苹果幼树生理指标对土壤水分调控的响应研究

Response of Physiological Indexes of Young Apple Trees to Soil Moisture Regulation

为研究苹果幼树的适宜生长条件,以山西果树研究所的基砧为八角海棠、中间砧为SH6的5 a生晋富1号为试材,滴灌处理共设置4个土壤水分下限:80%θ_(c)(W1)、70%θ_(c)(W2)、60%θ_(c)(W3)、50%θ_(c)(W4),对照处理(CK,地面灌溉)灌水下限为60%θ_(c)(θ_(c)为田间持水率),各处理灌水上限均为田间持水量。通过分析苹果幼树生理指标的月变化规律,发现各处理的叶片气孔导度、叶片光合速率、叶片蒸腾速率月变化趋势相同,均为先增后减;叶片水势月变化趋势为明显下降-逐步升高-小幅下降,叶片水分利用率月变化趋势为先减后增。经过差异性分析发现:滴灌条件下,W1和W4的叶片气孔导度、叶片水势、蒸腾速率差异显著,W3和W4的光合速率差异显著,各处理的叶片水分利用率无显著性差异;灌水下限相同时,W3和CK的叶片光合速率差异显著。本研究基于TOPSIS综合分析,确定了各试验的贴进度,其中W3的贴进度最大,即滴灌灌水下限为田间持水量的60%时,最适宜苹果幼树生长发育。

In order to study the suitable growth conditions of young apple trees,the five-year-old Jinfu No.1 with Malus illinoensis as base stock and SH6 as intermediate stock in Shanxi Fruit Research Institute was used as test material.Four soil moisture limits were set in drip irrigation treatment,namely 80%θ_(c)(W1),70%θ_(c)(W2),60%θ_(c)(W3),50%θ_(c)(W4),and the lower limit of irrigation for control treatment(CK,surface irrigation)was 60%θ_(c)(θ_(c)was field water holding rate),the upper limit of irrigation was field capacity.By analyzing the monthly variation of physiological indexes of young apple trees,it was found that the stomatal conductance,photosynthetic rate and transpiration rate of leaves in all treatments had the same monthly variation trend,which increased first and then decreased.The monthly variation trend of leaf water potential was significantly decreased,gradually increased and then slightly decreased,while the monthly variation trend of leaf water use efficiency was firstly decreased and then increased.The difference analysis showed that under drip irrigation,there were significant differences in stomatal conductance,leaf water potential and transpiration rate between W1 and W4,and significant differences in photosynthetic rate between W3 and W4,while there was no significant difference in leaf water use efficiency between different treatments.At the same lower limit of irrigation,the photosynthetic rate of leaves of W3 and CK was significantly different.Based on the comprehensive analysis of TOPSIS,this study determined the planting schedule of each experiment,among which W3 had the largest planting schedule,that is,when the lower limit of drip irrigation water was 60%of the field capacity,it was the most suitable for the growth and development of apple saplings.