Daniel Leobardo Ochoa-Martínez

Virus asociados al amarillamiento de Hibiscus sabdariffa en Guerrero, México

In the producing area of roselle (Hibiscus sabdariffa L.) in the state of Guerrero, five plots with an incidence of 90-100 % of plants showing vein chlorosis, mosaic and yellowing were observed in the autumn-winter 2014 crop cycle. Asymptomatic and symptomatic plants were collected and grafted onto healthy plants and at 17 days after inoculation vein chlorosis and mosaic were observed in plants grafted with leaves showing symptoms. DNA and RNA were extracted from plants collected in the field and those grafted that showed symptoms and analyzed for phytoplasmas, begomoviruses, viruses of the family Potyviridae and Okra mosaic virus (OkMV). No amplification were obtained for phytoplasmas, viruses of the family Potyviridae and Okra mosaic virus in plants collected in the field and grafted that showed symptoms; only they were positive for begomoviruses. Secuences from eigth plants with symptoms collected at field and one grafted showing symptoms had a similarity of 95 % and 91 %, respectively, with Okra yellow mosaic Mexico virus (OkYMMV). Two plants with symptoms collected at field showed a lower similarity with different begomoviruses. These results indicate that yellowing of Hibiscus sabdariffa is associated with a viral complex in which OkYMMV is present.

Detection of Pineapple mealybug wilt-associated virus 1 and 3 in Mexico

In El Bajo Papaloapan, the main producing area of pineapple of Mexico, leaves with typical symptoms of viral infection consisting in chlorosis, flaccidity, reduced growth and reddening were collected. By RT-PCR with specific primers for the hsp70 gene and subsequent sequencing were detected Pineapple mealybug wilt virus associated-virus 1 (PMWaV-1) and Pineapple mealybug wilt virus associated-3 (PMWaV-3). From the sequences obtained a tree was done with sequences from different regions of the world available in GenBank in order to know their similarity. The sequence obtained from the Mexican isolate PMWaV-1 was genetically related to the sequences of isolates from Cuba, Taiwan, Thailand and Hawaii and more distant from the Australian isolate. The sequence obtained for the Mexican isolate PMWaV-3 was more related to isolates from Hawaii, Cuba, Australia and Taiwan and more distant from the Thailand isolate. This is the first report of the presence of these two viruses in Mexico.