Breeding for increased drought tolerance in wheat: a review

2018 ◽  
Vol 69 (3) ◽  
pp. 223 ◽  
Author(s):  
Reza Mohammadi
Keyword(s):  
Drought Tolerance ◽  
Plant Breeding ◽  
Genetic Gain ◽  
Complex Traits ◽  
Crop Yields ◽  
Wheat Yield ◽  
Yield Potential ◽  
Limiting Factor ◽  
Wheat Cultivars ◽  
The Impact

Drought, being a yield-limiting factor, has become a major threat to international food security. It is a complex process, and drought tolerance response is carried out by various genes, transcription factors, microRNAs, hormones, proteins, co-factors, ions and metabolites. This complexity has limited the development of crop cultivars for drought tolerance. Breeding for drought tolerance is further complicated because several types of abiotic stress, such as high temperatures, high irradiance, and nutrient toxicities or deficiencies, can challenge crop plants simultaneously. Although marker-assisted selection is now widely deployed in wheat, it has not contributed significantly to cultivar improvement for adaptation to low-yielding environments, and breeding has relied largely on direct phenotypic selection for improved performance in these difficult environments. Advances in plant breeding to produce improved and higher performing wheat cultivars are key to making dryland food-production systems more efficient and more resistant to pressure from drought, extremes of cold and heat, unpredictable rainfall, and new pests and diseases. For optimal performance, wheat cultivars can be targeted to specific farming systems, depending on local conditions and stresses. Genetic gain in wheat yield potential during the last century has been achieved by plant breeding and is well documented. It has been studied by comparing, in the same field trial, the yield of cultivars characterised by different years of release. Genomic selection (GS) and high-throughput phenotyping (HTP) have attracted the interest of plant breeders, and both approaches promise to revolutionise the prediction of complex traits, including growth, yield and adaptation to stress. This review describes the impact of drought on yield, trends in yield for boosting crop yields to meet the projected demands of rising global population by 2050, and genetic gain achieved by plant breeding in the last decades; and gathers known functional information on the genes, metabolites and traits and their direct involvement in conferring drought tolerance in wheat. In addition, it discusses recently developed techniques (i.e. GS and HTP) integrated with approaches such as breeding, genetics, genomics, and agronomic strategies for improving drought in wheat.

scholarly journals Over-Optimistic Projected Future Wheat Yield Potential in the North China Plain: The Role of Future Climate Extremes

Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 145
Author(s):  
Rui Yang ◽  
Panhong Dai ◽  
Bin Wang ◽  
Tao Jin ◽  
Ke Liu ◽  
...  
Keyword(s):  
Drought Stress ◽  
North China Plain ◽  
North China ◽  
Crop Yields ◽  
Wheat Yield ◽  
Yield Potential ◽  
Severe Drought ◽  
The North ◽  
The North China Plain ◽  
Stress Environments

Global warming and altered precipitation patterns pose a serious threat to crop production in the North China Plain (NCP). Quantifying the frequency of adverse climate events (e.g., frost, heat and drought) under future climates and assessing how those climatic extreme events would affect yield are important to effectively inform and make science-based adaptation options for agriculture in a changing climate. In this study, we evaluated the effects of heat and frost stress during sensitive phenological stages at four representative sites in the NCP using the APSIM-wheat model. climate data included historical and future climates, the latter being informed by projections from 22 Global Climate Models (GCMs) in the Coupled Model Inter-comparison Project phase 6 (CMIP6) for the period 2031–2060 (2050s). Our results show that current projections of future wheat yield potential in the North China Plain may be overestimated; after more accurately accounting for the effects of frost and heat stress in the model, yield projections for 2031-60 decreased from 31% to 9%. Clustering of common drought-stress seasonal patterns into key groups revealed that moderate drought stress environments are likely to be alleviated in the future, although the frequency of severe drought-stress environments would remain similar (25%) to that occurring under the current climate. We highlight the importance of mechanistically accounting for temperature stress on crop physiology, enabling more robust projections of crop yields under future the burgeoning climate crisis.

