氮肥与烯效唑耦合对主干结果形核桃光合特性的影响

Effects of nitrogen fertilizer coupled with uniconazole on photosynthetic characteristics of trunk fruit-shaped walnut

选温185主干结果形核桃(Juglans regia L.)为研究材料,设置不同浓度梯度的氮肥与烯效唑耦合模式,研究其对核桃果实膨大期光合特性的影响。结果表明,氮肥与烯效唑耦合处理核桃净光合速率(Pn)绝大多数处理高于对照,处理氮(N)665.5 g/株、烯效唑(S)250 mg/L达到最大,为21.17μmol/(m^2·s),较对照提高37.99%;胞间二氧化碳(Ci)变化较稳定,氮肥是影响核桃Ci的主要因素,高氮肥处理具有较大的Ci;蒸腾速率(Tr)与气孔导度变化幅度较大且变化趋势一致,都在处理N 665.5 g/株、S 150 mg/L达到最大值,高浓度的烯效唑对蒸腾速率(Tr)与气孔导度有一定抑制作用;瞬时水分利用率(WUE)随处理变化较小,总体呈低浓度促进,高浓度抑制的现象;气孔限制值(Ls)的主要影响因素为氮肥,低氮肥对提高Ls有一定促进作用,高浓度氮肥出现抑制现象;高氮肥与高烯效唑耦合处理能提高叶片饱和水汽压亏缺(Vpdl)。施氮肥665.5 g/株和喷施烯效唑250 mg/L耦合处理对主干结果形核桃的光合性能提升最好,达到核桃的高产优质栽培。

The trunk fruit-shaped walnut(Juglans regia L.) of Wen185 walnut was selected as the research material, and the coupled mode of nitrogen fertilizer with uniconazole with different concentration gradient was set to study the effect of nitrogen fertilizer on the photosynthetic characteristics of walnut fruits during the expansion stage. The results showed that the net photosynthetic rate(Pn) of walnut treated with nitrogenous fertilizer coupled with uniconazole was higher than that of the control group,among them,N 665.5 g/plant, uniconazole(S) 250 mg/L treatment reached the maximum, which was 21.17 μmol/(m^2·s),an increase of 37.99%. Compared with the control group, intercellular carbon dioxide(Ci) change was relatively stable. The high nitrogen fertilizer treatment had a large Ci, and the high nitrogen treatment had great Ci value;Transpiration rate(Tr) and stomatal conductance had a large range of variation and the variation trend was consistent, both reached the maximum value in treatment N 665.5 g/plant, S 150 mg/L, and high concentration enizolium treatment had a certain inhibitory effect on transpiration rate(Tr) and stomatal conductance. The instantaneous water use rate(WUE) changed little with the treatment, which was promoted by low-concentration and inhibited by high-concentration on the whole. The main influencing factors of stomatal limiting value(Ls) was nitrogen fertilizer, and low nitrogen fertilizer promoted the improvement of Ls value to a certain extent,while high nitrogen fertilizer inhibited it. In addition, the coupling treatment of high nitrogen fertilizer and high uniconazole can increase the leaf saturated vapor pressure deficit(Vpdl). The combination treatment of 665.5 g/plant nitrogen fertilizer and250 mg/L uniconazole improved the photosynthetic performance of trunk fruit-shaped walnut the best, which achieved the high yield and high quality cultivation of walnut.