Assessment of genetic stability in micropropagules of Jatropha curcas genotypes by RAPD and AFLP analysis

Abstract

Jatropha curcas (Euphorbiaceae), a drought resistant non edible oil yielding plant, has acquired significant importance as an alternative renewable energy source. Low and inconsistent yields found in field plantations prompted for identification of high yielding clones and their large scale multiplication by vegetative propagation to obtain true to type plants. In the current investigation plantlets of J. curcas generated by axillary bud proliferation (micropropagation) using nodal segments obtained from selected high yielding genotypes were assessed for their genetic stability using Randomly Amplified Polymorphic DNA (RAPD) and Amplified Fragment Length Polymorphism (AFLP) analyses. For RAPD analysis, 21 out of 52 arbitrary decamer primers screened gave clear reproducible bands. In the micropropagated plantlets obtained from the 2nd sub-culture, 4 out of a total of 177 bands scored were polymorphic, but in the 8th and 16th sub-cultures (culture cycle) no polymorphisms were detected. AFLP analysis revealed 0.63%, 0% and 0% polymorphism in the 2nd, 8th and 16th generations, respectively. When different genotypes, viz. IC 56557 16, IC 56557 34 and IC 56557 13, were assessed by AFLP, 0%, 0.31% and 0.47% polymorphisms were found, respectively, indicating a difference in genetic stability among the different genotypes. To the best of our knowledge this is the first report on assessment of genetic stability of micropropagated plantlets in J. curcas and suggests that axillary shoot proliferation can safely be used as an efficient micropropagation method for mass propagation of J. curcas.