title: High level of molecular and phenotypic biodiversity in Jatropha curcas from Central America compared to Africa, Asia and South America.
abstract: BACKGROUND
  The main bottleneck to elevate jatropha (Jatropha curcas L.) from a wild species to a profitable biodiesel crop is the low genetic and phenotypic variation found in different regions of the world, hampering efficient plant breeding for productivity traits. In this study, 182 accessions from Asia (91), Africa (35), South America (9) and Central America (47) were evaluated at genetic and phenotypic level to find genetic variation and important traits for oilseed production.
  
  
  RESULTS
  Genetic variation was assessed with SSR (Simple Sequence Repeat), TRAP (Target Region Amplification Polymorphism) and AFLP (Amplified fragment length polymorphism) techniques. Phenotypic variation included seed morphological characteristics, seed oil content and fatty acid composition and early growth traits. Jaccard's similarity and cluster analysis by UPGM (Unweighted Paired Group Method) with arithmetic mean and PCA (Principle Component Analysis) indicated higher variability in Central American accessions compared to Asian, African and South American accessions. Polymorphism Information Content (PIC) values ranged from 0 to 0.65. In the set of Central American accessions. PIC values were higher than in other regions. Accessions from the Central American population contain alleles that were not found in the accessions from other populations. Analysis of Molecular Variance (AMOVA; P < 0.0001) indicated high genetic variation within regions (81.7%) and low variation across regions (18.3%). A high level of genetic variation was found on early growth traits and on components of the relative growth rate (specific leaf area, leaf weight, leaf weight ratio and net assimilation rate) as indicated by significant differences between accessions and by the high heritability values (50-88%). The fatty acid composition of jatropha oil significantly differed (P < 0.05) between regions.
  
  
  CONCLUSIONS
  The pool of Central American accessions showed very large genetic variation as assessed by DNA-marker variation compared to accessions from other regions. Central American accessions also showed the highest phenotypic variation and should be considered as the most important source for plant breeding. Some variation in early growth traits was found within a group of accessions from Asia and Africa, while these accessions did not differ in a single DNA-marker, possibly indicating epigenetic variation.
authors.forename: Luis Rodolfo
authors.initials: LR
authors.lastname: Montes Osorio
authors.forename: Andres Fransisco
authors.initials: AF
authors.lastname: Torres Salvador
authors.forename: Raymond Elmar Etienne
authors.initials: RE
authors.lastname: Jongschaap
authors.forename: Cesar Augusto
authors.initials: CA
authors.lastname: Azurdia Perez
authors.forename: Julio Ernesto
authors.initials: JE
authors.lastname: Berduo Sandoval
authors.forename: Luisa Miguel
authors.initials: LM
authors.lastname: Trindade
authors.forename: Richard Gerardus Franciscus
authors.initials: RG
authors.lastname: Visser
authors.affiliation: Plant Breeding, Wageningen University and Research Centre, PO Box 386, 6700 AJ Wageningen, The Netherlands. robert.vanloo@wur.nl.
authors.forename: Eibertus Nicolaas
authors.initials: EN
authors.lastname: van Loo
mesh_terms: D000349:Africa; D054458:Amplified Fragment Length Polymorphism Analysis; D001208:Asia; D044822:Biodiversity; D016000:Cluster Analysis; D031286:Jatropha / Q000145:classification / Q000235:genetics*; D018895:Microsatellite Repeats / Q000235:genetics; D010802:Phylogeny; D010940:Plant Proteins / Q000145:classification / Q000235:genetics; D013020:South America
chemical_list: D010940:Plant Proteins