Agronomic and Yield Characteristics of Grain Sorghum as Influenced by Environment Factors and Genotype

Genotypes tested in different locations, years or planting dates often change in yield due to the response of genotypes to environmental factors such as temperature, soil fertility etc. The objectives of the present study were to evaluate the effects of environment factors on agronomic and yield characteristics of grain sorghum and to identify the most adapted B-line(s) to different environments in Egypt. Six environments with 25 sorghum B-lines were conducted at two locations (Giza and Shandaweel) in 2012 and 2013 years and two planting dates in Giza location. A randomised complete block design was used in each environment with three replications. Mean squares due to genotype × environment were significant for all studied traits. Increasing temperature from second planting date to first planting date in Giza across seasons caused the significant decrease in grain yield per plant (GYPP) by about 15.3%. This reduction in yield was associated with significant decreases in the number of grains/plant (GPP) (9.29%), plant height (PH) (7.31%) and days to 50% flowering (DTF) (6.92%). Moreover, higher temperature in 2012 than 2013 season in Shandaweel caused significant (p<0.01) reduction in GYPP by 18.04%, GPP (34.76%) and DTF (8.33%). Though the temperature was higher in Shandaweel than Giza, the increase in GYPP in Shandaweel than Giza could probably due to the better physical and chemical properties of the soil. Across all environments, the B-line BTX-TSC-20 followed by ICSB-88003 showed the highest GYPP. BTX-TSC-20 followed by ICSB-1808 under E1 and E3 environments (Giza, first planting date in 2012 and 2013), ICSB-14 and ICSB-88003 under E2 and E4 (Giza, second planting date in 2012 and 2013), ICSB-11 followed by BTX 2-1 under E5 (Shandaweel, 2012 season) and ICSB-88003 followed by ICSB-70 under E6 (Shandaweel, 2013 season) were the most adapted B-lines.

Yield Adaptability and Stability of Grain Sorghum Genotypes across Different Environments in Egypt using AMMI and GGE-biplot Models

Presence of G×E interaction reduces the correlation between genotypic and phenotypic parameters and complicates progress of selection. Among several methods proposed for evaluation of the GE interaction, the AMMI and GGE-biplot are the most informative models. The objective of this study was to estimate the G×E interaction in sorghum parental lines and to identify sorghum B-lines of stability and adaptability across different environments using the AMMI and GGE-biplot models. Six environments with 25 sorghum B-lines were conducted at two locations in Egypt (Giza and Shandaweel) in two years and two planting dates in one location (Giza). A randomized complete block design was used in each environment (yield trial) with three replications. The AMMI analysis of variance indicated that the genotype (G), environment (E) and GE interaction had significant influence (p≤0.01) on sorghum grain yield. Based on AMMI model, BTX TSC-20 followed by ICSB-1808 showed both high yielding and stability across the test environments. However, ICSB-8001 (G11) and BTX-407 (G21), showed maximum stability, but with moderate grain yield. Based on GGE-biplot method, BTX TSC-20 (G25) was the winning genotype for the mega-environment which consists of E1 and E3, ICSB-14 (G3) for the mega-environment (E2 and E4), while BTX 2-1 (G20) for E5 mega-environment, ICSB-88003 (G12) and ICSB-70 (G6) for the mega-environment E6. These genotypes are the most adapted to the respective environments.

Leaf Amino Acids and Anatomical Traits of Drought Tolerant vs Sensitive Genotypes of Quinoa (Chenopodium quinoa Willd.) under Elevated Levels of Water Stress

Many plants accumulate compatible osmolytes at high levels in plant cells such as amino acids and/or develop special epidermal cell bladders which may serve as external water reservoirs and having small and thick-walled cells in response to water deficit. The objectives of the present investigation were: (i) to study effects of water stress on the anatomical traits and accumulation of free amino acids in quinoa leaves and (ii) to describe differences among drought tolerant and sensitive genotypes in such traits following the imposition of water deficit. A field experiment was carried out in the growing season 2015/2016, using a split plot design with five replications. Main plots were allotted to three irrigation regimes, i.e. well watering (WW) [95% field capacity (FC)], moderate water stress (WS) [65% FC] and severe water stress (SWS) [35% FC] and sub plots to five genotypes. Mean squares due to genotypes, irrigation regimes and their interaction were significant (p≤0.01) for studied leaf free amino acids and anatomical traits. Water stress caused a significant decrease in leaf thickness under WS and SWS, upper and lower epidermis under WS, palisade and spongy layers under SWS, but caused a significant increase in palisade and spongy layers under WS and upper and lower epidermis under SWS. The genotype CICA-17 (tolerant) had the thickest leaf and upper epidermis and second thickest lower epidermis, palisade and spongy layers. Contents of each amino acid were significantly increased due to water stress, except Leucine. Increases in amino acid content increased by increasing severity of water stress. Maximum increase (109.6%) was shown by Threonine under SWS, but minimum (8.08%) was by Arginine under WS. Under SWS, the tolerant genotype CICA-17 showed the highest mean increase percentage (47.9%) in total amount of amino acids relative to WW; it showed the highest increase in all amino acids, especially Proline, Methionine and Phenylalanine.