In recent years, Yam black spot caused by Alternaria dioscoreae Vasant Rao became more prevalent throughout the hill yam growing area in the east part of Liaoning province, China. Study of biological characteristics of the pathogen showed that the optimal temperature and pH for its colony growth were 25-30℃ and 6-8 respectively; the optimal temperature, RH, pH and carbon source for conidium germination were 20-25℃,100%,6-7 and saccharose respectively. The conidium lethal temperature was 48℃.
The coat protein gene and its 3′ noncoding region of a watermelon isolate of Cucumber green mottle mosaic virus (CGMMV-LN) in Liaoning, China was determined and compared with other isolates. The gene encoding the coat protein of CGMMV-LN comprises of 486 nucleotides and encodes a putative protein of 161 amino acids. Sequence comparisons showed that the coat protein of this isolate was identical to that of seven CGMMV isolates infecting cucurbits in Europe and Asia. The 3′ noncoding region of CGMMV-LN consists of 176 nucleotides, which is same as that of CGMMV-KOM, CGMMV-KW and CGMMV–SH.
