scholarly journals PHYSIOLOGICAL CHARACTERIZATION OF SIX WHEAT GENOTYPES FOR DROUGHT TOLERANCE

2016 ◽  
Vol 4 (2) ◽  
pp. 184-196
Author(s):  
HanifChachar Muhammad ◽  
Nazir Ahmed Chachar ◽  
Qamaruddin Chachar ◽  
Mujtaba Sheikh Muhammad ◽  
Sadaruddin Chachar ◽  
...  

Pakistan is one of the most severely affected countries by Global climate change, it is an agriculture based country and its economy (21%) mainly depend on agriculture production. Wheat is the major staple food crop in Pakistan and takes key position in the national economy. It contribute 12.5% share in agriculture and 2.9% in the country’s GDP. Frequent droughts and scarcity of the water severely affecting the wheat production. To fulfill the feed requirements of rapidly growing population, it is necessary to explore the advanced genetic resource that can be able to perform better in changing climate. Six wheat genotypes were tested for their early seedling and physiological performance under different water stress environments. The seeds of six wheat genotypes (Khirman, Chakwal-86, MSH-36, DH-3/48, NIA Amber and NIA-10 10/8) were tested for physiological characterization under pot house experiment for individual genotypic response to water stress. The variance of analysis shows two-way interaction water stress [Control (normal four irrigations) and terminal drought (Soaking dose) and wheat genotypes (P≤ 0.05). Seven physiological indices, including Proline content, Glycine-betaine, Total sugars, Total chlorophyll, Nitrate Reductase Activity ((NRA), Potassium (K+) content, and Osmotic potential (OP) were used to evaluate the drought tolerance of six wheat genotypes. From the current data it was illustrated that, MSH-36 and DH-3/48 exhibited the tolerance followed by, Khirman and Chakwal-86 by maintaining their osmotic potential and accumulation of higher proline and glycine-betaine content that helpful for plant to enhancing their tolerance under water stress and to maintain their growth and development, whereas NIA Amber and NIA-10 10/8 are the drought sensitive genotypes as they could not maintain their osmotic potential under drought stress environment.

2004 ◽  
Vol 31 (12) ◽  
pp. 1149 ◽  
Author(s):  
István Molnár ◽  
László Gáspár ◽  
Éva Sárvári ◽  
Sándor Dulai ◽  
Borbála Hoffmann ◽  
...  

The physiological and morphological responses to water stress induced by polyethylene glycol (PEG) or by withholding water were investigated in Aegilops biuncialis Vis. genotypes differing in the annual rainfall of their habitat (1050, 550 and 225 mm year–1) and in Triticum aestivum L. wheat genotypes differing in drought tolerance. A decrease in the osmotic pressure of the nutrient solution from –0.027 to –1.8 MPa resulted in significant water loss, a low degree of stomatal closure and a decrease in the intercellular CO2 concentration (Ci) in Aegilops genotypes originating from dry habitats, while in wheat genotypes high osmotic stress increased stomatal closure, resulting in a low level of water loss and high Ci. Nevertheless, under saturating light at normal atmospheric CO2 levels, the rate of CO2 assimilation was higher for the Aegilops accessions, under high osmotic stress, than for the wheat genotypes. Moreover, in the wheat genotypes CO2 assimilation exhibited less or no O2 sensitivity. These physiological responses were manifested in changes in the growth rate and biomass production, since Aegilops (Ae550, Ae225) genotypes retained a higher growth rate (especially in the roots), biomass production and yield formation after drought stress than wheat. These results indicate that Aegilops genotypes, originating from a dry habitat have better drought tolerance than wheat, making them good candidates for improving the drought tolerance of wheat through intergeneric crossing.


