Abstract

At present, due to the increasing popularity of Jatropha curcas as a source of biodiesel and the generation of nontoxic and high yielding varieties of the plant, there is an immediate need for genetic improvement. However, conclusions on the genetic basis of J. curcas are still inconsistent. The objective of this study is to use amplified fragment length polymorphisms (AFLP) to survey the genetic diversity ofJ. curcas in Southeast Asian countries and China to aid in genetic improvement, and to preliminarily get the message on the genetic relationships of J. curcasbetween China and Southeast Asian. We collected a total of 240 samples from three Asian countries, two African countries and different geographical regions in China. In this study, six AFLP primer combinations were used to amplify, and they yielded a total of 352 scorable loci, 14.78% of which were polymorphic. The number of loci scored per primer combination ranged from 53 (E-ACT/M-CAA and E-ACG/M-CAT) to 68 (E-ACC/M-CAA), with an average of 58.67 loci per primer combination. The rate of polymorphisms found for different primer combinations ranged from 12.90 (E-ACA/M-CAT) to 16.98% (E-ACG/M-CAT). The AMOVA revealed that 36.18% of the variance occurred among populations and 63.82% occurred within populations. The above indicators suggest that the genetic germplasms of J. curcas have a narrow genetic diversity in China and Southeast Asia. The clustering of genotypes based on the AFLP markers shows that the genetic relationship between cluster II and III is close, indicating that the origin of J. curcas in China may be from Southeast Asian. Our next work is to find the bands linkage with specific populations or specific properties and convert it into a sequence-characterized amplified region marker to aid in the genetic improvement of this energy plant.

Key words: Jatropha curcas, genetic diversity, amplified fragment length polymorphism, genetic relationship.

Abbreviation

AFLP, Amplified fragment length polymorphisms; RAPD, random amplified polymorphic DNA; RFLP, restriction fragment length polymorphism; MAS,marker assisted selection; SCAR, sequence characterized amplified region; CTAB,cetyl trimethyl ammonium bromide; EDTA, ethylene diamine tetraacetic acid; PVP,polyvinylpyrrolidone; PCR, polymerase chain reaction; GS, genetic similarity;UPGMA, unweighted pair group method analysis; AMOVA, analysis of molecular variance.