Development And Identification Of The New Triticale Lines Derived From Trigeneric Hybrids

Triticale is a great man-made cereal developed by crossing wheat and rye, a promising crop and avaluable genetic resource for transferring desirable genes, such as disease-resistance genes to wheat from rye. It has been used to produce wheat-rye chromosome addition, substitution and translocation lines. Trigeneric hybrids involving Triticum, Psathyrostachys and Secale were obtained by a cross between the wheat-P. huashanica amphiploid 'PHW-SA'(2n= 8x= 56, AABBDDNsNs) and the triticale cultivar 'Zhongsi 828'(2n= 6x= 42, AABBRR) in 2008. It has been identified and selected toward different directions during selfing generations. In this study, the trigeneric hybrid F6 and F7 were analyzed by GISH, FISH, agronomic traits and HMW-GSs. The results come as follow:1. Nine to fifteen yellowish-green hybridization signals were observed in the F6 derivatives from trigeneric hybrids with 2n= 39-44. The results revealed that seven F6 lines were hexaploid triticale with the same chromosome constitution(2n= 6x= 42,14R). Some other cytotype and chromosome fragments also been observed in F6 lines. All of the F6 derivatives were resistant to stripe rust, showing only 0 or 0; infection types. Agronomic traits such as spike length, spikelet and tillering, number, length and width of flag leaf in F6 progenies were decent and potential. The mature period of the F6 plants is later than their parents for at least two weeks, and they could be directional selected toward grain crop and late-mature forage in the following years.2. The 21 F6 derivatives were identified in F7 selfing generation. Three triticale K14-783-3, K14-802-1 and K14-827-1 were obtained. The meiotic behaviors of the F7 trigenetic hybrid come as follow:K14-783-3, 2n= 42= 1.46 ?+15.50 ? (ring)+4.82 ? (rod); K14-802-1, 2n= 42=1.25 ?+15.38 ? (ring)+5 ? (rod); K14-827-1, 2n= 42=0.14 ?+18.23 ? (ring)+2.65 ? (rod), indicating the cytogenetic stability of these triticale materials. The cytotypes of K14-783-3 and K14-802-1 were common hexaploid triticale with the same chromosome constitution(2n= 6x=42, AABBRR). A pair of 4D chromosomes replaced a pair of 4B chromosomes in K14-827-1. The presence of 4D and the disappearance of 4B chromosomes had been verified by genome-and species-specific DNA polymorphisms with SSR primers.3. All of three F7 trigenetic hybrid show immunity to stripe rust, tillering profusely with vigorous growth and wonderful flag leaf length and width. The spike morphologies were cone with a full awn, plump seeds, excellent spikelet number in the main spike and high seed setting rate, combining the best characteristics of both parents. Three F7 trigenetic hybrids were late-mature for 15 days, could be a supplier supplying forage when other plants went out of use.4. The glutenin composition of three F7 trigeneric hybrid progenies was same to their one of the parents, Zhongsi 828.