Early Maturing Drought Tolerant Rice Variety BRRI dhan71 Suitable for Drought Prone Environment in Bangladesh

Drought is the second most treacherous climate-related risk for rice production in rainfed lowland areas. To counter this climate vulnerability, a new rice variety with enhanced drought tolerance was developed. The promising line IR82589-B-B-84-3 was subjected to advanced yield trials to evaluate specific and general adaptability with standard check in on-station as well as on-farm conditions of Bangladesh following randomized complete block (RCB) design with three replications in wet (T. Aman) season. IR82589-B-B-84-3 was developed as a drought-tolerant rice variety BRRI dhan71, which plant height 108 cm and growth duration 115 days after proper evaluation by National Seed Board (NSB) Bangladesh. It was found that this variety is the higher drought tolerance (up to 28 days) during reproductive stage. It can produce 5.5 t/ha grain yield in standard condition and 4.0 t/ha grain yield in medium drought condition but 3.0-3.5 t/ha grain yield in severe drought condition. Grain yield is also not affected by water scarcity during reproductive stage where parch water table depth is more than 70-80 cm from the surface and reduced soil moisture (<20%). Thousand grain weight of the variety is 24 gm, amylose content is 24%. It has long, erect and deep green colored flag leaf. The results indicated that farmers can maximize net profit by cultivating BRRI dhan71 because it required less input, early maturing than existing varieties, drought tolerant and they also get opportunity to cultivate Mustard, Barley, Potato and vegetables after harvesting it. Thus total productivity will be augmented and food security can also be sustained by the cultivation of BRRI dhan71.

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Genetic Diversity, Population Structure, and Marker-Trait Association for Drought Tolerance in US Rice Germplasm

Plants ◽

10.3390/plants8120530 ◽

2019 ◽

Vol 8 (12) ◽

pp. 530

Author(s):

Uttam Bhattarai ◽

Prasanta K. Subudhi

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

Drought Tolerance ◽

Grain Yield ◽

Ssr Markers ◽

Harvest Index ◽

Reproductive Stage ◽

Trait Association ◽

Drought Tolerant ◽

Rice Genotypes

Drought is a major constraint in some rice-growing areas of the United States. Its impact is most severe at the reproductive stage resulting in low grain yield. Therefore, assessment of genetic and phenotypic variation for drought tolerance in US rice germplasm is necessary to accelerate the breeding effort. Evaluation of 205 US rice genotypes for drought tolerance at the reproductive stage revealed tolerant response in rice genotypes Bengal, Jupiter, Cypress, Jazzman, Caffey, and Trenasse. Harvest index and fresh shoot weight were identified as important traits to explain the majority of variability among the genotypes under drought tolerance. Genotyping with 80 SSR markers indicated a low level of genetic diversity in US germplasm. Population structure analysis grouped the genotypes into eight clusters. The genotypes from California, Louisiana, and Arkansas formed distinct subgroups. Texas genotypes were similar to those from Louisiana and Arkansas. Marker-trait association analysis showed significant association of RM570 and RM351 with grain yield, spikelet fertility, and harvest index whereas shoot dry weight showed association with RM302 and RM461. The drought-tolerant genotypes identified in this study and the SSR markers associated with drought tolerance attributes will be helpful for development of improved drought-tolerant rice varieties through marker assisted selection.

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Probable omnigenic effect and evolutionary insights of aerobic adaptation allele OsNCED2T on qDTY12.1 effecting grain yield under reproductive stage drought stress in rice

10.1101/2021.03.10.434074 ◽

2021 ◽

Author(s):

C Parameswaran ◽

B Cayalvizhi ◽

S Sanghamitra ◽

N Anandan ◽

K Jawahar Lal ◽

...

