Drought-tolerance indices in a tall fescue population and its polycross progenies

2012 ◽  
Vol 63 (4) ◽  
pp. 360 ◽  
Author(s):  
Maryam Ebrahimiyan ◽  
Mohammad Mahdi Majidi ◽  
Aghafakhr Mirlohi ◽  
Mahdi Gheysari
Keyword(s):  
Soil Moisture ◽  
Drought Tolerance ◽  
Tall Fescue ◽  
Moisture Stress ◽  
Forage Yield ◽  
Soil Moisture Stress ◽  
Drought Tolerant ◽  
Second Year ◽  
Drought Tolerance Indices ◽  
Tolerance Indices

Development of drought-tolerant cultivars is hampered by a lack of effective selection criteria. In this research, drought tolerance of 75 genotypes of tall fescue in three sets (25 parental, 25 early, 25 late-flowering progenies) was evaluated under no soil moisture stress and soil moisture stress in the field during 2009 and 2010. Five drought-tolerance indices were calculated: stress tolerance (TOL), mean productivity (MP), geometric mean productivity (GMP), stress susceptibility index (SSI), and stress tolerance index (STI). These calculations were based on forage yield (dry matter basis) under drought (Ys) and non-drought (Yp) conditions. Soil moisture stress caused significant reduction in forage yield. Considerable genetic variation for drought tolerance was found among genotypes. A moderately high relationship was found between Yp and Ys using regression analysis, with a clear relationship in the second year. Indices GMP and STI were found to be valuable aids in the selection of drought-tolerant, high-yielding genotypes. Plots of the first and second principal components identified drought-tolerant genotypes in each set. Results indicated that selection for drought-tolerant genotypes should be planned separately for first year (establishment stage) and second year (productive stage) in tall fescue.

scholarly journals GAS EXCHANGE AND FERN WATER POTENTIALS OF WATER-STRESSED ASPARAGUS

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1166g-1167
Author(s):  
Daniel Drost ◽  
Darlene Wilcox-Lee
Keyword(s):  
Soil Moisture ◽  
Gas Exchange ◽  
Carbon Assimilation ◽  
Moisture Stress ◽  
Carbon Dioxide Assimilation ◽  
Soil Moisture Stress ◽  
Drought Tolerant ◽  
Water Potentials ◽  
Intermediate Response ◽  
Low Levels

Asparagus is considered a relatively drought tolerant plant, but few studies are available on the gas exchange response to soil moisture stress. Seedlings were grown in the greenhouse for six months before initiation of the water stress treatments. Soils were allowed to dry to matric potentials of -0.05, -0.3 and -0.5 MPa before rewatering to pot capacity. Gas exchange and fern water potentials were measured diurnally on asparagus plants when soil matric potentials reached their minima. Decreasing soil matric potentials decreased net carbon dioxide assimilation, stomatal conductance and fern water potential. Assimilation rates (6 am) were between 3 and 5 umols m-2 s-1 for all soil moisture treatments. Carbon assimilation rates of 10, 8, and 7 umols m-2 s-1 were recorded at 10 am for the -0.05, -0.3 and -0.5 MPa soil matric potentials, respectively. Assimilation rates decreased sharply over the remainder of the day. The diurnal pattern for conductance were similar to the assimilation rates. Fern water potentials were greater in the -0.05 MPa than in the -0.5 MPa treatment for all measurement periods with an intermediate response for soil matric potentials of -0.3 MPa. Fern water potentials were highest at 6 am (-0.2 to -0.6 MPa) before declining to their minima (-1.5 to -1.8 MPa) at 10 am. Water potentials remained at these low levels throughout the day before recovering slightly at 6 pm.

scholarly journals Physiological Screening for Drought Tolerance Traits in Vegetable Amaranth (Amaranthus tricolor) Germplasm

Agriculture ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 994
Author(s):  
Norain Jamalluddin ◽  
Festo J. Massawe ◽  
Sean Mayes ◽  
Wai Kuan Ho ◽  
Ajit Singh ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Geometric Mean ◽  
Tolerance Index ◽  
Genotypic Differences ◽  
Amaranthus Tricolor ◽  
Drought Tolerant ◽  
Drought Tolerance Indices ◽  
Tolerance Indices ◽  
Screening Trials

Amaranth (Amaranthus tricolor), an underutilized climate smart crop, is highly nutritious and possesses diverse drought tolerance traits, making it an ideal crop to thrive in a rapidly changing climate. Despite considerable studies on the growth and physiology of plants subjected to drought stress, a precise trait phenotyping strategy for drought tolerance in vegetable amaranth is still not well documented. In this study, two drought screening trials were carried out on 44 A. tricolor accessions in order to identify potential drought-tolerant A. tricolor germplasm and to discern their physiological responses to drought stress. The findings revealed that a change in stem biomass was most likely the main mechanism of drought adaptation for stress recovery, and dark-adapted quantum yield (Fv/Fm) could be a useful parameter for identifying drought tolerance in amaranth. Three drought tolerance indices: geometric mean productivity (GMP), mean productivity (MP) and stress tolerance index (STI) identified eight drought-tolerant accessions with stable performance across the two screening trials. The highly significant genotypic differences observed in several physiological traits among the amaranth accessions indicate that the amaranth panel used in this study could be a rich source of genetic diversity for breeding purposes for drought tolerance traits.

