百合鳞茎腐烂病菌鉴定及种质资源抗性评价

Identification of pathogens for lily bulb rot and resistance evaluation of lily germplasm resources

【目的】鉴定云南红河地区百合鳞茎腐烂病病原菌并评价百合种质资源抗性,为百合优质生产及抗性品种选育提供参考依据。【方法】收集引起云南百合鳞茎腐烂病样,进行病原菌分离、培养后,通过光学显微镜观察孢子形态及产孢细胞形态和大小,并基于百合鳞茎腐烂病病原菌ITS和TEF-1α序列相似性构建系统发育进化树,鉴定引起红河地区切花百合鳞茎腐烂病的病原种类。以梯伯百合鳞茎和橙影百合叶片为试验材料,筛选最优百合鳞茎腐烂病接种方式;评价156份百合种质对层出镰刀菌(Fusarium proliferatum)的抗性强弱并确定抗性等级。【结果】在云南红河地区切花百合鳞茎腐烂病样中,通过分离、纯化培养后获得15株形态相异的疑似百合鳞茎腐烂病病原菌,其中11号病样致病力最强;光学显微镜下,11号菌株的病原菌小孢子数量多,无镰刀形大孢子。系统发育进化树结果显示,11号菌株与MW015680.1:2-519层出镰刀菌LC13659等同属层出镰刀菌的序列相似性达98%以上,11号菌株分别与F.proliferatum strain MW016480.1:2-519和F.proliferatum strain MK414217.1:20-677聚为一支,因此将11号菌株鉴定为层出镰刀菌。使用百合鳞片菌饼有伤接种方法的病情等级最高。156份百合种质对层出镰刀菌的抗性评价结果显示,经鳞片接种后,病情指数(DI)最小的是栽培品种Fredo,为18.33%;以Arbatax、Pretty Woman等为代表的69份百合资源为中抗(MR);其中DI最高的种质是野百合1(保山)和滇百合(丽江),达到96.67%。【结论】导致云南红河地区百合鳞茎腐烂病主要病原菌为层出镰刀菌,鳞片有伤接种是百合抗性鉴定适用的方法,筛选出1份高抗百合层出镰刀菌种质Fredo可作为抗性育种材料。

【Objective】The study aimed to identify the pathogens for lily bulb rot in Honghe area of Yunnan and evaluate the resistance of lily germplasm resources,providing reference for high-quality lily production and the breeding of resistant varieties.【Method】Samples of lilies with bulb rot disease in Yunnan were collected.After isolating and culturing the pathogen,the spore morphology,as well as the morphology and size of sporulating cells,were observed under an optical microscope.A phylogenetic tree was constructed based on the similarity of ITS and TEF-1αsequences of the pathogens for lily bulb rot to identify the pathogen species causing bulb rot diseased cut lilies in Honghe area.Tibo lily bulbs and Chengying lily leaves were used as test materials to screen for the optimal inoculation method for lily bulb rot disease.The resistance of 156 lily germplasms to Fusarium proliferatum were evaluated,and the resistance grades were determined.【Result】In the samples of bulb rot diseased cut lilies in the Honghe area of Yunnan,15 strains of suspected pathogenic fungi with different morphologies were obtained through isolation and purification,among which strain No.11 showed the highest virulence.Under the optical microscope,strain No.11 had a large number of microspores,with no sickle-shaped megaspore.The phylogenetic tree results showed that strain No.11 had more than 98%sequence similarity with F.proliferatum MW015680.1:2-519 strain LC13659,strain No.11 was clustered with F.proliferatum strain MW016480.1:2-519 and F.proliferatum strain MK414217.1:20-677.Therefore,strain No.11 was identified as F.proliferatum.The disease level was the highest when using lily scale injury inoculation.The results of resistance evaluation of 156 lily germplasms to F.proliferatum showed that,after scale inoculation,the cultivated variety Fredo had the lowest disease index(DI),which was 18.33%.The 69 lily resources,represented by Arbatax and Pretty Woman,exhibited moderate resistance(MR).Among them,the germplasms with the highest DI were Wild Lily 1(Baoshan)and Yunnan Lily(Lijiang),reaching 96.67%.【Conclusion】The main pathogen causing lily bulb rot disease in Honghe area of Yunnan is F.proliferatum.Scale injury inoculation is a suitable method for resistance identification in lilies,and one lily germplasm highly resistant to F.proliferatum,Fredo,is selected.