Reaksi Embrio Somatik Kedelai terhadap Polietilena Glikol dan Penggunaannya untuk Seleksi In Vitro terhadap Cekaman Kekeringan

Abstract

The objectives of this experiment wl)re to determine the ability of polyethylene glycol (PEG) to suppress soybean somatic embryos (SE) regeneration, to determine the use PEG as selective agent in the medium, and the regeneration of plantlet from in vitro selected SE on medium containing PEG. To determine the effect of PEG on regeneration, SE frem three soybean genotypes 83731, Tidar and MSC8606 were subjected to selective medium containing 0, S, 10, IS, and 20% PEG. In vitro selection to identify variant SE, that were tolerance to stress condition due to PEG, was conducted by exposing SE of soybean genotypes 83731, MLG2999, and MSC8606 directly to the medium containing 200/. PEG for three months or by subjecting them subsequently to 10%, 15% or 20% PEG, each for one month period, respectively. The secondary somatic embryos developed from explants on the selective medium were germinated and regenerated. The results showed that selective medium containing PEG inhibited soybean SE development. The sub-lethal level (lethal dose> 95%) were identified at concentration of 20% PEG. Direct selection at 20% PEG resulted in less SE survival than that through stepwise increased of PEG concentration. However, the results of the later approach of in vitro selection gave more escaped. At the end in vitro selection, . 98 plantlets were regenerated from SE that tolerated stress condition due to PEG. The plantlets were grown in the glass house to produce SC2 and SC3 generation of seeds.