Variations in morphological traits, agronomic traits and traits related to drought tolerance in indigenous Thai rice varieties

The identification of traits associated with drought tolerance in popcorn is a contribution to support selection of superior plants under soil water deficit. The objective of this study was to choose morphological traits and the leaf greenness index, measured on different dates, to estimate grain yield (GY) and popping expansion (PE), evaluated in a set of 20 popcorn lines with different genealogies, estimated by multiple regression models. The variables were divided into three groups: morpho-agronomic traits—100-grain weight (GW), prolificacy (PR), tassel length (TL), number of tassel branches, anthesis-silking interval, leaf angle (FA) and leaf rolling (FB); variables related to the intensity of leaf greenness during the grain-filling period, at the leaf level, measured by a portable chlorophyll meter (SPAD) and at the canopy level, calculated as the normalized difference vegetation index (NDVI). The inbred lines were cultivated under two water conditions: well-watered (WW), maintained at field capacity, and water stress (WS), for which irrigation was stopped before male flowering. The traits GY (55%) and PE (28%) were most affected by water restriction. Among the morpho-agronomic traits, GW and PR were markedly reduced (>10%). Under dry conditions, the FA in relation to the plant stalk tended to be wider, the FB curvature greater and leaf senescence accelerated (>15% at 22 days after male flowering). The use of multiple regression for the selection of predictive traits proved to be a useful tool for the identification of groups of adequate traits to efficiently predict the economically most important features of popcorn (GY and PE). The SPAD index measured 17 days after male flowering proved useful to select indirectly for GY, while, among the morphological traits, TL stood out for the same purpose. Of all traits, PR was most strongly related with PE under WS, indicating its use in breeding programs. The exploitation of these traits by indirect selection is expected to induce increments in GY and PE.

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Exogenously Used 24-Epibrassinolide Promotes Drought Tolerance in Maize Hybrids by Improving Plant and Water Productivity in an Arid Environment

Plants ◽

10.3390/plants10020354 ◽

2021 ◽

Vol 10 (2) ◽

pp. 354

Author(s):

El-Sayed M. Desoky ◽

Elsayed Mansour ◽

Mohamed M. A. Ali ◽

Mohamed A. T. Yasin ◽

Mohamed I. E. Abdul-Hamid ◽

...

Keyword(s):

Drought Tolerance ◽

Agronomic Traits ◽

Water Productivity ◽

Positive Association ◽

Net Photosynthesis ◽

Antioxidant Enzyme Activities ◽

Severe Drought ◽

Arid Environments ◽

Maize Hybrids ◽

Semi Arid

The influence of 24-epibrassinolide (EBR24), applied to leaves at a concentration of 5 μM, on plant physio-biochemistry and its reflection on crop water productivity (CWP) and other agronomic traits of six maize hybrids was field-evaluated under semi-arid conditions. Two levels of irrigation water deficiency (IWD) (moderate and severe droughts; 6000 and 3000 m3 water ha−1, respectively) were applied versus a control (well-watering; 9000 m3 water ha−1). IWD reduced the relative water content, membrane stability index, photosynthetic efficiency, stomatal conductance, and rates of transpiration and net photosynthesis. Conversely, antioxidant enzyme activities and osmolyte contents were significantly increased as a result of the increased malondialdehyde content and electrolyte leakage compared to the control. These negative influences of IWD led to a reduction in CWP and grain yield-related traits. However, EBR24 detoxified the IWD stress effects and enhanced all the above-mentioned parameters. The evaluated hybrids varied in drought tolerance; Giza-168 was the best under moderate drought, while Fine-276 was the best under severe drought. Under IWD, certain physiological traits exhibited a highly positive association with yield and yield-contributing traits or CWP. Thus, exogenously using EBR24 for these hybrids could be an effective approach to improve plant and water productivity under reduced available water in semi-arid environments.

