月季根癌病病原菌分离及抗病资源初步筛选

从月季品种金玛丽、曼海姆、杏花村、梅郎口红的根部肿瘤组织中纯化了9株分离物,根据其在MW选择性培养基上的单菌落形态初步判断其为根癌土壤杆菌。以根癌土壤杆菌高度保守的virD2和ipt基因的部分序列设计引物对分离的菌株进行PCR检测,其中有6株菌株能扩增出virD2和ipt基因片段,为根癌土壤杆菌毒性菌株。采用针刺涂抹法接种向日葵、荷花蔷薇幼茎,6株菌株均能在供试植株上形成肿瘤,一个月后肿瘤大小有显著差异,说明分离获得的根癌土壤杆菌株毒性有差异。以强毒性菌株J-5-1在田间接种了部分蔷薇属野生资源,以鉴定其对根癌病的抗性。根据发病率、肿瘤大小、肿瘤干质量以及感病后植株生长状况将植物的根癌病抗性分为高度抗病、中度抗病、中度感病、高度感病4个类型。

Isolation of the pathogenic bacteria from rose crown gall and selection of the resistance resources from Rosa spp.

Nine isolates were purified from the crown galls on rose plants and were characterized as Agrobacterium tumefaciens strains according to the colony morphology on the selective MW medium. The PCR results with the highly conservative virD2 and ipt sequence as primers showed that 6 isolates were virulent. Furthermore, these strains revealed various pathogenicity to different extents as the crown gall formed on the young stems of Helianthus annuus L. and R. multiflora f. carnea showed different sizes after needle-pricking inoculation. Twelve materials of Rosa spp. were inoculated with the highly virulent strain J-5-1 as a test for resistance to crown gall disease. According to disease incidence, tumor size and weight and its impact on hosts’ growth, these materials were categorized as: highly resistant, moderately resistant, moderately susceptible and highly susceptible.