Soybean (Glycine max L.) is one of the most essential sources of high-grade protein and oil. Although growing soybeans can occur in different environmental conditions and are very productive in warm temperatures, their cultivation in cold climates, including Northern Kazakhstan, leads to considerable yield losses. The presented study sought to investigate soybean cultivars growing in the cold climate of northern Kazakhstan and find the optimal ratio of the growing season duration and crop yields. Soybean productivity and the cropping season length revealed a significant negative correlation. Early flowering is one of the relevant approaches for reducing the growing season and improving soybean seed production. A MADS-box SEPALLATA3 (GmSEP3) gene expression, known to promote regular and early flowering, received analysis. The GmSEP3a expression in soybean cultivars with high yield was also valid, with a significant positive correlation between GmSEP3a expression and soybean yield. The soybean cultivars, viz., Suiyang 1, Sibiryachka, No. 86, Niva, and Beidou 43 surfaced as high-yielding cultivars under environmental conditions of Northern Kazakhstan. The pertinent study revealed that the GmSEP3a gene can become a gene marker for screening early-ripening soybean cultivars with high yields in low-temperate climates. The promising results can also help identify potential soybean cultivars for cold-weather cultivation.
Soybean (Glycine max L.), early maturing cultivars, growing season duration, productivity, plant height, transcription factors, warm and cold climate
The study highlights the need to enhance soybean yields in Kazakhstan, focusing on early ripening cultivars. The GmSep3a gene correlates with high yields and early ripening, offering a potential genetic marker for breeding. Among 90 cultivars analyzed, only five exceeded 10 t/ha, which shows promise for further improvement. This gene marker could aid in developing soybean cultivars suited for cold climates like Kazakhstan.