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Grain Yield ◽

Genomic Region ◽

Favorable Allele ◽

Severe Drought ◽

Evolutionary Analysis ◽

Synonymous Snps ◽

Drought Tolerant ◽

Genomic Regions

AbstractYield associated quantitative trait loci (qDTY) under drought stress provides significant advantage for grain yield in rice. The major, stable qDTY12.1 was identified in a mapping population developed from upland cultivars Vandana and Way Rarem. Further, introgression line comprising of qDTY12.1 genomic region was characterized to have multiple genes (NAM, DECUSSATE) regulating the drought tolerance under severe drought stress substantiated through recently proposed omnigenic model for complex traits. Recently, plastid localized NCED2T allele present within the qDTY12.1 genomic region was characterized for conferring aerobic adaptation in lowland varieties. Since, NCED2T is evolutionary fixed in upland cultivars and Vandana was found to have the favorable allele of NCED2T, we hypothesized that this favorable allele might confer omnigenic effect on qDTY12.1 genes. Our evolutionary analysis using non synonymous SNPs present in genes namely NCED, NAM, and DECUSSATE and qDTY12.1 genomic regions showed specific grouping of Vandana with upland cultivars only for NCED gene and its adjoining genomic regions. However, non synonymous SNPs in NAM and DECUSSATE genes and its adjoining genomic regions of drought tolerant varieties were closely related and grouped together in the phylogenetic analysis. Moreover, ecotype specific differentiation and greater nucleotide difference with wild relatives was also observed for DECUSSATE gene in rice. This finding indicates differential evolution of qDTY12.1 regions for upland and drought tolerance and omnigenic effect of NCED2T gene in qDTY12.1. Further, we propose a breeding model for enhancing genetic gain for yield under severe drought stress by incorporation of NCEDT, qDTY12.1 and other drought tolerant QTLs for membrane stability in rice.

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Drought Tolerant near Isogenic Lines (NILs) of Pusa 44 Developed through Marker Assisted Introgression of qDTY2.1 and qDTY3.1 Enhances Yield under Reproductive Stage Drought Stress

Agriculture ◽

10.3390/agriculture11010064 ◽

2021 ◽

Vol 11 (1) ◽

pp. 64

Author(s):

Priyanka Dwivedi ◽

Naleeni Ramawat ◽

Gaurav Dhawan ◽

Subbaiyan Gopala Krishnan ◽

Kunnummal Kurungara Vinod ◽

...

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Grain Quality ◽

Reproductive Stage ◽

Recurrent Parent ◽

Near Isogenic Lines ◽

Improvement Project ◽

Isogenic Lines ◽

Drought Tolerant ◽

Rice Improvement

Reproductive stage drought stress (RSDS) is detrimental for rice, which affects its productivity as well as grain quality. In the present study, we introgressed two major quantitative trait loci (QTLs), namely, qDTY2.1 and qDTY3.1, governing RSDS tolerance in a popular high yielding non-aromatic rice cultivar, Pusa 44, through marker-assisted backcross breeding (MABB). Pusa 44 is highly sensitive to RSDS, which restricts its cultivation across drought-prone environments. Foreground selection was carried out using markers, RM520 for qDTY3.1 and RM 521 for qDTY2.1. Background selection was achieved with 97 polymorphic SSR markers in tandem with phenotypic selection to achieve faster recurrent parent genome (RPG) recovery. Three successive backcrosses followed by three selfings aided RPG recoveries of 98.6% to 99.4% among 31 near isogenic lines (NILs). Fourteen NILs were found to be significantly superior in yield and grain quality under RSDS with higher drought tolerance efficiency (DTE) than Pusa 44. Among these, the evaluation of two promising NILs in the multilocational trial during Kharif 2019 showed that they were significantly superior to Pusa 44 under reproductive stage drought stress, while performing on par with Pusa 44 under normal irrigated conditions. These di-QTL pyramided drought-tolerant NILs are in the final stages of testing the All India Coordinated Rice Improvement Project varietal trials for cultivar release. Alternately, the elite drought-tolerant Pusa 44 NILs will serve as an invaluable source of drought tolerance in rice improvement.

