玉米花生间作和磷肥对间作花生光合特性及产量的影响

Effects of maize-peanut intercropping and phosphate fertilizer on photosynthetic characteristics and yield of intercropped peanut plants

揭示玉米(Zea mays)和花生(Arachis hypogaea)间作提高花生对弱光利用能力的光合特点及磷(P)肥效应,对阐明间作花生适应弱光的光合机理和提高间作花生的产量具有重要意义。该试验于2011–2012年在河南科技大学试验农场分析了间作花生功能叶的叶绿素含量与构成、光响应曲线和CO2响应曲线特点和荧光参数。结果表明:与单作花生相比,施P与不施P条件下玉米和花生间作显著(p<0.01)提高了花生功能叶的叶绿素b含量,降低了叶绿素a/b,显著提高了光系统II最大光化学效率(Fv/Fm)、实际光化学效率(ΦPSII)、光化学猝灭系数(qP)、表观量子效率(AQY)和弱光时的光合速率,显著降低了气孔导度、二磷酸核酮糖羧化酶羧化速率(Vcmax)、电子传递速率(Jmax)和磷酸丙糖利用速率(TPU);与不施P相比,施P有利于提高间作花生功能叶的叶绿素含量,显著提高了ΦPSII、qP、Vcmax、Jmax和TPU,说明间作花生通过提高功能叶的叶绿素b含量,改变叶绿素构成,提高了光系统II的Fv/Fm、ΦPSII和qP,增强了对光能的捕获和转化能力,提高了对弱光的利用能力,而并非提高了对CO2的羧化固定能力;施P有利于提高间作花生对弱光的利用能力和产量,土地当量比提高了6.2%–9.3%。

Aims Our objective was to determine the enhanced utilization of weak light in intercropped peanut plants （Arathis hypogaea） and the regulatory effects of phosphate （P） fertilizer in maize-peanut intercropping system, which is of great significance to elucidate photosynthetic adaptation mechanism of intercropped peanut plants and to increase the yield. Methods Chlorophyll （Chl） content and composition, photosynthetic light response curves, photosynthetic CO2 response curves, and fluorescence parameters in the functional leaves of intercropped peanut plants were studied at the experimental farm of Henan University of Science and Technology in 2011 and 2012. Important findings The Chl b content was higher, and the Chl a/b ratio was lower, in the functional leaves of intercropped peanut plants than in those of single cropped peanut plants with or without P fertilizer application. There were higher values of maximum photochemical efficiency （Fv/Fm）, actual photochemical efficiency （ФPsii）, photochemical quenching coefficient （qp） of photosystem I1, apparent quantum yield （AQY）, and photosynthetic rate, but lower values of stomatal conductance, RuBP carboxylation rate （Vcmax）, electron transport rate （Jmax）, and triose-phosphate utilization rate （TPU） in the functional leaves of intercropped peanut plants than in those of sin- gle cropped peanut plants. Application of P fertilizer was beneficial to improving chlorophyll content, ФPSII and qp of photosystem II, Vcmax, Jmax, and TPU in the functional leaves of intercropped peanut plants. It suggested that intercropped peanut plants could make more efficient use of weak light because of the higher Fv/Fm, （bpsu and qp of photosystem II resulting from higher Chl b content and changes chlorophyll composition of functional leaves, which strengthened the capacity of light absorption and transformation, but not because of the higher CO2 rate of fixation and improved carboxylation efficiency. Application of P fertilizer was beneficial to improving the utiliza- tion of weak light and to increasing the yield of intercropped peanut, resulting in an increase in the land equivalent ratio of the maize-peanut intercropping system by 6.2%-9.3%.