玉米-大豆带状间作对大豆生长、光合荧光特性及产量的影响

Effects of Shading on Growth,Photosynthetic Fluorescence Characteristics and Yield of Soybean in Maize-soybean Intercropping Systems

为了探究玉米-大豆间作对大豆生长策略、光合荧光特性及产量的影响,以大豆品种中黄39为试材,采用玉米-大豆带状间作和大豆净作2种不同的种植模式,研究间作下大豆的形态、物质分配及光合荧光参数的变化规律。结果表明,间作大豆植株的株高在四节期(V4期)、始荚期(R3期)和鼓粒期(R6期)分别比净作增加22.47%、47.33%和32.72%。在V4期,间作大豆除株高显著高于净作外,大豆茎粗、主茎节数、茎叶柄生物量和叶绿素含量在净作和间作下均差异不显著。在R3和R6期,间作大豆植株的茎、柄生物量显著增加,但叶生物量、叶绿素a含量、叶绿素总含量及净光合速率(Pn)显著低于净作大豆。对于叶绿素荧光参数,间作大豆叶片非光化学淬灭系数(NPQ)在V4、R3和R6期分别显著高出净作大豆12.2%、5.04%和7.2%,而间作大豆叶片的PSII实际的光化学量子效率(F'q/F'm)、光化学淬灭系数(q P)和PSII反应中心潜在的激发能捕获效率(F_v/F_m)与净作大豆相比差异不显著。在产量构成因素中,间作大豆的单株荚数、单株粒数、百粒重及单株产量均显著低于净作,分别降低27.78%、12.33%、20.72%。间作下玉米对大豆生育后期的生长、光合特性的影响直接导致大豆产量及构成因素的下降。因此,在玉米-大豆带状间作种植模式下,要提高间作大豆产量,需降低大豆生育后期玉米荫蔽程度。本研究结果为间作大豆栽培及高产提供了一定的依据。

The objective of this experiment was to clarify change law of morphology, photosynthetic fluorescence parameters and dry matter distribution in soybean. This study based on two different patterns of maize-soybean intercropping employed soybean monoculture Zhonghuang 39 as the experiment material, and the effect of maize soybean intercropping on growth, photosynthetic fluorescence and grain yield of soybean were studied. The results showed that, compared with monoculture, the plant height of soybean at the fourth trifoliolate stage （V4）, beginning pod stage （R3） and full seed stage （R6） increased by 22.47%, 47.33%and 32.72%, respectively. In addition, plant height was significantly higher than that of intercropping, the stem diameter, internode number, the total biomass of stem, leaf, petiole, and the chlorophyll content had no significant differences between monoculture and intercropping at the fourth trifoliolate stage. At the stages of R3 and R6, the biomass of stem and petiole of soybean in intercropping increased significantly but the biomass of leaf, chlorophyll （a） content, total chlorophyll content and net photosynthetic rate （Pn） were found to be significantly lower than those in monoculture. With the succession of the growing stages of the soybean, the chlorophyll fluorescence parameter （NPQ） and Fo of soybean leaves in intercropping increased first, and then decreased, while F＇q/F＇m, qP and Fm showed a gradual decline. The chlorophyll fluorescence parameter NPQ in intercropping at stages of V4, R3 and R6 were significantly higher than that in monoculture about 12.2%, 5.04% and 7.20%, respectively. There were no significant differences on the parameters F＇q/F＇m, qP and Fv/Fm between intercropping and monoculture. In terms of yield components, the pod per plant, seeds per plant and hundred-grain weight of soybean at in intercropping were significantly lower than those in monoculture. Consequently, intercropped maize would affect the growth and photosynthetic characteristics of soybean at the late growth stage, which directly decreases the grain yield components of soybean. The results provide a basis for intercropping soybean cultivation and high yield.