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Meta-QTL and ortho-MQTL analyses identified genomic regions controlling rice yield, yield-related traits and root architecture under water deficit conditions

Scientific Reports ◽

10.1038/s41598-021-86259-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Bahman Khahani ◽

Elahe Tavakol ◽

Vahid Shariati ◽

Laura Rossini

Keyword(s):

Water Deficit ◽

Root Architecture ◽

Agronomic Traits ◽

Heading Date ◽

Dry Weight ◽

Genetic Dissection ◽

Rice Varieties ◽

Average Confidence ◽

Stable Qtls ◽

Genomic Regions

AbstractMeta-QTL (MQTL) analysis is a robust approach for genetic dissection of complex quantitative traits. Rice varieties adapted to non-flooded cultivation are highly desirable in breeding programs due to the water deficit global problem. In order to identify stable QTLs for major agronomic traits under water deficit conditions, we performed a comprehensive MQTL analysis on 563 QTLs from 67 rice populations published from 2001 to 2019. Yield and yield-related traits including grain weight, heading date, plant height, tiller number as well as root architecture-related traits including root dry weight, root length, root number, root thickness, the ratio of deep rooting and plant water content under water deficit condition were investigated. A total of 61 stable MQTLs over different genetic backgrounds and environments were identified. The average confidence interval of MQTLs was considerably refined compared to the initial QTLs, resulted in the identification of some well-known functionally characterized genes and several putative novel CGs for investigated traits. Ortho-MQTL mining based on genomic collinearity between rice and maize allowed identification of five ortho-MQTLs between these two cereals. The results can help breeders to improve yield under water deficit conditions.

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Drought tolerance in selected aerobic and upland rice varieties is driven by different metabolic and antioxidative responses

Planta ◽

10.1007/s00425-021-03659-4 ◽

2021 ◽

Vol 254 (1) ◽

Author(s):

Giovanni Melandri ◽

Hamada AbdElgawad ◽

Kristýna Floková ◽

Diaan C. Jamar ◽

Han Asard ◽

...

Keyword(s):

Drought Tolerance ◽

Upland Rice ◽

Vegetative Stage ◽

Clear Understanding ◽

Multiple Time ◽

Rice Varieties ◽

Antioxidant Power ◽

Antioxidative Response ◽

Biomass Loss ◽

Osmotic Acclimation

Abstract Main conclusions Sugar-mediated osmotic acclimation and a strong antioxidative response reduce drought-induced biomass loss at the vegetative stage in rice. Abstract A clear understanding of the physiological and biochemical adaptations to water limitation in upland and aerobic rice can help to identify the mechanisms underlying their tolerance to low water availability. In this study, three indica rice varieties-IR64 (lowland), Apo (aerobic), and UPL Ri-7 (upland)-, that are characterized by contrasting levels of drought tolerance, were exposed to drought at the vegetative stage. Drought-induced changes in biomass, leaf metabolites and oxidative stress markers/enzyme activities were analyzed in each variety at multiple time points. The two drought-tolerant varieties, Apo and UPL Ri-7 displayed a reduced water use in contrast to the susceptible variety IR64 that displayed high water consumption and consequent strong leaf dehydration upon drought treatment. A sugar-mediated osmotic acclimation in UPL Ri-7 and a strong antioxidative response in Apo were both effective in limiting the drought-induced biomass loss in these two varieties, while biomass loss was high in IR64, also after recovery. A qualitative comparison of these results with the ones of a similar experiment conducted in the field at the reproductive stage showed that only Apo, which also in this stage showed the highest antioxidant power, was able to maintain a stable grain yield under stress. Our results show that different metabolic and antioxidant adaptations confer drought tolerance to aerobic and upland rice varieties in the vegetative stage. The effectiveness of these adaptations differs between developmental stages. Unraveling the genetic control of these mechanisms might be exploited in breeding for new rice varieties adapted to water-limited environments.

