Allelochemicals In Arundinaria Argenteostriatus: Distribution And Influence Factors.

Arundinaria argenteostriatus is a species of ground cover bamboo, which leaves showed very strong allelopathy. To understanding the distribution characters of the allelochemical in Arundinaria argenteostriatus, the allelopathy of different parts of Arundinaria argenteostriatus was evaluated by a bioassay with Lactuca sativa L. and Agrostis stolonifera as the targets. Furthermore, the influence factors on the allelochemicals was probed with an artificial simulated method.The main results were as following:1. The result of bioassay showed that the allelopathy of leave was the strongest in Arundinaria argenteostriatus. At 2g/L concentration, the germination percentage of Lactuca sativa L. which cultivated in the culture medium containing bamboo leave powder was the lowest with 66.67%, and the germination percentage of medium containing bamboo stem, bamboo root, bamboo rhizome were 84.44%,81.11%,77.76%; The inhibitions of bamboo leave to Lactuca sativa L. and Agrostis stolonifera were maximum , 63.20% and 31.66%, and that of bamboo stem, bamboo root, bamboo rhizome to Lactuca sativa L. were14.87%,14.87%,5.27%, and to Agrostis stolonifera were 14.87%,14.87%,5.27%.2. Bamboo leave sample was drying by different ways after collecting, and the bioassay showed, the influence of natural indoor dry method to the allelopathy of Arundinaria argenteostriatus was the smallest, at 2g/L concentration, the inhibition ratios to Lactuca sativa L. and Agrostis stolonifera was 85.88% and 70.56%, and the difference was remarkable compared with other drying methods. The inhibition ratios of the bamboo leave by baking under 60℃, freeze drying on sampling day, freeze drying after sealing 1day, freeze drying after sealing 2 days, freeze drying after sealing 4 days, freeze drying after sealing 6 days to Lactuca sativa L. were 34.88%,51.38%,40.78%,42.02%,43.93%, and that of Agrostis stolonifera were 13.72%,49.16%,60.65%,61.98%,60.46%,55.66%.3. During the different growth periods, the bioassay result showed that the bamboo leave sample in March had the strongest allelopathy to Lactuca sativa L. and the sample of July was the weakest, the EC₅₀ were 0.73 g/L,3.69g/L.EC₅₀ rose gradually from March, and reached the maximum in July, then dropped, and slightly undulating from September to February of the next year. For Agrostis stolonifera, the bamboo leave sample in February was the strongest and the weakest was that in April, the EC₅₀ was 0.21g/L,6.11g/L. EC₅₀ rose gradually from February, and until April reached the maximum, then dropped, and slightly undulating from August to January of the next year.4. Put Arundinaria argenteostriatus in the condition of 4℃for 12h,24h,and 40℃for 12h,24h, then collected the leave sample. The bioassary result showed that the difference of leave allelopathy activity was not remarkable. At 2g/L concentration, the leave sample inhibition ratios of the 4 process modes and the contrast to Lactuca sativa L. were 57.23%,59.58%,49.38%,49.26%,46.08%, and to Agrostis stolonifera were 50.28%,35.11%,48.52%,37.88%,39.17%; Treated by temperature stress, the chlorophyll content in bamboo leave sample slightly declined, the relative electric conductivity declined under low temperature stress and rose under high temperature stress, the content of SOD had no obviously change, the content of MDA slightly declined.The water stress experiment showed that the inhibition ratios of bamboo leave treated by drought stress and flooding stress to target plants were had no obviously change. Treated by drought stress for 2,4,6,8,10d, At 2g/L concentration, the inhibition ratios to Lactuca sativa L. were 24.87%,20.72%,22.92%,24.22%,19.77%, and to Agrostis stolonifera were 18.87%,26.43%,21.88%,29.53%,22.45%; Treated by flooding stress for 2,4,6,8,10d, the inhibition ratios to Lactuca sativa L. were 13.62%,14.32%,17.54%,21.49%,17.57%, and to Agrostis stolonifer were 10.89%,11.38%,3.41%,16.45%,13.08%, which compared with the inhibition ratio of the contrast (24.49%å’Œ23.56%) , the difference was not remarkable. In bamboo leave that treated by drought stress, the chlorophyll content rose gradually reached the maximum at 6d, then dropped, the tendency of relative electric conductivity was rising, the 10d was almost twice of the contrast, the tendency of SOD content was rising too, the MDA content had no obviously change.