Somaclonal variation among somatic embryo derived plants — Evaluation of agronomically important somaclones and detection of genetic changes by RAPD in Cymbopogon winterianus

A total of one hundred five plants of Cymbopogon winterianus derived from indirect somatic embryogenesis were established in the field. Extensive somaclonal variation was noticed within these plants for all eight agronomic characters such as plant height, diameter of bush, number of tiller/clump, number of leaves/clump, leaf length, leaf breadth, weight of 100 leaves and oil content in relation to the donor parent. Significant variations were also recorded for two major constituents of essential oil such as citronellal and geraniol in some selected somaclones. Ten somaclones that were retained improved oil content and quality in initial screening and, in a replicated trial, were further assessed for their stability in the field for four clonal propagations. Out of the ten superior somaclones only five superior somaclones (SC1, SC2, SC3, SC6 and SC10) which showed relative stability both in oil content and quality were subjected to random amplified polymorphic DNA (RAPD) analysis. Out of the eighteen primers used, ten primers revealed polymorphism showing distinctly different banding patterns in the five improved somaclones, which were equally prominent in their differences from the control. Out of the 44 polymorphic bands, 30 were parental bands which were missing from some somaclonal progenies and 14 were novel non-parental bands which were detected only in some somaclones that confirmed the presence of genetic changes due to somaclonal variation.