Drought tolerant wheat varieties developed through mutation breeding technique

Wheat (Triticum aestivum L.) is one of the major basic stable crops grown worldwide, however, it is sensitive to environmental stresses like drought. With climate change, drought stress is becoming an increasingly severe constraint on wheat production which affects the plant growth and development, physiological functions, grain formation, grain quality and ultimately the yield. Various responses including biochemical, physiological, morphological, and molecular adaptations are shown by plants to survive in the drought stress condition. Drought escape, avoidance and tolerance are important coping mechanisms of wheat plant under drought environment. Several mechanisms such as accumulation of ABA, osmotic adjustment, and induction of dehydrins may confer drought tolerance by maintaining the high tissue water potential. As the root structure and root biomass define the pattern of water extraction from the soil, enhanced root and suppressed shoot growth resulting in higher root: shoot ratio facilitated plants to drought tolerance. The development of drought tolerance varieties becomes an important due to the uneven distribution of rainfall and water shortage. Some growth stage-specific physio-morphological traits are fundamental targets to breed drought-tolerant wheat varieties. Mutation breeding, molecular breeding, genome engineering techniques including gene pyramiding, gene stacking, and transgenics are employed to breed wheat for tolerance to abiotic stresses including drought. Omics decode the entire genome to have better understanding of plant molecular responses that will provide precise strategies for crop improvement. This paper discusses the wheat plant’s responses to drought stress, their defense mechanisms and modern techniques for the development of drought tolerant wheat varieties.

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EMS Derived Wheat Mutant BIG8-1 (Triticum aestivum L.)—A New Drought Tolerant Mutant Wheat Line

International Journal of Molecular Sciences ◽

10.3390/ijms22105314 ◽

2021 ◽

Vol 22 (10) ◽

pp. 5314

Author(s):

Marlon-Schylor L. le Roux ◽

Nicolas Francois V. Burger ◽

Maré Vlok ◽

Karl J. Kunert ◽

Christopher A. Cullis ◽

...

Keyword(s):

Amino Acids ◽

Water Deficit ◽

Triticum Aestivum L ◽

Water Deficit Stress ◽

Drought Response ◽

Fibrous Root ◽

Wheat Varieties ◽

Breeding Programs ◽

Response Characteristics ◽

Drought Tolerant

Drought response in wheat is considered a highly complex process, since it is a multigenic trait; nevertheless, breeding programs are continuously searching for new wheat varieties with characteristics for drought tolerance. In a previous study, we demonstrated the effectiveness of a mutant known as RYNO3936 that could survive 14 days without water. In this study, we reveal another mutant known as BIG8-1 that can endure severe water deficit stress (21 days without water) with superior drought response characteristics. Phenotypically, the mutant plants had broader leaves, including a densely packed fibrous root architecture that was not visible in the WT parent plants. During mild (day 7) drought stress, the mutant could maintain its relative water content, chlorophyll content, maximum quantum yield of PSII (Fv/Fm) and stomatal conductance, with no phenotypic symptoms such as wilting or senescence despite a decrease in soil moisture content. It was only during moderate (day 14) and severe (day 21) water deficit stress that a decline in those variables was evident. Furthermore, the mutant plants also displayed a unique preservation of metabolic activity, which was confirmed by assessing the accumulation of free amino acids and increase of antioxidative enzymes (peroxidases and glutathione S-transferase). Proteome reshuffling was also observed, allowing slow degradation of essential proteins such as RuBisCO during water deficit stress. The LC-MS/MS data revealed a high abundance of proteins involved in energy and photosynthesis under well-watered conditions, particularly Serpin-Z2A and Z2B, SGT1 and Calnexin-like protein. However, after 21 days of water stress, the mutants expressed ABC transporter permeases and xylanase inhibitor protein, which are involved in the transport of amino acids and protecting cells, respectively. This study characterizes a new mutant BIG8-1 with drought-tolerant characteristics suited for breeding programs.

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Canopy Temperature and Chlorophyll Content are Effective Measures of Drought Stress Tolerance in Durum Wheat

Notulae Scientia Biologicae ◽

10.15835/nsb10410288 ◽

2018 ◽

Vol 10 (4) ◽

pp. 575-583 ◽

Cited By ~ 1

Author(s):

Fereshteh JOKAR ◽

Rahmatollah KARIMIZADEH ◽

Asad MASOUMIASL ◽

Reza AMIRI FAHLIANI

Keyword(s):

