罗布麻种子老化过程中的生理生化特性

罗布麻（Apocynum venetum）集中成片分布于盐碱、沙荒地区，耐寒耐旱，耐盐碱耐风沙。自然严酷条件下，罗布麻种子活力变化对其种群的环境适应性具有重要影响，因此采用人工老化的方法，研究其在逆境条件下的生理变化，可探明罗布麻种子活力的劣变规律、种群的扩繁机制以及罗布麻种子的贮藏特性和寿命。在相对湿度100%、温度分别为35 ℃和50 ℃的条件下，对罗布麻种子处理84 h，测定其生理生化指标。结果表明,在相同温度下，随着老化时间延长，种子电导率在初期先下降后升高，脱氢酶、过氧化物酶逐渐降低，浸出液可溶性糖逐渐升高。老化温度越高，对种子造成的影响越大。罗布麻种子对高温逆境在生理上有响应，种子抗热性较强。

Physiological and biochemical characteristics of Apocynum venetum seeds in the process of artificial aging

Apocynum venetum,mainly distributing in the salinization and sandy area,is drought-cold tolerance and alkali-wind tolerance,and is suitable for various climate and soil.The response of seed vigor of A.venetum to harsh environments greatly affects the adaption of its population.Therefore,the objective of this study is to understand the physiological and biochemical characteristics of A.venetum seed in the process of artificial aging for verifying the rule of seed deterioration,disperse mechanism of population,and seed storage characters and longevity.An experiment was conducted to test the seed physiological characteristics of A.venetum under the conditions of relative humidity of 100% and 35 ℃ and 50 ℃ for 84 h.The results of this experiment showed that the seed electronic conductivity decreased in the initial stage and then increased in the late stage,and the activity of POD and SOD decreased gradually,whereas laching of soluble sugar increased under the same aging temperature as the aging time increased.The aging condition with high temperature impacted seed more greatly than that with low temperature.A.venetum seed responded to stress resistance with high temperature and was heat-resistance.