PRIMARY ROOT SYSTEM IN SOFT WHEAT VARIETIES DIFFERING IN MATURITY AND DROUGHT RESISTANCE
The primary root system in spring soft wheat varieties differing in a year of seed reproduction, maturity, and drought resistance was studied in the steppe zone of Altai Territory. A field experiment was conducted in 2010-2012. The object of research included 12 cultivars of spring soft wheat. It has been found that the variety factor accounts for 45% of the total variation in primary root length, the year factor 21%, and year-variety relationship is statistically insignificant. The medium-late varieties are characterized by the well-developed primary root system. The drought-resistant genotypes have the largest number of primary roots. No significant correlation between thousand-kernel weight and the number and length of primary roots was found. The length and the number of primary roots in spring soft wheat considerably depend on weather conditions, when grain formation takes place. The seeds derived from plants subjected to droughts in the second half of growing period form a short primary root system as compared with plants, grain formation of which occurs in moisture abundance. The varieties with prolonged ontogenesis have the well-developed primary root system. The drought-resistant genotypes germinate with the larger number of primary roots than nonresistant ones do, but catch up with them as to the total length in 7 days.