Phenotyping cowpea accessions at the seedling stage for drought tolerance using the pot method

AbstractOne of the most important screening techniques used in cowpea selection for drought tolerance is screening at the seedling stage. The objective of this study was to phenotype 60 cowpea genotypes for seedling drought tolerance in screen houses (glasshouse and greenhouse). A triplicated 6 × 10 alpha lattice design with four blocks was used for the experiments. After planting, pots were watered to field capacity, thereafter watering was completely withheld for 4 weeks after planting (WAP), when plants were at the three-leaf stage. Principal component analysis revealed that of the 14 variables, the first four expressed more than 1 eigenvalue. Data showed that PC1, PC2, and PC3 contributed 39.3%, 15.2%, and 10% respectively, with 64.68% total variation. Bartlett’s test of sphericity was significant at p<0.05, while the Kaiser-Meyer-Olkin measure of sampling adequacy was 77. A PCA plot and biplot showed that the number of pods (NP), seeds per pod (SP), survival count (SC), pod weight (PWT), and stem wilting in week one (WWK1) had the most significant contributions to genetic variability to drought tolerance and to yield after stress imposition Based on the PCA, biplot, and cluster plot, the accessions IT 07-292-10, IT 07-274-2-9, IT90K-59, 835-911, RV 343, and IT 95K-2017-15 had the maximum variability in terms of number of pods, seeds per pod, survival count, pod weight and wilting in week one after drought imposition. Cowpea accessions 835-911, IT 07-292-10, RV 344, Kangorongondo, and IT 90K-59 were the major individuals that contributed mainly to domain information model (DIM) 1 and 2. The accessions that contributed the least were IT 89KD288, Chibundi mavara, and TVU12746. Thirty-six cowpea accessions from both screen houses were tolerant to drought, 15 were moderately tolerant, while 23 were susceptible. The findings of the study provided a useful tool for screening and determining drought-tolerant and susceptible accessions at the seedling stage. Thirty-six cowpea accessions from both screen houses were tolerant to drought as well as those that showed great variability can be used as parents in future cowpea breeding programmes.

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Dissection of Drought Tolerance in Upland Cotton Through Morpho-Physiological and Biochemical Traits at Seedling Stage

Frontiers in Plant Science ◽

10.3389/fpls.2021.627107 ◽

2021 ◽

Vol 12 ◽

Author(s):

Zobia Zahid ◽

Muhammad Kashif Riaz Khan ◽

Amjad Hameed ◽

Muhammad Akhtar ◽

Allah Ditta ◽

...

Keyword(s):

Drought Tolerance ◽

Principal Component ◽

Field Capacity ◽

Seedling Stage ◽

Physiological Traits ◽

Genotypic Differences ◽

Biochemical Traits ◽

Drought Tolerant ◽

Wide Range ◽

Physiological And Biochemical

Cotton is an important fiber and cash crop. Extreme water scarceness affects the growth, quality, and productivity of cotton. Water shortage has threatened the future scenario for cotton growers, so it is imperative to devise a solution to this problem. In this research, we have tried to machinate a solution for it. 23 genotypes have been screened out against drought tolerance at the seedling stage by evaluating the morphological, physiological, and biochemical traits in a triplicate completely randomized design plot experiment with two water regimes [50 and 100% field capacity]. Genotypic differences for all the morphological and physiological traits revealed highly significant differences except transpiration rate (TR). Moreover, the interaction between genotype and water regime (G × W) was highly significant for root length (RL, 5.163), shoot length (SL, 11.751), excised leaf water loss (ELWL, 0.041), and stomatal conductance (SC, 7.406). A positively strong correlation was found in TR with relative water content (RWC; 0.510) and SC (0.584) and RWC with photosynthesis (0.452) under drought conditions. A negative correlation was found in SC with SL (−0.428) and photosynthesis (−0.446). Traits like RL, SL, SC, photosynthesis, proline, catalase, and malondialdehyde were visible indicators, which can differentiate drought-tolerant genotypes from the susceptible ones. A wide range of diversity was found in all the morpho-physiological traits with the cumulative variance of four principal components (PCs) 83.09% and three PCs 73.41% under normal and water-stressed conditions, respectively, as per the principal component analysis. Hence, selection criteria can be established on the aforementioned traits for the development of drought-tolerant cultivars. Moreover, it was found that out of 23 experimental varieties, NIAB-135, NIAB-512, and CIM-554 could be used to devise breeding strategies for improving drought tolerance in cotton.

