Pathogen identification of yellow decline disease of Citrus japonica in Fujian province
Kumquat,Citrus japonica is one of the most important fruit trees in Youxi county,Fujian province,China.The yellow decline disease of kumquat has been occurring seriously in the decades.In the survey,we found that the poorly growing,chlorotic trees were with few fibrous roots,female nematodes attached to roots with posterior portion of the body protruding from the root surface,and a large number of second juveniles(J2)were observed in the rhizosphere soil,while few or no nematodes were found from soil beneath adjacent healthy trees with dense root systems.According to morphological and molecular characteristics,phylogenetic analysis with maximum likelihood and Bayesian analysis based on the rDNA-ITS region or D2-D3 expansion region of 28S rDNA,the nematode was identified to be Tylenchulus semipenetrans.This is the first report of T.semipenetrans parasitizing kumquat in China,and the nematode was confirmed to be causal agent of slow decline disease of kumquat.The results will provide a theoretical basis for developing effective manage strategies of the nematode disease.
NETL
NSTL
万方数据
