Fertility Restoration To Several Hybridization Descendants In Triticeae Grasses

The majority species of perennial Triticeae grasses had the characters of barren tolerance, stronger tress tolerance, excellent quality and high yield, which were precious gene bank in crop varietal improvement. In order to create new forage grass germplasms of parental superior characters, wide crosses between Elymus canadensis of excellent quality and high yield from north America (2n=4x=28, genome SSHcHc) and Hordeum brevisubulatum(2n=4x=28,genome H1H1H2H2), E. dahuricus(2n=6x=42, genome SpSpHpHpYpYp), E. cylindricus(2n=6x=42, genome SoSoHoHoYoYo) of strong drought resistance and tillering from China were made respectively, and 3 intergeneric and interspecific hybrids F1 which were completely sterile were successfully gotten. The sterility of hybrids F1 were restored with the methods of inducing chromosome doubling with colchicines and by backcross, and Elymus canadensis- Hordeum brevisubulatum doubling plants and its descendants, E. canadensis- E. dahuricus hybrid F1 and backcross 1(BC1), E. canadensis- E. cylindricus hybrid F1 and BC1 were identified and analysed based on morph-biology, cytology, isozyme and AFLP maker. The main results as follows:1. The suitable colchicine concentration and treatment time for the tillering plants of E. canadensis- H. brevisubulatum triploid hybrid F1 were 0.15%～0.20% and 12～24h respectively, and 17 chromosome doubling plants were got by colchicine induction, and 16 natural chromosome doubling clumped plants were found in field.2. The average chromosome pairing configuration at metaphaseⅠin pollen mother cells (PMCMⅠ) of the natural chromosome doubling plant, natural chromosome doubling F1 and cochicines induced chromosome doubling plant of triploid hybrid F1 were 0.04Ⅰ+ 20.96Ⅱ, 0.03Ⅰ+ 20.98Ⅱa nd 0.03Ⅰ+ 20.97Ⅱrespectively, their pollen fertility rate were 84.97%, 94.08% and 90.21% respectively, the seed set were 77.51%, 83.87% and 80.13% respectively, and had higher fertility.3. The growth vigour of chromosome doubling plant and its descendants were stronger, their growth periods were 147d, and had the characters of long flowering duration, long growth period after fructification and late withering, and their morpholo- gical characters of plant height, leaf length and width, ear length and width et al. exceled hybrid F1, and had the strong tillering vigor and capability of salt tolerance from paternal H. brevisubulatum.4. The E. canadensis-H. brevisubulatum chromosome doubling plant and doubling F1 had uniformity and genetic stability in the isozyme zymograms token(bands number, locus and intensity) of esterase (EST), proxidase (POD) and superoxide dismutase (SOD) isozyme at the same growth-development stage, but they were significantly different from the hybrid F1 and their parents in isozyme band patterns, the isozyme zymograms can be used as genetic marker to identify fertility recovering of chromosome doubling plant of hybrid.5. The percentage of polymorphism loci of AFLP markers with 19 primer combina- tions to E. canadensis- H. brevisubulatum chromosome doubling plant and doubling F1, their parents and hybrid F1 was 84.60%; UPGMA cluster analysis based on AFLP markers indicated that the genetic diversity between E. canadensis and H. brevisubula- tum was maximal, and the genetic diversity between hybrid F1 and♀E. canadensis was lesser, and the genetic diversity among chromosome doubling plant and doubling F1～F4 was the least.6. The growth rate of E. canadensis- E. dahuricus hybrid F1 was more than its parents, and the growth rate of E. canadensis- E. cylindricus hybrid F1 was in the middle of parents, their growth periods were 139d and 132d respectively, plant height were 150.05cm and 143.67cm, plant type was similar to E. canadensis, the size and number of leaves were bigger, the ear of F1 hybrids was bigger than their parents, had the strong tillering vigor.7. E. canadensis- E. dahuricus hybrid F1 and E. canadensis- E. cylindricus hybrid F1 were pentaploid (2n=5x=35), the average chromosome pairing configurations at PMCMⅠwere 19.04Ⅰ+7.45Ⅱ+0.28Ⅲ+0.02Ⅳand 5.82Ⅰ+14.31Ⅱ+ 0.15Ⅲrespec- tively, the important reasons why hybrid F1 was sterile was that chromosome pairing behavior was irregular.8. The percentage of polymorphism loci of AFLP markers with 13 primer combina- tions to E. canadensis- E. dahuricus hybrid F1, E. canadensis- E. cylindricus hybrid F1 and their parents with was 83.56%, and they were significantly different from the hybrid F1 and their parents in AFLP fingerprint, the fingerprint can be used as molecular marker to identify hybrid F1 and their parents; the cluster analysis indicated that the genetic diversity between E. canadensis and E. dahuricus was bigger than that of E. canadensis and E. cylindricus, and the genetic diversity between two hybrids F1 and their paternal was lesser.9. The system of tissue culture and plant regeneration two hybrids F1 of E. canadensis- E. dahuricus and E. canadensis- E. cylindricus were established. MS medium as the basic medium, the concentration combination of optimal medium on callus induction, callus subculture, plantlets differentiation and rooting were 400mg/L CH +3.0mg/L 2,4-D,400mg/L CH + 1.0mg/L 6BA+0.5 mg/L 2,4-D,400mg/L CH +3.0mg/L 6BA +0.5mg/L NAA and 0.5mg/L NAA + 0.5mg /L IBA respectively. On the system of tissue culture, eight variation plants were achieved by colchicine induction callus of two hybrids F1.10. Four BC1 lines of [E. canadensis×E. dahuricus]×E. canadensis and three BC1 lines of [E. canadensis×E. cylindricus ]×E. canadensis were obtained, their choromo- some number trended to E. canadensis.