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Improving Drought Tolerance in Mungbean (Vigna radiata L. Wilczek): Morpho-Physiological, Biochemical and Molecular Perspectives

Agronomy ◽

10.3390/agronomy11081534 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1534

Author(s):

Chandra Mohan Singh ◽

Poornima Singh ◽

Chandrakant Tiwari ◽

Shalini Purwar ◽

Mukul Kumar ◽

...

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Crop Production ◽

Mitigation Strategies ◽

Theoretical Research ◽

Whole Genome Sequence ◽

Complex Nature ◽

Drought Tolerant ◽

Breeding Programmes ◽

The Impact

Drought stress is considered a severe threat to crop production. It adversely affects the morpho-physiological, biochemical and molecular functions of the plants, especially in short duration crops like mungbean. In the past few decades, significant progress has been made towards enhancing climate resilience in legumes through classical and next-generation breeding coupled with omics approaches. Various defence mechanisms have been reported as key players in crop adaptation to drought stress. Many researchers have identified potential donors, QTLs/genes and candidate genes associated to drought tolerance-related traits. However, cloning and exploitation of these loci/gene(s) in breeding programmes are still limited. To bridge the gap between theoretical research and practical breeding, we need to reveal the omics-assisted genetic variations associated with drought tolerance in mungbean to tackle this stress. Furthermore, the use of wild relatives in breeding programmes for drought tolerance is also limited and needs to be focused. Even after six years of decoding the whole genome sequence of mungbean, the genome-wide characterization and expression of various gene families and transcriptional factors are still lacking. Due to the complex nature of drought tolerance, it also requires integrating high throughput multi-omics approaches to increase breeding efficiency and genomic selection for rapid genetic gains to develop drought-tolerant mungbean cultivars. This review highlights the impact of drought stress on mungbean and mitigation strategies for breeding high-yielding drought-tolerant mungbean varieties through classical and modern omics technologies.

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Evaluation of Drought Tolerance in Arkansas Cowpea Lines at Seedling Stage

HortScience ◽

10.21273/hortsci15036-20 ◽

2020 ◽

Vol 55 (7) ◽

pp. 1132-1143

Author(s):

Qirui Cui ◽

Haizheng Xiong ◽

Yufeng Yufeng ◽

Stephen Eaton ◽

Sora Imamura ◽

...

Keyword(s):

Drought Tolerance ◽

Block Design ◽

Seedling Stage ◽

University Of Arkansas ◽

Drought Treatment ◽

Breeding Lines ◽

Drought Tolerant ◽

Dry Conditions ◽

Main Plot ◽

The University

Cowpea [Vigna unguiculate (L.) Walp.] is not only a healthy, nutritious, and versatile leguminous crop; it also has a relatively high adaptation to drought. Research has shown that cowpea lines have a high tolerance to drought, and many of them can survive more than 40 days under scorching and dry conditions. The cowpea (Southern pea) breeding program at the University of Arkansas has been active for more than 50 years and has produced more than 1000 advanced breeding lines. The purpose of this study was to evaluate the drought-tolerant ability in Arkansas cowpea lines and use the drought-tolerant lines in cowpea production or as parents in cowpea breeding. A total of 36 University of Arkansas breeding lines were used to screen drought tolerance at the seedling stage in this study. The experiment was conducted in the greenhouse using a randomized complete block design (RCBD) with two replicates, organized in a split-plot manner, where the drought treatment (drought and nondrought stress) as the main plot and the cowpea genotypes as the subplot. Drought stress was applied for 4 weeks, and three drought-tolerant–related traits were collected and analyzed. Results showed that cowpea breeding lines: ‘17-61’, ‘17-86’, ‘Early Scarlet’, and ‘ARBlackeye #1’ were found to be drought tolerant.