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Genetic Dissection of Epistatic Interactions Contributing Grain Yield Variability in Rice under Drought

Current Genomics ◽

10.2174/1386207324666210713112127 ◽

2021 ◽

Vol 22 ◽

Author(s):

Ratna Rani Majumder ◽

Nitika Sandhu ◽

Shailesh Yadav ◽

Margaret Catolos ◽

Ma. Teresa Sta. Cruz ◽

...

Keyword(s):

Drought Stress ◽

Grain Yield ◽

Genetic Background ◽

Reproductive Stage ◽

Yield Variability ◽

Marker Interval ◽

Negative Interaction ◽

Epistatic Interactions ◽

Lattice Design ◽

Drought Tolerant

Aims: The aim of the present study was to evaluate the performance of ‘high’-‘low’ yielding pyramided lines (PLs) with the same combinations of qDTYs in Samba Mahsuri, MR219 and IR64-Sub1 genetic backgrounds and understand the genetic interactions of QTL and with genetic background affecting grain yield. Background: Epistasis regulates the expression of traits governed by several major/minor genes/QTL. Multiple pyramided lines (PLs) with the same grain yield QTL (qDTYs) combinations but possessing grain yield variability under different levels of reproductive stage drought stress were identified in different rice genetic backgrounds at International Rice Research Institute (IRRI). Objectives: The objectives of the present study were to evaluate the performance pyramided lines (PLs) with drought QTL in the backgrounds of Samba Mahsuri, MR219 and IR64-Sub1 under reproductive stage drought stress (RS) and NS (non-stress) conditions ii) to understand the effect of epistatic interactions of qDTYs and with genetic background on GY under the differential level of stress iii) to identify the promising drought-tolerant lines with high yield under drought and higher background recovery in different genetic backgrounds. Results: Several digenic interactions were found in different genetic backgrounds, 13 interactions in Samba Mahsuri, 11 in MR219 and 20 in IR64-Sub1 backgrounds. Among all digenic interactions, one QTL × QTL interaction, 17 QTL × background and 26 background × background interactions resulted in GY reduction in low yielding PLs in different genetic backgrounds under LSS or LMS. Negative interaction of qDTY3.1, qDTY4.1 and qDTY9.1 with background markers and background × background interactions caused up to 15% GY reduction compared to the high yielding PLs under LMS in the Samba Mahsuri PLs. In MR219 PLs, the negative interaction of qDTY2.2, qDTY3.2, qDTY4.1 and qDTY12.1 with the background marker interval RM314-RM539, RM273-RM349 and RM445-RM346, RM473D-RM16, respectively resulted in 52% GY reduction compared to the high yielding PLs under LSS. In IR64-Sub1 PLs, qDTY6.1 interacted with background loci at RM16-RM135, RM228-RM333, RM202-RM287 and RM415-RM558A marker interval under LSS; and at RM475-RM525 marker interval under LMS, causing GY reduction to 58% compared to the high yielding PLs. Conclusion: High yielding PLs in Samba Mahsuri (IR 99734:1-33-69-1-22-6), MR219 (IR 99784-156-87-2-4-1) and IR64-Sub1 (IR 102784:2-89-632-2-1-2) backgrounds without any negative interactions were identified. The identified selected promising PLs may be used as potential drought-tolerant donors or may be released as varieties for drought-prone ecosystems in different countries. Methods: The experiments were conducted in 2015DS (dry season), 2015WS (wet season) and 2017 DS at IRRI, Los Baños, Philippines, in a transplanted lowland ecosystem under lowland severe stress (LSS), moderate lowland stress (LMS) and lowland non-stress (LNS). The experiments were laid out in alpha lattice design with two replications.

