Javier Hernández-Morales

Quality of three sizes of prickly pear cactus stems (Opuntia ficus indica L. 'ATLIXCO')

Nowadays, the prickly pear cactus stem has become an important part of the human diet due to its nutraceutical properties. Consumers show different preferences in the size of prickly pear cactus stems. The objective of this study was to evaluate some quality changes due to the effect of prickly pear cactus stem size in refrigeration (8 ± 2°C) for six days. The hypothesis was that the quality parameters vary according to the size and the storage time. Cut resistance, weight loss, color, titratable acidity, ascorbic acid and chlorophyll were evaluated in three prickly pear cactus stem sizes (5.0 to 10.5; 10.6 to 16.9 y 17.0 to 22 cm) of Opuntia ficus indica L. ‘Atlixco’ (thorns were removed), kept refrigerated at 8 ± 2°C for six days. The smallest size showed the highest weight lost (3.22%). Content of chlorophyll a, b, and total was directly proportional to the size and it increased with the storage time during the evaluated days. Also, the ascorbic acid content decreased significantly with the storage time.

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.