Regeneration Rate of Eggplant Somatic Embryogenic In Various Maturation Media

Abstract

Ralstonia solanacearum is one of the most important pathogen that causes bacterial wilt disease in eggplant and inhibits eggplant production. Improvement of eggplant varieties resistant to bacterial wilt can be accomplished through genetic manipulation. Regeneration of in vitro plants isone of the important tools to supports plant improvementthrough biotechnology. This study was aimed to determine the rate of eggplant regeneration in various maturation media, and to find the best medium for eggplant regeneration based on maturation rate and the number of cotyledon produced. We used resistant eggplant (accession 032) as the material to produce somatic embryogenic.There were 7 types of regeneration media used in this research. MS medium was supplemented with a certain concentration of plant growt regulators , such as: 1 mg / L + BAP 1 mg / L, NAA 4mg / L, TDZ 0.005 mg / L, TDZ 0.001 mg / L, CuSO₄ 2mM + BAP 1 mg / L, CuSO₄ 2mM + BAP 2 mg / L and Kinetin 1 mg / L + CuSO₄ 2mM. Three clumps of callus per plate with three replications were transferred to MS suplemented medium. The parameters observed were the color of callus before and after they were transfered to regeneration medium, the day of formation of globular, heart-shaped, tubular and cotyledonary phase, and the number of cotyledons formed. The results obtained showed the somatic embryogenic color of the 032 genotype was white with friable structure before being transferred to regeneration medium and was turned to yellowish white after being transferred to the regeneration medium. On the day sixth, friable embryogenic somatic of eggplant was developed into nodule on medium MS + NAA 4 mg / L, MS + CuSO₄ 2mM + BAP medium 1 mg / L, and MS + CuSO₄ 2mM + BAP 2 mg / L. Somatic embryogenic callus of accession 032 were able to pass complete globular, heart-shaped, tubular and cotyledonary phase. The most responsive medium for somatic embryogenic callus regeneration, based on the days of the callus phases formation and the number of early-phase cotyledons obtained, were MS medium suplemented with CuSO₄ 2mM + BAP,and CuSO₄ 2 mM + BAP 2 mg / L.
Keywords: eggplant, Ralstonia solanacearum, regeneration, cotyledonary, clump, BAP