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The introduction of dwarfing genes triggered a wave of "green revolution". A number of wheats dwarfing genes have been reported in previous studies, and only a small fraction of these have been applied to production practices. Therefore, the development of novel dwarfing genes for wheat is of great value. In this study, a novel dwarfing site, Rht-yz, identified in the Yanzhan mutation, is located on chromosome 4B (30-33MB) and its mechanism of action is different from that of Rht-B1b (C-T mutation), but whether it affects the Rht-B1a (TraesCS4B02G043100) or other genes is unclear. Exogenously applied GA3 experiments showed that Rht-yz is one of the gibberellin-insensitive dwarf genes. The effects of the dwarf gene Rht-yz on agronomic traits in wheat were evaluated in the field using Yanzhan, Yanzhan mutations, F2:3 and F3:4 lines. The results showed that Rht-yz improved lodging resistance by reducing plant height, increasing diameter, wall thickness and mechanical strength of the basal stem. In terms of yield traits, Rht-yz had negative effects on tiller number plant-1, biomass plant-1 and yield plant-1, but had no significant effect on harvest index, 1000-kernel weight and spike traits. In addition, Rht-yz significantly increased crude protein, wet gluten and starch content. Therefore, the rational use of the new dwarfing site Rht-yz has potential and value in dwarf wheat breeding. [ABSTRACT FROM AUTHOR]

Stem and leaf rust have a tremendous impact on wheat yields. The spread of these diseases can compromise any country’s food security. The Sr and Lr resistance genes, comprising 60 and 80 genes, respectively, are gradually losing their effectiveness due to the emergence of virulent populations of rust pathogens. This research reports the results of field and molecular studies of resistance to the two types of rust in several varieties and lines of spring soft wheat. It is discovered that the Sr2, Sr21, Sr32, and Sr35 genes have virtually no effect on resistance to stem rust, as with an average plant disease severity of 42.2% the four genes proved ineffective. However, the area under the disease progress curve in the presence of Sr2 was reliably lower by 3.2% (p < 0.01). Regarding the coefficient of infection, susceptibility in the presence of Sr21 or Sr35 was reliably lower by 3.5%. The Lr19, Lr24, Lr27, and Lr39 leaf rust genes retain their positive effect on wheat resistance to the disease. The Lr19 and Lr39 genotypes showed moderate resistance in 100% of the cases. The average coefficient of infection in the presence of both genes amounted to 6.5 units, with an average plant disease severity equal to 16.3%. The Lr39 gene reliably reduced the area under the disease progress curve by 4.5 units. The obtained findings indicate the need to identify donors of Sr resistance genes for their use in selection. There is also a need to study the influence and prevalence of the Lr24 and Lr27 genes in different varieties and lines of spring soft wheat. [ABSTRACT FROM AUTHOR]

Colchicine is a substance used to induce mutations in order to regulate important agronomic traits. The genotypes Pavlodarskoe 4, Quartet, and PI 289324, originating from Kazakhstan, the Russian Federation, and Hungary, respectively, were used as materials. The objective of this study was to investigate the effects of different colchicine concentrations (0.0, 0.04, 0.06, 0.08, and 0.1%) and treatment times (6, 12, and 24 h) on the agronomic traits of proso millet (Panicum miliaceum L.) and to assess the genetic diversity of the M2 generation using inter simple sequence repeat (ISSR) markers. The experiment was conducted in 2021 for the M1 generation and in 2022 for the M2 generation, from May to September. The percentage of field germination decreased with increasing colchicine concentrations and exposure durations. The mean field germination percentages were 48.57% in Pavlodarskoe 4, 43.28% in Quartet, and 53.14% in PI 289324 under colchicine treatment. Chlorophyll-defective M1-M2 plants were obtained using various colchicine concentrations and exposure periods. The highest number of mutational modifications was attained with the 0.08–0.1% concentrations of colchicine. Based on the research results, a total of 248 plants with chlorophyll-defective mutations were selected from 2214 plants. The growing seasons of M1 and M2 plants were shortened by higher colchicine concentrations (0.08–0.1%) combined with soaking times of 12 and 24 h. Thus, the longest growing season (84 days) was observed with a 6 h treatment time for PI 289324, while the shortest (78 days) was recorded for 12 and 24 h treatments. The possibility of obtaining morphological mutations using colchicine has been confirmed. The ISSR primers amplified a total of 1333 fragments; 1281 bands were found to be polymorphic, and 52 bands were monomorphic. The percentage of polymorphism varied from 80 to 100%, with an average of 96.11%. Most of the different allelic bands were detected when applying the 0.08% colchicine concentration. These positive variations are a great opportunity to use colchicine as a tool for improving agronomic traits in plant breeding. [ABSTRACT FROM AUTHOR]