Evaluation of cassava germplasm (14 cultivars) for drought tolerance at seedling stage

Drought stress is one of the key plant stresses reducing grain yield in cereal crops worldwide. Although it is not a breeding target in Northern Europe, the changing climate and the drought of 2018 have increased its significance in the region. A key challenge, therefore, is to identify novel germplasm with higher drought tolerance, a task that will require continuous characterization of a large number of genotypes. The aim of this work was to assess if phenotyping systems with low-cost consumer-grade digital cameras can be used to characterize germplasm for drought tolerance. To achieve this goal, we built a proximal phenotyping cart mounted with digital cameras and evaluated it by characterizing 142 winter wheat genotypes for drought tolerance under field conditions. The same genotypes were additionally characterized for seedling stage traits by imaging under controlled growth conditions. The analysis revealed that under field conditions, plant biomass, relative growth rates, and Normalized Difference Vegetation Index (NDVI) from different growth stages estimated by imaging were significantly correlated to drought tolerance. Under controlled growth conditions, root count at the seedling stage evaluated by imaging was significantly correlated to adult plant drought tolerance observed in the field. Random forest models were trained by integrating measurements from field and controlled conditions and revealed that plant biomass and relative growth rates at key plant growth stages are important predictors of drought tolerance. Thus, based on the results, it can be concluded that the consumer-grade cameras can be key components of affordable automated phenotyping systems to accelerate pre-breeding for drought tolerance.

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Root and shoot characteristics as selection criteria for drought tolerance in bread wheat (Triticum aestivum L.) at seedling stage under tropical environment

Discovery and Innovation ◽

10.4314/dai.v17i1.15692 ◽

2006 ◽

Vol 17 (1) ◽

Author(s):

PK Kimurto ◽

MG Kinyua ◽

R Birech ◽

PC Korir ◽

EM Njoka ◽

...

Keyword(s):

Triticum Aestivum ◽

Drought Tolerance ◽

Bread Wheat ◽

Selection Criteria ◽

Seedling Stage ◽

Tropical Environment

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Evaluation of green gram genotypes for drought tolerance by PEG (polyethylene glycol) induced drought stress at seedling stage

Legume Research - An International Journal ◽

10.18805/lr-4149 ◽

2019 ◽

Author(s):

M. Jincya ◽

V. Babu Rajendra Prasad ◽

P. Jeyakumara ◽

A. Senthila ◽

N. Manivannan

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Moisture Stress ◽

Germination Percentage ◽

Seedling Stage ◽

Green Gram ◽

Stress Index ◽

Seedling Mortality ◽

Seed Vigour ◽

Selection Of

Drought stress is one of the major constraints for pulse production which negatively affecting its growth and production. Screening and selection of desirable genotypes for drought tolerance is the first and foremost important step in pulse breeding program. In green gram standardization for moisture stress was done under laboratory conditions using various concentration of PEG 6000 and 50% seedling mortality was observed at 0.5 MPa of moisture stress. Using this level of moisture stress 108 green gram genotypes were screened for their drought tolerance at seedling level and the following parameters viz., germination percentage, promptness index, radicle length, root length stress index, germination stress index and seed vigour were recorded. Observations revealed that the following green gram genotypes COGG 1332, VGG 16069, VGG 17003, VGG 17004, VGG 17009, VGG 17019 and VGG 17045 were found highly tolerant to moisture stress at seedling stage.

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

10.1101/2020.07.10.196915 ◽

2020 ◽

Cited By ~ 1

Author(s):

Gabriel V. Nkomo ◽

Moosa M. Sedibe ◽

Maletsema A. Mofokeng

Keyword(s):

Drought Tolerance ◽

Principal Component ◽

Field Capacity ◽

Seedling Stage ◽

Lattice Design ◽

Drought Tolerant ◽

Bartlett’S Test ◽

Breeding Programmes ◽

Four Blocks ◽

Domain Information

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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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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Genetic Overlap of Drought-Tolerance Loci between Germination Stage and Seedling Stage Analyzed Using Introgression Lines in Soybean

ACTA AGRONOMICA SINICA ◽

10.3724/sp.j.1006.2011.00477 ◽

2011 ◽

Vol 37 (3) ◽

pp. 477-483 ◽

Cited By ~ 4

Author(s):

Peng-Cheng QIU ◽

Wen-Bo ZHANG ◽

Can-Dong LI ◽

Hong-Wei JIANG ◽

Chun-Yan LIU ◽

...

Keyword(s):

Drought Tolerance ◽

Introgression Lines ◽

Seedling Stage ◽

Genetic Overlap ◽

Germination Stage

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Construction of a high density genetic map and QTL mapping of PEG-induced drought tolerance at the early seedling stage in sesame using whole genome re-sequencing

10.21203/rs.3.rs-50720/v2 ◽

2020 ◽

Author(s):

Junchao Liang ◽

Yanying Ye ◽

Xiaowen Yan ◽

Tingxian Yan ◽

Yueliang Rao ◽

...

Keyword(s):

Drought Tolerance ◽

Qtl Mapping ◽

Genetic Map ◽

Phenotypic Variation ◽

Root Length ◽

High Density ◽

Seedling Stage ◽

Whole Genome ◽

Major Qtls ◽

Ril Population

Abstract BackgroundImprovement in sesame (Sesamum indicum L.) drought tolerance at seedling stage is important for yield stability. Genetic approaches combing with conventional breeding is the most effective way to develop drought-tolerant cultivars. So far, only a few studies have been reported to reveal gene/ quantitative trait loci (QTL) controlling drought tolerance in sesame. To identify the genomic regions associated with drought tolerance, we constructed a high-density genetic map using a recombinant inbred line (RIL) population through whole genome re-sequencing (WGRS) technique. QTLs contributing to three seedling traits were identified under both non-stress and water stress conditions.ResultsThree drought tolerance related traits and their relative values (the ratio of value under stress to value under control condition), including seedling weight (SW), shoot length (SL) and root length (RL), were evaluated under control and PEG-induced osmotic conditions at seedling stage in a RIL population derived from cross of Zhushanbai (ZSB) and Jinhuangma (JHM). Significant variation and high broad sense heritability were observed for all traits except SW under stress condition in the population. With this population, a high-density linkage map with 1354 bin markers was constructed through WGRS strategy. Composite interval mapping analysis was performed for all the traits as well as their relative phenotypic data. A total of 34 QTLs were detected for these traits under both conditions and their relative values, and 13 stable QTLs associated with seven traits were revealed in two independent experiments, explaining on average, 4.95-16.26% of phenotypic variation for each QTL. Four of them contributed more than 10% of phenotypic variation. One region on chromosome 12 contained two major QTLs related to RL under osmotic condition and relative RL. Seven candidate genes underlying major QTLs for drought tolerance were identified according to gene descriptions and variations between parents.ConclusionThe current study reports the first QTL mapping of drought tolerance related traits through a RIL population and first QTL detection of root related trait (root length) in sesame. These findings will provide new genetic resources for molecular improvement of drought tolerance and candidate gene identification in sesame.

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