| 摘要: |
| 【目的】探索不同种植年限人参地土壤中放线菌的生态差异，分离筛选有较好防效的生防放线菌。【方法】采用稀释平板法及皿内琼脂块法，对采自黑龙江省铁力市小兴安岭南麓桃山、石长不同种植年限（1，5和7年）人参地土壤样品中的放线菌进行分离测数及拮抗放线菌筛选。【结果】①在石长样点，种植5，7年人参地土壤的放线菌总数和链霉菌数量分别为106×105，193×105 CFU/g和41×105，83×105 CFU/g，其年份间差异均达到极显著水平（P＜0.01）；小单孢菌及未鉴定放线菌数量分别为11×105，20×105 CFU/g和54×105，90×105 CFU/g，其年份间差异均达到显著水平（P＜0.05），表现出随种植年限的增加，放线菌总数、链霉菌数量及小单孢菌数量均呈增加趋势。桃山样点从高氏1号培养基上分离到的放线菌总数随种植年限的变化趋势与石长样点类似，但高氏1号培养基上的链霉菌数量和小单孢数量及腐殖酸琼脂培养基上的链霉菌数量和放线菌总数则随种植年限的增加而减少。②在筛选出的271株放线菌中，有108株对人参土传病害靶标病原菌有拮抗性，约占全部筛选放线菌总数的40%；在桃山样点，从种植1年人参地土壤筛选到的对5株靶标病原菌有拮抗性的放线菌株数，分别约为种植5年人参地土壤的2.2～12倍，表现出种植年限愈长的土壤中拮抗放线菌株数愈少的变化趋势。③拮抗性较强的菌株有15株，约占全部放线菌的4%，其中以黄色类群较多。④供试土壤有机质及速效N、P、K含量能充分满足放线菌生长，与放线菌数量无显著相关性；土壤pH与拮抗放线菌株数之间的相关性达到显著或极显著水平。【结论】随种植年限增加，人参土传病害加重与土壤放线菌数量的变化，特别是与拮抗放线菌数量的减少有一定关系。 |
| 关键词: 人参 土壤放线菌 生态特性 拮抗性 生物防治 |
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| 基金项目:国家自然科学基金重点项目（30630054）；“十一五”国家科技支撑计划项目（2006BAD05B07） |
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| Study on actinomycetic ecology in soil with the different cultivating years of ginseng |
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| Abstract: |
| 【Objective】The study was to find out ecological difference of the actinomyces among different years in Ginseng soil in Taoshan and Shichang in the southern of Xiao Hinggan Ling,Tieli city,Heilongjiang Province,and screen antagonistic actinomycetes,in order to offer a foundation for biocontrol against soil borne disease.【Method】The quantity of actinomycetes was determined via dilution and plating.Dual culture and agar piece method was used to screen antagonistic actinomycetes and measure the inhibition.【Result】 ①The total actinomycetes and Stremptomyces were 106×105 CFU/g and 193×105 CFU/g of 5 years,41×105 CFU/g and 83×105 CFU/g of 7 years respectively,there existed very significant difference(P＜0.01);The numbers of Micromonospra and unidentified actinomyces were 11×105 CFU/g and 20×105 CFU/g,54×105 CFU/g and 90×105 CFU/g,significant difference respectively(P＜0.05).The numbers of total actinomyces,Stremptomyces,and micomonospra showed an increasing trend with the increase of planting time in Shichang site.The trend of total actinomycetes separated from Gause’ No.1 medium in Taoshan was similar with that in Shichang.But the number of Stremptomyces and Micromonospra separated from Gause’s No.1 medium as well as the total actinomycetes and Stremptomyces sparated from humic acid agar showed a decreasing trend with the increase of planting time.②Among 271 strains selected from tested soil,108 strains had antagonistic action to target pathogenic fungi of soil borne diseases,40% being isolated Actinomycetes.In Taoshan,the antagonistic actinomycetes against 5 targets screened from the soil of 1 year were 2.2-12 times higher than that of 5 year in Taoshan,indicating antagonistic actinomycetes decreased along with the planting years.③Quantity and ratio of broad spectrum antagonistic actinomycetes were as that.Flavus were the major genus among Streptomyces,15 with strong activity,accounting for 4%.④The percentage of antimicrobal actinomycetes to total actinomycetes had no relation with their soil nutrients,but pH had.【Conclusion】 Along with cultivating years,the soil borne diseases aggravation was related with the quantity change of actinomycetes,especially the reduction of antagonistic actinomycetes. |
| Key words: ginseng soil actinomycetes ecological characteristic antagonism biological control |
