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.