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Drought Resistance Indices for Screening of Potato (Solanum tuberosum L.) Genotypes

Turkish Journal of Agriculture - Food Science and Technology ◽

10.24925/turjaf.v7i8.1118-1124.2226 ◽

2019 ◽

Vol 7 (8) ◽

pp. 1118

Author(s):

Zerihun Kebede Beyene ◽

Firew Mekbib ◽

Tesfaye Abebe ◽

Asrat Asfaw

Keyword(s):

Stress Tolerance ◽

Solanum Tuberosum L ◽

Geometric Mean ◽

Strong Association ◽

Principal Component ◽

Screening Tools ◽

Tolerance Index ◽

Lattice Design ◽

Terminal Drought ◽

Drought Tolerant

In breeding for drought tolerance, availability of precise, cheap and easy to apply selection tool is critical. The aim of the present study was to identify potential screening tools that are useful for selection of drought tolerant genotypes in potato and select drought resistant potato genotypes. The study assessed sixty clones arranged in a 10×6 alpha lattice design with two replicates in a managed stress experiment. Two irrigation treatments were applied: fully watered non-stress and terminal drought, where the irrigation water supply to the crop was withheld after 50 % flowering to induce post-flowering stress. Stress indices were calculated based on tuber yield of genotypes in both stressed and non-stressed conditions. Identification of drought tolerant genotypes based on a single index was less informative as different indices identified different genotypes as drought tolerant. Hence, to determine the most desirable drought tolerant clones rank sum of indices, correlation, and bi-plot display of the principal component analysis was employed. The indices modified stress tolerance index based on non-stressed yield, Men productivity, Geometric mean productivity, Stress tolerance index, Harmonic mean, modified stress tolerance index based on stressed yield and Yield index exhibited strong association with both yield under stressed and non-stressed yield. These indices discriminated drought tolerant genotypes with higher tuber yielding potential both under stress and non-stress conditions. Genotypes CIP-398180.612, CIP-397069.5, and CIP-304371.67 were identified as drought tolerant. These genotypes could be potentially grown both under drought prone and potential environments and these selection attributes could help to develop climate resilient potato varieties.

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Divergence analysis of drought tolerant Genotypes of Wheat (Triticum astivum L.)

Bangladesh Journal of Agricultural Research ◽

10.3329/bjar.v39i3.21982 ◽

2015 ◽

Vol 39 (3) ◽

pp. 385-396

Author(s):

MA Zaman ◽

MNA Siddquie ◽

M Mahbubur Rahman ◽

MY Abida ◽

MJ Islam

Keyword(s):

Grain Yield ◽

Agricultural Research ◽

Wide Spectrum ◽

Principal Component ◽

Mean Value ◽

Research Centre ◽

Lattice Design ◽

Drought Tolerant ◽

Cluster Distance ◽

Component Loading

Thirty genotypes of wheat were grown in an Alpha Lattice Design with three replications for evaluation and divergence analysis. Seeds were sown on 24 November 2011 at Regional Wheat Research Centre, Bangladesh Agricultural Research Institute, Shyampur, Rajshahi. Significant variation was observed among the genotypes and these are grouped into six clusters. Clusters III and VI were comprised of maximum number of genotypes (6) followed by clusters I, IV, and V with 5 genotypes and the minimum genotypes (3) were in cluster II. The maximum inter-cluster distance was recorded between the Cluster VI and Cluster II followed by cluster III and Cluster II, which indicates that genotypes belonging to these distant clusters could be used in hybridization programme for getting a wide spectrum of variation among the segregates. The minimum intercluster distance was found between the Cluster IV and Cluster I followed by that of Cluster V and Cluster IV. The maximum intra-cluster distance was recorded in Cluster II, consisted of three genotypes of diverse origin followed by Cluster V consisting of five genotypes which indicated that the genotypes of these clusters might have considerable diversity among themselves. While the minimum distance was computed in Cluster I composed of five genotypes which indicated that these genotypes were genetically very close to each other. Considering the eigenvalues of all principal component analysis the PC1, PC2, PC3, PC4, and PC5 with values contributed 30.78%, 20.11%, 17.75%, 10.93%, and 7.63%, respectively, of the total variation. The results revealed from the present study that the first principal component had high positive component loading from grains/spike and high negative loading from grain yield. Considering the clusters mean value, the genotype of Cluster II and VI are most divergent and maximum heterosis and wide variability in genetic architecture may be expected from the crosses between the genotypes belonged to these clusters. More specifically the cluster II could be selected for dwarf in nature, early heading and maturity and bold grain size. The genotypes from the cluster IV could be selected for maximum spikes/m2 and maximum grain yield. The positive value of both vectors for days to heading and spikes/m2 indicated that these traits had the highest contribution towards divergence among the 30 drought tolerant wheat genotypes. DOI: http://dx.doi.org/10.3329/bjar.v39i3.21982 Bangladesh J. Agril. Res. 39(3): 385-396, September 2014

