| Carya cathayensis is a peculiar economic tree species and dried fruit in China.Due to its high nutritional and economic value,the industry of hickory has been greatly developed in recent years.However,the trunk canker of hickory caused by Botryosphaeria dothidea has been widespread in the main producing areas of hickory in Western Zhejiang,and the affected area has gradually expanded,seriously restricting the sustainable development of hickory industry.Through the research on the basic biology of trunk canker fungus and the quantitative monitoring technology of infection and transmission,which not only provides a research foundations for the analysis of the catastrophic mechanism of hickory,but also provides a basis and guidance for more ecological and long-term control of the occurrence and harm of hickory.The main findings are as follows:(1)By inoculating the branches of Carya cathayensis with different branch ages,it was found that with the increase of branch ages,the size of lesions spread showed a decreasing trend.The length of lesions of 1st and 2nd year branches was significantly larger than that of 3 and 4 years old branches.When the ambient temperature was 25℃and the relative humidity was close to 75%,the success rate of trunk canker fungus infection on the branches and seedlings of hickory was the highest and the lesion spread faster.However,the fruit and leaves of hickory can not be harmed.(2)According to the phylogenetic results,combined with morphological identification and sequence alignment analysis,the collected pathogens were divided into 5 groups:the first group was B.dothidea,with 89 isolates,accounting for 92.71%of the isolates;the second group was B.fabicerciana,4 strains were isolated,with 4.17%of the isolates;the third group was B.corticis,with 1 isolate,accounting for 1.04%of the isolates;the fourth group was B.qingyuanensis,a total of 1 strain was isolated,accounting for 1.04%of the isolates;The fifth group was Lasiodiplodia theobromae,which accounted for 1.04%of the isolated strains.Therefore,the pathogen B.dothidea was identified as the dominant species causing trunk canker in Changhua Town,Longgang Town,Qingliangfeng Town,Tuankou Town and TaiyangTown of Lin’an District.(3)A q-LAMP detection system for trunk canker fungus was established,and the system could theoretically detect genomic DNA at the concentration of 0.001 ng/μL and spore DNA at the concentration of 1×10~1/mL,which paved the way for the successful application of this technology in hickory forest.(4)Using the established q-LAMP detection technology,the asymptomatic samples on the trunk surface can be detected;and with the increase of the distance between the sampling points and the visible lesions,the DNA quantity of the detected trunk canker fungus decreases continuously,but when the collection distance exceeds 20 cm,the detection success rate will be greatly reduced.At the same time,the technology can monitor the changes of spore quantity in rainwater and air,and provide guidance for the prediction and prevention of trunk canker. |
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