Evaluation of drought tolerance indices for barley landraces under irrigated and dry conditions / Avaliação de índices de tolerância seca para terraços de cevada em condições irrigadas e secas

Barley cultivation for drought areas requires a reliable assessment of drought tolerance variability among the breeding germplasms. Hence, 121 barley landraces, advanced breeding lines, and varieties were evaluated under both moisture non-stress and stress field conditions using a lattice square (11×11) design with two replications for each set of the trials. Twelve drought tolerance indices (SSI, TOL, MP, GMP, STI, YI, YSI, HM, SDI, DI, RDI, and SSPI) were used based on grain yield under normal (Yp) and drought (Ys) conditions. Analysis of variance showed a significant genetic variation among genotypes for all indices except for TOL and SSPI indices. Yp had a very strong association with Ys (r = 0.92**) that indicates high yield potential under non-stress can predict better yield under stress conditions. Yp and Ys were positively and significantly correlated with MP, GMP, STI, YI, HM, and DI indices, whereas they were negatively correlated with SSI and SDI. In principal component analysis (PCA), the first PC explained 64% of total variation with Yp, Ys, MP, GMP, STI, YI, HM, and DI. The second PC explained 35.6% of the total variation and had a positive correlation with SSI, TOL, SDI, and SSPI. It can be concluded that MP, GMP, STI, YI, HM and DI indices with the most positive and significant correlation with the yield at both non-stress and stress environments would be better indices to screen barley genotypes, although none of the indices could undoubtedly identify high yield genotypes under both conditions.

O cultivo de cevada para áreas secas exige uma avaliação confiável da variabilidade da tolerância à seca entre os germoplasmas reprodutores. Assim, 121 linhagens crioulas de cevada (linhas de reprodução avançada e variedades) foram avaliadas em campo sob condições sem estresse e com estresse de umidade do solo, utilizando-se para isso um arranjo experimental de malha quadrada (11×11), com duas repetições para cada conjunto de ensaios. Foram utilizados 12 índices de tolerância à seca (SSI, TOL, MP, GMP, STI, YI, YSI, HM, SDI, DI, RDI e SSPI), com base no rendimento de grãos sob condições normais sem estresse (Yp) e com estresse de seca (Ys). A análise de variância mostrou uma variação genética significativa entre os genótipos para todos os índices, com exceção dos índices TOL e SSPI. Yp teve uma associação muito forte com Ys (r = 0,92**), o que indica que o potencial de alto rendimento sob condições sem estresse pode prever melhor rendimento sob condições de estresse. Yp e Ys foram positivamente e significativamente correlacionados com os índices MP, GMP, STI, YI, HM e DI, enquanto, foram correlacionados negativamente com os índices SSI e SDI. Na análise de componentes principais (PCA), o primeiro PC explicou 64% da variação total com Yp, Ys, MP, GMP, STI, YI, HM e DI. O segundo PC explicou 35,6% da variação total e apresentou correlação positiva com SSI, TOL, SDI e SSPI. Pode-se concluir que, os índices MP, GMP, STI, YI, HM e DI com a correlação mais positiva e significativa com a produção nos ambientes sem estresse e com estresse seriam melhores índices para a seleção de genótipos de cevada, embora nenhum dos índices pudesse concretamente identificar genótipos de alto rendimento sob ambas as condições.

Assessment of Genetic Diversity for the Properties Related to the Quality of Hexaploid Bread Wheat (SeriM82 / Babax) under Drought Stress

In order to study the diversity of related characteristics of bakery quality in 167 bread wheat genotypes (SeriM82 / Babax), along with their parents, were evaluated based on two replications. The measured traits including protein content, zeolite sediment volume, bread volume, moisture content, grain hardness, water absorption, wet gluten, gluten index, gluten elasticity, Sodium dodecyl sulfate (SDS) sedimentation volume and quantitative trait of 1000 seed weight according to standards International. After analysis of variance, the data of the experiments and the comparison of the meanings were performed using multivariate methods, cluster analysis and factor analysis, genotyping grouping and the relationship between the variables (traits). The result of variance showed that genotype was significant for protein, bread volume, wet gluten, gluten index, sedimentation of sodium dodecyl sulfate and 1000 grain weight at 1% level. Factor analysis from 11 traits examined, 4 factors with 60% variance, the first factor with variance of 27.48% including traits of protein content, zeolite sediment volume, bread volume, moisture content and water absorption, the second factor with variance of 4.8% Includes wet gluten characteristics, gluten elasticity, SDS sedimentation volume, third factor with 10.16% variance, including seed hardness and gluten index, and fourth factor with variance of 9.85% of 1000 seed weight. The results of factor coefficient evaluation indicate the importance of protein content traits, zeolite sediment volume, bread volume, moisture content and water absorption in selection of suitable genotypes for drought conditions. Based on cluster analysis (intra-group variance algorithm), genotypes were divided into eight groups, the fifth group had high baking quality and could be used in breeding programs to improve the quality of baking.