Estimates of relative yield potential and genetic improvement of wheat cultivars in the Mediterranean region

2009 ◽  
Vol 147 (3) ◽  
pp. 323-332 ◽  
Author(s):  
O. SENER ◽  
M. ARSLAN ◽  
Y. SOYSAL ◽  
M. ERAYMAN
Keyword(s):  
Grain Yield ◽  
Bread Wheat ◽  
Genetic Improvement ◽  
Mediterranean Region ◽  
Block Design ◽  
Wheat Yield ◽  
Relative Yield ◽  
Yield Potential ◽  
Wheat Cultivars ◽  
The Mediterranean

SUMMARYInformation about changes associated with advances in crop productivity is essential for understanding yield-limiting factors and developing new strategies for future breeding programmes. National bread wheat (Triticum aestivum L.) yields in Turkey have risen by an average of 20·8 kg/ha/year from 1925 to 2006. Annual gain in yield attributable to agronomic and genetic improvement averaged c. 11·6 kg/ha/year prior to 1975, but is now averaging c. 15·1 kg/ha/year. In the Mediterranean region, however, the wheat yield trend line (10·9 kg/ha/year) is c. 0·38 lower than that of Turkey. In order to understand whether such a trend was due to the cultivars released over the years, 16 bread wheat cultivars, commonly grown in the region and representing 23 years of breeding, introduction and selection (from 1976 to 1999), were grown in a randomized complete block design with three replicates across 2 years. Data were collected on maturation time, plant height, spike length, spikelet number/spike, grain number/spike, grain weight/spike, 1000 seed weight, harvest index and grain yield. None of the measured plant traits showed any historical cultivar patterns; therefore, the increase in grain yield could not be attributed to a single yield component. Several physiological traits changed during two decades of cultivar releases in the Mediterranean region that led to a genetic gain in grain yield of about 0·5% per year. Years of data and the present field study in the Mediterranean region suggested that the genetic improvement in wheat seemed inadequate and should be reinforced with modern agricultural management practices as well as technological innovations.

Analyzing Temperature and Precipitation Influences on Yield Distributions of Canola and Spring Wheat in Saskatchewan

2017 ◽  
Vol 56 (4) ◽  
pp. 897-913 ◽  
Author(s):  
Ting Meng ◽  
Richard Carew ◽  
Wojciech J. Florkowski ◽  
Anna M. Klepacka
Keyword(s):  
Crop Yield ◽  
Spring Wheat ◽  
Climate Model ◽  
Crop Yields ◽  
Wheat Yield ◽  
Growing Season ◽  
Weather Data ◽  
Growth Stages ◽  
Yield Distribution ◽  
The Impact

AbstractThe IPCC indicates that global mean temperature increases of 2°C or more above preindustrial levels negatively affect such crops as wheat. Canadian climate model projections show warmer temperatures and variable rainfall will likely affect Saskatchewan’s canola and spring wheat production. Drier weather will have the greatest impact. The major climate change challenges will be summer water availability, greater drought frequencies, and crop adaptation. This study investigates the impact of precipitation and temperature changes on canola and spring wheat yield distributions using Environment Canada weather data and Statistics Canada crop yield and planted area for 20 crop districts over the 1987–2010 period. The moment-based methods (full- and partial-moment-based approaches) are employed to characterize and estimate asymmetric relationships between climate variables and the higher-order moments of crop yields. A stochastic production function and the focus on crop yield’s elasticity imply choosing the natural logarithm function as the mean function transformation prior to higher-moment function estimation. Results show that average crop yields are positively associated with the growing season degree-days and pregrowing season precipitation, while they are negatively affected by extremely high temperatures in the growing season. The climate measures have asymmetric effects on the higher moments of crop yield distribution along with stronger effects of changing temperatures than precipitation on yield distribution. Higher temperatures tend to decrease wheat yields, confirming earlier Saskatchewan studies. This study finds pregrowing season precipitation and precipitation in the early plant growth stages particularly relevant in providing opportunities to develop new crop varieties and agronomic practices to mitigate climate changes.

Preserving Spring Oat Yields in New York Through Varietal Resistance to Crown Rust

2020 ◽  
Vol 21 (1) ◽  
pp. 36-39 ◽  
Author(s):  
Michael R. Fulcher ◽  
David Benscher ◽  
Mark E. Sorrells ◽  
Gary C. Bergstrom
Keyword(s):  
New York ◽  
Field Studies ◽  
Crown Rust ◽  
Yield Potential ◽  
Resistant Variety ◽  
Limiting Factor ◽  
Breeding Lines ◽  
Rust Susceptibility ◽  
Pathogen Populations ◽  
The Impact

Crown rust is the principal disease of spring oat in New York. Management with resistance genes is effective but contingent on understanding varietal responses to local pathogen populations. Field studies were conducted from 2015 to 2018 to assess the crown rust susceptibility of commercial cultivars and public breeding lines under natural conditions in New York. Three of the 10 commercial varieties trialed were determined to be resistant, and breeding lines from five different states also exhibited resistance. On average, yield was reduced by 34.56 kg/ha for every 1% increase in crown rust severity, whereas the impact on test weight was negligible. A race differential panel was deployed in 2018 at a central screening nursery to determine the range of pathogen virulence present. Susceptible interactions were observed on only five crown rust differentials, and virulence on all five has been recorded at high levels across the country. Crown rust may be a limiting factor to oat production in New York, but yield potential and crop value can be preserved by planting an appropriately resistant variety.