2020 ◽  
Vol 7 (2) ◽  
pp. 44-60
Author(s):  
R. Bousba ◽  
M. Rached-Kanouni ◽  
N. Benghersallah ◽  
A. Djekoune ◽  
N. Ykhlef

AbstractSurvival under stressful circumstance depends on the plant’s aptitude to perceive the stimulus, generate and transmit the signals, and initiate various physiological and biochemical changes. This study aims to evaluate the exogenous seed treatment by abscissic acid (ABA) in durum wheat genotypes under water stress conditions. In this investigation, a hydroponic experiment was conducted to evaluate the potential role of exogenously applied abscicic acid in improving drought tolerance in wheat. Three contrasting wheat genotypes were used in this work: Hoggar, Hedba3 and Sigus. Two levels of water stress were induced: 2h and 4h, the aim of this work was to evaluate the action of seed exogenous treatment with ABA for 8 and 16h on physiological and biochemical parameters like stomatal resistance, antioxidant enzyme activity and quantification of ABA by HPLC. The results showed that water stress caused a decrease in endogenous ABA concentration in the roots of the stressed varieties with the exception of Hedba3. Furthermore, after ABA treatment for 16h, the two genotypes Hedba 3 and Hogar showed a higher accumulation of this phytohormone, compared to Sigus variety which marks a decrease in this concentration and which can be explained by the consumption of the ABA in the defense against the ROS.


2020 ◽  
Vol 9 (2) ◽  
Author(s):  
N. Borah ◽  
P.K. Borua ◽  
S. Roy ◽  
S.P. Saikia

The global climate change is occurring at an unpredictable rate, where periods of drought are predicted to be extremely severe. The drought tolerance in Teak (Tectona grandis Linn. f.) accessions; collected from North East India was screened under water stress conditions created by reducing irrigation doses. Parameters targeted for screening were vegetative growth, physiological parameters and chemical constituents of leaves. Water stress treatment revealed that plant height, leaves number/plant, average leaf area, N, P, K, Ca, Cl and Na content were significantly decreased by increasing the level of water stress conditions in all studied accessions. Variations in the physiological parameters among different accessions may be due to different intensities of natural selection acting upon the traits in their natural habitat. The aim of the study was to determine source variation in Tectona grandis Linn. f. accessions collected from 41 locations of North East India and to identify the best sources to be utilised for reforestation and further genetic improvement work. In our study, three promising drought tolerant accessions were screened in a decreasing order of drought tolerance viz. GKU-24, GKU-37 and BNU-10 whereas; the drought stress had the most adverse effect on ASM-124 and LUT-45.


2021 ◽  
Author(s):  
Baozhu Li ◽  
Ruonan Fan ◽  
Guiling Sun ◽  
Ting Sun ◽  
Yanting Fan ◽  
...  

Abstract Background and aims As drought threatens the yield and quality of maize (Zea mays L.), it is important to dissect the molecular basis of maize drought tolerance. Flavonoids, participate in the scavenging of oxygen free radicals and alleviate stress-induced oxidative damages. This study aims to dissect the function of flavonoids in the improvement of maize drought tolerance. Methods Using far-infrared imaging screening, we previously isolated a drought overly insensitivity (doi) mutant from an ethyl methanesulfonate (EMS)-mutagenized maize library and designated it as doi57. In this study, we performed a physiological characterization and transcriptome profiling of doi57 in comparison to corresponding wild-type B73 under drought stress. Results Under drought stress, doi57 seedlings displayed lower leaf-surface temperature (LST), faster water loss, and better performance in growth than B73. Transcriptome analysis reveals that key genes involved in flavonoid biosynthesis are enriched among differentially expressed genes in doi57. In line with these results, more flavonols and less hydrogen peroxide (H2O2) were accumulated in guard cells of doi57 than in those of B73 with the decrease of soil water content (SWC). Moreover, the capacity determined from doi57 seedling extracts to scavenge oxygen free radicals was more effective than that of B73 under the drought treatment. Additionally, doi57 seedlings had higher photosynthetic rates, stomatal conductance, transpiration rates, and water use efficiency than B73 exposed to drought stress, resulting in high biomass and greater root/shoot ratios in doi57 mutant plants. Conclusion Flavonoids may facilitate maize seedling drought tolerance by lowering drought-induced oxidative damage as well regulating stomatal movement.


