scholarly journals HEAT AND DROUGHT STRESS EFFECT IN WHEAT GENOTYPES: A REVIEW

2021 ◽  
Vol 1 (2) ◽  
pp. 77-79
Author(s):  
Sandesh Paudel ◽  
Netra Prasad Pokharel ◽  
Susmita Adhikari ◽  
Sarah Poudel

Bread wheat (Triticum aestivum L.) belonging to family Poaceae is the most important cereal crop as it contributes major portion to the world food for the world’s population. Similarly, it is the third most cultivated cereal crop in Nepal in terms of production and area. Wheat is a winter season crop which is usually grown within a temperature range of 15-250C in cold and dry weather. However frequent irrigations are crucial for proper growth of the plant, high yield and high quality of the grain. The annual productivity of wheat has been reported to be 2.49 tons per hectare. Water is found to be one of the most important factors in wheat production and by far not a single water stress tolerant variety has been introduced thus water management is necessary. In Nepal around 35% of the total wheat is cultivated under rainfed condition annually and in Terai this is around 19%. This cultivated area faces a severe drought stress during growing stage and heat stress during anthesis stage. Various studies have suggested that the combined impacts of drought and heat stress had a significant harmful effect on wheat than individual stresses (Stress and Review, 2017). Under drought stress days to anthesis and days to maturity were reduced by 10% and 14% while under heat stress these were reduced by 16% and 20% respectively. Combined effect of drought and heat stress caused reduction in DTA by 25% DTH by and 31%.

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1000
Author(s):  
Maryke Labuschagne ◽  
Carlos Guzmán ◽  
Keneuoe Phakela ◽  
Barend Wentzel ◽  
Angeline van Biljon

Drought and temperature stress can cause considerable gluten protein accumulation changes during grain-filling, resulting in variations in wheat quality. The contribution of functional polymeric components of flour to its overall functionality and quality can be measured using solvent retention capacity (SRC). The aim of this study was to determine the effect of moderate and severe drought and heat stress on SRC and swelling index of glutenin (SIG) in six durum wheat cultivars with the same glutenin subunit composition and its relation with gluten protein fractions from size exclusion high performance liquid chromatography. Distilled water, sodium carbonate and sucrose SRC reacted similarly to stress conditions, with moderate heat causing the lowest values. Lactic acid SRC and SIG reacted similarly, where severe heat stress highly significantly increased the values. SIG was significantly correlated with sodium dodecyl sulphate sedimentation (SDSS) and flour protein content (FPC) under all conditions. Lactic acid SRC was highly correlated with FPC under optimal and moderate heat stress and with SDSS under moderate drought and severe heat. SIG was negatively correlated with low molecular weight glutenins under optimal and drought conditions, and combined for all treatments. The relationship between SRC and gluten proteins was inconsistent under different stress conditions.


2000 ◽  
Vol 80 (4) ◽  
pp. 739-745 ◽  
Author(s):  
B. L. Duggan ◽  
D. R. Domitruk ◽  
D. B. Fowler

Crops produced in the semiarid environment of western Canada are subjected to variable and unpredictable periods of drought stress. The objective of this study was to determine the inter-relationships among yield components and grain yield of winter wheat (Triticum aestivum L) so that guidelines could be established for the production of cultivars with high yield potential and stability. Five hard red winter wheat genotypes were grown in 15 field trials conducted throughout Saskatchewan from 1989–1991. Although this study included genotypes with widely different yield potential and yield component arrangements, only small differences in grain yield occurred within trials under dryland conditions. High kernel number, through greater tillering, was shown to be an adaptation to low-stress conditions. The ability of winter wheat to produce large numbers of tillers was evident in the spring in all trials; however, this early season potential was not maintained due to extensive tiller die-back. Tiller die-back often meant that high yield potential genotypes became sink limiting with reduced ability to respond to subsequent improvements in growing season weather conditions. As tiller number increased under more favourable crop water conditions genetic limits in kernels spike−1 became more identified with yield potential. It is likely then, that tillering capacity per se is less important in winter wheat than the development of vigorous tillers with numerous large kernels spike−1. For example, the highest yielding genotype under dryland conditions was a breeding line, S86-808, which was able to maintain a greater sink capacity as a result of a higher number of larger kernels spike−1. It appears that without yield component compensation, a cultivar can be unresponsive to improved crop water conditions (stable) or it can have a high mean yield, but it cannot possess both characteristics. Key words: Triticum aestivum L., wheat, drought stress, kernel weight, kernel number, spike density, grain yield


