Asymmetric somatic hybridization between mixed wheat and Psathyrostachys juncea / 生物工程学报

ABSTRACT

Psathyrostachys juncea is a potential source of useful genes, such as the barley yellow dwarf virus resistance, salt tolerance and drought tolerance, for wheat improvement. Conventional sexual hybridization between wheat and Psathyrostachys juncea is very difficult to occur as the two are sexual incompatible. Somatic hybridization is a promising technique for creating hybrids across the sexual border. Here we report a fusion system for somatic hybridization of wheat using PEG method. Mixed protoplasts of two wheat (Triticum aestivum L. cv. Jinan 177) culture cells (cha9 and 176) were used as the recipients to fuse with the donors, the protoplasts of Psathyrostachys juncea (Fisch.) Nevski irradiated with ultraviolet light (UV) at an intensity of 380 microW/cm2 for 1 min or 2 min. Sixteen clones were generated in the combination I, (wheat 176 + wheat cha9 + P. juncea 1 min UV treatment) and five of the hybrid clones could differentiate to green plants. All the regenerated clones were confirmed as somatic hybrids by cytological, isozyme, chromosome and random amplified polymorphic DNA (RAPD) analysis. Chloroplast genome of the hybrids was analyzed using 7 pairs of wheat-specific chloroplast microsatellite (SSR) primers. Three clones were obtained from the combination II (wheat 176 + wheat cha9 + P. juncea 2 min UV treatment), and all browned slowly and died in 3 months. This result indicated that the mixed wheat cells was helpful to the formation and regeneration of hybrid callus and the dosage of the UV had significant effect on the development of the fusion products.