Molecular Cytogenetics Study On Perennial Wheat In North Cold Region

Thinopyrum is a genus of wild relatives and belongs to the third level gene source of wheat, which contains many extremely useful gene for wheat improvement and and is one of the excellent donors of the modified trait in wheat. In this study, the hybrids offspring derived from the hybridization of Octoploid Tritelytrigia and Th. intermediate,were analyzed and detected by the methods, such as morphological and cytological observation, SSR analysis and detection of genomic in situ hybridization, which aimed at breeding the base materials that carry with St and E genome and also has economic value.Morphological and cytological observations indicated that F1 hybrids were amphiphilic intermediate type; plants were perennial, with luxuriant growth, but had no seed in their first year. At 2-3 years of age, a small amount of seeds were produced, and the chromosome number was 49; F2-F3 generation plants were mostly of the intermediate types, perennial, and existed underground rhizomes, their bud sheath was purple, and some varieties appeared purple anthers, chromosome number of root tip was between 42 and 56.The F4-F6 were separate into grass type, Tritelytrigia types(included perennial, biennial and annual) and three types of common wheat.The results of molecular marker showed that 16 hybrid offspring plants contained chromosomes E, St of Th. intermediate. Using five pairs of SSR specific primers of E genome to identify 16 wild-type materials, the results showed that the 16 materials containing 1EL, 2ES, 3EL, 5ES, 7ES, 7EL.Using the Th. intermediate as probe to detect the lines 2-19(forage type), we obtained 39 and a half of carried with signals in 42 chromosomes, and 9 of 39 chromosomes carried with signals when we used the Pseudoroegneria strigosa as the probe for the detection; Using Th. intermediate as probe to detect the lines 5-6(biennial type), the result showed that 14 of 53 chromosomes carrying with hybridization signals, and 3 and a half chromosomes carrying with signals when we used P. strigosa as the probe, which indicated that biennial type exists St chromosome composition. Using Th. intermediate as probe todetect the lines 4-11(common type), there was a small ectopic fragment in 42 chromosomes.The cold-hardy perennial wheat that obtained from this study plays an important role in the use of barren land for farming, in soil and water conservation, in variety improvement, and also for increasing wheat and grass yield.