陕西主栽核桃品种‘香玲’对水分胁迫的生理生化响应

Physiological and Biochemical Responses of Shaanxi Main Walnut Cultivar ‘Xiangling' to Water Stress

以陕西主栽核桃品种‘香玲’嫁接幼苗为试材,在4种水分处理下,对连续胁迫40d及复水后‘香玲’幼苗叶片的生理生化指标进行动态研究。结果表明,与对照(土壤相对含水量80%)相比,随处理时间的延长,3种胁迫程度(轻度60%、中度40%、重度20%)下叶片相对含水量均逐渐下降,水分饱和亏、相对电导率及丙二醛(MDA)质量摩尔浓度均逐渐上升;抗氧化物酶活性、细胞渗透调节物质及叶绿素质量分数均呈现先增加后减少或直接减少的趋势。在轻度胁迫持续40d复水后,‘香玲’幼苗的生长与对照基本一致;当中度和重度胁迫持续24d时,2个处理的‘香玲’幼苗均受到不可恢复性伤害。这为‘香玲’核桃栽培中水分管理提供了理论依据。

Grafted seedlings of ＇Xiangling＇ walnut cultivar of Shaanxi province were used as experimental materials, the dynamic changes in physiological and biochemical indicators of leaves were detected under 4 different water treatments after continuous stress for 40 d and rehydration. The results indicated that compared with the control （soil relative water content 80G）, with the time going on,the leaf relative water content decreased under mild （60%）, moderate （40%） and severe （20%） stress, and the water saturation deficit, relative electrical conductivity and MDA molality showed an upward trend; protective enzymes activities, osmotic adjustment substances, chlorophyll a, b and to tal chlorophyll mass fraction increased at the first then reduced or directly reduced. Rehydration after 40 d under mild stress, the growth of ‘Xiangling＇ seedlings recovered back to the level of the control; while it could not be restored under moderate and severe stress for 24 d. This result provides a theo- retical basis for water management of the cultivation in ‘Xiangling＇ walnut.