种植密度和行距配置对玉米穗位叶光合特性的影响

Effects of Planting Density and Row Spacing Form on Photosynthetic Characters of Maize Ear Leaf

玉米穗位叶叶绿素含量、净光合速率(Pn)、最大光化学效率(Fv/Fm)、实际光化学效率(ΦPSⅡ)均随密度增大而呈降低趋势,且均在生育后期差异较显著。光合作用关键酶磷酸烯醇式丙酮酸羧化酶(PEP-Case)和1,5-二磷酸核酮糖羧化酶(RuBPCase)活性亦呈降低趋势。叶绿素含量、Pn、Fv/Fm、ΦPSⅡ、PEPCase和RuBPCase活性在低密度下各行距配置间均无显著差异,但在中高密度下,"80+40"配置均高于其他配置,尤其是在生育后期差异显著,适宜的行距配置可提高穗位叶光合能力。

The chlorophyll content, net photosynthesis rate （Pn）, maximum photochemical efficiency of PS II （Fv/Fm） and actual quantum yield of PS II linear electron （ФPS II ） were negatively correlated with the density, especially in the late growth stage. The activities of photosynthesis key enzymes （PEPCase and RuBPCase） performed consistent with them. The results indicated that the high density was unfavorable to photosynthesis of the ear leaves. Under low density, the chlorophyll content, Pn, Fv/Fm, ФPSII and the activities of PEPCase and RuBPCase had no significant differences among all row spacing forms; but under middle - high densities, these values of the So, the photosynthetic capacity of Key words Maize; Planting ＂80 ＋40＂ form were the greatest, particularly at later development stages. ear leaves could be raised by the optimum row spacing form.