RESUMEN
Begomoviruses belong to the family Geminiviridae are associated with several disease symptoms, such as mosaic and leaf curling in Jatropha curcas. The molecular characterization of these viral strains will help in developing management strategies to control the disease. In this study, J. curcas that was infected with begomovirus and showed acute leaf curling symptoms were identified. DNA-A segment from pathogenic viral strain was isolated and sequenced. The sequenced genome was assembled and characterized in detail. The full-length DNA-A sequence was covered by primer walking. The genome sequence showed the general organization of DNA-A from begomovirus by the distribution of ORFs in both viral and anti-viral strands. The genome size ranged from 2844â¯bp-2852â¯bp. Three strains with minor nucleotide variations were identified, and a phylogenetic analysis was performed by comparing the DNA-A segments from other reported begomovirus isolates. The maximum sequence similarity was observed with Euphorbia yellow mosaic virus (FN435995). In the phylogenetic tree, no clustering was observed with previously reported begomovirus strains isolated from J. curcas host. The strains isolated in this study belong to new begomoviral strain that elicits symptoms of leaf curling in J. curcas. The results indicate that the probable origin of the strains is from Jatropha mosaic virus infecting J. gassypifolia. The strains isolated in this study are referred as Jatropha curcas leaf curl India virus (JCLCIV) based on the major symptoms exhibited by host J. curcas.
Asunto(s)
Begomovirus/genética , ADN Viral/aislamiento & purificación , Genoma Viral , Jatropha/virología , Enfermedades de las Plantas/virología , Begomovirus/patogenicidad , Evolución Biológica , Euphorbia/virología , Transferencia de Gen Horizontal/genética , Virus del Mosaico/genética , Filogenia , Hojas de la Planta/virología , Proteínas Virales/genéticaRESUMEN
Jatropha curcas L. belongs to family Euphorbiaceae, native to South America and widely distributed in South and Central America, attained significant importance for its seed oil which can be converted to biodiesel, a renewable energy source alternative to conventional petro-diesel. Very few attempts were made to understand the extent of genetic diversity that exists in J. curcas. Therefore, the present investigation was undertaken to asses the genetic diversity among 28 diverse germplasm collected from distinct geographical areas in India. The overall percentage of polymorphism (PP) was found to be 50.70 and 60.95 by RAPD and AFLP, respectively. The mean PP was found to be 9.72 and 20.57 by RAPD and AFLP, respectively. The mean genetic similarity was observed to be 0.89 by RAPD and 0.88 by AFLP. Among the germplasm JCI20 found to be the most diverged one. The dendrogram analysis of RAPD and AFLP data showed good congruence, but better resolution and more polymorphism was observed with AFLP. When the dendrogram of RAPD was compared with AFLP dendrogram, the major clustering pattern was found to be similar; however, changes in minor grouping were observed. In both RAPD and AFLP analysis clustering of germplasm did not show any correlation with the geographical area of collection. Low genetic diversity observed in J. curcas and the clustering pattern indicates that the distribution of species might have happened through anthropogenic activity and warrants the need for widening the genetic base. The present study will provide pavement for further intra-population studies on narrow geographical areas, to understand the population genetic structure, phylogeography, molecular ecological studies. The marker information and the characterized germplasm help in further improvement of the species through marker assisted breeding programs.
Asunto(s)
Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Variación Genética , Jatropha/genética , Técnica del ADN Polimorfo Amplificado Aleatorio , Cartilla de ADN/genética , Geografía , India , Filogenia , Polimorfismo Genético , Semillas/genéticaRESUMEN
Jatropha curcas L., a member of the Euphorbiaceae, is widely distributed in different parts of the globe. In the present study, 12 microsatellites were isolated from J. curcas and their cross-species amplification was checked in six species of genus Jatropha. Within J. curcas, observed and expected heterozygosities ranged from 0.94 to 0.54 and from 0.95 to 0.56, respectively. Of the 12 loci, five showed significant deviation from Hardy-Weinberg equilibrium. There was no significant linkage disequilibrium detected between any of the loci. The markers isolated in the present investigation will be useful for assessing the population diversity and genetic structure of J. curcas and also in other species of Jatropha.