大棚草莓重茬栽培土壤根际菌物和线虫数量变化的研究

通过比较大棚重茬草莓的幼果期、盛果期和采果后期及不同土壤处理（太阳能处理、原美草莓重茬病防治剂处理、溴甲烷熏蒸处理）的根际微生物的数量和种类变化,证实了原美防治剂的生态安全性及土壤处理效果.结果表明,大棚草莓根际土壤中真菌数量随着草莓发育进程的推进有增大趋势,细菌数量先升高后降低呈单峰曲线分布,放线菌数量盛果期有所上升,到采果后上升幅度较大.不同土壤处理后比对照土壤根际中细菌富集,真菌、放线菌受到抑制,土壤由＂真菌型＂土壤向＂细菌型＂土壤转化.用原美草莓重茬病防治剂处理过的土壤比对照土壤真菌少,约为对照的1/10,且与其他处理无差异;在盛果期放线菌数量太阳能、原美草莓重茬病防治剂、溴甲烷处理分别比对照减少85.9%、84.0%和71.1%;细菌数量在盛果期比对照土壤高2～3倍.同时,通过淘洗法测定了土壤处理对根际线虫数量的影响,其数量变化与土壤处理无明显规律.

Study on the variation of microflora and nematode in the rhizosphereof replanted strawberry with different soil treatments

The population densities and varieties of fungi,bacteria and actinomycetes at three stages in the rhizosphere soil of replanted strawberry,treated with solar heating,Yuanmei medicament and methyl bromide,were studied to prove the ecological safety and effect of Yuanmei medicament.In the rhizosphere of control or replanted strawberry,the population of fungi and actinomycetes increased,and the population of bacteria increased earlier and diminished later from the stage of young fruit to post harvest.After different soil treatments,rhizosphere bacteria accumulated,whereas the fungi and actinomycetes reduced compared to that of the control.So the soil have changed from fungi style to bacteria style.After soil treatment with Yuanmei medicament the fungi population in soil was only 1/10 that of control,and there were no differences from that of the other two treatments.Treatments with solar heating,Yuanmei medicament and methyl bromide reduced the population of actinomycetes by 85.9%,84.0% and 71.1%,respectively,whereas the numbers of bacteria were two or three times more than that of control in the heavy seed period.The number of nematodes detected in soil through washing analysis was not directly related to the soil treatments.