Studies On Breeding Of Hybrid Descendants Between Agropyron Mongolicum Keng. And A.cristatum Gaertn. Cv. 'Fariway'

The genetic differences, agronomic characters and fertility recovering of hybrids F3 and 11 lines of F4 were studied through morphology, cytology and isozyme electrophoresis. The main results were as follows:(1) The growing days of hybrids F3 were 217 days, growth rate was faster relatively. The growing days of line 1 to 7 and line 9 to 10 of F4 were 174 days, line 8 and 11 were 176 days the growth rate of line 1, 2, 8 and 9 were faster relatively, line 3 was slower and the rest of 6 lines were in the middle of parents.(2) The average plant height of hybrid F3 was 73.30cm, tiller number of individuals was 82.92; ear type of hybrids F3 was steady compared with F2. The average plant height of 11 lines of F4 were 65.79cm, the tiller ability was distinctive, line 1, 5, 6 and 7 were higher in tiller number, total tiller number of individuals was over 100 and tended toward father; line 9, 10 were lower in tiller number, total tiller number of individuals were respectively 36.22 and 34.00; the tiller ability of line 2, 4 and 8 was in the middle, ear type variation of 11 lines of F4 was steady relatively.(3) The pollen fertility rate of hybrid F3 was 66.59%, and the seed set was 28.07 . The pollen fertility of 11 lines of F4 were higher, the pollen fertility rate of line 1, 2, 4, 5 and 9 was about 82%, line 3, 6, 7 and 10 was about 78%, line 7 and 8 was about 73%; the seed set of line 4, 8, 10 and 11 was about 58%, line 1, 2 and 5 was about 46%, line 3, 6, 7 and 9 was about 38%.(4) The average chromosome pairing configuration at metaphase I in pollen mother cell of F3 was 0.23 I +6.88 II; bivalent frequency of 11 lines of F4 was high ranging from 6.95 to 6.99, the univalent frequency was low ranging from 0.02 to 0.05. there was a few B chromosomes in line 6 and 9.(5) There were great differences in band phenotypes of POD EST and SOD isozymes at different developing stages. Isozyme band phenotype can be used as genetic marker in protein level to identify F3 and 11 lines of F4. Cluster analysis showed that 13 tested plant materals were divided into 6 groups.The above results can be used as theory foundation for breeding new cultivars of crested wheatgrass.