Source - sink balance and manipulating sink - source relations of wheat indicate that the yield potential of wheat is sink-limited in high-rainfall zones

2010 ◽  
Vol 61 (10) ◽  
pp. 852 ◽  
Author(s):  
Heping Zhang ◽  
Neil C. Turner ◽  
Michael L. Poole
Keyword(s):  
Grain Yield ◽  
Western Australia ◽  
Unit Area ◽  
Grain Filling ◽  
Yield Potential ◽  
Limiting Factor ◽  
Wheat Cultivars ◽  
High Rainfall ◽  
Sink Size ◽  
Source Sink

Grain yield depends on the number of grains per unit area (sink) and the availability of assimilates (source) to fill these grains. The aim of the current work was to determine whether wheat yield in the high-rainfall zone of south-western Australia is limited in current cultivars by the size of the sink or by the assimilates available for grain filling. Three wheat cultivars (Calingiri, Chara and Wyalkatchem) and two breeding lines (HRZ216 and HRZ203) were grown in four replicates in the field from 2005 to 2007. Dry matter and water soluble carbohydrates (WSC) at anthesis and maturity were measured and used to determine the source and sink balance of the crop. In 2007, three further treatments were applied to manipulate the sink–source relationships: (i) spikelets were removed on main stems to increase the source : sink ratio; (ii) incoming solar radiation was reduced by 40% by shading after anthesis to reduce the availability of assimilates to grains; and (iii) supplemental irrigation was used to maintain the capacity for photosynthesis by an improved water supply during grain filling. The source–sink balance of the crops showed that the potential source was 25% greater than the actual grain yield in average and above-average seasons (2005 and 2007), suggesting that sink size, represented by the number of grain per unit area, was a limiting factor to yield potential. However, the source may have become a limiting factor in a drought season (2006). The grain yield increased with increased number of grains/m2 and kernel weight remained relatively stable even when grain number increased from 7000 to 16 000 per m2. The removal of half of the spikelets on the main stem did not increase kernel mass of the remaining grains and an additional 33 mm of irrigation water did not increase grain yield, but significantly (P < 0.05) increased WSC left in stems and leaf sheaths at maturity. Shading after anthesis did not significantly reduce grain yield of the current cultivars Calingiri and Wyalkatchem, but it reduced grain yield by 23–25% (P < 0.05) in Chara and HRZ203. The source–sink balance over three seasons and three independent experiments in 2007 suggested that the yield of the current wheat cultivars is more sink- than source-limited and that breeding wheat with a larger sink size than in the current cultivars may lift the yield potential of wheat in the high-rainfall zone of south-western Australia.

Genetic gain in grain yield and oil content of Noug (Guizotia abyssinica) in Ethiopia

2021 ◽  
Vol 27 (01) ◽  
pp. 2234-2251
Author(s):  
A. H. Wirtu ◽  
Keyword(s):  
Seed Yield ◽  
Genetic Gain ◽  
Oil Content ◽  
Plant Biomass ◽  
Yield Potential ◽  
Genetic Advance ◽  
Guizotia Abyssinica ◽  
Genetic Progress ◽  
Periodic Evaluation ◽  
The Impact

The primary and extended objective of plant breeding is to advance productivity to match the lengthening food requirements of people. Estimation of genetic advance from a breeding program and periodic evaluation of improvement in the genetic gain of a crop through released varieties is therefore needed to perceive changes and success generated by breeding activities. Periodic valuation of genetic progress of crop varieties is required to perceive the effectiveness of past breeding activities in genetic yield potential and prompt future selection criteria to aid further improvement. A total of 5 varieties have been released in Ethiopia, from 1988 to 2010. However, the level of genetic progress was not quantified. This study aimed to assess the genetic gain in seed yield potential and oil content of Noug (Guizotia abyssinica) and estimate changes made to yield related traits by genetic improvement of the crop. The experiment was conducted using 5 noug improved varieties and one local variety arranged in RCBD with four replications in 2016/17 main cropping season under rainfed condition. Results indicated that seed yield increased significantly during these 22 years. The estimated annual yield gain was 10.36 kg ha-1 year–1(1.58% per year), reflecting the important efforts of the past breeding programs. Number of head per plant, number of seed per head, Seed yield per plant, biomass yield, harvest and oil content were also increased significantly by 1.72%, 1.71%, 1.85%, 0.33%, 1.03% and 0.34% per year, respectively. The endeavor should be encouraged and extended to accomplish more advances in these and other relevant traits. Noug breeding has not ascertained plateau in Ethiopia. Thus, development of higher yielding varieties of noug should persist to lengthen Noug grain yields if past tendency intends the prospective. To see the impact of the accomplishment in the genetic advance of noug research, it is compulsory to covenant huge scale popularization of the released varieties.

