| Two trigeneric hybrids were synthesized by crossing amphiploid Triticale(Jinsong49) with Tritileymus and Trititrigia(Zhong5), the morphology and cytogenetic characters of the trigeneiric hybrids and their derivatives were characterized by C-banding and genome in situ hybridizations.. In the selfed progenies of two trigeneric hybrids, 5 germplasms with good traits were obtained. The character and origination of the resistant gene to powdery mildew in Shannong030-1 were analysised, and the RAPD markers of this resistant gene were constructed. Results were as follows:1. The morphological trait and cytogenetic characters of octoploid Jinsong49,Tritileymus, Zhong5 were identified, they all had the chromosome number of 2n=56, and could form 28 bivalent at PMC MI. Chromosome constitution of Jinsong49 were confirmed by C-banding and in situ hybridization, it had 22 pair of wheat chromosomes and 6 pair of rye chromosomes as 1R,2R,4R,5R,6R,7R. Results of in situ hybridization indicated that Tritileymus had 44 wheat chromosomes and 12 Leymus mollis chromosomes.2. Use the Jinsong49 as female parent, pollinated with Tritileymus and Zhong5, two trigeneric hybrids as Triticum-Secale-Leymus, Triticum-Secale-Elytirgia were obtained. The morphological characters of the trigeneric hybrids and their progenies were studied, it showed that the selfed derivatives of Jinsong49/Tritileymus were inclined to Jinsong49. While the progenies of Jinsong49/Zhong5 showed extensive segregation in morphology, some new type and mediate phenotype were observed.3. The mean of chromosome configuration in Jinsong49/Tritileymus F1, and Jinsong49/ Zhong5 F1 were 13.17â… +20.82â…¡+0.37â…¢+0.02â…£ and 14.32â… +20.28â…¡+0.32â…¢+0.04â…£ respectively,and their relative chaotic coefficient were 0.34 and 0.38,they were higher apparently than their parent.In the course of microsporagenesis and male gametophyte development, high frequency of laggard can be observed at meiotic AI, as well as the micronucleoli in tetrad. The sterile rate of mature pollen in two trigeneric hybrids were 55.9% and 59.2% respectively. And some abnormal phenomenon were observed4. Using labelled genome DNA of Secale cereale and Leymus mollis as probes,in situ hybridizations showed that there were 6 Secale and 6 Leymus chromosome in the Jinsong49/TritileymusF1, and the GISH pattern of microspores showed that some of rye chromatins exist in the nucleus, some exist in the cytoplasm as micronucleoli, while most Leymus chromatin present in the microspore as the micronucleoli.5. In the selfed derivatives of two trigeneric hybrids, with generation increased, the meanof chromosome number tends to decreased, the chromosome number of progenies from Jinsong49/Zhong5 seems to decrease faster. The results also indicated that the homologous pairing way,and the speeds of chromosome number decreased in the progenies of these two trigeneric hybrids were different.6. Using labelled genome DNA of Secale cereale and Leymus mollis as probes ,genome DNA of Chinese spring as blocked DNA, in situ hybridization were applied to analysis the chromosome constitution of the progenies from Jinsong49/Tritileymu. The results showed most selfed derivative plant contained 8-12 rye chromosomes,but Leymus chromosome was not observed. Analysis of chromosome constitution on germplasm lines L049-5 and L050-1 by using C-banding techniques showed that 5 pair of rye chromosome of them were 1R,2R,5R,6R, 7R.The chromosome constitutions of the progenies from Jinsong49/Zhong5 were identified by C-banding and in situ hybridization, and it was found that chromosomes of rye and Elytrigia existed simultaneously in the selfed derivative plant. And germplasm line W1044-2 had one pair of 1R chromosome and one pair of Elytrigia chromosome, germplasm line W1037-1 had one pair of Elytrigia chromosome and had no rye chromosomes.7.In the progenies of Jinsong49/Tritileymus, a stable germplam line named Shannong 030-1 were obtained. Its chromosome number was 2n=42, and could form 21 bivalents at PMC MI. Resistance ide...
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