Improvement of embryo rescue technique using 4-chloroindole-3 acetic acid in combination with in vivo grafting to overcome barriers in lentil interspecific crosses

摘要

Widening the genetic base of minor grain legume crops such as lentil (Lens culinaris Medik.) is important for achieving future gains in productivity. In order to access genes from wild lentil species embryo rescue techniques are required to overcome reproductive barriers. Removing the seed coat from developing 14-day old immature hybrid seeds and culturing the interspecific zygotic embryos in medium containing auxin 4-chloroindole-3 acetic acid (4-Cl-IAA) improved successful hybrid recovery. Addition of 4-Cl-IAA to media also increased shoot proliferation when combined with a low concentration of zeatin. No significant difference in shoot elongation was observed between 4-Cl-IAA or IAA treatments. Hybrid shoots were then successfully grafted in vivo onto faba bean rootstocks. Hybrids were obtained from crosses of L. culinaris with L. tomentosus Ladiz., L. lamottei Czef., and L. odemensis Ladiz. This efficient and simple embryo rescue protocol resulted in seed production of large interspecific F-2 populations from inherently weak zygotic embryos produced from wide hybridization.