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Distinctness of 110 rice (Oryza sativa L.) varieties of Bangladesh through morphological traits

Journal of the Bangladesh Agricultural University ◽

10.3329/jbau.v12i1.21236 ◽

2014 ◽

Vol 12 (1) ◽

pp. 29-36

Author(s):

MS Rahman ◽

MKH Sohag ◽

L Rahman

Keyword(s):

Morphological Traits ◽

Leaf Blade ◽

Oryza Sativa L ◽

Flag Leaf ◽

Leaf Sheath ◽

Seed Colour ◽

Rice Varieties ◽

Nodal Root ◽

Two Hybrid ◽

Research Institute

A total of 110 rice varieties of which 108 local (From Bangladesh Rice Research Institute) and two hybrid varieties (From ACI Ltd. Bangladesh) were used to identify the morphological traits during July, 2008 to June, 2009. These varieties represented four types viz. T. Aman (n=92), B. Aman (n=15), Boro (n=2) and Jhum accession (n=1) as described by Bangladesh Rice Research Institutes literature. Though all these materials were varied ecotypically but grown in one (T. Aman) season. Irrespective of groups of all, 90 varieties were appeared distinctly morphologically from others due to seed colour; stigma colour; anthocyanin colouration of leaf sheath, nodes and lemma:palea, presence of awn and nodal root. Among 90 distinct varieties 19 were distinctly different from others by four traits, nine by three traits, 24 by two traits and 38 varieties by only single trait. The rest 20 varieties were distinguished flag leaf: attitude of the leaf blade. This was done to assess the quality traits of distinctness as major concern and was noninfluenced by the environment. DOI: http://dx.doi.org/10.3329/jbau.v12i1.21236 J. Bangladesh Agril. Univ. 12(1): 29-36, June 2014

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Selection of drought-tolerant rice varieties from the rice variety bank of Can Tho university

The Journal of Agriculture and Development ◽

10.52997/jad.8.02.2019 ◽

2019 ◽

Vol 02 ◽

pp. 65-70

Author(s):

Tin Q. Huynh

Keyword(s):

Water Stress ◽

Drought Tolerance ◽

Rice Variety ◽

Mekong Delta ◽

Rice Cultivation ◽

Rice Varieties ◽

Wetting And Drying ◽

Drought Tolerant ◽

Susceptible Control ◽

Rice Improvement

Drought has been a big problem and damaged seriously to rice cultivation and production in Vietnam and the Mekong Delta region; evaluating drought tolerance of rice is a major objective for the rice improvement programmes in Can Tho University. Fifty-two collected rice varieties including resistant and susceptible control varieties were screened for water stress under the artificial drought condition. Marker RM223 was used to identify the drought tolerance genotypes for some selected varieties with good and moderate tolerant scores. After 30 days of water stress, the results were 6 varieties of good tolerant, 8 varieties of moderate tolerance, 36 varieties of moderately susceptible and 2 varieties of susceptible to drought. Analyses of PCR showed that 10 varieties expressed the similar bands with the resistant control variety. Four varieties (LH8, MTL812, Lua Canh and VB1) with good tolerant to drought were recommended to use for genetic materials of rice breeding program and applying in alternative wetting and drying irrigation technique for rice cultivation.

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Study some of Wheat Cultivars Based on Morphological Traits and Drought Tolerance Indices

Journal of Crop Breeding ◽

10.29252/jcb.9.21.44 ◽

2017 ◽

Vol 9 (21) ◽

pp. 44-55

Author(s):

Maryam Tahmasb Ali ◽

Ali Asghari ◽

Omid Safalian ◽

Hamidreza Mohammaddoust Chaman Abad ◽

Ali Rasoul Zadeh

Keyword(s):

Drought Tolerance ◽

Morphological Traits ◽

Wheat Cultivars ◽

Drought Tolerance Indices ◽

Tolerance Indices

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miR2105 regulates ABA biosynthesis via OsbZIP86-OsNCED3 module to contribute to drought tolerance in rice

10.1101/2021.09.21.461241 ◽

2021 ◽

Author(s):

Weiwei Gao ◽

Mingkang Li ◽

Songguang Yang ◽

Chunzhi Gao ◽

Yan Su ◽

...

