Evaluation of 17 sweet potato (Ipomoea batatas L.) genotypes across five environments for high yield and stability

Abstract

The study was carried out in five regions of Bangladesh—Gazipur, Bogura, Jamalpur, Jashore, and Chattogram—utilizing a randomized complete block design and involving 17 genotypes of sweet potatoes. The objective was to evaluate their performance, environmental adaptability, and stability in terms of root yield. The analysis was carried out using fixed and random effects models. The results revealed that BARI Mistialu-12 had the highest storage root yield (45.35 t/ha). Among the locations, Bogura (sandy loam soil) achieved the highest yield, at 37.05 t/ha, followed by Jamalpur (36.15 t/ha). ANOVA showed significant variation in root yield across genotype, environment, and their interaction (GEI). Both the additive main effects and multiplicative interaction (AMMI) effect models and a linear mixed model (LMM) confirmed substantial GEI variance. Considering LMM, 53.58% of the total variation was due to genotypes, with a selection accuracy of 94%, leading to the use of a best linear unbiased prediction (BLUP) index for genotype selection. BARI Mistialu-12, BARI Mistialu-16, BARI Mistialu-11, BARI Mistialu-8, BARI Mistialu-2, and BARI Mistialu-13 were identified as high-performing genotypes in the BLUP index. Based on the AMMI stability value (ASV), the first two principal components explained 74.60% of the total GEI variance (20.16%), with BARI Mistialu-14 being the most stable genotype. Additionally, the interaction principal components axis analysis identified Bogura, Jashore, and Chattogram as key testing sites for root yield. The weighted average of absolute scores biplot highlighted BARI Mistialu-16 as the most stable variety. In the megaenvironment analysis, BARI Mistialu-11 and BARI Mistialu-2 excelled in Jamalpur, while BARI Mistialu-12 and BARI Mistialu-16 led in Gazipur, Bogura, and Jashore. Bogura was the best location for production. These findings are crucial for future breeding efforts to expand the sweet potato industry, demonstrating consistent high-yield potential across various agroecological conditions.