Drought Tolerance ◽

Durum Wheat ◽

Stress Tolerance ◽

Chlorophyll Content ◽

Geometric Mean ◽

Canopy Temperature ◽

Stress Conditions ◽

Tolerance Index ◽

Wheat Varieties ◽

Drought Tolerant

Durum wheat (Triticum durum L.) is used for the preparation of multiple food products, including pasta and bread. Its production is restricted due to diverse environmental stresses i.e. drought and heat stress. Here, comparative analysis of durum wheat varieties was done by studying canopy temperature depression (CTD) and chlorophyll content (CHL), yield and yield contributing traits to evaluate their performance under stress and low stress conditions. Twelve durum wheat genotypes were studied under stressful and low-stress conditions in Gachsaran region of Iran. CTD and CHL were measured at two stages, from the emergence of fifty percent of inflorescence (ZGS 54) to watery ripe stage (ZGS 71). According to stress tolerance index (STI), mean productivity (MP) and geometric mean productivity (GMP) indices, genotype G10 exhibited the most, while genotype G6, the least relative tolerance, respectively. Based on MP and GMP, genotype G10 was found to be drought tolerant, while genotype G2 displayed the lowest amount of MP and GMP. Therefore these genotypes are recommended to be used as genitors in artificial hybridization for improvement of drought tolerance in other cultivars. All indices had high correlation with grain yield under stress and non-stress condition, indicating more suitability of these indices for selection of resistant genotype. Results of the present study showed that among drought tolerance indices, harmonic mean (HM), GMP, CTD and modified STI index (K2STI) can be used as the most suitable indicators for screening drought tolerant cultivars.

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Pemuliaan Mutasi untuk Perbaikan terhadap Umur dan Produktivitas pada Kedelai

Jurnal AgroBiogen ◽

10.21082/jbio.v9n3.2013.p135-142 ◽

2016 ◽

Vol 9 (3) ◽

pp. 135 ◽

Cited By ~ 2

Author(s):

Asadi Asadi

Keyword(s):

Cropping System ◽

Mutation Breeding ◽

Energy Agency ◽

High Productivity ◽

Drought Tolerant ◽

Early Maturing ◽

Seed Irradiation ◽

New Varieties ◽

The Government ◽

Mutant Lines

To support the government policy in improving soybean production, it is suggested to plant early maturing (<80 days), drought tolerant and high yielding varieties to be applied in the cropping system of rice-ricesoybean and rice-rice-rice-soybean in lowland, and in dryland cropping system of rice-soybean or rice-other palawija crops. Mutation breeding in soybean for early maturity and high productivity in soybean can be applied to obtain some new varieties. The breeding procedures included selection using bulk method for M1 population, followed by the pedigree method for M2-M5 generations. Evaluation of uniformity (homozygous) of lines is done on the M4 generation. Yield and adaption testing are conducted during M5-M8 generations. Through mutation breeding early maturity soybean varieties were released elsewhere. In national research institutes such as The National Nuclear Energy Agency (Batan) Indonesia, soybean mutation breeding activities were begun since 1972, while in Indonesian Center for Agricultural Biotechnology and Genetic Resources Research and Development (ICABIOGRAD), it was started in 2009. Batan has released two early maturing soybean varieties through seed irradiation such as Tengger in 1991 and Meratus in 1998. While in 2011 ICABIOGRAD through irradiation of calli-derived embryo zygotic has selected 50 early maturing and potentially yielding soybean mutant lines. While through seed irradiation in 2012, 15 soybean advanced lines that matured earlier and demontrated higher yield were also obtained.

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Endophytic Bacterial Microbiome Diversity in Early Developmental Stage Plant Tissues of Wheat Varieties

Plants ◽

10.3390/plants9020266 ◽

2020 ◽

Vol 9 (2) ◽

pp. 266 ◽

Cited By ~ 1

Author(s):

Jana Žiarovská ◽

Juraj Medo ◽

Matúš Kyseľ ◽

Lucia Zamiešková ◽

Miroslava Kačániová

Keyword(s):

Drought Stress ◽

Bacterial Diversity ◽

Early Developmental Stage ◽

Wheat Varieties ◽

Drought Tolerant ◽

Microbiome Diversity ◽

Bacterial Microbiome ◽

Early Developmental ◽

Production Characteristics

Endophytic bacteria are an important part of different functions in plants that lead to plants’ production characteristics as well as their stress response mechanisms. Endophytic bacterial diversity was analyzed in this study to describe 16S rRNA variability and changes in the leaves of drought-tolerant and drought-susceptible wheat when growth under in vitro conditions. A metagenomic analysis was applied and a pilot exploratory study was performed to prove this type of analysis as applicable to tracking endophytic bacterial diversity changes when a drought stress is applied to an in vitro culture of wheat. The study showed that the changes in the bacterial endophytes’ variabilities associated preferentially with the drought stress varietal characteristics of the analyzed wheat instead of the applied stress conditions.

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RNAseq analysis reveals drought-responsive molecular pathways with candidate genes and putative molecular markers in root tissue of wheat

Scientific Reports ◽

10.1038/s41598-019-49915-2 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 8

Author(s):

Mir Asif Iquebal ◽

Pradeep Sharma ◽

Rahul Singh Jasrotia ◽

Sarika Jaiswal ◽

Amandeep Kaur ◽

...

