GROW-OUT AND CHEMICAL TESTS FOR GENETIC PURITY AND RELATED TRAITS OF WHEAT (Triticum aestivum L.) VARIETIES FROM SEEDS OF DIFFERENT SOURCES AT DURAME, SOUTHERN ETHIOPIA

Abstract

Wheat is a food security crop and seed supply of improved varieties has given attention to boost production and ensure food sovereignty in Ethiopia. The seed suppliers focused on ensuring the physical purity and germination of wheat seed and less attention to genetic purity that has direct effect on ultimate yields. This research was conducted to evaluate bread wheat varieties for seed quality, yield, and yield-related traits, and determine the varieties genetic purity of different seed sources. The seeds samples of Kakaba and Kingbird varieties were obtained from Kulumsa Agricultural Research Center, Ethiopian Agricultural Business Corporation, Faris Abdela Seed Producer, and South Seed Enterprise. The eight treatments in factorial combination evaluated at field in randomized complete block design with three replications at Durame. Sodium Hydroxide (0.5% NaOH), Potassium Hydroxide (0.5% KOH), Phenol Acid (1% C6H5OH) and Gibberellic Acid (100ppm GA3) were used for genetic purity test. The physical, physiological and chemical tests were conducted in completely randomized design with three replications at Durame Plant Seed Quality Testing Laboratory and Seed Quality Testing laboratory of Haramaya University, respectively. The collected seed samples of the two varieties had 99.59, 12.79 and 88.5% mean physical purity, moisture content and germination, respectively, and hundred seeds weight of 35.64g. Seed source, variety and interaction of the two factors significantly influenced most of the phenology and growth traits, yield components, seed yield, seed physical and physiological quality parameters. Moreover, the seed yield of the two varieties produced from seeds obtained from four seed sources ranged from 5.54 to 6.43 t ha-1 that the lowest and highest yield was obtained from Kingbird and Kakaba varieties produced from seeds obtained from Ethiopian Agricultural Business Corporation and Kulumsa Agricultural Research Center, respectively. The two varieties produced higher seed yield from seeds obtained from Kulumsa Agricultural Research Center than seeds obtained from other seed sources. The off-types for Kakaba and Kingbird varieties ranged from 0.16-0.7% and 0.18-0.85%, respectively, and the mean off-types for two varieties was lowest (0.17%) and highest (0.78%) in plants grown from seeds obtained from Kulumsa Agricultural Research Center and Faris Abdela Seed Producer, respectively. The normal seedlings germination and speed of germination ranged from 92 to 97.33% and 24.133 to 26.6, respectively, whereas seedling vigour index I and II ranged from 2247 to 2974 and 37.33 to 49.32, respectively. The seeds of the two varieties produced from seeds collected from Kulumsa Agricultural Research Center had highest mean values for all seed quality parameters. The seeds showed reactions to all chemicals, of which 1.32% to 6.68% seeds had light brown color as reaction to 5% NaOH, 0 to 5.33% and 94.67 to 100% seeds develop dark brown color as reaction to 0.5% KOH and 1%C6H5OH, respectively. The seedlings that had >25% length above the seedlings length at control ranged from 8.14 to 19.2% as response of GA3 at 100 ppm concentration. The results showed the seeds obtained from Kulumsa Agricultural Research Center better perform for all parameters than other seed suppliers. Therefore, It is essential that seed production, processing, and storage adhere strictly to the existing seed certification scheme in order to produce and market quality seeds that meet the required standards.