Short Communication: Evaluation of drought tolerance indices for genotype selection of foxtail millet (Setaria italica)

Lapuimakuni S, Khumaida N, Ardie SW. 2018. Evaluation of drought tolerance indices for genotype selection of foxtail millet (Setaria italica). Trop Drylands 2: 37-40. Foxtail millet (Setaria italica (L.) Beauv) is one of underutilized crop grown for its nutritious grain and its relative tolerance to drought stress. Although foxtail millet has been reported as to be relatively tolerant to drought stress, the drought tolerance level of this crop is varied between genotypes. Thus, breeding approaches to develop drought-tolerant foxtail millet variety is of great importance. This study aimed to: (i) evaluate several drought tolerance indices to determine one or more predictors among studied indices, and (ii) identify the drought tolerance level of the evaluated foxtail millet genotypes. Eight foxtail millet genotypes were planted in a greenhouse with a completely randomized design and five replications under both drought and normal watering conditions. Staggered planting was applied to synchronize flowering time. Water was withheld for 15 days during the flowering period, and then plants were re-watered until harvest time. Multiple indices for drought tolerance were calculated based on the potential yield (Yp) under non-stress and yield (Ys) under stress conditions. Based on the correlation, principal component analysis, and cluster analysis, yield index (YI) and harmonic mean (HM) were considered the best indices for the selection of drought-tolerant foxtail millet genotypes. By using the best indices, two foxtail millet genotypes (ICERI-5 and ICERI-6) were considered as drought tolerant genotypes.