Keyword(s):

Regulatory Networks ◽

Stomatal Closure ◽

Root Tissue ◽

Limited Information ◽

Rna Seq ◽

Wheat Roots ◽

Wheat Varieties ◽

Genomic Resources ◽

Drought Tolerant ◽

Putative Candidate Gene

Abstract Drought is one of the major impediments in wheat productivity. Traditional breeding and marker assisted QTL introgression had limited success. Available wheat genomic and RNA-seq data can decipher novel drought tolerance mechanisms with putative candidate gene and marker discovery. Drought is first sensed by root tissue but limited information is available about how roots respond to drought stress. In this view, two contrasting genotypes, namely, NI5439 41 (drought tolerant) and WL711 (drought susceptible) were used to generate ~78.2 GB data for the responses of wheat roots to drought. A total of 45139 DEGs, 13820 TF, 288 miRNAs, 640 pathways and 435829 putative markers were obtained. Study reveals use of such data in QTL to QTN refinement by analysis on two model drought-responsive QTLs on chromosome 3B in wheat roots possessing 18 differentially regulated genes with 190 sequence variants (173 SNPs and 17 InDels). Gene regulatory networks showed 69 hub-genes integrating ABA dependent and independent pathways controlling sensing of drought, root growth, uptake regulation, purine metabolism, thiamine metabolism and antibiotics pathways, stomatal closure and senescence. Eleven SSR markers were validated in a panel of 18 diverse wheat varieties. For effective future use of findings, web genomic resources were developed. We report RNA-Seq approach on wheat roots describing the drought response mechanisms under field drought conditions along with genomic resources, warranted in endeavour of wheat productivity.

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Methods for evaluation of wheat breeding material for drought tolerance

Visnyk of Lviv University Biological series ◽

10.30970/vlubs.2020.82.05 ◽

2020 ◽

pp. 63-79

Author(s):

S. Pykalo ◽

◽

O. Demydov ◽

T. Yurchenko ◽

S. Khomenko ◽

...

Keyword(s):

Drought Tolerance ◽

Wheat Breeding ◽

Wheat Varieties ◽

Advantages And Disadvantages ◽

Breeding Material ◽

Leading Role ◽

Drought Tolerant ◽

Grain Trade ◽

The Creation ◽

Conducting Research

Wheat is one of the most valuable cereals on the planet and plays a leading role in the food supply of mankind. The range of wheat is very large, since it is cultivated on five continents in most countries of the world. The genetic improvement of wheat is crucial because of its direct impact on the economic development, international grain trade and food security of the country, so the relevance of research in solving many genetic-breeding problems regarding this crop is growing and acquires a qualitatively new character. The increase in productivity is the most important criterion in the cultivation of any crops, in particular wheat. Drought is one of the main limiting environmental factors that reduce plant productivity. In order to guarantee agriculture from losses in dry years, it is necessary to have varieties tolerant to moisture deficiency. That is why one of the priority areas of wheat breeding is the creation of varieties tolerant to the action of water deficiency. The success of breeding when creating drought tolerant forms largely depends on the correct assessment of the degree of their tolerance. Conducting research on the assessment of genotypes for tolerance to water stress is one of conditions for increasing efficiency of the breeding process of this culture. The results obtained in the analysis of literature data, found that for screening of wheat varieties for drought tolerance there are many methods based on different principles of action, and each of them has its advantages and disadvantages. To accelerate the breeding process and obtain reliable results, it is necessary to apply various methods of researching samples on specific signs of tolerance to stress. The choice of method largely depends on the degree of its complexity, the duration of the assessment and throughput. Therefore, the creation of new and improvement of existing methods for assessing wheat breeding material for drought tolerance in conditions of increasing water deficit or temperature increase will make it possible to objectively characterize the level of adaptability of promising genotypes and predict their behavior in appropriate environmental conditions.

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Evaluation of drought-tolerance in some tropical wheat genotypes (Triticum aestivum L.) at different osmotic-stress level

Ilmu Pertanian (Agricultural Science) ◽

10.22146/ipas.46435 ◽

2020 ◽

Vol 5 (2) ◽

pp. 66

Author(s):

Muhammad Kadir ◽

Kaimuddin Kaimuddin ◽

Yunus Musa ◽

Muh Farid Badaruddin ◽

Amin Nur

Keyword(s):

Drought Tolerance ◽

Osmotic Stress ◽

Abiotic Factors ◽

Block Design ◽

Triticum Aestivum L ◽

Potential Donor ◽

Wheat Varieties ◽

Tropical Condition ◽

Wheat Genotypes ◽

Drought Tolerant

Abiotic factors, such as temperature and drought, are the main factors limiting the cultivation under the tropical condition. Two-stage experiments were conducted to examine the drought-tolerant potential of some wheat genotypes against the osmotic stress under the tropical condition at the Laboratory and Greenhouse of Hasanuddin University and Indonesian Cereal Research Institute. The experiments were arranged in a randomized block design with the split-plot pattern and respectively provided with four and three replications. The main plot was potential osmotic stress (0, -0. 33 , and -0.67 MPa) and the sub-plot was selected wheat genotypes (17 genotypes). The results indicates that based on the germination percentage, shoot/root ratio, proline content, stomatal behavior, and relative water content, the wheat lines of O/HP-78-A22-3-7, WBLL*2KURUKU, O/HP-6-A8-2-10, and O/HP-22-A27-1-10 are identified to have better drought-tolerance than the others genotypes based on the analysis of responses to parameters observed. The positively adaptive response of some tropical wheat genotypes to drought stress may be used as a potential donor for further development of drought-tolerant wheat varieties under the tropical climate in Indonesia.

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