Physiological responses of drought tolerance in orchardgrass (Dactylis glomerata) in association with persistence and summer dormancy

2018 ◽  
Vol 69 (5) ◽  
pp. 515 ◽  
Author(s):  
Fatemeh Saeidnia ◽  
Mohammad Mahdi Majidi ◽  
Aghafakhr Mirlohi ◽  
Benyamin Ahmadi
Keyword(s):  
Water Stress ◽  
Drought Tolerance ◽  
Physiological Responses ◽  
Genotypic Variation ◽  
Dactylis Glomerata ◽  
Water Soluble ◽  
Soluble Carbohydrates ◽  
Drought Tolerant ◽  
Summer Dormancy ◽  
Water Soluble Carbohydrates

The genetic basis of physiological responses to drought and its association with productivity, persistence and summer dormancy is not clear in orchardgrass (Dactylis glomerata L.). Thirty-six orchardgrass genotypes were evaluated under water stress and non-stressed conditions during 2 years (2013–14). High genotypic variation was observed for all of the agronomic and physiological traits. Water stress reduced dry matter yield, relative water content and chlorophyll content while significantly increasing carotenoids, water-soluble carbohydrates, proline and chlorophyll a : b ratio. The results indicated that carotenoids and proline accumulation could not be used for discriminating drought-tolerant genotypes of orchardgrass, whereas water-soluble carbohydrates may be used to achieve this purpose. Moreover, the results showed that the stable genotypes that have lower changes in productivity from normal to water-stress environments also have more persistence. No association was found between summer dormancy and drought tolerance measured by both physiological and yield-based drought-tolerance indices. Some of the drought-tolerant genotypes had relatively high persistence and better autumn recovery, a characteristic useful for the development of new synthetic varieties.

scholarly journals Variation of Water-Soluble Carbohydrates and Grain Yield in Iranian Cold Barley Promising Lines Under Well-Watered and Water Stress Conditions

2014 ◽  
Vol 68 (1) ◽  
pp. 65-75
Author(s):  
Soleiman Mohammadi ◽  
Reza Kas Nazani ◽  
Ayda Hosseinzadeh Mahootchi ◽  
Keiwan Ftohi
Keyword(s):  
Water Stress ◽  
Grain Yield ◽  
Water Deficit ◽  
Dry Matter ◽  
Water Soluble ◽  
Stress Conditions ◽  
Soluble Carbohydrates ◽  
Dry Matter Content ◽  
Water Stress Condition ◽  
Water Soluble Carbohydrates

ABSTRACT In order to evaluate promising lines in terms of grain yield and water-soluble carbohydrates remobiliza-tion, an experiment with fifteen promising lines and two checks was carried out under full irrigation and terminal water stress conditions at Miyandoab Agricultural Research and Natural Resources Station. Mobilized dry matter content and remobilization percentage from shoot to grain under water deficit (177mg)(11.2%) were greater than those under well watering condition. The lowest (110 mg) and the highest (260mg) mobilized dry matter to grain were obtained for C-79-18 and C-83-15lines, respectively. Water deficit reduced grain yield of barley genotypes by 200-1600 kg/ha, and mean grain yield reduction was 800 kg/ha. Line 14 with 5.880and 5.300t/ha grain yield in favorable and water stress conditions was superior to the other lines. Under water deficit condition, line 14 had greater grain yieldby20% and 38% than the Bahman and Makouee cultivars, respectively. The results showed that greater grain yield in tolerant lines under water deficit was due to remobilization of unstructured carbohydrates from shoot to grain. Thus, it seems that selection of lines with higher translocated dry matter and contribution of pre-anthesis assimilate in grain filling under water stress, the suitable way for achieving genotypes with high grain yield under water stress condition.

Effect of Different Durations of Water Withholding on Regrowth Potential and Non-Structural Carbohydrate Content in Rhodes Grass (Chloris gayana Kunth)

1982 ◽  
Vol 9 (1) ◽  
pp. 113 ◽  
Author(s):  
J Kigel ◽  
A Dotan
Keyword(s):  
Water Stress ◽  
Leaf Length ◽  
Water Soluble ◽  
Soluble Carbohydrates ◽  
Rhodes Grass ◽  
Water Soluble Carbohydrates ◽  
Positive Linear Correlation ◽  
Structural Carbohydrate ◽  
Chloris Gayana ◽  
Chloris Gayana Kunth

The effect of water stress on the regrowth potential of Rhodes grass was studied in plants grown under controlled conditions at 27/22°C and 16-h photoperiods, and subjected to different periods of water withholding. After water was withheld, the levels of water-soluble carbohydrates (WSC) in the roots and basal parts of the leaves gradually increased from 2-4% to 8-9%, while the level of starch in the leaves remained stable below 1%. Regrowth and elongation of leaves that took place after cutting was increased markedly by withholding water for 6-10 days before cutting. A positive linear correlation was shown between initial leaf regrowth and the total amount of WSC present at cutting time. However, this initial advantage of the stressed plants gradually disappeared during the regrowth period, and no significant differences in leaf length and weight were found at later stages between the watered and stressed plants.

Genotypic variation in the accumulation of water soluble carbohydrates in wheat

2012 ◽  
Vol 39 (7) ◽  
pp. 560 ◽  
Author(s):  
C. Lynne McIntyre ◽  
David Seung ◽  
Rosanne E. Casu ◽  
Gregory J. Rebetzke ◽  
Ray Shorter ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Empirical Studies ◽  
Genotypic Variation ◽  
Grain Filling ◽  
Water Soluble ◽  
Soluble Carbohydrates ◽  
Winter Cereals ◽  
Expression Of Genes ◽  
Water Soluble Carbohydrates ◽  
Selection For

Water-soluble carbohydrates (WSC) stored in the stems and leaf sheaths of winter cereals provide an important source of assimilate for remobilisation during grain-filling. Consequently, WSC are a major contributor to wheat grain yield and grain size in all environments but especially where photosynthesis is compromised as occurs where water is limiting. Breeding programs targeting greater WSC should provide improved varieties with greater and more stable yields in stress environments. To facilitate selection for WSC, genetic and genomic approaches are being used to determine the genetic basis of – and define DNA probes for – marker-aided selection for this important drought-adaptive trait. Empirical studies have identified both WSC concentration and content to be under complex genetic control of many genes. Quantitative trait loci (QTL) for WSC have been identified in several wheat populations with individual QTL explaining small amounts of phenotypic variation, typically of less than 20%. Many of these QTL are common across multiple, genetically-unrelated wheat populations. Evaluation of gene expression in high and low WSC wheat progeny lines from a well characterised wheat population has identified significant differences in expression of genes from different gene categories. For example, high WSC progeny lines have higher levels of expression of genes involved in carbohydrate metabolism and lower levels of expression of genes involved in cell wall and amino acid metabolism than low WSC lines. Genetic mapping reveals several candidate genes co-locating with QTL for WSC. In addition, expression QTL (eQTL) for selected candidate genes co-locate with WSC QTL; co-location of the genes and eQTL with WSC QTL make these genes stronger candidate genes for the WSC trait.

scholarly journals Genetic Diversity of Selected Rice Genotypes under Water Stress Conditions

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 27
Author(s):  
Mahmoud M. Gaballah ◽  
Azza M. Metwally ◽  
Milan Skalicky ◽  
Mohamed M. Hassan ◽  
Marian Brestic ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Water Stress ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Ssr Markers ◽  
Similarity Index ◽  
Stress Conditions ◽  
Yield Potential ◽  
Drought Tolerant ◽  
Rice Genotypes

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.

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