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Screening the USDA Watermelon Germplasm Collection for Drought Tolerance at the Seedling Stage

HortScience ◽

10.21273/hortsci.46.9.1245 ◽

2011 ◽

Vol 46 (9) ◽

pp. 1245-1248 ◽

Cited By ~ 19

Author(s):

Haiying Zhang ◽

Guoyi Gong ◽

Shaogui Guo ◽

Yi Ren ◽

Yong Xu ◽

...

Keyword(s):

Drought Tolerance ◽

Clustering Analysis ◽

Growth And Development ◽

Citrullus Lanatus ◽

Germplasm Collection ◽

Normal Growth ◽

Seedling Stage ◽

Breeding Lines ◽

Germplasm Collections ◽

Drought Tolerant

Because of the growing threat of global warming, drought stress could severely affect the normal growth and development of crop plants. To alleviate such an adverse effect, there is a need to screen watermelon germplasm collections to identify genetic sources for potential drought tolerance. In the present study, 820 accessions of USDA's Citrullus PIs and 246 watermelon breeding lines were evaluated for their drought tolerance at the seedling stage under extreme water stress conditions in a greenhouse. Significant variations in drought tolerance were observed in the Citrullus germplasm collections. Using fast clustering analysis, the tested watermelon materials could be assigned into four groups, including tolerant, intermediate tolerant, moderately sensitive, and sensitive, respectively. The most drought-tolerant Citrullus germplasm, including 13 Citrullus lanatus var. lanatus and 12 C. lanatus var. citroides accessions, were originated from Africa. These genetic materials could be used for rootstock breeding or for developing drought-tolerant watermelon cultivars.

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Multivariate Analysis of Morpho-Physiological Traits Reveals Differential Drought Tolerance Potential of Bread Wheat Genotypes at the Seedling Stage

Plants ◽

10.3390/plants10050879 ◽

2021 ◽

Vol 10 (5) ◽

pp. 879

Author(s):

Mohammed Mohi-Ud-Din ◽

Md. Alamgir Hossain ◽

Md. Motiar Rohman ◽

Md. Nesar Uddin ◽

Md. Sabibul Haque ◽

...

Keyword(s):

Multivariate Analysis ◽

Drought Tolerance ◽

Water Content ◽

Total Variation ◽

Bread Wheat ◽

Weight Ratio ◽

Principal Component ◽

Physiological Traits ◽

Wheat Genotypes ◽

Drought Tolerant

Drought is one of the foremost environmental stresses that can severely limit crop growth and productivity by disrupting various physiological processes. In this study, the drought tolerance potential of 127 diverse bread wheat genotypes was evaluated by imposing polyethylene glycol (PEG)-induced drought followed by multivariate analysis of several growth-related attributes. Results showed significant variations in the mean values of different morpho-physiological traits due to PEG-induced drought effects. Correlation analysis revealed that most of the studied traits were significantly correlated among them. The robust hierarchical co-clustering indicated that all the genotypes were clustered into four major groups, with cluster 4 (26 genotypes) being, in general, drought-tolerant followed by cluster 1 (19 genotypes) whereas, cluster 2 (55 genotypes) and 3 (27 genotypes) being drought-sensitive. Linear discriminant analysis (LDA) confirmed that around 90% of the genotypes were correctly assigned to clusters. Squared distance (D2) analysis indicated that the clusters differed significantly from each other. Principal component analysis (PCA) and genotype by trait biplot analysis showed that the first three components accounted for 71.6% of the total variation, with principal component (PC) 1 accounting for 35.4%, PC2 for 24.6% and PC3 for 11.6% of the total variation. Both PCA and LDA revealed that dry weights, tissue water content, cell membrane stability, leaf relative water content, root-shoot weight ratio and seedling vigor index played the most important discriminatory roles in explaining drought tolerance variations among 127 wheat genotypes. Our results conclude that the drought-tolerant and -sensitive wheat genotypes identified in this study would offer valuable genetic tools for further improvement of wheat productivity in arid and semi-arid regions during this time of unpredictable climate change.