2021 ◽  
Vol 486 ◽  
pp. 118964
Author(s):  
Macarena Férriz ◽  
Dario Martin-Benito ◽  
Isabel Cañellas ◽  
Guillermo Gea-Izquierdo

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 27
Author(s):  
Mahmoud M. Gaballah ◽  
Azza M. Metwally ◽  
Milan Skalicky ◽  
Mohamed M. Hassan ◽  
Marian Brestic ◽  
...  

Drought is the most challenging abiotic stress for rice production in the world. Thus, developing new rice genotype tolerance to water scarcity is one of the best strategies to achieve and maximize high yield potential with water savings. The study aims to characterize 16 rice genotypes for grain and agronomic parameters under normal and drought stress conditions, and genetic differentiation, by determining specific DNA markers related to drought tolerance using Simple Sequence Repeats (SSR) markers and grouping cultivars, establishing their genetic relationship for different traits. The experiment was conducted under irrigated (normal) and water stress conditions. Mean squares due to genotype × environment interactions were highly significant for major traits. For the number of panicles/plants, the genotypes Giza179, IET1444, Hybrid1, and Hybrid2 showed the maximum mean values. The required sterility percentage values were produced by genotypes IET1444, Giza178, Hybrid2, and Giza179, while, Sakha101, Giza179, Hybrid1, and Hybrid2 achieved the highest values of grain yield/plant. The genotypes Giza178, Giza179, Hybrid1, and Hybrid2, produced maximum values for water use efficiency. The effective number of alleles per locus ranged from 1.20 alleles to 3.0 alleles with an average of 1.28 alleles, and the He values for all SSR markers used varied from 0.94 to 1.00 with an average of 0.98. The polymorphic information content (PIC) values for the SSR were varied from 0.83 to 0.99, with an average of 0.95 along with a highly significant correlation between PIC values and the number of amplified alleles detected per locus. The highest similarity coefficient between Giza181 and Giza182 (Indica type) was observed and are susceptible to drought stress. High similarity percentage between the genotypes (japonica type; Sakha104 with Sakha102 and Sakha106 (0.45), Sakha101 with Sakha102 and Sakha106 (0.40), Sakha105 with Hybrid1 (0.40), Hybrid1 with Giza178 (0.40) and GZ1368-S-5-4 with Giza181 (0.40)) was also observed, which are also susceptible to drought stress. All genotypes are grouped into two major clusters in the dendrogram at 66% similarity based on Jaccard’s similarity index. The first cluster (A) was divided into two minor groups A1 and A2, in which A1 had two groups A1-1 and A1-2, containing drought-tolerant genotypes like IET1444, GZ1386-S-5-4 and Hybrid1. On the other hand, the A1-2 cluster divided into A1-2-1 containing Hybrid2 genotype and A1-2-2 containing Giza179 and Giza178 at coefficient 0.91, showing moderate tolerance to drought stress. The genotypes GZ1368-S-5-4, IET1444, Giza 178, and Giza179, could be included as appropriate materials for developing a drought-tolerant variety breeding program. Genetic diversity to grow new rice cultivars that combine drought tolerance with high grain yields is essential to maintaining food security.


2015 ◽  
Vol 723 ◽  
pp. 705-710
Author(s):  
Wei Shun Cheng ◽  
Dan Li Zeng ◽  
Na Zhang ◽  
Hong Xia Zeng ◽  
Xian Feng Shi ◽  
...  

The effects of exogenous abscisic acid and two sulfonamide compounds: Sulfacetamide and Sulfasalazine were studied on tolerance of watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai var. lanatus] under drought stress and compared with abscisic acid effects. Eight-week old plants were treated with ABA (10 and 25 mg/L), Sulfacetamide (25, 50 and 100 mg/L) and Sulfasalazine (25,50 and 100 mg/L). Solutions were sprayed daily and sampling was done at 0 h, 48 h, 96 h, 144 h and 48 h after re-watering (recovery phase or 192 h). Treated plants showed relatively greater drought tolerance. This indicates that, Sulfacetamide and Sulfasalazine may improve resistance in watermelon, like ABA, increasing levels of proline, glycine betaine and malondialdehyde and the activity of ascorbate peroxidase. Daily application of Sulfasalazine and Sulfacetamide during drought stress period was effective in increasing watermelon plants tolerance to drought as was ABA.


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