Chebotar G. Alleles of dwarfing genes Rht8, Rht-B1, Rht-D1, photoperiod insensitivity Ppd-D1 of bread wheat and their effects on the agronomic traits

Object: genetic determination of agronomic traits of cereal. Aim: установить аллельное состояния генов короткостебельности Rht8, Rht-B1, Rht-D1 и Ppd-D1 у современных сортов и линий-аналогов мягкой пшеницы, изучить их эффекты на агрономические признаки и определить аллели гена Ppd-D1 у образцов Aegilops tauschii Сoss. Methods: methods of DNA isolation, PCR analysis, electrophoresis in polyacrylamide and agarose gels, sequencing, hibrydolodgy and statistical analysis, field observation. Novelty: presents the identification of alleles of Rht8, Rht-B1, Rht-D1, Ppd-D1 genes and their complexes in modern winter and spring wheat varieties. The genetic distance between Rht8с and Ppd-D1а in the haplotype of Ukrainian varieties has been clarified. A new structure variant of Ррd-D1b allele was identified in the Ae. tauschii Coss. accessions. The molecular structure of the new allelic variant with amplification product size of 429 bp was sequenced. Results: it was shown that the presence of Rht8c, Rht-B1b, Rht-B1e and Rht-D1b genes reduced plant height by 14%, 19%, 31% and 16% at the average, as well as the coleoptile length (P = 0,01). The presence of Rht-B1e or Ppd-D1b alleles in a genotype can lead to the reduction of productive tillering. The plants that carried one (Rht8c – middle height) and two (Rht8c+Rht-B1e, Rht8c+Rht-B1b, Rht8c+Rht-D1b – semidwarf) dwarfing genes did not significantly differ in ear length, but their ear length was lower than that of the tall parents. Such a decrease in ear length did not affect the number or mass of grains per plant by increasing ear density. The tendency towards reduction of the number of sterile flowers was observed. 1000-grain weight and grain size were much more dependent on the vegetation conditions than on the number and quality of dwarfing genes of the genotype. Application stage: the results of investigations using in the lessons on biology of Odesskiy national university name I.I. Mechnikov. Application area: SIE of NAAN, research establishments and high school of MES and NAS of Ukraine.