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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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Genome-wide association study for yield and yield related traits under reproductive stage drought in a diverse indica-aus rice panel

10.21203/rs.2.24272/v1 ◽

2020 ◽

Author(s):

Aditi Bhandari ◽

Nitika Sandhu ◽

Jérôme Bartholome ◽

Tuong-Vi Cao-Hamadoun ◽

Nourollah Ahmadi ◽

...

Keyword(s):

Grain Yield ◽

Field Experiments ◽

Genome Wide Association Study ◽

Reproductive Stage ◽

Phenotypic Variance ◽

Rice Varieties ◽

Drought Tolerant ◽

Genome Wide ◽

Close Proximity ◽

Genomic Regions

Abstract Background Reproductive-stage drought stress is a major impediment to rice production globally. Conventional and marker-assisted breeding strategies for developing drought tolerant rice varieties are being optimized by mining and exploiting adaptive traits, genetic diversity; identifying the alleles and understanding their interactions with genetic backgrounds for contributing to drought tolerance. Field experiments were conducted in this study to identify marker-trait associations (MTAs) involved in response to yield under reproductive-stage drought. A diverse set of 280 indica-aus accessions was phenotyped for grain yield and nine yield-related traits under normal condition and under two managed drought environments. The accessions were genotyped with 215,250 single nucleotide polymorphism markers. Results The study identified a total of 220 significant MTAs and candidate gene analysis within 200kb window centred from GWAS identified SNP peaks detected these MTAs within/ in close proximity to 47 genes, 4 earlier reported major grain yield QTLs and 8 novel QTLs for 10 traits. The significant MTAs were majorly located on chromosomes 1, 2, 5, 6, 11 and 12 and the percent phenotypic variance captured for these traits ranged from 5 to 88%. The significant positive correlation of grain yield with yield-related traits, except flowering time, observed under different environments point towards their contribution in improving rice yield under drought. Seven promising accessions were identified for use in future genomics-assisted breeding program targeting grain yield improvement under drought. Conclusion These results provide a promising insight into the complex-genetic architecture of grain yield under reproductive-stage drought under different environments. Validation of major genomic regions reported in the study can be effectively used to develop drought tolerant varieties following marker-assisted selection as well as to identify genes and understanding the associated physiological mechanisms.

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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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The Effect of Calcium Chloride on Drought Tolerance of Mulberry

International Journal of Scientific Research in Science Engineering and Technology ◽

10.32628/ijsrset207624 ◽

2020 ◽

pp. 177-186

Author(s):

Cha JinMyong ◽

Ri CholUk ◽

Kim Chol Min ◽

Ri Huang Gi ◽

Ri Do Hun Qin Bo

Keyword(s):

Drought Tolerance ◽

Calcium Chloride ◽

Treated Group ◽

Severe Drought ◽

Drought Condition ◽

Effective Measure ◽

Biochemical Responses ◽

Cacl2 Concentration ◽

Silkworm Cocoon ◽

Physiological And Biochemical

Drought stress greatly affects the quality and yield of mulberry leaves, which eventually influences the production of silkworm cocoon. In this study, the effect of calcium chloride on drought tolerance of mulberry was investigated. Different concentrations of CaCl2 solutions were sprayed on the leaves of mulberry under drought condition, and the physiological and biochemical responses were measured. As a result, the spray of CaCl2 on leaves (CaCl2-spray-on-leaves) was proved to have gradual increases in measure parameters as compared to CaCl2-untreated case under the same drought condition; furthermore, 20mM CaCl2-treated group showed a significant increase (P<0.05), which indicates the optimal CaCl2 concentration for improving the drought tolerance of mulberry. This study demonstrated that CaCl2-spray-on-leaves can be an effective measure to ameliorate the drought tolerance of mulberry in the severe-drought areas.

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Genome-wide association study for yield and yield related traits under reproductive stage drought in a diverse indica-aus rice panel

10.21203/rs.3.rs-26606/v2 ◽

2020 ◽

Author(s):

Aditi Bhandari ◽

Nitika Sandhu ◽

Jérôme Bartholome ◽

Tuong-Vi Cao-Hamadoun ◽

Nourollah Ahmadi ◽

...