scholarly journals Identification of Drought Tolerant Genotypes in Dryland Wheat using Drought Tolerance Indices

2018 ◽  
Vol 10 (28) ◽  
pp. 13-26
Author(s):  
Morteza Kamrani ◽  
Asghar Mehraban ◽  
Manoochehr Shiri ◽  
◽  
◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Drought Tolerant ◽  
Drought Tolerance Indices ◽  
Tolerance Indices

scholarly journals Evaluation of Selection Indices for Drought Tolerance in Some Chickpea (Cicer Arietinum L.) Genotypes

2014 ◽  
Vol 17 (1) ◽  
pp. 6-12 ◽  
Author(s):  
Naser Sabaghnia ◽  
Mohsen Janmohammadi
Keyword(s):  
Drought Tolerance ◽  
Strong Correlation ◽  
Crop Production ◽  
Block Design ◽  
Stressed Condition ◽  
Potential Yield ◽  
Drought Tolerant ◽  
Selection Indices ◽  
Drought Tolerance Indices ◽  
Tolerance Indices

Abstract Drought is one of the major abiotic stresses in agriculture worldwide, which limits crop production. The chickpea cultivation areas of Iran are fourth in the world after India, Pakistan and Turkey while most areas (95 %) are planted in rainfed condition and are grown in rotation with cereals. This investigation was carried out to investigate the effect of drought stress seed yield characteristic in seven genotypes of chickpea. A field experiment with two humidity regimes (stressed and non-stressed) was performed in a randomized complete block design layout with three replicates. The analysis of variance for both potential yield (YP) and stress yield (YS) indicated significant differences among seven chickpea genotypes. Also, significant differences were observed among chickpea genotypes regarding twelve drought tolerance indices. Based on the YP, the genotypes FLIP 03-64C, FLIP 98-106C, Arman and Azad had the highest yield under non-stressed condition, while the genotypes FLIP 98-106C and Azad displayed the highest yield under stressed condition. Therefore, the genotypes FLIP 98-106C and Azad are good candidates for commercial recommendation to farmers in both rainfed and irrigated conditions. The relationships among drought tolerance indices are graphically displayed in a plot of two first principal components analysis. The first and second components justified 95.46 % of the variations between criteria (59.36 and 36.10 % for PC1 and PC2, respectively). The STI, K1STI, MP, GMP and PI indices exhibited strong correlation with YP, while YI showed strong correlation with YS; therefore, YS can discriminate drought tolerant genotypes with high grain yield under stress conditions.

scholarly journals Evaluation of Drought Tolerance Indices for Screening Some of Corn (Zea mays L.) Cultivars under Environmental Conditions

2013 ◽  
Vol 5 (3) ◽  
pp. 388-393 ◽  
Author(s):  
Mohhamad Reza NAGHAVI ◽  
Alireza POUR ABOUGHADAREH ◽  
Marouf KHALILI
Keyword(s):  
Zea Mays ◽  
Drought Tolerance ◽  
Stress Tolerance ◽  
Zea Mays L ◽  
Stress Conditions ◽  
Tolerance Index ◽  
Drought Tolerant ◽  
Drought Tolerance Indices ◽  
Stress Susceptibility ◽  
Tolerance Indices

In order to study the effect of drought stress on eight cultivars corn (Zea mays L.), an experiment was conducted in a factorial experimental on the basis of randomized complete block design under two irrigated conditions during 2010-2011 cropping season. Twelve drought tolerance/resistance indices including stress tolerance index (STI), stress susceptibility index (SSI), tolerance index (TOL), geometric mean production (GMP), mean production (MP), yield index (YI), yield stability index (YSI), drought resistance index (DI), relative drought index (RDI), stress susceptibility percentage index (SSPI) and modified stress tolerance (K1STI and K2STI) were calculated based on grain yield under drought and irrigated conditions. Yield in stress and non-stress conditions were significantly and positively correlated with STI, GMP, MP, YI, TOL, DI, RDI, YSI, SSPI, K1STI, and K2STI and negatively correlated with SSI. Yield in stress and non-stress conditions were significantly and positively correlated with STI, GMP, MP, YI, TOL, DI, RDI, YSI, SSPI, K1STI, and K2STI and negatively correlated with SSI. Screening drought tolerant cultivars using ranking method, three dimensional plots discriminated cultivars ‘KSC720’, KSC 710GT and ‘KSC 700’ as the most drought tolerant. Cluster analysis classified the cultivars into three groups i.e., tolerant, susceptible and semi-susceptible to drought conditions. In general, Results of this study showed that among drought tolerance indices STI, YI, SSPI, K1STI, and K2STI can be used as the most suitable indicators for screening drought tolerant cultivars and ‘KSC720’, KSC 710 GT and ‘KSC 700’ had the highest tolerance to drought in our studies condition.

