First Report of a New Isolate of Metarhizium rileyi from Maize Fields of Quivicán, Cuba.

Metarhizium rileyi (Farlow) Samson is an important entomopathogenic fungus of more than 30 species of Lepidoptera larvae. The aim of this research was to characterize isolate of M. rileyi from Quivicán, Cuba on the basis of morphological and molecular approaches. The fungus was isolated from samples of S. frugiperda larvae collected from maize fields of Quivicán municipality, Mayabeque province, Cuba, and it was cultured on PDA + Ampicillin solid media for morphological characterization. The DNA was isolated using CTAB method and internal transcribed spacer (ITS1, ITS4) were used as the primers for the amplification. The amplified products of 1335 bp were purified and sequenced at CINVESTAV-IPN in both the directions using the above primers. A consensus sequence was obtained by alignment of the forward and reverse sequences for this region and deposited in GenBank (MG637450). The fungus produced slightly cottony colony of pale green color and dispersed conidia and septal mycelium were observed under the optical microscope. A BLAST search of the sequence in GenBank revealed a 99% of identity with several strains of N. rileyi (e.g., AF368501.1, AB268359.1 and EU553337.1) and M. rileyi (e.g., KY436756.1). This is the first report of M. rileyi isolate from maize fields of Quivicán in Cuba and this is important for biodiversity studies and is another possibility for Integrated Pest Management.

Expression analysis and biochemical characterization of beans plants biofortificated with zinc.

The present work was carried out in greenhouse conditions at the Centro de Investigación en Alimentación y Desarrollo AC in Delicias, Chihuahua, México. Four different concentrations (0, 25, 50 and 100 µM L-1) of Zn chelate and sulfate were used to study the antioxidant system of Phaseolus vulgaris L. Three genes related with antioxidant activity [superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT)] were selected for expression study. Results showed that when Zn chelate at 50 and 100 µM L-1 were applied SOD was repressed and GSH-Px expression was low at 0, 25 and 100 µM L-1 while with sulfate form SOD expression was low and GSH-Px expression was strong in all treatment. CAT was highly expressed in all form and treatments. For a biochemical study the same enzymes were spectrophotometrically measured. SOD activity shows differences in both forms of Zn, chelate form was different at 25, 50 and 100 µM L-1 with less activity at 100 µM L-1 and sulfate treatment shows differences in all concentrations used. GSH-Px activity shows significant differences with sulfate form at 25, 50 µM L-1 where at 50 µM the activity was higher and low at 100 µM L-1, CAT does not exhibit significant differences but with chelate treatment at 50-100 µM L-1 the activity was higher compared to sulfate. Finally, to raise the Zn concentration in bean under biofortification program is a promising strategy in cropping systems in order to increase the ingestion of zinc and antioxidant capacity in the general population and provided the benefits that this element offered in human health.