Evaluation of physiological screening techniques for drought-resistant breeding of durum wheat genotypes in Iran

This paper summarizes the results of a project aimed to evaluate the use of physiological traits (such as canopy temperature and chlorophyll content) in determining drought tolerance of durum wheat genotypes under a variety of environmental conditions. Six durum wheat genotypes were planted in rainfed and supplementary irrigation conditions in Gachsaran of Iran for two years (2007 to 2009). Five drought tolerance indices including stress susceptibility index (SSI), stress tolerance index (STI), tolerance index (TOL), mean productivity (MP) and geometric mean productivity (GMP) were calculated. Canopy temperature depression (CTD) and chlorophyll content (CHL) was used to estimate crop yield and to rank genotypes. CTD and CHL were measured at three stages from emergence of 50% of inflorescence (Zadoks Growth Scale54) to watery ripe stage (ZGS71). Genotypes G5 (OUASERL-1) and G6 (Stj//Bcr/LKS41CD94) were superior genotypes for both environments with high PC1 and low PC2 in biplot analysis. The results of genotypes CTD in ZGS69 stage and CHL in grain filling stage had high significant differences. The significant and positive correlation of MP, SSI, STI, CHL and CTD showed that these indices were more effective in identifying high yielding genotypes under both conditions and the result showed that CTD and CHL played important roles to search for the physiological basis of grain yield of wheat and CTD and CHL can successfully be used as a selection criterions in breeding programs.Key words: Canopy temperature, chlorophyll content, drought stress, durum wheat

Stability analysis for seed yield of chickpea (<i>Cicer arietinum</i> L.) genotypes by experimental and biological approaches

A range of environmental factors restricts the production of chickpea; therefore, introducing compatible cultivars to a range of environments is an important goal in breeding programs. This research aims to find high-yielding and stable chickpea genotypes to rainfed condition. Fourteen advanced chickpea genotypes with two control cultivars were cultivated in a randomized complete block design in four regions of Iran during 2017–2020 growing seasons. The first two principal components of AMMI explained 84.6 and 10.0 % of genotype by environment interactions, respectively. Superior genotypes based on simultaneous selection index of ASV (ssiASV), ssiZA, ssiDi and ssiWAAS were G14, G5, G9 and G10; those based on ssiEV and ssiSIPC were G14, G5, G10 and G15 and those based on ssiMASD were G14, G5, G10 and G15. The AMMI1 biplot identified G5, G12, G10 and G9 as stable and high-yielding genotypes. Genotypes G6, G5, G10, G15, G14, G9 and G3 were the most stable genotypes in the AMMI2 biplot. Based on the harmonic mean and relative performance of genotypic values, G11, G14, G9 and G13 were the top four superior genotypes. Factorial regression indicated that rainfall is very important at the beginning and end of the growing seasons. Genotype G14, in many environments and all analytical and experimental approaches, has good performance and stability. Partial least squares regression identified genotype G5 as a suitable genotype for moisture and temperature stresses conditions. Therefore, G14 and G5 could be candidates for introduction of new cultivars

Food security through translational biology between wheat and rice

Wheat and rice are the most important food crops in agriculture providing around 50% of all calories consumed in the human diet. While both are C3 species, the evolution and domestication of wheat and rice occurred in very different environments, resulting in diverse anatomical and metabolic adaptation. This review focuses on the current understanding of their adaptation in an agronomic context. The similarities and differences between wheat and rice are discussed, focusing on traits related to phenology, photosynthesis, assimilate partitioning, and lodging resistance, these being the main abiotic drivers of yield expression in most agro‐ecosystems. Currently, there are significant knowledge gaps in the major biological processes that account not only for differential adaption among cultivars within each species, but even between the two species. By addressing what is known as well as where gaps exist in a comparative context, this review aims to highlight translational research approaches that could provide insights into the genetic improvement of both crops

Identification of mega-environments for grain sorghum in Brazil using GGE biplot methodology.

The performance of genotypes in a wide range of environments can be affected by extensive genotype × environment (G × E) interactions, making the subdivision of the testing environments into relatively more homogeneous groups of locations (mega-environments) a necessary strategy. The genotype main effects + genotype × environment interaction biplot method (GGE) allows identification of megaenvironments and selection of stable genotypes adapted to specific environments and mega-environments. The objectives of this study were to identify mega-environments regarding sorghum [Sorghum bicolor (L.) Moench] grain yield and demonstrate that the GGE biplot method can identify essential locations for conducting tests in different mega-environments. A total of 22 competition trials of grain sorghum genotypes were conducted over three crop seasons across several production locations in Brazil. A total of 25, 22, and 30 genotypes were evaluated during the first, second, and third crop seasons, respectively. After identifying the presence of G × E interactions, the data were subjected to adaptability and stability analyses using the GGE biplot method. A phenotypic correlation network was used to express functional relationships between environments. The GGE biplot was found to be an efficient approach for identifying three mega-environments in grain sorghum in Brazil, selecting representative and discriminative environments, and recommending more adaptive and stable grain sorghum genotype

Mediciones no paramétricas corregidas y sin corregir en ensayos multiambientales de estabilidad con trigo duro

