Effect Of Simulated Acid Rain On Seed Germination Of Various Acid-fast Plant

There were many academic researches about ecophysiology effects of acid rain on plant. But most research on acid rain does not consider the genetic composition of seeds and the inherent variations in seed mass and germination date, the potentially diverse patterns of plant response are neglected within a population. Therefore, we examined the physiological and biochemical effects of aicd rain on seed germination of various acid-fast plants in acidic deposition area. The purpose was to determine the reasons of the reasons of growth and decline dynamics of crop population and its yield change. It is important to decline injure of acid rain on agriculture.Effects of acid rain on seed germination of various acid-fast plants, in which rice (O. sativa), wheat (T. aestivum) and rape (B.chinensis var. oleifera) seeds were used as experimental materials, were investigated in this paper. The purpose was to understand the responses of seed germination on acid rain stress, difference of acid fastness and the reasons of the difference. The study methods and the main results were given as follows.Rice, wheat and rape seeds were treated with simulated acid rain at pH 2.0, 2.5, 3.0, 3.5,4.0 and 5.0 levels for 7 days in order to researching the effects of acid rain on germination indexes (percentage germination, germination energy, germination index, vigor index, percentage of abnormal germination) and physiological activities indexes (water absorption rate, respiratory rate, storage reserve loss rate, storage reserve transformation rate, inhibition index of root length, inhibition index of shoot length) of various acid-fast seeds. The results indicated that 3 kinds of seeds didn't germinate at pH 2.0 and pH 2.5. When pH ≥3.0, the former four germination indexes of the three species increased in relation with decreased acidity levels. The maximal amplitude difference of each index was that ricetill to 7AR. The purpose was to understand the responses of seed germination on stress time. With prolonged stress time, germination indexes decreased at the same acidity levels. The storage reserve loss/transformation rate of rice/wheat decreased with prolonged stress time at the same acidity levels. The storage reserve transformation rate of rape decreased and the storage reserve loss rate increased. The inhibition indexes of root/shoot length of 3 kinds of seeds increased with prolonged stress time at the same acidity levels. The stress time when significant difference of each index above was perceptible between treatment group and control group was that rice>wheat>rape. The maximal amplitude difference of each index was also rice