Effect of embryoids age, size and shape for improvement of regeneration efficiency from microspore-derived embryos in wheat (Triticum aestivum L.)

摘要

For rapid production of doubled haploid plants through isolated microspore culture is very promising target and useful tool in crop plants. But there are some problems for low rates of embryogenesis, regeneration, albinism and all genotype do not show in androgenetic response. Therefore, the aim of this investigation were to screen some androgenetic responsive cultivars, efficient and reproducible plant regeneration system through isolated microspore cultura of wheat. For improvement of regeneration efficiency experiments were conducted on embryoids age, size and shape on regeneration. Different sizes of embryos were classified into three categories, such as large (> 2.0 - 3.0 mm), medium (1.0 - 1.9 mm) and small (< 1.0 mm). Results indicated that size of the embryo is an important factor for efficient regeneration. It was observed that large embryos produced higher percentage of green plantlets and small embryos showed low regeneration. Embryoids age and shape are also very important factor for regeneration. The present investigation demonstrated that transfer of embryos to semi-solid regeneration medium at an early age, e.g. three - five weeks, showed significant and effective results for the production of regenerated green plants in comparison to prolonged age (six - eight weeks). Transfer of embryos to the regeneration medium after six weeks produced four - five times higher albinos than the earlier age. This results indicate that embryo shape (torpedo, heart and globular) plays an important role for regeneration. Large and heart shaped embryoids produced higher percentage of green plantlets and lower albinos in all cases. This investigation has increased the knowledge for efficient plant regeneration system through proper microspore-derived embryoids using in age, size and shaped in wheat microspore culture.