This study was done to evaluate yield stability of 20 improved durum wheat genotypes (G1 to G20). Tests were done in a randomized complete block design with 4 replications for 3 years at 5 sites in multi-environment trials. Data were analyzed with the five nonparametric stability measurements of Thennarasu (NP) according to ranks of corrected and uncorrected procedures. Results for the combined analysis of variance for environment (E), genotype (G) and GE interaction was significant, suggesting different responses of the various genotypes in the study and the requirement of yield stability analysis. In this study, low values determined by uncorrected NPs (UNP2, UNP3, and UNP4) were associated with high mean yield, but other nonparametric stability measurements were not positively correlated with mean yield and were thus characterized as having a static concept of stability. Although, according to both corrected and uncorrected stability parameters, genotypes G7, G8, G13 and G14 were stable but only G7 flowing to G8 had high mean yields. Results of the factor analysis, Spearman's rank correlation and the bootstrap resampling procedure of the nonparametric stability measurements and mean yield indicated that using ranks of uncorrected data would be useful for simultaneous selection for both mean high yield and stability. In conclusion, according to results of these different nonparametric stability measurements, genotype G7 is recommended for commercial release as a favorable durum wheat genotype for the environmental conditions in Iran.Se estudi&oacute; la estabilidad del rendimiento de 20 genotipos mejorados (G1-G20) de trigo duro en un dise&ntilde;o en bloques completos al azar con 4 repeticiones de 3 a&ntilde;os en 5 ambientes diferentes. Los datos fueron analizados con las cinco medidas de estabilidad no param&eacute;tricas de Thennarasu (NP), de acuerdo a los rangos de los procedimientos corregidos y sin corregir. El an&aacute;lisis de varianza combinado para los ambientes (E), los genotipos (G) y la interacci&oacute;n GE fue significativo, lo que sugiere una respuesta diferencial de los genotipos y la necesidad de analizar el rendimiento de la estabilidad. En este estudio, se asociaron valores bajos de NP no corregidos (UNP2, UNP3 y UNP4) con un elevado rendimiento medio, pero las otras medidas no param&eacute;tricas de estabilidad no se correlacionaron positivamente con el rendimiento medio y se consideraron como concepto est&aacute;tico de estabilidad. Sin embargo, de acuerdo con los par&aacute;metros de estabilidad, tanto corregidos como sin corregir, los genotipos G7, G8, G13 y G14 se mantuvieron estables, pero solamente G7 y G8 tuvieron un elevado rendimiento medio. Los resultados del an&aacute;lisis factorial, de la correlaci&oacute;n de Spearman y del procedimiento bootstrap de nuevo muestreo de las mediciones de estabilidad no param&eacute;tricas y la media de rendimiento, indicaron que ser&iacute;a &uacute;til utilizar datos incorrectos no corregidos para seleccionar de forma simult&aacute;nea elevados rendimientos y estabilidad. En conclusi&oacute;n, de acuerdo con los resultados de las diferentes mediciones de estabilidad no param&eacute;tricas, se recomienda el genotipo G7 de trigo duro para su uso comercial como el m&aacute;s favorable en Ir&aacute;n

Determining heritability, reliability anD stability of grain yielD anD yielD-relateD components in Durum wheat (TriTicum durum l.)-607 Agricultural Academy

abstract KaRimizadeh, R., m. mohammadi, m. aRmion, m. K. Shefazadeh and h. ChalajouR, 2012. determining heritability, reliability and stability of grain yield and yield-related components in durum wheat (Triticum durum l.). Bulg. J. Agric. Sci., The major objectives of the study were to (1) evaluate genotypic yield performances of eighteen durum wheat genotypes, (2) determine their reliability and stability parameters and (3) estimate variance components and heritability of yield and yield-related traits. eighteen durum wheat genotypes were evaluated in two conditions (rainfed and well watered) in ilam and Gachsaran agricultural research stations of iran during from 2009 to 2011 to identify patterns of genotype by environment interactions and their stabilities in terms of seed yield and yield-related components. Seed yield and its components are affected by plant genotype and environmental conditions. There were significant differences between genotypes of one or two years at each location for all the traits. Significant differences among years or between conditions were obtained in terms of all traits. Genotypes x environment interactions at all the traits were highly significant. Thus, the stabilities of eighteen durum wheat genotypes were different for all the traits. according to the stability parameters, G6 and G12 genotypes were stable for grain yield. Genotypes, Ga//2*Chen/ alTaR84 and ShaG_26/SniTan were considered as having high adaptability to both rainfed and irrigated conditions while ouaSeRl -1(G5) and oSSl-1/4/mRBSh/3/RaBi//GS/CR/5/ hna (G8) were considered as having low adaptability to both rainfed and irrigated conditions. The estimates of heritability values with limited phenotypic variance definition were 0. 006, 0.163, -0.025, 0.396, 0.327, 0.346 and -0.075 for grain yield, plant height, test weight, thousand kernel weight, peduncle length, spike length, and number of grains per spike ranged respectively. The heritability with complete phenotypic variance definition were 0.001, 0.025, -0.006, 0.040, 0.114, 0.164 and -0.024 for the same traits, respectively. moderate or low heritability values estimated for all the traits showed that family selection method could be used instead of individual selection in the breeding programs for improving grain yield and its components