scholarly journals GAS EXCHANGE AND FERN WATER POTENTIALS OF WATER-STRESSED ASPARAGUS

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1166G-1167
Author(s):  
Daniel Drost ◽  
Darlene Wilcox-Lee
Keyword(s):  
Soil Moisture ◽  
Gas Exchange ◽  
Carbon Assimilation ◽  
Moisture Stress ◽  
Carbon Dioxide Assimilation ◽  
Soil Moisture Stress ◽  
Drought Tolerant ◽  
Water Potentials ◽  
Intermediate Response ◽  
Low Levels

Asparagus is considered a relatively drought tolerant plant, but few studies are available on the gas exchange response to soil moisture stress. Seedlings were grown in the greenhouse for six months before initiation of the water stress treatments. Soils were allowed to dry to matric potentials of -0.05, -0.3 and -0.5 MPa before rewatering to pot capacity. Gas exchange and fern water potentials were measured diurnally on asparagus plants when soil matric potentials reached their minima. Decreasing soil matric potentials decreased net carbon dioxide assimilation, stomatal conductance and fern water potential. Assimilation rates (6 am) were between 3 and 5 umols m-2 s-1 for all soil moisture treatments. Carbon assimilation rates of 10, 8, and 7 umols m-2 s-1 were recorded at 10 am for the -0.05, -0.3 and -0.5 MPa soil matric potentials, respectively. Assimilation rates decreased sharply over the remainder of the day. The diurnal pattern for conductance were similar to the assimilation rates. Fern water potentials were greater in the -0.05 MPa than in the -0.5 MPa treatment for all measurement periods with an intermediate response for soil matric potentials of -0.3 MPa. Fern water potentials were highest at 6 am (-0.2 to -0.6 MPa) before declining to their minima (-1.5 to -1.8 MPa) at 10 am. Water potentials remained at these low levels throughout the day before recovering slightly at 6 pm.

scholarly journals Multi-Environment Screening of Durum Wheat Genotypes for Drought Tolerance in Changing Climatic Events

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 875
Author(s):  
Sourour Ayed ◽  
Afef Othmani ◽  
Imen Bouhaouel ◽  
Jaime A. Teixeira da Silva
Keyword(s):  
Drought Tolerance ◽  
Durum Wheat ◽  
Geometric Mean ◽  
Principal Component ◽  
Tolerance Index ◽  
Wheat Genotypes ◽  
Drought Tolerant ◽  
Drought Tolerance Indices ◽  
Tolerance Indices ◽  
Modern Varieties

Durum wheat is the most widely grown cereal in Tunisia, but its production is threatened by drought, which is exacerbated by climate change. This study aimed to identify drought-tolerant durum wheat genotypes from five modern varieties and six landraces in a multi-environment trial at two sites (Kef and Siliana, Tunisia) during three growing seasons under rainfed and irrigated conditions. Six drought tolerance indices (mean productivity (MP), geometric mean productivity (GMP), stress susceptibility index (SSI), tolerance index (TOL), stress tolerance index (STI), and yield stability index (YSI)) were used to evaluate the 11 genotypes. The environment was the dominant source of variation for grain yield (GY; 94.27%), followed by the environment × genotype interaction (4.06%) and genotype (1.65%). Cluster analysis based on GY identified four environment-based groups with distinct water treatments, extreme minimum/maximum temperatures, and rainfall. Principal component analysis and a correlation matrix revealed that drought tolerance indices significantly correlated with GY in non-stressed and stressed conditions and could be separated into four groups. Based on STI, MP, and GMP, G6 and G8 (landraces) were the most drought-tolerant genotypes attaining high GY in both conditions. TOL was able to discriminate G1, G3, and G5 (modern varieties) as well as drought-susceptible genotypes, all of which were suitable for irrigation. Genotypes G7, G9, G10, and G11 (landraces), which had high SSI and lowest STI, MP, GMP, and YSI values, were susceptible to drought and were thus not suitable for cultivation in both conditions. Finally, G2 and G4 (modern varieties), which had an intermediate rank for different indices, were classified as semi-tolerant or sensitive genotypes. Drought tolerance indices and genotype ranks were helpful tools to screen drought-tolerant genotypes with a large adaptation to a range of environments, namely irrigated and rainfed conditions (landraces G6 and G8), or genotypes with the ability to adapt (modern varieties G1, G3, and G5) to irrigated conditions.

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