Розмір шрифту:
HYBRIDIZATION BETWEEN HEXAPLOID TRITICALE AND SYNTHETIC WHEAT
Остання редакція: 2017-06-29
Тези доповіді
We present here the results of hybridization and morphotype formation studies in the generated hybrid populations (F1 – F5) obtained from the cross between hexaploid triticale ABDR and synthetic wheat ABD and their comparision with other hybrid combinations derived by the employing of the same hexaploid triticale accession. Triticale ABR (genome AABBRR, 2n = 42) is locally produced in the Genetic Resources Institute of ANAS by the second author of this abstract in 1974 and was used in all crosses of current study as a female or maternal plant. This triticale differentiated from other triticales by its originating from hybridization between Kihara’s synthetic wheat ABS (T.durum × Ae. squarrosa, genome AABBDD, 2n = 42) and Secale cereale ssp. segetale (genome RR, 2n = 14). The paternal synthetic wheat plant ABD [(T.beoticum× Ae.taushii) × Ae.speltoides, genome AADDSS, 2n = 42)], which is used in the cross to triticale ABDR, also have been locally produced in the Genetic Resources Institute of ANAS by the same author in 1982. Other employed paternal plants were presented by 3 botanical varieties of T. aestivum species: var. lutescens (cultivar Bezostaya 1, genome AABBDD, 2n = 42), var. graecum (local cultivar Grekum 75/50, genome AABBDD, 2n = 42), var. velutinum (genome AABBDD, 2n = 42) and by local Georgian wheat species T. macha Dek. et Men. (2n = 42, AABBDD). Field works including hybridization and phenotype analysis of hybrid populations within five generations carried out for a period of 6 years (2007-2013). The emasculation and pollination in the field were carried out during the months of April-May 2007. No embryo rescue or hormone treatment was applied for the production of F0 seeds. Seeds (shriveled and weak) were obtained from all hybrid combinations, with the average seed set 17,82% ranging from 11,79% to 22,45% and average seed germination rate 36,15% ranging from 12,5% to 52,5%. The combination of ABDR with synthetic wheat ABD showed nearly the high seed set (22,37%) and germination rate equal to 45%. F1 hybrids from all subjected crosses had a morphology that is intermediate between that of the parental forms, including the latter combination. On the basis of morphological appearance the all segregants within the four hybrid generations (F2 – F5) from all hybrid combinations were divided to three morphotype groups: triticale-like plants (maternal type); intermediate-like (both parental combining type) and wheat-like plants (paternal type). The results showed that the prevalence of certain type of segregants over the other in all hybrid combinations depends on their spike fertility and if in the early F2 generation this indicator was different for all three morphotypes it tended to increase for wheat-like plants in the later generations (F3 - F5) almost for all studied combinations. If most segregants (44%) in F2 of ABDR × ABD cross were short-stemmed triticale-like plants with high level of sterility, then starting from F3 towards to F5 the proportion of wheat-like plants is increased significantly (70% - F3, 89% - F4, 92% - F5, respectively). In our study morphotype formation in the hybrid combination of triticale ABDR with synthetic wheat mainly differed from other combinations by large percentage of segregants revealing short and compact spike with the broad colour range (from the light yellow to blackish), that is common for goatgrasses.
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