Keyword(s):

Grain Yield ◽

Field Experiments ◽

Genome Wide Association Study ◽

Agronomic Traits ◽

Reproductive Stage ◽

Phenotypic Variance ◽

Rice Varieties ◽

Drought Tolerant ◽

Genome Wide ◽

Genomic Regions

Abstract Background Reproductive-stage drought stress is a major impediment to rice production in rainfed areas. Conventional and marker-assisted breeding strategies for developing drought-tolerant rice varieties are being optimized by mining and exploiting adaptive traits, genetic diversity; identifying the alleles, and understanding their interactions with genetic backgrounds for their increased contribution to drought tolerance. Field experiments were conducted in this study to identify marker-trait associations (MTAs) involved in response to yield under reproductive-stage (RS) drought. A diverse set of 280 indica-aus accessions was phenotyped for ten agronomic traits including yield and yield-related traits under normal irrigated condition and under two managed reproductive-stage drought environments. The accessions were genotyped with 215,250 single nucleotide polymorphism markers. Results The study identified a total of 219 significant MTAs for 10 traits and candidate gene analysis within a 200kb window centred from GWAS identified SNP peaks detected these MTAs within/ in close proximity to 38 genes, 4 earlier reported major grain yield QTLs and 6 novel QTLs for 7 traits out of the 10. The significant MTAs were mainly located on chromosomes 1, 2, 5, 6, 9, 11 and 12 and the percent phenotypic variance captured for these traits ranged from 5 to 88%. The significant positive correlation of grain yield with yield-related and other agronomic traits except for flowering time, observed under different environments point towards their contribution in improving rice yield under drought. Seven promising accessions were identified for use in future genomics-assisted breeding programs targeting grain yield improvement under drought. Conclusion These results provide a promising insight into the complex genetic architecture of grain yield under reproductive-stage drought in different environments. Validation of major genomic regions reported in the study will enable their effectiveness to develop drought-tolerant varieties following marker-assisted selection as well as to identify genes and understanding the associated physiological mechanisms.

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Development of Drought Tolerant Rice Variety BRRI dhan66 for Rainfed Lowland Ecosystem of Bangladesh

Bangladesh Rice Journal ◽

10.3329/brj.v23i1.46080 ◽

2020 ◽

Vol 23 (1) ◽

pp. 45-55

Author(s):

M A Kader ◽

T L Aditya ◽

R R Majumder ◽

T K Hore ◽

A K M Shalahuddin ◽

...

Keyword(s):

Flag Leaf ◽

Rice Variety ◽

Economic Loss ◽

Reproductive Stage ◽

Wet Season ◽

Rice Varieties ◽

Commercial Cultivation ◽

Drought Tolerant ◽

Rainfed Lowland ◽

Prone Area

A newly released drought tolerant rice variety BRRI dhan66 suitable for rainfed lowland ecosystem of Bangladesh is an improvement over existing drought tolerant rice varieties. The variety has satisfactorily been passed in the proposed variety trial conducted in the farmers’ field. As a result, National Seed Board (NSB) approved this variety for commercial cultivation in the wet season (T. Aman) in 2014. It has modern plant type with 120 cm plant height and matures in 110-115 days. The important feature of this variety is higher drought tolerance during reproductive stage. It can produce 4.5-5.0 t/ha grain yield without irrigation during reproductive stage. It can produce satisfactory yield when soil moisture remains <20% and perch water table depth is more than 70-80 cm from the surface. The seed size of the variety is 24 g with intermediate long bold grain. It has long, wide and erect flag leaf with deep green colour. It is highly promising as a drought tolerant rice variety for cultivation in the drought prone area, which helps farmers’ to get rid of huge economic loss and is contributing in sustaining food security. Bangladesh Rice j. 2019, 23(1): 45-55

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