Assessing the genetic diversity of castor bean from Chiapas, Mexico using SSR and AFLP markers.

摘要

Due to the chemical and physical properties of castor oil (Ricinus communis) that make it a valuable raw material for numerous industrial applications, including the production of biofuel, interest to develop more and better varieties has been increased. However, despite this interest, Mexico does not currently have any varieties of enhanced castor for which yield and adaptation have been optimized to justify sizeable production. Although some varieties have been introduced, there are problems with adaptation. Given the need to develop castor bean varieties with outstanding agronomic characteristics and good adaptation, a collection of local R. communis seeds has been initiated. However, there has been wide phenotypic variation among collections. The objective of this study was to assess the diversity and genetic relationships among accessions of R. communis from the state of Chiapas, Mexico using AFLP (amplified fragment length polymorphism) and SSR (simple sequence repeat) markers. In this research 53% of the AFLP markers were polymorphic; additionally, we detected high levels of genetic diversity (71%). The combinations E-AAC+M-CAG and E-ACG+M-CAG presented a PIC value of 0.415 and 0.425 and an RP of 41.98 and 46.11, respectively, indicating that these combinations are useful in studies of genetic characterization. Additionally, 100% of the SSR primers were polymorphic, with an average of 5.5 alleles per locus. The SSR primer Rco23 generated a PIC value of 0.812, an SI of 1.919 and four uncommon alleles (0.05, 0.06, 0.07, 0.07), indicating that this SSR primer was particularly informative for this study. A dendrogram was generated with the markers obtained from these studies, allowing for the identification of two main groups of accessions. Collectively, these studies will allow for the development of at least two different populations through the recombination of genotypes by genetic similarity and will provide a foundation for the breeding program.Digital Object Identifier http://dx.doi.org/10.1016/j.indcrop.2012.04.033