Effect Of Soil Drought Stress On Physiological And Biochemical Characteristics In 3 Apricot (Prunus Armeniaca L.) Varieties

Physiological and biochemical Characteristics, characteristics against drought in 3 Prunus armeniaca L. varieties were studied in this paper. Theory base will be preferred for selection of varieties in Prunus armeniaca L. against drought and primary indexes against drought, study of mechanism against drought.Experiment was conducted with the leaves of 3-year-old Prunus armeniaca L. under four soil moisture treatments (soil relative water content 75±2%, 65±2%, 55±2%, 45±2%, respectively) and CK with supplying water usually in field conditions. The effects of soil drought stress on physiological and biochemical characteristics in Prunus armeniaca L. were studied in this paper. Through testing of indexes under four soil moisture treatments, the results were as follows:(1) Relative water content of leaves (LRWC) decreased under soil drought stress. With decreasing heavily about soil relative water content, relative water content of leaves decreased rapidly. On the other hand, decreasing speed about 3 Prunus armeniaca L. varieties was nearly, and their LRWC was as follows: Jinhuanghou > Xiangbai > Jintaiyang.Relative water deficit of leaves (RWD) increased slowly under stress, and their increasing value of 3 Prunus armeniaca L. varieties was as follows under D treatment: Jinhuanghou > Jintaiyang > Xiangbai. Under long time stress, RWD of Jinhuanghou increased quickly, and their increasing speed was nearly under D treatment.(2) SPAD value kept stable. It showed that the effects of soil drought stress on chlorophyll content was small. Their SPAD value was as follows: Jinhuanghou>Xiangbai> Jintaiyang. Chlorophyll fluorescence parameter changed under stress. Fv, Fm, Fv/Fo, Fv/Fm, Area decreased and Fo increased.(3) Soluble sugar and proline content (Pro) increased under stress. Pro decreased formerly and increased later. Their accumulation was as follows: Jintaiyang > Xiangbai > Jinhuanghou. However, soluble sugar increased always. Their accumulation was as follows: Jinhuanghou > Jintaiyang > Xiangbai.(4) Membrane permeation increased rapidly. Their increasing speed about Jinhuanghou andXiangbai was quicker than that of Jintaiyang. On the other hand, the membrane permeation about Jintaiyang kept the highest, and Jinhuanghou kept the lowest. Superoxide dismutase (SOD) activity increased slowly under stress. The increasing speed about Jintaiyang and Xiangbai was quicker than that of Jinhuanghou. However, Superoxide dismutase activity about Jinhuanghou always kept the highest. (5) Indole-3-acetic acid (IAA) content decreased, and their decreasing speed was nearly.The characteristics against drought in 3 Prunus armeniaca L. varieties were different under different water treatment. It was as follows under CK^ 75 + 2% and 65 + 2% treatments: Jintaiyang>Xiangbai>Jinhuanghou; However, it was Xiangbai>Jintaiyang > Jinhuanghou under 55+2% and 45 + 2% treatments. With the decrease of soil relative water content (SRWC), correlation among parameters lowered. Among of them, Fv, Fm, soluble sugar content, SOD activity, Fv/Fm, Area, Fv/Fo, IAA, LRWC, Fo, SPAD values and RWD are regarded as the first factor of effecting apricot against drought, and RWD, SPAD value, Pro, Fo, LRWC, membrane permeation, IAA content, Fv/Fo, Fv/Fm and SOD activity as the second factor.