氚水示踪法研究非充分灌溉条件下作物耐旱性

Crop Drought Resistance Study under Insufficient Irrigation Conditions with the Method of Tritium Water

以￣３Ｈ＿２Ｏ为示踪剂，用同位素示踪法对非充分灌溉的７大类作物耐旱性进行了试验研究，经６３个品种的５００余个样品的￣３Ｈ＿２Ｏ测定结果表明：在土壤含水量为凋萎系数以下的极度干旱状况下，作物处于萎蔫失水耐受时间时，给作物灌溉￣３Ｈ＿２Ｏ且复水时间为１．５ｈ，作物吸氘水量随此时间增值大的，其耐旱性强。同时发现，吸￣３Ｈ＿２Ｏ的量─—作物抗萎蔫能力与作物耐旱性成正比。将￣３Ｈ＿２Ｏ法与耐旱性盆栽鉴定法比较结果表明，氘水示踪失水作物抗萎蔫恢复能力是一种判别作物耐旱性的有效方法。

The drought resistance of more than 500 samples of 63 varieties among 7types of crop under the insufficient irrigation conditions have been studied with themethod of isotopic trace technique with ￣3H_2O as tracer. The results show that underthe serious dry condition with the soil water content below the wilting coefficient,andwhen crop is still in the flaccid hardiness period,the crop whose uptake of tritium waterincreases areater with the extension of the repeat irrigation time possesses strongerdrought resistance when irrigated of ￣3H_2O-flaccid hardiness capacity is positively relat-ed with the crop drought resistance. The result of comparing drought resistance deter-mination method of￣3H_2Owith that of potting shows that the capacity restoration ofcrop flaccid resistance with tritium water is an effective method for the determination ofthe crop drought resistance.