Grain weight in wheat cultivars released from 1920 to 1990 as affected by post-anthesis defoliation

1997 ◽  
Vol 128 (3) ◽  
pp. 273-281 ◽  
Author(s):  
B. C. KRUK ◽  
D. F. CALDERINI ◽  
G. A. SLAFER
Keyword(s):  
Grain Yield ◽  
Plant Breeding ◽  
Field Experiments ◽  
Wheat Breeding ◽  
Grain Weight ◽  
Yield Potential ◽  
Sink Strength ◽  
Wheat Cultivars ◽  
The Difference ◽  
Source Sink

Although it has been generally recognized that the difference in yield potential amongst wheat cultivars released in different eras is related to differences in their reproductive sink strength, there have been few investigations about changes in source–sink ratios as a consequence of wheat breeding. In the present study, two field experiments, in which plots were fertilized and irrigated and lodging and diseases were prevented, were carried out with seven cultivars (including a commercial hybrid) representing different periods of plant breeding in Argentina from 1920 to 1990. The cultivars were defoliated during post-anthesis to analyse the response of grain weight at particular positions within the spike (which have intrinsic differences in potential size).Individual grain weight was virtually unaffected by defoliation in the old cultivars, but modern cultivars exhibited a significant reduction in individual grain weight for several positions within the spike, although this reduction was small (c. 15%) and many grains were unaffected. In addition, no relationship was found between individual grain weight in the controls and its reduction due to defoliation.We concluded that if the source–sink ratio is further reduced, the grain yield of modern wheats will be simultaneously limited by the source and the sink. Future breeding should therefore attempt to improve simultaneously both sink and source strengths.

scholarly journals Seedling emergence and yield performance of wheat cultivars depending on seed vigor and sowing density

2017 ◽  
Vol 39 (1) ◽  
pp. 58-65 ◽  
Author(s):  
Julia Abati ◽  
Cristian Rafael Brzezinski ◽  
José Salvador Simoneti Foloni ◽  
Claudemir Zucareli ◽  
Manoel Carlos Bassoi ◽  
...  
Keyword(s):  
Grain Yield ◽  
Management Practices ◽  
Block Design ◽  
Seedling Emergence ◽  
Wheat Yield ◽  
Seed Vigor ◽  
Yield Potential ◽  
Wheat Cultivars ◽  
Yield Performance ◽  
Randomized Block Design

Abstract: The use of high quality seeds, the appropriate management practices and the selection of promising genotypes are strategies to exploit the wheat yield potential. Thus, the goal of this study was to evaluate the effect of the vigor level of wheat seeds submitted to different sowing densities on seedling emergence, tillering and yield performance culture. The experiments were conducted in Londrina and Ponta Grossa, Paraná state, Brazil, with a completely randomized block design, in a 2x2x2 factorial scheme, with four replications. Two levels of seed vigor (high and low), two sowing densities (200 and 400 viable seeds per m2) and two wheat cultivars (BRS Sabiá and CD 150) were evaluated. The conducted tests were: seedling emergence, number of tillers, yield components, grain yield and apparent harvest index. The use of high vigor seeds helps the establishment of the plant stand and yield performance in both locations. The 400 seeds per m2 seedling density results in a lower number of tillers per plant in both locations. BRS Sabiá, in Ponta Grossa, has the highest grain yield.

The impact of variation in grain number and individual grain weight on winter wheat yield in the high yield potential environment of Ireland

2017 ◽  
Vol 87 ◽  
pp. 40-49 ◽  
Author(s):  
Joseph P. Lynch ◽  
Deirdre Doyle ◽  
Shauna McAuley ◽  
Fiona McHardy ◽  
Quentin Danneels ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Wheat Yield ◽  
Grain Weight ◽  
Yield Potential ◽  
High Yield ◽  
Grain Number ◽  
Winter Wheat Yield ◽  
The Impact ◽  
High Yield Potential
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