Identification of RAPD markers linked to high yielding plants of Hevea brasiliensis

Abstract

Since the upper limit of productivity of any trait of a living organism is determined by the genetic makeup, manipulation of the genetic makeup is important to achieve a high productive unit. Plant breeding is a proven technique used to modify the genetic makeup of a particular species. Therefore, genetically improved Hevea clones are produced by conventional breeding methods. Due to perennial nature of the crop, selection the elite genotypes from the breeding population is a serious problem in the current breeding programme. The exploration of genetic markers provides a good solution in breaking up of this limitation. Present study was carried out to find out the possibility to separate potentially high yielders from poor yielders, using the Randomly Amplified Polymorphic DNA (RAPD) technique for the establishment of a genetic marker for rubber breeders. Due to the highly cross-pollinated nature of Hevea, 168 Fi individuals from a cross between PB-235 and IAN-45/710 were used as the segregation population for the study. According to the yield performances, total population was aligned and 10 individuals from each extreme were subjected to Randomly Amplified Polymorphic DNA (RAPD) technique. The bulked segregant analysis facilitates easy selection of potentially polymorphic primers for the two groups. Initially 17 primers showed variation in their banding pattern for the pooled DNA. When the individual plant selection, there were only 8 primers from the above 17 were given a polymorphism for the two phenotypic groups. Totally 59 bands were generated by those 8 Operon primers. There are four bands, which were star graded as significant bands for the separation of two phenotypic groups in the RAPDistance computer programme. The 7th band of OPE-14, the 2nd band of OPE-07, the 5th band of OPS-20, and the 1SI band of OPB-14 were the most significant bands for the separation of those two groups. These bands clearly differentiated the two groups. The tree diagram, which was generated by the total band scores for all primers, indicated three clusters; two high yielders and one all the poor yielders excluding one out of nine. These results showed that this technique could be successfully used in germplasm identification and genetic diversity analysis of Hevea bracilliensis.