RESUMEN
Sixty-seven isolates of Phytophthora infestans collected from Himalayan hill regions and subtropical planes of India were characterized by RAPD markers to assess diversity and differentiation based on location of origin. Ten random decamer primers generated 161 polymorphic fragments. Association of P. infestans isolates on the dendrogram and PCO plot revealed two clear grouping based on geographical location of origin-hill isolates and plane isolates. Quantification of diversity by Shannon index of diversity analysis demonstrated that most of the diversity was present with a particular population (hill or plane) of P. infestans isolates, with 85% variation being within and 15% being between hill and plane isolates. Subtropical plane isolates of P. infestans exhibited higher variability compared to hill isolates and they were more dispersed on the PCO plot. No clear differentiation of isolates based on mating type was reflected on the dendrogram and PCO plot.
Asunto(s)
ADN/metabolismo , Cartilla de ADN/química , Marcadores Genéticos , Variación Genética , Modelos Estadísticos , Filogenia , Phytophthora/genética , Reacción en Cadena de la Polimerasa , Polimorfismo Genético , Técnica del ADN Polimorfo Amplificado AleatorioRESUMEN
RAPD based fingerprinting of 21 serovars of Bacillus thuringiensis (Bt) representing different serotypes was performed using 19 random decamer primers. A total of 172 polymorphic fragments, ranging in size from 161-2789 bp, were amplified from 13 of the 19 primers. Pairwise genetic similarity analysis revealed very low similarity values, ranging from 3-68%, among the serovars of Bt, indicating high genetic divergence. Nineteen serovars of Bt fell in two major clusters and remaining two formed solitary clusters in the dendogram. Clustering of Bt strains established genetic relatedness between serovars and serotypes. It has been suggested that RAPD analysis can be used for genotypic characterization of Bt to complement flagellar serotyping.