ABSTRACT
Zucchini yellow mosaic virus (ZYMV) is a destructive cucurbit virus that causes extensive losses in the yield and quality of cucurbits (e.g., zucchini). At present, the analysis of genetic evolution of ZYMV is mainly based on CP sequence, and there has been little progress in addressing its phylogenetic relationships and evolution at the whole genome level. In this study, the whole genome sequences of ZYMV isolated from Shanxi Wenshui (ZYMV-WS) and 109 other reported ZYMV isolates were used to explore their phylogenetic relationships. The results showed that ZYMV-WS had the highest level of nucleotide homology (94.35%) to ZYMV-SXSG, and the amino acid sequences of ZYMV-BR3 were identical (97.37%) to those of ZYMV-WS. In addition, the phylogenetic analysis of ZYMV revealed that all the isolates were clustered into two major branches, and its population structure assessment demonstrated a marked genetic differentiation between A4 and B. Furthermore, we also discovered the sites of specific amino-acid alteration, and their possible association with functional changes. These results will help to better understand the genetic diversity and phylogenetic process of ZYMV, and lay a theoretical foundation for the effective prevention and control of ZYMV infection in the near future.
ABSTRACT
A baixa produtividade e a qualidade dos frutos de melancia estão quase sempre associadas à ocorrência de fitopatogenos, dentre estes destacam as doenças de etiologia viral. Visando o entendimento do complexo vírus/planta de melancia, este trabalho teve o objetivo de avaliar os danos e sintomas induzidos pelos vírus PRSV-W, CMV, ZYMV e WMV, quando inoculados em plantas de melancia, cv. 'Crimson sweet', aos 5, 12 e 19 dias após a emergência (DAE). Os vírus PRSV-W, CMV, ZYMV e WMV influenciaram significativamente (p<0,05) na redução do peso da matéria fresca da parte aérea, na coloração da polpa e redução no peso dos frutos da melancia. Assim como, no teor de sólidos solúveis (ºBrix). Sendo mais significativa em plantas inoculadas com CMV. De modo geral, os vírus PRSV-W, WMV, CMV e ZYMV afetaram o desenvolvimento, a produção da planta da melancia e consequentemente, limita a qualidade do fruto.
Watermelon is one of the most important vegetables grown in Brazil. However, there are several factors responsible for low productivity of crops. Among these stands out the occurrence of associated virus culture. Thus, this study aimed to assess the damage and symptoms of PRSV-W, CMV, ZYMV and WMV inoculated at 5, 12 and 19 days after emergence (DAE). According to the results, PRSV-W viruses, CMV, ZYMV and WMV influenced significantly (p <0.05) reduction in the fresh weight of shoots and on pulp and reduction of fruit weight of inoculated plants. As noted on pulp plants inoculated with PRSV-W, at 5 DAE. With regard to the soluble solids content (° Brix) was dramatically reduced by the virus and inoculation period, in this case being more significant fruits of plants inoculated with CMV presented Brix 3.67 to 5.11 depending on the inoculation period. In general, viruses PRSV-W, WMV, CMV, ZYMV and influence the development and consequently the production of watermelon. Thus, an important factor for the reduction in the quality of fruit produced.