土壤微生态环境对樱桃树“黑疙瘩”病发生的影响

Effects of Soil Microecological Environment on Occurrence of 'Black Humor' Disease in Cherry Tree

研究陕西"黑疙瘩"病樱桃树根际土壤微生态环境,分析其对樱桃树"黑疙瘩"病发病的影响,可为后期防治工作提供理论和实践依据。本研究采用传统微生物学、分子生物学及生物化学相结合的方法,对陕西白鹿原发病樱桃树根际土壤理化性质、土壤酶活性及可培养微生物数量、优势细菌种类与健康樱桃树根际的差异进行了分析,结果表明:健康樱桃树根际土壤全磷、速效钾、有效磷、碱解氮平均含量高于病株根际,土壤有机碳含量低于病株根际,而土壤全氮、全钾含量及pH根际间差异不显著;健康樱桃树根际土壤蛋白酶、脲酶、转化酶及多酚氧化酶活性高于病株根际,而脱氢酶和过氧化氢酶活性低于病株根际。土壤根际微生物分析表明,健康樱桃树根际土壤的可培养细菌、放线菌数量显著高于病株根际,尤其是优势细菌种类及数量;而霉菌平均数量则相反,但差异不显著。因此,根际土壤可培养细菌、放线菌的减少及优势细菌分布不均,以及速效养分的减少、酶活性的降低可能是影响樱桃树"黑疙瘩"病发生的原因之一。

The methods of traditional microbiology, molecular biology and biochemistry were combined to study thedifferences of rhizosphere soil physical and chemical properties, soil enzyme activities and the culturahle microorganismdiversities between healthy and diseased cherry trees in the White Deer Prairie Shaanxi for the prevention and control of ＇Blacktumor＇ disease. The results showed that the contents of total phosphorus, available potassium, available phosphorus and availablenitrogen of healthy rhizosphere soil were significantly higher than those of diseased one, organic carbon content of healthyrhizosphere soil was significantly lower than that of diseased one. Total nitrogen, total potassium contents and pH had nosignificant difference between healthy and diseased rhizosphere soils. The activities of protease, urease, invertase and PPOenzymes of healthy rhizosphere soil were much higher than those of diseased one, but the activities of DHA and CAT enzymes ofhealthy rhizosphere soil were lower. The population of culturable bacteria and actinomyces of healthy rhizosphere soil weresignificantly more than diseased one, particularly of dominant bacteria, the mean population of streptomyces of healthyrhizosphere soil were lower than those of diseased one but without significant difference. The decrease of the number ofculturable bacteria and actinomycetes, the imbalance proportion of dominant bacteria in the rhizosphere soil, the decrease ofavailable fertilizer and enzyme activities may be the causes of Black tumor disease.