Multi-Trait Selection Index for Simultaneous Selection of Water Yam (Dioscorea alata L.) Genotypes

Abstract

Water yam (Dioscorea alata L.) is the most widely cultivated yam species with good agronomic attributes. However, several biotic and abiotic constraints and its lower food quality such as poor pound ability limit its production and use. Therefore, the identification of superior genotypes with suitable characteristics is needed for water yam improvement. This study aims to assess a panel of half-sib (progenies with one parent in common) and full-sib (progenies with the same male and female parents) progenies as well as their parents for selection of desirable ideotypes based on their agronomic and quality characteristics. A total of 280 progenies from bi-parental populations as well as five parents were evaluated, and a significant variation was observed (p < 0.01) in their performances for the eight traits used in the study. A moderate to high broad-sense heritability (30% < H2–H2 ≥ 60%) was observed for all traits except for tuber pound ability (H2 < 30%). Positive correlations were displayed between the traits, while the hierarchical clustering grouped genotypes into three clusters indicating the potential for selection of diverse genotypes for multiple traits from the four families under study. Plant vigor and number of tubers per plant contributed (p < 0.01) positively to the yield per plant in the path coefficient analysis. Using the multi-trait genotype–ideotype distance index (MGIDI), a total of 39 most promising genotypes were identified. These promising genotypes could be further used as progenitors in D. alata improvement programs targeting good agronomic and quality traits targeted for farmers and end users.

Genetic Analysis in Crops

“…However, various biotic and abiotic stressors impose constraints, leading to low yields and inferior tuber quality in water yam production. Ouattara et al conducted a comprehensive analysis of 285 water yam genotypes, evaluating eight key traits through ANOVA and PCA [12]. They explored the interrelationships among agronomic and tuber quality traits using Pearson's correlation coefficients, revealing noteworthy findings.…”

“…A positive correlation emerged between tuber yield per plant and both plant vigor and the number of tubes per plant. Conversely, a significant negative correlation was observed between the dry matter content and tuber yield per plant, as well as tuber oxidation browning and boiled tuber quality [12]. Identifying superior genotypes possessing favorable characteristics is pivotal for enhancing water yam cultivation.…”

“…Moreover, analysis using the multi-trait genotypeideotype distance index (MGIDI) highlighted four traits exhibiting desired genetic gains across all families, including plant vigor, number of tubers per plant, yield per plant, and dry matter content. Conversely, yam anthracnose disease, tuber oxidation browning, boiled yam quality, and pounded yam quality displayed undesired gains in selection across the families [12]. These promising genotypes and traits hold potential as valuable contributors to water yam improvement programs, catering to the needs of both farmers and end users by enhancing agronomic and quality traits.…”