Peculiarities of creation of soybean breeding material in the southern Steppe of Ukraine

Abstract

Peculiarities of soybean hybridization in the Southern Steppe of Ukraine are described. Advantages of using natural transpollination of lines with gene pollen sterility to increase the number of hybrid plants are shown. Some drought-resistant forms with a set of valuable traits were found in the collection.

The aim and tasks of the study. To improve the effectiveness of hybridization, to increase the hybrid plant number, to screen the soybean collection for forms that would be adapted to dry conditions and have a set of valuable agronomic and biochemical features.

Material and methods. The investigation was carried out in the experimental field of Plant Breeding and Genetics Institute (the South of Odessa region). Every year, about 1,000 soybean collection accessions were examined. The main criteria for selection of parents were yield capacity, drought resistance and biochemical parameters. Seeds of female sterile lines with pollen sterility genes (msp, ms₄, ms₁Urbana or ms₁Tonica) mixed with seeds of domestic high-yielding varieties were planted in 10-rowed plots for natural hybridization.

Results and discussion. The dry environment of the Southern Steppe of Ukraine makes soybean crossing very difficult. To increase the hybrid number, we carried out both artificial and natural hybridization using lines with gene pollen sterility. Natural pollination was carried out using lines with pollen sterility genes. This approach increases the hybrid plant number about by 6 times. Homozygous fertile families are selected from hybrid progeny. Using this approach, we bred variety ‘Farvater’, which is listed in the State Register of Plant Varieties of Ukraine.

Over more than 30 study years, we investigated about 6,000 soybean collection accessions and selected the most adapted to our environment forms, which we recommend as starting material for breeding drought-resistant varieties that would be adapted to the steppe zone. Among these forms, there are varieties ‘Yug30’, ‘Medeia’, ‘Vorskla’, ‘Ahat’, ‘Sprint’, ‘Ametist’, ‘Romantyka’, ‘Valiuta’, ‘Yuvileina’, ‘Altaiir’, ‘Melpomena’ with yield capacity exceeding the standard in dry conditions. ‘Sakamoto wase’ (Japan), ‘Ussuriyskaya670’(Far East, Russia) and ‘Ke-Shuan’ (China) had increased protein content in seeds (45.4, 43.9 and 42.4%, respectively). Crossing accession VIR 5048 (Kazakhstan) with Ukrainian variety ‘Medeia’ generated a series of highly productive breeding lines with protein content of 43-46%. Ukrainian varieties ‘Odeska150’, ‘Melpomena’, ‘Feniks’, ‘Anatoliyivka’, ‘Oksana’, ‘Berehynia’ were noticeable for increased protein content. The average protein content was 41-42%, but in some years it reached 46%.

Contents of trypsin and lypoxygenase inhibitors in seeds were very variable. ‘Yuvileina’, ‘Donka’ and ‘Znakhidka’ had the lowest amounts of trypsin inhibitors (28.6-36.1 mg/kg), and ‘Ustia’, ‘Eldorado’, ‘Romantyka’, ‘Kyivska98’, and ‘Yug30’had decreased activity of lypoxygenase (0.33-0.38 Units).

Conclusions. We demonstrated that natural hybridization based on pollen sterility genes increased the hybrid number by 6 times in comparison with manual crossing. Varieties and collection accessions with high productivity parameters, high protein content and other economically valuable features were selected in dry years