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Screening for Eruca genotypes tolerant to polyethylene glycol-simulated drought stress based on the principal component and cluster analyses of seed germination and early seedling growth

Plant Genetic Resources ◽

10.1017/s1479262115000519 ◽

2015 ◽

Vol 15 (2) ◽

pp. 187-193 ◽

Cited By ~ 3

Author(s):

Banglian Huang ◽

Jianjie Su ◽

Guangyu Zhang ◽

Xiaoqing Luo ◽

Huan Wang ◽

...

Keyword(s):

Cluster Analysis ◽

Polyethylene Glycol ◽

Drought Tolerance ◽

Total Variation ◽

Principal Component ◽

Upgma Cluster ◽

Drought Tolerant ◽

Tolerant Species ◽

Upgma Cluster Analysis ◽

Simulated Drought

Water deficit is an environmental factor that constrains crops to express their ecophysiological potential and causes crop yield reduction. Eruca vesicaria has been reported to be one of the most drought-tolerant species in Cruciferae. In this study, polyethylene glycol-simulated drought tolerance was evaluated in one line of Brassica carinata, one line of Brassica napus and 249 Eruca lines based on the principal component analysis (PCA) and unweighted pair-group arithmetic average (UPGMA) cluster analysis. The PCA based on eight drought tolerance indices indicated that the first three components accounted for 85.46% of the total variation, with principal component (PC) 1 accounting for 43.89%, PC2 for 27.85% and PC3 for 13.73% of the total variation. The UPGMA cluster analysis indicated that B. napus cultivar Zhongshuang 9 and Eruca lines could be clustered into five major groups, with group 1 being, in general, drought sensitive, group 2 being slightly–medium drought tolerant, group 3 being drought tolerant, group 4 being highly drought sensitive and group 5 being highly drought tolerant. B. carinata cultivar XB1, as an outstander, showed high drought sensitivity. The UPGMA cluster dendrogram provides a good representation of the similarity matrix (r= 0.68). The drought-tolerant Eruca materials obtained in this study will be valuable for genetic improvement not only in Eruca itself, but also in Brassica crops since they are drought-tolerant lines from a drought-tolerant species.

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Screening of Pearl Millet Genotypes Suitable for Drought Tolerance at Early Seedling Stage

Indian Journal of Agricultural Research ◽

10.18805/ijare.a-5718 ◽

2021 ◽

Author(s):

R.C. Meena ◽

Supriya Ambawat ◽

C. Tara Satyavathi ◽

Moola Ram ◽

Vikas Khandelwal ◽

...

Keyword(s):

Water Stress ◽

Drought Tolerance ◽

Pearl Millet ◽

Pennisetum Glaucum ◽

Climatic Factors ◽

Crop Improvement ◽

Seedling Stage ◽

Drought Tolerant ◽

Early Seedling ◽

Improvement Programs

Background: Pearl millet [Pennisetum glaucum (L.) Br.] is the most widely grown staple food of majority of poor and small land holders in Asia and Africa. It is also consumed as feed and fodder for livestock. It is the sixth most important cereal crop in the world next to maize, rice wheat, barley and sorghum. The temperature is one of the key climatic factors and has profound effect on the growth and development of the pearl millet. It can only be managed through developing hybrid varieties which can tolerate high temperature during germination and early seedling stages.The present study aimed to identify drought tolerant genotypes of pearl millet at seedling stage. Methods: This experiment was carried out at Mandor during kharif 2018 with five selected pearl millet advanced hybrids MH 2192, MH 2224, MH 2228, MH 2354 and MH 2359 along with three checks RHB 177, MPMH 17 and 86M86 which were tested under polyethylene glycol (PEG) (5% and 10%) induced osmotic stress. Various physiological parameters were recorded 15 days after sowing and statistical analysis made using Windostat software. Result: The results revealed that shoot length, seedling dry weight, relative water content, membrane stability index and chlorophyll content decreased significantly with PEG induced water stress in all the hybrids while root length and catalase activity increased significantly under water stress. Among 5 hybrids, two hybrids viz. MH 2359 and MH 2354 performed better and found to be superior under PEG induced water stress. Thus, various drought tolerance indices may further be studied for these two hybrids and can be used in development of drought tolerant genotypes which may prove helpful for crop improvement programs of pearl millet.

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

Agronomy ◽

10.3390/agronomy11050875 ◽

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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