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Transgenic Rice ◽

Crucial Role ◽

Agronomic Traits ◽

Stomatal Closure ◽

Plant Tolerance ◽

Rice Plants ◽

Transgenic Rice Plants ◽

Aba Biosynthesis

AbstractInduced abscisic acid (ABA) biosynthesis plays an important role in plant tolerance to abiotic stresses, including drought, cold and salinity. However, regulation pathway of the ABA biosynthesis in response to stresses is unclear. Here, we identified a rice miRNA, osa-miR2105 (miR2105), which plays a crucial role in ABA biosynthesis under drought stress. Analysis of expression, transgenic rice and cleavage site showed that OsbZIP86 is a target gene of miR2105. Subcellular localization and luciferase activity assays showed that OsbZIP86 is a nuclear transcription factor. In vivo and in vitro analyses showed that OsbZIP86 directly binds to the promoter of OsNCED3, and interacts with OsSAPK10, resulting in enhanced-expression of OsNCED3. Transgenic rice plants with knock-down of miR2105 or overexpression of OsbZIP86 showed higher ABA content, more tolerance to drought, a lower rate of water loss, more stomatal closure than wild type rice ZH11 under drought stress. These rice plants showed no penalty with respect to agronomic traits under normal conditions. By contrast, transgenic rice plants with miR2105 overexpression, OsbZIP86 downregulation, or OsbZIP86 knockout displayed less tolerance to drought stress and other phenotypes. Collectively, our results show that a regulatory network of ‘miR2105-OsSAPK10/OsbZIP86-OsNCED3’ control ABA biosynthesis in response to drought stress.One-sentence summary‘miR2105-OsbZIP86-OsNCED3’ module plays crucial role in mediating ABA biosynthesis to contribute to drought tolerance with no penalty with respect to agronomic traits under normal conditions.

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High-yielding NERICA mutant rice for upland areas and hope for Bangladeshi farmers.

10.1079/9781789249095.0006 ◽

2021 ◽

pp. 53-64

Author(s):

Mirza Mofazzal Islam ◽

Shamsun Nahar Begum ◽

Rigyan Gupta

Keyword(s):

Drought Tolerance ◽

Grain Yield ◽

Crop Production ◽

Upland Rice ◽

Vital Role ◽

High Yield ◽

Rice Varieties ◽

Commercial Cultivation ◽

Drought Tolerant ◽

Different Doses

Abstract Drought is an important stress phenomenon in Bangladesh that greatly hampers crop production. So, it is imperative to develop drought-tolerant rice varieties. Low-yielding, non-uniform flowering and late-maturing Africa rice - New Rice for Africa (NERICA), viz. NERICA-1, NERICA-4 and NERICA-10 varieties - were irradiated with different doses of gamma-rays (250, 300 and 350 Gy) in 2010. M1 plants were grown and M2 plants were selected based on earliness and higher grain yield. The desired mutants along with other mutants were grown as the M3 generation during 2011. A total of 37 mutants from NERICA-1, NERICA-4 and NERICA-10 were selected on the basis of plant height, short duration, drought tolerance and high yield in the M4 generation. In the M5 generation, six mutants were selected for drought tolerance, earliness, grain quality and higher yield. With respect to days to maturity and grain yield (t/ha), the mutant N1/250/P-2-6-1 of NERICA-1 matured earlier (108 days) and had higher grain yield (5.1 t/ha) than the parent. The mutant N4/350/P-4(5) of NERICA-4 also showed a higher grain yield (6.2 t/ha) than its parent and other mutants. On the other hand, NERICA-10 mutant N10/350/P-5-4 matured earlier and had a higher yield (4.5 t/ha) than its parent. Finally, based on agronomic performance and drought tolerance, the two mutants N4/350/P-4(5) and N10/350/P-5-4 were selected and were evaluated in drought-prone and upland areas during 2016 and 2017. These two mutants performed well with higher grain yield than the released upland rice varieties. They will be released soon for commercial cultivation and are anticipated to play a vital role in food security in Bangladesh.

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