Screening and Identification of Sugar Beet Drought Tolerant Diploid Pollinators under Field Conditions

Water shortage is one of the important factors limiting agricultural productivity in arid and semi-arid regions of the world. Introduction of improved varieties for these regions is of a high importance. In this research, 46 sugar beet pollinators (half-sib families) along with two conventional checks (Jolgeh and Gadouk) and a drought tolerant hybrid (IR7) were evaluated in a 46-genotype experiment based on randomized complete block design with 6 replications in one-row plots of 7m length under drought stress condition. The seeds of the families were sown in the filed in April 2012 at Motahari Research Station, Karaj, Iran. The irrigations were done as usual based on 90 mm evaporation from the class A evaporation pan until the thinning and weeding (establishment) stage. Subsequent irrigations were applied on the basis of 200 mm evaporation from the pan. During the growing season, characters such as the number of the established plants and wilt score were recorded. After harvest, the quality analysis was performed and the best family was identified. Results of analysis of variance showed that the genotypes were significantly different for root yield, sugar yield and white sugar yield but their differences were not significant for the quality characters. Mean comparison of the traits displayed that the half-sib family 12 (AR-F3-17-HSF.8) produced the highest root yield and sugar yield compared with the other families and its difference with the drought tolerant check (IR7) for root yield was significant at 5% probability level. Considering the lower sugar content of this family (12.85%) as compared with IR7 (13.17%), new half-sib families can be developed from this family and by selection for sugar content, this trait and hence sugar yield could be improved in the subsequent hybrids. Keywords: Drought stress, half-sib, pollinator, sugar beet :