遮阴对两个绿豆品种光合作用和生长发育的影响

为了确定绿豆(Phaseolus aureus)作为套种作物的适宜性,以小槐花园叶绿豆和大花叶子绿豆两个品种为试验材料,通过田间试验和盆栽试验对其耐阴能力及其机理进行了研究。测定不同遮阴处理(全光照、遮光率30%和72%)下,绿豆在初花期的叶片光合参数、叶绿素含量和光合酶(Ru BPCase)活性,研究绿豆生长发育和营养品质对弱光的响应。结果表明,在遮光30%时,大花叶子绿豆的净光合速率(P_n)、气孔导度(G_s)、蒸腾速率(T_r)、水分利用效率(WUE)和Ru BPCase活性较全光照显著下降了24%、18%、12%、13%和21%(P0.05),而小槐花园叶绿豆无显著变化(P0.05)。在遮光72%时,两种绿豆的P_n、G_s、T_r和WUE等光合参数均显著下降了约11%。在遮光30%时,大花叶子绿豆的营养生长受到显著影响而小槐花园叶绿豆无显著变化;但在遮光72%时,两种绿豆的营养生长均受到显著抑制,干物质产量比全光照降低了约34%。两种遮阴处理与全光照相比,种子产量显著降低了约37%。综上可知,小槐花园叶绿豆具有一定的耐阴能力,能耐30%的遮光,适宜作为林果行间的套种作物。

Effect of shading on photosynthesis and growth in two Phaseolus aureus varieties

In order to determine the suitability of Phaseolus aureus as interplanting crops, field experiments and pot trials were conducted under full natural light, and 30 and 72% shading to test the shade tolerance of two Mung bean varieties, including Small Robinia-flower Round-leaf (SRRPA) and Big Lace-leaf Mung bean(BLPA) in 2015.The photosynthetic parameters, chlorophyll content, and RuBPCase activity in leaves of the Mung beans were measured during the first bloom stage.In addition, the response of growth and nutritional quality to weak light was studied.The results showed that, the net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), water use efficiency (WUE) and RuBPCase activity of BLPA significantly decreased by 24%, 18%, 12%, 13%, and 21%, respectively, than that under full light, whereas these parameters showed no significant change at 30% shading in SRRPA in response to shading.Photosynthetic parameters, including Pn, Gs, Tr, and WUE, in the two Mung bean varieties were significantly decreased by more than 11% under 72% shading.Vegetative growth of BLPA was significantly inhibited, but that of SRRPA revealed no significant change at 30% shading.In addition, vegetative growth of the Mung beans was significantly inhibited at 72% shading, and dry matter yield decreased by more than 34%, compared to those under full light.Shading treatments significantly reduced seed yield by over 37% compared to that under full light.These results indicated that SRRPA had the ability of resisting shade, and could tolerate 30% shading, which was suitable for intercropping.