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| Identification of New Materials of Trigeneric Hybridization Between Trititrigia and Triticale (×Triticosecale) |
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Abstract The trigeneric hybridization is mainly produced by recombination or structural rearrangement among chromosomes of different species, and they are the individuals with excellent gene set. Through screening, identification and breeding, the wheat traits were obtained, as well as genes, resistance to germplasm or direct breeding of new varieties. So far, the domestic and foreign scholars have been a large number of polygeneric hybrids. Its descendants were analyzed and the results showed that the offspring differentiation of the hybridization was extremely complicated, which generated some new germplasm for the improvement of wheat genetics. In this study, polygeneric hybrid was produced by an octoploid trititrigia (wheatgrass 8, AABBDDEE, 2n=56) and a hexaploid triticale (Hashi 209, AABBRR, 2n=42). Wheatgrass 8 of the male parent was obtained from the hybridization of Chinese Spring and Thinopyrum intermedia. Hashi 209 of the female parent was final election in 1996 and called "Nongqing 2" by Heilongjiang Provincial Variety Approval Committee, which was cultivated in 1990 using the hybridization between "triticale 2" (octoploid triticale, bred by Academician Bao Wenkui from Chinese Academy of Agricultural Sciences) and "Rosner"(a hexaploid triticale). Then, a part of hybrid F6 generations of polygeneric hybrid were analyzed and identified by morphological and molecular cytogenetic methods, which was aimed at discussing the cytogenetics' rule of polygeneric hybrid and breeding hybrids of Triticum-Thinopyrum-Rye with the important agronomic traits, such as a large spike, more flowers and grains, and resistance to disease. It will provide the basic material for the improvement of Triticale and Triticum. The morphological results showed that the significant differences of morphological characteristics were divided into triticale type, normal wheat type and intermediate type. There were 5 lines of triticale type, which were lodging resistance and large spikelets. Their pollen mother cell meiosis was observed with the univalent, and the thousand kernel weight was more than 40 g in 4 lines. The results of molecular marker and genome in situ hybridization showed that 3 lines (14-4, 3-29-3, and h-29) were hexaploid triticale with R and E chromosomes. The kernel of line 14-4 was full and the thousand-grain weight was 47.6 g, which was better than its parental Hashi 209. There were 8 lines of normal wheat types. Their maturity was normal and the chromosome number of root tip cell was 42. There were 5 lines with the genetic components of R group chromosome and line 14-22 carried the chromosomal translocation of R genome, additionally, line w-16 carried the chromosomal translocation and substitution of E genome. There were 7 lines of intermediate type and all lines had the genetic components of R genome. The plants were height (94~120 cm), more tillers (5~15) and grains. The spikelet number was from 16 to 36. The kernel number of main spike in line h-7 was 122 and the threshing was difficult. Line 11-26 carried the chromosomal translocation of R genome. Besides of carrying the genetic components of R group chromosome, line 11-21-2 carried E chromosomes, but the chromosome number of root tip cell was 52. It was less the genetic instability. Line14-4, 3-29-3 and h-29 that obtained from the research were new germplasms of Triticum-Thinopyrum-Rye, which provides theoretical and material bases for breeding triticale and creating wheat polygeneric hybrids.
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Received: 02 December 2016
Published: 31 March 2017
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