Plants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 518 ◽  
Author(s):  
Nelimor ◽  
Badu-Apraku ◽  
Tetteh ◽  
N’guetta

Climate change is expected to aggravate the effects of drought, heat and combined drought and heat stresses. An important step in developing ‘climate smart’ maize varieties is to identify germplasm with good levels of tolerance to the abiotic stresses. The primary objective of this study was to identify landraces with combined high yield potential and desirable secondary traits under drought, heat and combined drought and heat stresses. Thirty-three landraces from Burkina Faso (6), Ghana (6) and Togo (21), and three drought-tolerant populations/varieties from the Maize Improvement Program at the International Institute of Tropical Agriculture were evaluated under three conditions, namely managed drought stress, heat stress and combined drought and heat stress, with optimal growing conditions as control, for two years. The phenotypic and genetic correlations between grain yield of the different treatments were very weak, suggesting the presence of independent genetic control of yield to these stresses. However, grain yield under heat and combined drought and heat stresses were highly and positively correlated, indicating that heat-tolerant genotypes would most likely tolerate combined drought and stress. Yield reduction averaged 46% under managed drought stress, 55% under heat stress, and 66% under combined drought and heat stress, which reflected hypo-additive effect of drought and heat stress on grain yield of the maize accessions. Accession GH-3505 was highly tolerant to drought, while GH-4859 and TZm-1353 were tolerant to the three stresses. These landrace accessions can be invaluable sources of genes/alleles for breeding for adaptation of maize to climate change.


2014 ◽  
Vol 41 (11) ◽  
pp. 1148 ◽  
Author(s):  
Rashmi Awasthi ◽  
Neeru Kaushal ◽  
Vincent Vadez ◽  
Neil C. Turner ◽  
Jens Berger ◽  
...  

High temperatures and decreased rainfall are detrimental to yield in chickpea (Cicer arietinum L.), particularly during grain filling. This study aimed to (i) assess the individual and combined effects of drought and heat stress on biochemical seed-filling processes, (ii) determine genotypic differences in heat and drought tolerance, and (iii) determine any cross-tolerance. Plants were grown outdoors in the normal growing season when temperatures during seed filling were <32−20°C or were planted late (temperatures >32−20°C; heat stress). Half of the pots were kept adequately watered throughout, but water was withheld from the others from the initiation of seed filling until the relative leaf water content reached 50% of the irrigated plants (drought stress); all plants were rewatered thereafter until seed maturit. Water was withheld for 13 days (normal sowing) and 7 days (late sowing), so soil moisture decreased by 54–57%. Tests on leaves and seeds were performed after the stress. Individual and combined stress damaged membranes, and decreased cellular oxidising ability, stomatal conductance, PSII function and leaf chlorophyll content; damage was greater under combined stress. Leaf Rubisco activity increased with heat stress, decreased with drought stress and decreased severely with combined stress. Sucrose and starch concentrations decreased in all seeds through reductions in biosynthetic enzymes; reductions were greater under combined stress. These effects were more severe in heat- and drought-sensitive genotypes compared with drought-tolerant genotypes. Drought stress had a greater effect than heat stress on yield and the biochemical seed-filling mechanisms. Drought- and heat-tolerant genotypes showed partial cross-tolerance.


Foods ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2142
Author(s):  
Barbara Laddomada ◽  
Antonio Blanco ◽  
Giovanni Mita ◽  
Leone D’Amico ◽  
Ravi P. Singh ◽  
...  

Droughts and high temperatures are the main abiotic constraints hampering durum wheat production. This study investigated the accumulation of phenolic acids (PAs) in the wholemeal flour of six durum wheat cultivars under drought and heat stress. Phenolic acids were extracted from wholemeals and analysed through HPLC-DAD analysis. Ferulic acid was the most represented PA, varying from 390.1 to 785.6 µg/g dry matter across all cultivars and growth conditions, followed by sinapic acids, p-coumaric, vanillic, syringic, and p-hydroxybenzoic acids. Among the cultivars, Cirno had the highest PAs content, especially under severe drought conditions. Heat stress enhanced the accumulation of minor individual PAs, whereas severe drought increased ferulic acid and total PAs. Broad-sense heritability was low (0.23) for p-coumaric acid but ≥0.69 for all other components. Positive correlations occurred between PA content and grain morphology and between test weight and grain yield. Durum wheat genotypes with good yields and high accumulation of PAs across different growing conditions could be significant for durum wheat resilience and health-promoting value.


