ABSTRACT: Nowdays, the importance of Jatropha curcas L. lies in its high-quality seed oil, ideal for the manufacture of biodiesel. However, this new crop has several challenges including the knowledge of its biology, ecology, genetic diversity and geographic origin of its populations. There are a few studies on phenotypic and genotypic diversity in populations of Mesoamerica, from where it is probably native. In our investigation, we analyzed the genetic diversity and structure of populations of Mexico and Guatemala, emphasizing those from the Mexican state of Chiapas. We used two types of markers: a) direct adaptive value characteristics, such as fatty acids in the seed, floral variability and other morphological characters, and b) neutral molecular markers such as AFLP and SSR. The results of the chemical study showed that the contents of seed oil in 135 accessions from 38 sites ranged from 8.02% to 54.28%, with the most abundant fatty acids being oleic acid (18:1) and linoleic (18: 2). A discriminant analysis separated populations according to their geographical origin, which was verified with a Mantel test. Using the Monmonier algorithm, two genetic barriers were identified between the populations. In the molecular study, 152 useful markers were found with a global polymorphism of 81%. A conglomerate analysis revealed the highest coefficient of dissimilarity based on accessions reported so far. An analysis of molecular variance showed that most of variation is located within populations (87.8%) with a moderate differentiation between populations (ΦST = 0.121). A Bayesian analysis revealed that the number of genetic populations was 5, with mixed ancestry in most individuals. The genetic diversity and structure detected with SSR confirmed the previos findings.
BIT's 3rd Annual World Bioenergy Congress, Nanjing, Chinas; 04/2013