园艺学报 ›› 2019, Vol. 46 ›› Issue (5): 923-930.doi: 10.16420/j.issn.0513-353x.2018-0467

• 研究论文 • 上一篇    下一篇


杨秀梅1,瞿素萍1,张宝琼2,许 凤1,解玮佳1,*   

  1. 1云南省农业科学院花卉研究所,国家观赏园艺工程技术研究中心,云南省花卉育种重点实验室,昆明 650205;2云南农业大学热带作物学院,云南普洱 665000
  • 出版日期:2019-05-25 发布日期:2019-05-25
  • 基金资助:

Pathogenic Identification of Rhododendron Dieback and Investigation of Cultivar Resistance

YANG Xiumei1,QU Suping1,ZHANG Baoqiong2,XU Feng1,and XIE Weijia1,*   

  1. 1Flower Research Institute,Yunnan Academy of Agriculture Sciences,National Engineering Research Center for Ornamental Horticulture,Yunnan Key Laboratory for Flower Breeding,Kunming 650205,China;2College of Tropical Crops,Yunnan Agricultural University,Puer,Yunnan 665000,China
  • Online:2019-05-25 Published:2019-05-25

摘要: 在云南省昆明市晋宁区高山杜鹃盆花种植基地发现枯梢病,田间发病率达20%以上。发病植株顶梢枯死,茎杆溃疡,最终枯萎死亡。对病原菌进行组织分离培养和致病性测定,结果表明,病原菌菌落初期白色,后期呈灰黑色;分生孢子器球形,黑色;分生孢子单胞,近椭圆形至纺锤形,大小为(17.2 ~ 32.8)μm × (4.7 ~ 7.8)μm。以ITS通用引物对病原菌基因组DNA进行扩增并测序,同源性比对显示其与小新壳梭孢(Neofusicoccum parvum)的一致性达99%,结合形态学鉴定结果,确定该病原菌为小新壳梭孢。病原菌的最适生长温度为25 ℃;pH 5 ~ 7时菌丝生长加快,pH 7时最适于菌丝生长;以蔗糖为碳源、硫酸铵为氮源时菌丝生长最好。不同高山杜鹃品种对小新壳梭孢的抗性存在差异,18个品种中免疫品种2个,高抗品种2个,抗病品种3个,中感品种3个,感病品种4个,高感品种4个。

关键词: 高山杜鹃, 枯梢病, 小新壳梭孢, 生物学特性, 病情指数

Abstract: A new branch disease on Rhododendron was observed in a planting base in Jinning District,Kunming,Yunnan. The disease incidence was more than 20%. Disease symptoms included twig dieback and stem canker. Pathogens were isolated from the disease samples. The pathogenicity test,morphological and molecular identification were studied and cultivar resistance of Rhododendron were evaluated. The results showed that the mycelium was white initially and turned gray-black later. Conidia were one-celled,ellipsoidal to fusiform,with the length of 17.2 to 32.8 μm and the width of 4.7 to 7.8 μm. The internal transcribed spacer(ITS)region was amplified using the ITS1/ITS4 primer pair. BLAST analysis of the sequence showed 99% homology with the sequence of Neofusicoccum parvum. Based on the morphology and ITS sequence analysis,the pathogen was identified as N. parvum. The optimum temperature for mycelium growth was 25 ℃. The mycelial growth rate increased rapidly at pH 5–7,and the optimum pH value was 7. The utilization rates of sucrose and ammonium sulfate were the highest among all carbon and nitrogen sources,respectively. Different cultivars exhibited different disease resistances,including two immune cultivars,two highly resistant cultivars,three resistant cultivars,three moderately susceptible cultivars,four susceptible cultivars and four highly susceptible cultivars.

Key words: Rhododendron, dieback, Neofusicoccum parvum, biological characteristic, disease index