,光化学淬灭系数(q P)和非光化学淬灭系数(q N)无显著变化;速效氮能增加叶色突变体谷子叶绿素a、叶绿素b以及叶绿素a+b的含量,但类胡萝卜素施肥处理与对照间差异不明显。总之,速效氮能够提高叶色突变体谷子的光合作用,改善叶色突变带来的不利影响,从而促进生长。

The leaf color mutant has a phenotype which is easy to identify, and it has important value in both theoretical research and practical application. In this experiment, the leaf color mutant was selected from the mutant library of the Jingu 21 mutant which was induced by EMS mutation. The results showed that available nitrogen in creased the net photosynthetic rate（Pn）and water use efficiency（WUE）of leaf color mutant millet by 78.58%, 57.34%, respectively. Stomatal conductance（Gs）, transpiration rate（Tr）and intercellular CO2concentration（Ci）were no significant changes. Photosystem II（potential）maximum photochemical efficiency（Fv/Fm）, leaf photosystem II photochemical efficiency of quantum efficiency（Fv＇/Fm＇）, the actual photochemical quantum efficiency of photosystem II（ΦPSII）, and electron transport rate（ETR） of leaf color mutant millet leaves increased by 33.06%, 28.89%, 15.88%, 15.88%,respectively. Photochemical quenching coefficient（q P） and non photochemical quenching coefficient（q N） showed no significant changes. Available nitrogen could increase chlorophyll a, chlorophyll b and chlorophyll a＋b content of leaf color mutant millet, but the carotenoids no significant changes. In short, available nitrogen can improve the photosynthesis of leaf color mutant millet, improve the adverse effects of leaf color mutation, and promote the growth.