钾素对甜玉米苗期光合特性的影响

通过盆栽试验研究了钾对5种不同甜玉米品种苗期净光合速率、蒸腾速率、胞间二氧化碳浓度和蒸腾速率的影响, 旨在为甜玉米高效合理施用钾肥提供理论依据。结果表明，在相当于0-324.3kg/hm2钾肥施用量范围内，金茂3号、鲜美黄金蜜和贵甜一号等3个品种苗期光合速率、气孔导度和蒸腾速率均随着钾肥施用量增加而增加，胞间CO2浓度则表现出相反的变化规律。对于广甜特大金银粟和粤甜9号等2个品种而言，在0-270.25kg/hm2施用量范围内，钾肥对其上述光合特性表现出类似的影响规律，但随后增加钾肥用量，光合速率、气孔导度和蒸腾速率均有所降低而胞间CO2浓度升高。以上结果表明，上述5个甜玉米品种对钾的耐受能力存在差异，在制定合理钾肥施用量时应综合考虑其钾素营养特性。

Effects of Potassium on Photosynthetic Characters of Sweet Corn in Seedling Phasing

The influence of potassium on photosynthetic characters of sweet corn in seedling phasing was investigated. As the results shown, over the range of 0-324.3 kg/hm2 of examined in the present study, the increase in amount of K fertilizer applied would result in the increase of photosynthetic rate, stomatal conductance and transpiration rate for the three varieties of sweet corn like ＂Jin Mao III＂, ＂Xian Mei Huang Jin Mi＂ and ＂Gui Tian I＂, with the reverse trend for intercellular CO2 concentration. However, similar trend could only be observed for ＂Guang Tian Te Da Jin Yin Li＂ and ＂Yue Tian IX＂ through the range of 0-270.25 kg/hm2, over which the photosynthesis would be impressed due to the excess input of potassium, which was indicated by the increase in intercellular CO2 concentration.