Genetic Diversity in Jatropha curcas Populations in the State of Chiapas, Mexico

Abstract

Jatropha curcas L. has become an important source of oil production for biodiesel fuel. Most genetic studies of this plant have been conducted with Asian and African accessions, where low diversity was encountered. There are no studies of this kind focusing in the postulated region of origin. Therefore, five populations of J. curcas were studied in the state of Chiapas, Mexico, using amplified fragment length polymorphism (AFLP) markers. One hundred and fifty-two useful markers were obtained: overall polymorphism = 81.18% and overall Nei's genetic diversity (He) = 0.192. The most diverse population was the Border population [He: 0.245, Shanon's information index (I): 0.378]. A cluster analysis revealed the highest dissimilarity coefficient (0.893) yet to be reported among accessions. An analysis of molecular variance (AMOVA) revealed that the greatest variation is within populations (87.8%), followed by the variation among populations (7.88%). The PhiST value (0.121) indicated moderate differentiation between populations. However, a spatial AMOVA (SAMOVA) detected a stronger genetic structure

Genetic Diversity of Jatropha curcas in Southern Mexico

“…In our investigations (Ovando-Medina et al 2011c ) high variation and moderate structure were found in populations of J. curcas of Chiapas. Although clustering methods based on individuals are not useful to infer structure or other population attributes, we compared the Jaccard similarity index of accessions from Chiapas to that reported in other studies and found the lowest value (0.107) reported so far (Fig.…”

Drivers and Consequences of the First Jatropha curcas Plantations in Mexico

“…Additionally, studies on seed productivity in the native provenances were not available at the time of the first commercial plantations, so it was risky to start commercial plantations without having elite Mexican accessions. This situation led to authorities in charge of the programs to decide on the importation of seeds from countries where commercial plantations already existed, such as India and Thailand [7,16], sites where germplasm would have evolved under different conditions, would have less genetic diversity [28,29] and would be more susceptible to new diseases. As a result, in Chiapas, the seeds presented less than 40% germination, and the resulting seedlings showed poor development in 76% of the plots [7].…”

“…Since the years 2006 and 2007, national specimen collections were started by INIFAP [29] and other research centers in Michoacán, Chiapas, Morelos and Veracruz. Collectively, research has found a higher genetic diversity in morphology, flowers and fruits, oil content, fatty-acid composition, toxicity and grain yield in the Mexican provenances when compared with Asian and African provenances [28,29,43].…”

Genetic diversity and structure ofJatropha curcasL. in its centre of origin

“…The genomic DNA was isolated and purified by the method described by Doyle and Doyle (1990) modified for processing samples of 200 mg (Ovando-Medina et al, 2011a). In brief, 200 mg of healthy leaves and 60 mg of polyvinylpyrrolidone were ground with liquid nitrogen and then extracted with 1 ml of CTAB buffer (0.1% w/v hexadecyltrimethylammonium bromide, 5 mM EDTA, 1.5 M NaCl, 50 mM Trizma base and 0.1% v/v b-mercaptoethanol, pH 8.0).…”