No abstract

A multi-locations' experiments were carried out from 2018 to 2019 main cropping seasons in moisture stress areas of Ethiopia to estimate the genotype x environment interaction and to select stable and adaptable variety/ies for grain yield of bread wheat. The genotypes consisted of 23 genotypes and two standard checks arranged in alpha lattice design replicated three times. Data were taken for agronomic traits and diseases. Analysis of variances and stability analysis were carried out for grain yield using R software. Combined analysis of variance showed a highly significant (p≤0.01) difference among the genotypes, locations, and GEI for grain yield suggesting a differential response of genotypes across testing environments. The grand mean yield over nine environments was 5251.90 kg ha -1 and the mean yield of genotypes across nine environments ranged from 1539.29 kg ha -1 in 2018 at Dhera to 7621.87 kg ha -1 in 2018 at Kulumsa, respectively. The recorded mean yield of the standard check Deka (5066.543 kg ha -1 ) and Ogolcho (4018.39 kg ha -1 ) was below the grand mean yield of genotypes across environments. The Genotypes ETBW 9136 (5731.79 kg ha -1 ), ETBW 9139 (5844.87 kg ha -1 ), ETBW 9646 (5754.01 kg ha -1 ), ETBW9172 (5634.01 kg ha -1 ), ETBW9641 (5545.03 kg ha -1 ), ETBW 9080 (5545.31 kg ha -1 ) and ETBW9396 (5467.04 kg ha -1 ) gave the highest mean grain yield across environments, whereas the standard check Ogolcho recorded lowest mean grain yield across environments. The first four principal components of the GEI explained 85.6% of the variation. Additive main effects and multiplicative interaction (AMMI) stability parameters revealed that the genotypes ETBW 9080 (G11), ETBW 9172 (G12), ETBW 9646 (G19), ETBW 9396 (G13), ETBW 9452 (G14), ETBW 9136 (G5) and ETBW 9139 (G6) were high yielder and more stable inferring little interaction of genotypes with the environment whereas Ogolcho (G25), ETBW 9119 (G3), ETBW 9647 (G20) and ETBW 9065 (G8) was low yielder and unstable suggesting high interaction with the environments. Based on stability parameters and other agronomic traits, the genotypes viz. ETBW 9396 (G13) and ETBW 9080 (G11), were proposed for variety verification and possible release in 2021.

A multiplications evaluation was conducted with twenty-eight advanced bread wheat genotypes and two standard checks for two consecutive years 2017 and 2018 at Kulumsa, Asasa, Robe Arsi, Bekoji, Areka, Shambu, Holeta, Adet, Enawari, Awalgera, and Debra Zeit, Ethiopia. The objective of the paper was to describe the agronomic and quality related traits of newly developed bread wheat varieties “Boru” for optimum moisture areas of Ethiopia. Boru is a commercial name given for a newly released variety with the pedigree name SAUAL/MUTUS/6/CNO79//PF70354/MUS/3/PASTOR/4/BAV92*2/5/FH6-1-7/7/CNO79//PF. 70354/MUS/3/PASTOR/4/BAV92*2/5/FH6-1-7 which originated from CIMMYT germplasms. Boru is adapted within the range of altitude 2050 to 2780 masl with annual rainfall amount receiving from 620 to 1290 mm. Boru showed superior overall agronomic performances over the standard check Wane and Hidasse and it had a 9% and 14% yield advantage respectively. The new variety had a bold seed size than the two checks. Boru variety showed relative resistance to stem, yellow and leaf rust as compared to wheat varieties under production at the medium to high land wheat-growing agro-ecologies. Boru offers new hope for resource-poor farmers in rust-prone areas of Ethiopia.  It’s expected to replace the variety ‘Ogolcho’ in medium areas, and ‘Hidasse’ in high land areas of Ethiopia. In addition, the Boru variety is known for its higher protein content (14.37%) than standard check Wane (12.14%) and local check Hidasse (12.3%).

Plant diseases are among the major factors affecting the yield of wheat, especially rust diseases have historically been one of principal biotic production constraints in the world. Among the three main rusts affecting wheat, yellow rust, caused by Puccinia striiformis f. sp. tritici, and Stem rust caused by Puccinia graminis f. sp tritici are the most important disease in most wheat growing areas of Ethiopia. There are a limited number of resistant varieties available and new pathotypes that overcome the most widely deployed genes have arisen. The development of improved varieties of bread wheat (Triticum aestivum L.) has always remained a focal point for wheat breeders. Therefore, the purpose of this study was to select genotypes with good agronomic performance that have high grain yield and yield component with better rust resistance especially for stripe and stem rusts which are the major diseases in Ethiopia and to recommend the best genotypes to be released as new varieties and as an initial material in breeding. Twenty-Eight genotypes with two checks were evaluated in consecutive two years. From the twenty-eight tested genotypes almost all genotypes except one (ETBW9589) showed higher grain yield than the two standard checks (Kingbird and Ogolcho). But for the case of both rust diseases as AUDPC and CI showed that tested genotypes were exhibited different reaction responses, if we see one genotypes as an example ETBW9578 had the highest grain yield and good for yellow rust but as AUDPC showed it is very susceptible reaction response for stem rust. Generally phenotypic variation was observed for infection types, level of severity and reaction response for both diseases of the 28 tested elite bread wheat genotypes and the two standard checks. Reaction response for stem rust exhibited from susceptible (S) to Moderately resistance-moderately susceptible (M) and from immunity (0) to moderately resistance (MR) for the yellow rust. Around nine genotypes had good performance for all parameters; for grain yield and yield components and also for both rust diseases. The results of current study indicated that the genotypes had diversity regarding resistance reaction, ranging from complete resistance to susceptible. Most of the evaluated genotypes exhibited moderate resistance (MR) to moderately susceptible (MS) reactions under high disease pressure.