龙牙百合两种病害致病菌的分离、鉴定及抑制效应研究

Isolation,identification and inhibiting effects of pathogens that caused two kinds of diseases in Lilium brownii var. viridulum

关键词:  百合, 叶枯病, 病原分离和鉴定, 植物生长调节物质, 抑制效应

Key words:  Lilium brownii var. viridulum, leaf blight, pathogen isolation and identification, plant growth regulators, inhibiting effects

摘要:

利用常规组织分离法对广西永福地区种植的龙牙百合两种病害的病原菌进行了分离,并对分离菌株进行培养、纯化、回接和重新分离,最后利用形态学和分子生物学技术对致病菌株进行了鉴定; 同时观察了三种植物生长调节物质对两种致病菌的抑制效果。结果表明:两种病害(A和B)症状表明是叶枯病和青霉病,分别从感病叶片中分离得到4株和3株病原菌,病原菌室外回接发现只有菌株A-4和B-2分别致病,致病率均达到100%。形态学鉴定,A-4为葡萄孢属病原菌,菌落白色绒絮状,圆型; 菌丝匍匐向外、向上生长、气生,无色,有隔膜,有分枝,具有分生孢子和顶生孢子。B-2为青霉属病原菌,菌落圆形或不规则形,外围形成一圈白色绒毛状,中间蓝绿色; 菌丝细,匍匐生长,具横隔,分生孢子梗扫帚状,孢子呈球形。两类菌株分别获得全长522 bp和551 bp的序列,把ITS序列与Genbank中已登陆的序列进行相似性分析,并结合田间致病症状,认为龙牙百合叶枯病致病菌可能是椭圆葡萄孢,而青霉病致病菌是扩展青霉。三种植物生长调节物质对两种致病菌的抑制效果表明,0.1～1.0 mmol·L^-1 的SA不能完全抑制两种病原菌的生长,而0.5～1.0 mmol·L^-1BRs和Me-JA均能完全抑制病原菌A-4和B-2的生长。

Abstract:

The pathogens that caused two kinds of diseases in Lilium brownii var. viridulum were isolated using usual tissue isolation. Strains were cultivated, purified, reinoculated and reisolated. Morphological and molecular biological techniques were used to identify the strains. And three plant growth regulators were used to study the inhibiting effects on two pathogens. The results showed that two kinds of diseases were leaf blight(A)and penicilliosis(B)by the symptoms, and four strains and three strains were isolated from infected leaves, respectively. But only A-4 and B-2 caused two kinds of diseases, respectively. The incidences of A-4 and B-2 disease reinoculated in the field were all 100%. A-4 is a kind of fungi belonging to the genus Botrytis, and its colonial morphology is a circular form, with colorless mycelium, prostrate on the medium, aerial, diaphragms and branches. There are conidium and acrospore. B-2 is a kind of fungi belonging to the genus Penicillium, and its colonial morphology is a circular form or irregular, with white mycelium outside the circle and turquoise in the central, the mycelium prostrate on the medium and diaphragms. There were broom conidium and spherical spores. At last, the sequence of internal transcribed spacer(ITS)region of A-4 and B-2 were analyzed, the length was 522 bp and 551 bp, respectively. The sequence were compared with other species in the Genbank, respectively. The symptom in the field indicates that the pathogen of Lilium brownii var. viridulum leaf blight(A)and penicilliosis are Botrytis elliptica and Penicillium expansum. The inhibiting effects of three plant growth regulators on two pathogens indicated that two pathogens could not be fully inhibited by 0.1-1.0 mmol·L^-1 SA, but could be fully inhibited by 0.5-1.0 mmol·L^-1BRs or Me-JA.