Interspecific crosses between domestic and wild barley and embryo rescue to overcome sexual incompatibilities

Abstract

Abstract Increased salinity from irrigation and poor drainage has led to reduced production in semi‐arid and arid irrigated areas of the world. The narrow genetic variation among domestic barley (Hordeum vulgare L.) genotypes slows progress in developing varieties tolerant to biotic and abiotic stresses. A wild barley relative (H. bulbosum L.) is a genetic resource with tolerance to multiple stress conditions, especially salinity. New germplasm added to the USDA barley collection allows novel breeding opportunities. However, crosses between these species require embryo rescue. Crosses were made between diploid and tetraploidized domestic barley ♀ and tetraploid bulbous barley ♂. Immature embryos were rescued and placed on Murashige and Skoog (MS) or Gamborg's B‐5 (B‐5) media (no plant growth regulators, PGRs). Analysis of variance of families showed significant effects for the genotype × medium interactions, indicating each genotype responded to each medium type independently. Significant effects were observed for some traits due to both genotype and medium; and significant effects between media for some traits were observed indicating that those traits were affected by media type. Murashige and Skoog was found to be the better medium for most crosses compared to B‐5. Generally, results from this study indicated that it is difficult to draw broad conclusions about the most suitable medium composition for a broad spectrum of genotypes due to individual genotypes responding differently to the media type. Subsequent manuscripts by these authors will address the success of fertile crossed progeny.