HOMOLOGOUS FORM OF SOFT WHEAT FROM <i>TRITICUM KIHARAE DOROF. ET MIGUSCH</i>
Introduction. For the successful development of breeding in Russia, a genetically diverse source material is needed. Reducing genetic diversity is a global problem affecting most cultivated crops, including wheat. In this regard, the creation of a homologous soft wheat form in a representative of the second phylogenetic branch is very attractive. It is obvious that this form, which is phenotypically and, for sure, genotypically, will be close to soft wheat, nevertheless, will retain to some extent the properties of representatives of the second phyogenetic branch. Therefore, the resulting homologue, first, should be easier to cross with soft wheat. Secondly, because of the different genetic material, we can hope for a greater heterosis effect and, to some extent, inheritance of immune characteristics of representatives of the second phylogenetic branch by such hybrids. Therefore, the resulting genetically different homologous form of soft wheat will be a valuable source material for breeding improvement of Triticum aestivum L. Previously obtained under the influence of N-NMU full homologue showed phenomenal both phenotypic and certain genotypic similarity with soft wheat. The purpose of this work is to obtain a homologous soft wheat form from Triticum kiharae Dorof. et. Migusch (A<sup>b</sup>A<sup>b</sup>GGDD) under the influence of a cheaper and more affordable mutagen - colchicine. Materials and methods. The work on obtaining the homologue was carried out on the basis of a collection of wheat species available in the Federal Rostov agricultural research center, in the conditions of the Azov zone of the Rostov region. The seeds of the original T. kiharae were treated with 0.05% colchicine solution for 12 hours and then, after washing, sown. Results and discussion. During the next re-sowing of treated seeds in M<sub>3</sub>, a plant was found that was characterized by a bluish waxy coating, from the seeds of which a homologous form of soft wheat was obtained in the fourth generation. To prove the homologous soft wheat form, it was compared with the original T. kiharae and samples of T. aestivum in the corresponding phenotypic series, placing them according to the law of homologous series of hereditary variability. There were marked differences between the original T. kiharae and received by macromutation according to the structure of the ear, the ears and the shape of grains. So the ear of the homologous form is wider. Its awns diverge, which is a feature of soft wheat. The spikelets are much wider than those of T. kiharae , which is due to the large number of grains in them. They are quite similar in shape to soft wheat grains, whereas the original T. kiharae have more elongated and not as rounded. In the spikelets of the homologous form, three spines are clearly visible, while the original form has two, and the third is slightly pronounced. The spikelet scales of T. kiharae are more rigid than those of the homologue and the latter has a better threshing. At the same time, there is no special doubt about the origin of the alleged homologue from T. kiharae , since there are signs characteristic of the original wheat species. The awns are also black, only the tips are slightly lighter than those of T. kiharae . In the homologue, the pubescence of the ears is quite clearly expressed and the nervation on the spikelet scales characteristic of T. kiharae is well observed. If you divide T. kiharae and the resulting soft wheat homologue in the corresponding phenotypic series, according to the law of homologous series, you can clearly see the external similarity of the spelt spelt spiny and non-spiny, as well as their homologue T. kiharae , which make up one phenotypic series, and the resulting homologue fits perfectly into the series with samples of soft wheat. If you place T. kiharae and obtained from him a homologue of wheat in their respective phenotypic ranges, according to the law of homological rows, is clearly seen the resemblance of the ears of spelt, bearded and unbearded, and their homolog in T. kiharae constituting a single phenotypic number and the homologue fits into a number of samples of soft wheat. In T. kiharae and its homologue T. spelta , the coefficient of specific productivity (Csp) is close to T. miguschovae and significantly less than in soft wheat samples, which serves as additional evidence of its incomplete homology with soft wheat samples. As well as the original, T. kiharae A<sup>b</sup>A<sup>b</sup>GGDD phenotypically corresponded to samples of T. spelta L. A<sup>u</sup>A<sup>u</sup>BBDD, the resulting homologue clearly fit into the series with samples of soft wheat. Moreover, the coefficient of specific productivity (Csp), which characterizes the ratio of the mass of grain from the ear to the vegetative mass of the shoot in the resulting homologous form, clearly corresponded to a similar indicator of soft wheat samples and significantly exceeded that of the original form, which further confirms the fact of creating a homologue of soft wheat. Conclusions. Based on the fact of creating a complete homologue of T. aestivum from T. kiharae under the influence of N-NMU, a homologous form of soft wheat was obtained, but after processing the seeds of the latter with colchicine. The resulting form (homologue) in its phenotype almost corresponds to samples of soft wheat, while retaining some of the characteristic features of the original speltoid species T. kiharae. Accordingly, according to its production characteristics, the homologous form is clearly at the level of those of soft wheat. Thus, once again, a kind of resynthesis of soft wheat from the speltoid form is confirmed, that is, one of the possible ways of origin of T. aestivum is shown. At the same time, given the different genetic material of the homologous form, it seems to be a fairly valuable source material for selection.