Polypeptide variability among the coconut zygotic embryos in two culture conditions

Abstract

The growth of matured zygotic embryos of coconut in two types of media was studied. Twenty embryos of each West Coast Tall (WCT) and Chowghat Orange Dwarf (COD) were inoculated individually in Y3 liquid medium and solid medium. After 15 days the embryos in liquid medium was transferred to solid medium (liquid-solid medium). The germination percentage was recorded. Polypeptide pattern among the embryos in two different media was analyzed using 12% SDS –PAGE. In WCT the plantlet recovery was 34 per cent for the liquid-solid culture after 90 days. In COD the germination was 63% under liquid-solid media, where as only 40% under solid medium alone. The embryos recorded higher germination percentage and balanced root and growth under liquid-solid medium. Equal amount of protein from all the cultures separated using SDS –PAGE. Proteins from freshly extracted embryos served as control. Fresh embryos of both COD and WCT had many polypeptides ranging from 90 kDa to 12 kDa. Control embryos of COD and WCT had high amount of polypeptide at 40 kDa, which could not be detected in germinated embryos. In comparison with COD and WCT, a polypeptide at 44 kDa was present only in WCT. The abnormal embryo of WCT had higher accumulation of 55 kDa polypeptide. A 45 kDa polypeptide in COD showed variability between embryos cultured in two different media. It is present only in controls and embryos cultured in solid media. It showed that, embryos cultured in solid media have not initiated the germination process and the reserve proteins are present without hydrolysis.