木豆种子萌发生理对干旱胁迫的响应--岩溶水和外源水处理的对比

摘要

In this paper, responses of germination physiology of pigeon pea (Cajanus cajan) seeds to drought stress in karst water environment and non-karst (allogenic) water environment were studied to explore the adaptability of pigeon pea to karst environment. The results showed that: (i) Under drought stress of 20% PEG-6000, the germination rate, vigor index, germination index and biomass of pigeon pea seeds on day 7 cultivated with karst water were all greater than that of the allogenic water treatment group, while the seed germination stress index was signiifcantly smal er than that of the al ogenic water treatment group, suggesting that karst water environment was more favorable to pigeon pea seed germination. (i ) Without drought stress, the malondialdehyde (MDA) and superoxide dismutase (SOD) activities of pigeon pea seeds cultivated with karst water were al smal er than that of the allogenic water group. However, under drought stress, the SOD activity was signiifcantly higher than that of allogenic water group, suggesting pigeon pea SOD in karst water was able to more rapidly respond to external drought stress, and increase its own activity to reduce the damage to the plants. And (iii) with and without drought stress, the soluble protein level of the karst water group was higher than that of the al ogenic water group, while the free amino acid level was lower than that of the al ogenic water group. This difference was more signiifcant with the presence of drought stress, suggesting that the karst water environment was more favorable to the accumulation of soluble proteins and thus produced larger biomass. Hence, pigeon pea is a tree species that is adapted to high-calcium, alkaline environments in karst areas, and is of great signiifcance for the revegetation and rocky desertiifcation control in mountainous karst areas.%本文通过对比岩溶水环境与非岩溶水环境（外源水）中木豆种子的萌发生理对干旱胁迫的响应，来探究木豆对岩溶环境的适应性。结果表明：（1）在20% PEG-6000的干旱胁迫时，岩溶水培养下的木豆种子7天的种子萌发率、活力指数、发芽指数、生物量均大于外源水处理组，种子萌发胁迫指数显著小于外源水处理组，表明岩溶水环境对木豆种子萌发更有利；（2）在无干旱胁迫时，岩溶水培养下的木豆种子MDA、SOD活性均小于外源水组，但在干旱胁迫时，SOD活性显著高于外源水组，表明岩溶水中木豆SOD能更快速的响应外界干旱胁迫，提高自身的活性来减少其对植物的毒害；（3）在有和无干旱胁迫时，岩溶水组可溶性蛋白均高于外源水组，游离氨基酸均低于外源水组，在干旱胁迫时这种差别更明显，表明岩溶水环境更有利于可溶性蛋白的积累而形成较大的生物量。因此木豆是一种适合于岩溶区高钙偏碱环境下生长的树种，对岩溶山区的植被恢复及石漠化治理有重要意义。