2020 ◽  
Vol 16 (1) ◽  
pp. 1839710
Author(s):  
Yanwen Gui ◽  
Mohamed S Sheteiwy ◽  
Shuangguo Zhu ◽  
Li Zhu ◽  
Asfa Batool ◽  
...  

2017 ◽  
Vol 68 (9) ◽  
pp. 823 ◽  
Author(s):  
Rashmi Awasthi ◽  
Pooran Gaur ◽  
Neil C. Turner ◽  
Vincent Vadez ◽  
Kadambot H. M. Siddique ◽  
...  

Drought and heat stress are two major constraints that limit chickpea (Cicer arietinum L.) yield, particularly during seed filling. The present study aimed (i) to assess the individual and combined effects of drought and heat stress on oxidative metabolism during seed filling, and (ii) to determine any genetic variation in oxidative metabolism among genotypes differing in drought and heat tolerance and sensitivity. The plants were raised in outdoor conditions with two different times of sowing, one in November (normal-sown, temperatures <32°C−20°C (day–night) during seed filling), and the other in February (late-sown, temperatures >32°C−20°C (day–night) during seed filling). Plants were regularly irrigated to prevent any water shortage until the water treatments were applied. At both sowing times, the drought treatment was applied during seed filling (at ~75% podding) by withholding water from half of the pots until the relative leaf water content (RLWC) of leaves on the top three branches reached 42–45%, whereas leaves in the fully irrigated control plants were maintained at RLWC 85–90%. Drought-stressed plants were then rewatered and maintained under fully irrigated conditions until maturity. Several biochemical parameters were measured on the leaves and seeds at the end of the stress treatments, and seed yield and aboveground biomass were measured at maturity. Individual and combined stresses damaged membranes, and decreased PSII function and leaf chlorophyll content, more so under the combined stress treatment. The levels of oxidative molecules (malondialdehyde (MDA) and H2O2) markedly increased compared with the control plants in all stress treatments, especially across genotypes in the combined heat + drought stress treatment (increases in leaves: MDA 5.4–8.4-fold and H2O2 5.1–7.1-fold; in seeds: MDA 1.9–3.3-fold and H2O2 3.8–7.9-fold). The enzymatic and non-enzymatic antioxidants related to oxidative metabolism increased under individual stress treatments but decreased in the combined heat + drought stress treatment. Leaves had higher oxidative damage than seeds, and this likely inhibited their photosynthetic efficiency. Yields were reduced more by drought stress than by heat stress, with the lowest yields in the combined heat + drought stress treatment. Heat- and drought-tolerant genotypes suffered less damage and had higher yields than the heat- and drought-sensitive genotypes under the individual and combined stress treatments, suggesting partial cross-tolerance in these genotypes. A drought-tolerant genotype ICC8950 produced more seed yield under the combined heat + drought stress than other genotypes, and this was associated with low oxidative damage in leaves and seeds.


Author(s):  
V. Rajeswari ◽  
D. Vijayalakshmi ◽  
S. Srinivasan ◽  
R. Swarnapriya ◽  
S. Varanavasiappan ◽  
...  

Drought spells and heat stress have become quite common and agricultural production would experience a lag in near future. The combined effect of heat and drought stress is expected to cause negative impact on crop growth. Hence, an experiment was framed to assess the morphological and photosynthetic characters of chilli under combined drought and heat stress. Three different genotypes of chilli viz., K1, TNAU chilli hybrid CO 1, Ramanathapuram gundu were subjected to seven drought and temperature treatments. The experiment was designed in factorial completely randomized design (FCRD) at temperature controlled Open Top Chambers (OTC) and drought stress was gravimetically assesed. The results showed that, morphology and photosynthetic characters were affected irrespective of genotypes. The maximum reduction in plant height and leaf area was observed when plants were grown under 40% pot capacity and temperature of + 5°C from the ambient condition. The study also revealed that, the reduction of gas exchange parameters at 40% PC and A + 5°C with yield reduction of almost 76 per cent irrespective of genotypes. Stress treatments reduced the fruit length, fruit diameter compared to control in all genotypes. Stress Tolerence Index was calculated to study the physiological basis under combined drought and heat stress. The optimum level of stress by STI of 0.501 in 60% PC and A+ 3°C was standardized to study the basic physiological functions of chilli.


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