Studies On The Genetic Characters And Fertility Of The Hybrids Between Elymus Dahuricus And Hordeum Brevisubulatum

The genetic characters and fertility of the hybrids between Elyrnus dahuricus and Horde urn brevisubulaturn were studied by means of morphology, cytology, isozyme electrophoresis and RAPD. The results were as follows: (1) The morphological characteristics of hybrid F1 between E. dahuricus and H. brevisubulatum tended toward recurrent parent H. brevisubulaturn, and there were significant differences among backcross 1 (BC1) lines. The lepicena shape can be used as one of the important characteristics to identify hybrids.(2)The growing days,tiller ability, drought resistance and salt tolerance of the hybrid F1 were in the middle of the parents, the heterosis of F1 yield was stronger, there were significant differences in phenological period, tiller ability and regeneration rate between E. dahuricusX H. brevisubulaturn F1 and H. brevisubulaturn X E. dahuricus F1.The biological and agronomic characters of BC1 tended toward recurrent parent H. brevisubulaturn and there were significant differences among BC1 lines. (3) The meiosis of hybrid F1 was irregular and univalents existed universally, which was the main reason why hybrid F1 is infertile. The BC1 varied in chromosome number ranged from 28 to 35, the univalent frequency in meiosis of BC1 decreased and the bivalent frequency increased compared with that of F1, the ring bivalents in some BC1 lines were absolutely dominant. (4) The zymogram of POD and EST of hybrid F1 were the mutual suplementary isozymes of the parents or had hybrid bands. The zymogram of POD and EST of BC1 were affected obviously by recurrent parent H. brevisubulaturn. (5) The genetic differences among parents and their hybrids can be tested objectively by RAPD, which can be used as genetic marker to identify hybrid and to determine the plants with object characteristics. (6) Hybrid F1 is highly infertile, the fertilities of BC1 were enhanced in different degree, the pollen fertility rate of some BC1 lines reached to 73%, seed set reached to 14.6%, which showed that backcross is an effective ways to restore fertility to wide- cross hybrid F1.