Highly efficient embryo germination in vitro shortens the breeding cycle in Leymus chinensis

Abstract

Chinese leymus is a perennial grass in the Gramineae family, which is widely distributed in Northern China and Mongolia. The breeding cycle in Chinese leymus is time-consuming because of its high level of seed dormancy. To improve the breeding process, we established a simple technique that shortens the breeding cycle by culturing immature embryos in vitro to produce plantlets immediately. This technique can potentially save 1 yr in each sexual breeding cycle. Factors affecting germination of immature embryos were evaluated. Immature embryos at different developmental stages were cultured on Murashige and Skoog basic medium. The immature embryos collected 11–16 d after pollination expressed the maximum germination rate (100%), but the maximum efficiency of recovery was observed at 15–16 d after pollination. The germination time of embryos increased and length of the germinated shoots decreased as the age of the embryos increased. All plantlets survived transplantation to the field. Two generations were obtained within 2 yr starting from immature embryo cultures, as compared to one generation using conventional breeding techniques.