凤丹灰霉病病原鉴定与发病条件研究

Pathogen Identification and Incidence Conditions of Gray Mould on Paeonia ostii

于2015—2018年通过室内分离培养纯化镜检与室外定点定期观测,对凤丹灰霉病的病原及其流行规律与发病条件进行系统调查,为病害的有效防控提供理论依据。结果表明,凤丹灰霉病病原为灰葡萄孢(Botrytis cinerea Pers),主要从花萼开始侵染,随后从残留花瓣处侵入果实,导致果实软腐;病原菌不在病残体上越冬;凤丹灰霉病在3月上旬至6月上旬发生,生长季内呈"慢—快—慢"的S形变化趋势,温湿度与光照的变化是影响病害发生发展的主要因素。年份、花期、大田地势与土质类型对病害的发生有显著影响:花期降雨量越少的年份发生越轻,反之发生越重;开花越早发生越轻,反之越重;丘陵顶部发生最轻,丘陵坡地与丘陵阶地其次,丘间谷地发生最重;石砾土发生最轻,壤土其次,黏土发生最重。因此,凤丹灰霉病为低温高湿低光照型病害,发病程度与当年降雨量、植株营养状况、大田地势与土壤类型等因子密切相关。

This study investigated the pathogen,epidemic dynamics and inducing conditions of grey mould on Paeonia ostii,through isolation,culturing,purifying and microscope observation of pathogen in the laboratory and periodical investigation on fixed point outside from 2015 to 2018,in order to provide theoretical basis for effective prevention and control of the disease.The pathogen of grey mold was identified as Botrytis cinerea Pers,which first infected calyx,then invaded young fruit from the residual petals and induced soft rot.Botrytis cinerea did not overwinter on the dead flower and fruit.The grey mould occurred from early Mar to early Jun,and the epidemic dynamics displayed an‘S’curve from slow to fast and finally slow.Change of the daily temperature,humidity and illumination was the major factor influencing the epidemic dynamics.The conditional factors such as different years,blooming time,topographical condition and soil type had significant effects on the occurrence of the disease.The seriousness of the disease increased with the increase of precipitation at flowering stage in different years.The disease was more serious when the flower bloomed later.The disease seriousness increased when the topographical condition changed from hilltop to hillside,then to depression.The disease seriousness increased in the plantings from in gravel soil to loam and then to clay.Thus,the grey mold was a fungus disease developing fast under low temperature,high humidity and low illumination,and the seriousness was correlated with precipitation,plant nutrition status,topographical condition and soil type.