In Vitro Culture of ‘Myrobalan’ (Prunus cerasifera Ehrh.) Embryos

Abstract

In vitro embryo culturing has arisen as a powerful tool for embryo germination of low-viability seeds. This tool has been used to germinate seeds of early-maturing or hybrid Prunus species. ‘Myrobalan’ (Prunus cerasifera Ehrh.) is a widely used rootstock for plum and apricot cultivars and its interspecific hybrids have a clear potential for breeding purposes. However, early seed abortion is often a problem in interspecific crosses because no protocol has been established yet for ‘Myrobalan’ seeds. In this work, we developed a procedure for in vitro germination of embryos of different sizes. Various factors affecting embryo germination such as the culture media, the presence of cotyledons, the stratification temperature, and the embryo size were tested in three different ‘Myrobalan’ clones. The developed protocol includes the use of full embryos that were stratified at 4 °C and cultured in C2d culture medium. The germination rate was strongly affected by the embryo size and reached 90% germination with intermediate- to large-sized embryos (6.5 to 10 mm). However, smaller embryos could also be germinated, and up to 30% germination was achieved with 0.5- to 2-mm long embryos. The results obtained here provide a protocol for in vitro germination of ‘Myrobalan’ embryos that will likely be helpful in breeding programs.