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为进一步明确裸燕麦耗水量及其在不同土壤水分状况下的生理反应,论文在盆栽试验条件下,以负水头持续供水系统为供水装置,比较了裸燕麦、玉米、高粱、大麦和小麦旱地禾本科作物的水分耗散;设置40、60和80cm3个负水头控压高度,测定了“高-中-低”3种土壤湿度下裸燕麦孕穗期叶片光响应曲线及叶片保护酶活力。结果显示:裸燕麦蒸腾系数为455.37,显著(P<0.05)高于其他作物,较高叶片蒸腾速率和较低净光合速率是主要生理原因;降低土壤含水量将降低裸燕麦叶片相对叶绿素含量,但适度降低土壤含水量并未显著(P>0.05)降低叶片光合能力,而适度提高气孔受限程度,有利于提高叶片水分利用效率;超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)等叶片保护酶活性对不同土壤水分状况响应不一致,中等土壤湿度时SOD活性较高,高土壤湿度时POD活性较高,低土壤湿度时CAT活性响应程度较高。
In order to further clarify the water consumption of naked oats and their physiological responses under different soil moisture conditions, the paper studied the water supply system of negative-head continuous water supply system under the pot experiment conditions. Compared the dry oat, corn, sorghum, barley and wheat dryland Under the three soil moisture levels of “high-medium-low”, the light response curve and the protective enzyme activity of the leaves at the booting stage of naked oats were measured. The results showed that the transpiration coefficient of naked oats was 455.37, significantly higher than that of other crops (P <0.05). The higher leaf transpiration rate and lower net photosynthetic rate were the main physiological reasons. Decreasing the soil water content would reduce the relative chlorophyll content, However, moderately reducing soil water content did not significantly reduce photosynthetic capacity (P> 0.05), while moderately increasing stomatal limitation was conducive to increasing leaf water use efficiency. The activities of superoxide dismutase (SOD), peroxidase ), Catalase (CAT) and other leaf protective enzymes had different responses to different soil water conditions. SOD activity in medium soil moisture was higher, POD activity in high soil moisture was higher, and CAT activity in low soil moisture was higher .