CAJ | 학술논문

为探讨拟松材线虫（Bursaphelenchus mucronatus）携带细菌在对云南松（Pinus yunnanensis）致病过程中的作用，选用二年生云南松苗木、从四川省松材线虫病病区分离到的拟松材线虫、线虫携带的细菌及其代谢产物为材料，通过室内对云南松枝条韧皮部滴管和松针浸渍法接种，观察并计算松针枯黄率，测定不同处理时间后松针的总酚含量和苯丙氨酸解氨酶（phenylalanine ammonia-lyase，PAL）、多酚氧化酶（polyphenol oxidase，PPO）、过氧化物酶（peroxidase，POD）等的酶活性变化来表征细菌及其代谢产物对云南松的致病力.结果表明，从拟松材线虫体表分离的26种细菌中，枯草芽孢杆菌Ⅲ（Bacillus subtilis Ⅲ）、嗜麦芽寡养单胞菌Ⅰ（Stenotrophomonas maltophilia Ⅰ）、杓兰果胶杆菌（Pectobacterium cypripedii）、解淀粉芽孢杆菌Ⅰ（B.amyloliquefaciens Ⅰ）、枯草芽孢杆菌Ⅴ（B.subtilis Ⅴ）所致段斑长度属于最高值范围且差异均无统计学意义.在进一步盆栽试验中仅杓兰果胶杆菌致病作用明显，其中，无菌拟松材线虫+杓兰果胶杆菌和无菌拟松材线虫+杓兰果胶杆菌非蛋白代谢产物的混合处理对云南松针叶致病性最强，但两者间差异无统计学意义，而与其余各处理间差异有统计学意义；在对云南松松针苯丙烷类代谢的影响中，灭菌线虫+杓兰果胶杆菌非蛋白代谢产物的混合处理作用最强，可以导致松针总酚含量，酚类抗氧化产物 POD、PPO、PAL 活性不断减少，且各指标与枯黄率显著相关.由此可知，云南松拟松材线虫病的发生、发展与寄主苯丙烷类代谢的异常变化有关.
위탐토의송재선충（Bursaphelenchus mucronatus）휴대세균재대운남송（Pinus yunnanensis）치병과정중적작용，선용이년생운남송묘목、종사천성송재선충병병구분리도적의송재선충、선충휴대적세균급기대사산물위재료，통과실내대운남송지조인피부적관화송침침지법접충，관찰병계산송침고황솔，측정불동처리시간후송침적총분함량화분병안산해안매（phenylalanine ammonia-lyase，PAL）、다분양화매（polyphenol oxidase，PPO）、과양화물매（peroxidase，POD）등적매활성변화래표정세균급기대사산물대운남송적치병력.결과표명，종의송재선충체표분리적26충세균중，고초아포간균Ⅲ（Bacillus subtilis Ⅲ）、기맥아과양단포균Ⅰ（Stenotrophomonas maltophilia Ⅰ）、표란과효간균（Pectobacterium cypripedii）、해정분아포간균Ⅰ（B.amyloliquefaciens Ⅰ）、고초아포간균Ⅴ（B.subtilis Ⅴ）소치단반장도속우최고치범위차차이균무통계학의의.재진일보분재시험중부표란과효간균치병작용명현，기중，무균의송재선충+표란과효간균화무균의송재선충+표란과효간균비단백대사산물적혼합처리대운남송침협치병성최강，단량자간차이무통계학의의，이여기여각처리간차이유통계학의의；재대운남송송침분병완류대사적영향중，멸균선충+표란과효간균비단백대사산물적혼합처리작용최강，가이도치송침총분함량，분류항양화산물 POD、PPO、PAL 활성불단감소，차각지표여고황솔현저상관.유차가지，운남송의송재선충병적발생、발전여기주분병완류대사적이상변화유관.
Summary Pine wood nematode (PWN) is a destructive disease to pines.For the research on its pathogenic mechanism,the theory which is about the complex infection of PWN and the bacterium carried by it is recognized. Bursaphelenchus mucronatus is considered as a related species of Bursaphelenchus xylophilus ,which may be differentiation with the homologous species in different environments.In early studies,B.mucronatus was served as contrast species to B.xylophilus due to the weak or lacking pathogenicity.But recently,many reports have pointed out that it has the strong pathogenicity and can cause the widespread death of pines,which referred to Pinus thunbergii P.yunnanensis P.taiwanensis P.densata ,etc.The large numbers of P.yunnanensis were dead in Sichuan in recent years. However,no systematic study was conducted on the pathogenicity of the bacterium carried by B.mucronatus .This study has the aim of evaluating the effects of the bacterium carried by B.mucronatus on wilting ratio and phenylpropanoid metabolism of pine needles,and further exploring the effect of bacterium in the pathogenic process of B.mucronatus . <br> Two-year-old P.yunnanensis seedlings,B.mucronatus isolated from PWN disease district in Sichuan,the bacterium carried by B.mucronatus and its metabolite as the materials,the wilting ratio was calculated,and the total phenol content, phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), peroxidase (POD) activities were determined by the inoculation of burette to branch phloem of P.yunnanensis in laboratory,which represented the pathogenicity of the bacterium and its metabolite on P.yunnanensis . <br> The results showed that Pectobacterium cypripedii and its non-protein metabolite had strongest effect on P. yunnanensis in 26 species of bacteria isolated from the surface of nematodes,and the wilting degree and wilting ratio were significantly high in these two treatments.They caused the accumulation of total phenol content and the changes of PAL,PPO and POD activities,the PPO and POD activities of which increased from 12 h to 24 h and declined after 24 h,and PAL activities declined during 12 48 h.Moreover,in above each index,significant correlation with wilting ratio was observed,but among the indexes in phenylpropanoid metabolism,only PAL and PPO activities were found to have a significant correlation. <br> It is concluded that P.cypripedii and its non-protein metabolite can continuously decrease the phenolic antioxidants,which makes the metabolism to be disordered and induce cell toxicity of the needles through affecting the phenylpropanoid metabolism.And then,the needles display lesion,fading,browning,drying and even death. The above results reveal that the occurrence and development of PWN disease is closely related to the abnormal changes of the phenylpropanoid metabolism in host.