scholarly journals Stronger seasonal adjustment in leaf turgor loss point in lianas than trees in an Amazonian forest

2017 ◽  
Vol 13 (1) ◽  
pp. 20160819 ◽  
Author(s):  
Isabelle Maréchaux ◽  
Megan K. Bartlett ◽  
Amaia Iribar ◽  
Lawren Sack ◽  
Jérôme Chave
Keyword(s):  
Drought Tolerance ◽  
Osmotic Adjustment ◽  
Seasonal Adjustment ◽  
Carbon Uptake ◽  
Wet Season ◽  
Physiological Mechanisms ◽  
Turgor Loss Point ◽  
Drought Tolerant ◽  
Turgor Maintenance ◽  
Dry Conditions

Pan-tropically, liana density increases with decreasing rainfall and increasing seasonality. This pattern has led to the hypothesis that lianas display a growth advantage over trees under dry conditions. However, the physiological mechanisms underpinning this hypothesis remain elusive. A key trait influencing leaf and plant drought tolerance is the leaf water potential at turgor loss point ( π tlp ). π tlp adjusts under drier conditions and this contributes to improved leaf drought tolerance. For co-occurring Amazonian tree ( n = 247) and liana ( n = 57) individuals measured during the dry and the wet seasons, lianas showed a stronger osmotic adjustment than trees. Liana leaves were less drought-tolerant than trees in the wet season, but reached similar drought tolerances during the dry season. Stronger osmotic adjustment in lianas would contribute to turgor maintenance, a critical prerequisite for carbon uptake and growth, and to the success of lianas relative to trees in growth under drier conditions.

Carbohydrate accumulation and turgor maintenance in seedling shoots and roots of two boreal conifers subjected to water stress

1991 ◽  
Vol 69 (11) ◽  
pp. 2522-2528 ◽  
Author(s):  
R. S. Koppenaal ◽  
T. J. Tschaplinski ◽  
S. J. Colombo
Keyword(s):  
Water Stress ◽  
Drought Tolerance ◽  
Osmotic Adjustment ◽  
Picea Glauca ◽  
Pinus Banksiana ◽  
White Spruce ◽  
Jack Pine ◽  
Organic Solutes ◽  
Carbohydrate Accumulation ◽  
Turgor Loss Point

Water potential components and organic solutes were examined in shoots and roots of potted jack pine (Pinus banksiana Lamb.) and white spruce (Picea glauca (Moench) Voss) seedlings after exposure to 7 days of water stress. The osmotic potential at the turgor loss point (ψπTLP) decreased in shoots and roots of water-stressed seedlings of both species, resulting in the maintenance of positive turgor at lower xylem water potentials (ψX) compared with nonstressed seedlings. Following water stress, ψπTLP of shoots and roots declined by 0.28 MPa and 0.14 MPa, respectively, in jack pine, and 0.19 MPa and 0.28 MPa, respectively, in white spruce. The osmotic potential at saturation (ψπ100) was significantly lower after water stress only in jack pine roots. Active osmotic adjustment during water stress was confirmed by higher concentrations of organic solutes in white spruce shoots (1.4 × increase relative to nonstressed plants) and roots (1.7 ×) and in the roots (2.2 ×) but not the shoots of jack pine. Carbohydrates, particularly fructose and glucose, were the primary organic solutes accumulating in both species. Tissue elasticity was greater in the roots than the shoots of both jack pine and white spruce regardless of treatment. Consequently, the relative water content at the turgor loss point was 22% and 18% lower in the roots than in the shoots of jack pine and white spruce, respectively. Osmotic adjustment in the roots and shoots of these two boreal conifers suggests that preconditioning planting stock by exposure to water stress may increase carbohydrate concentrations and enhance seedling drought tolerance. Key words: carbohydrate accumulation, drought tolerance, organic solutes, osmotic adjustment, Picea glauca, Pinus banksiana, water potential components.

scholarly journals Evaluation of Drought Tolerance in Arkansas Cowpea Lines at Seedling Stage

HortScience ◽  
2020 ◽  
Vol 55 (7) ◽  
pp. 1132-1143
Author(s):  
Qirui Cui ◽  
Haizheng Xiong ◽  
Yufeng Yufeng ◽  
Stephen Eaton ◽  
Sora Imamura ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Block Design ◽  
Seedling Stage ◽  
University Of Arkansas ◽  
Drought Treatment ◽  
Breeding Lines ◽  
Drought Tolerant ◽  
Dry Conditions ◽  
Main Plot ◽  
The University

Cowpea [Vigna unguiculate (L.) Walp.] is not only a healthy, nutritious, and versatile leguminous crop; it also has a relatively high adaptation to drought. Research has shown that cowpea lines have a high tolerance to drought, and many of them can survive more than 40 days under scorching and dry conditions. The cowpea (Southern pea) breeding program at the University of Arkansas has been active for more than 50 years and has produced more than 1000 advanced breeding lines. The purpose of this study was to evaluate the drought-tolerant ability in Arkansas cowpea lines and use the drought-tolerant lines in cowpea production or as parents in cowpea breeding. A total of 36 University of Arkansas breeding lines were used to screen drought tolerance at the seedling stage in this study. The experiment was conducted in the greenhouse using a randomized complete block design (RCBD) with two replicates, organized in a split-plot manner, where the drought treatment (drought and nondrought stress) as the main plot and the cowpea genotypes as the subplot. Drought stress was applied for 4 weeks, and three drought-tolerant–related traits were collected and analyzed. Results showed that cowpea breeding lines: ‘17-61’, ‘17-86’, ‘Early Scarlet’, and ‘ARBlackeye #1’ were found to be drought tolerant.

Current topics in drought physiology

1992 ◽  
Vol 119 (3) ◽  
pp. 291-296 ◽  
Author(s):  
H. G. Jones ◽  
J. E. Corlett
Keyword(s):  
Water Stress ◽  
Drought Tolerance ◽  
Crop Yield ◽  
Crop Yields ◽  
Crop Management ◽  
Agricultural Crops ◽  
Rational Basis ◽  
Rapid Methods ◽  
Drought Tolerant ◽  
Dry Conditions

Drought is probably the most important factor limiting crop yields worldwide, therefore it is not surprising that there has been continuing interest in the ways in which drought affects crop yield. Efforts have been concentrated in this area in the hope that it would prove possible to use a knowledge of drought physiology to provide a rational basis for the development of rapid methods of breeding drought tolerant cultivars, and also to help in the improvement of crop management for dry conditions. The last five years have seen some important reassessments of the underlying principles and concepts involved in plant response to drought and these will be outlined in this brief review. Some of these important shifts in emphasis have been highlighted by Kramer (1988), Passioura (1988), Schulzeel al.(1988) and Boyer (1989), particularly in relation to the question of what measure of water stress is most relevant to plant function. As it is not possible to cover all aspects of drought physiology in a brief review of this nature, we highlight four topics where recent findings may have particular relevance to the improvement of drought tolerance in agricultural crops.

scholarly journals Intraspecific drought tolerance of Betula pendula genotypes: an evaluation using leaf turgor loss in a botanical collection

Trees ◽  
2020 ◽  
Author(s):  
Simon Hannus ◽  
Andrew Hirons ◽  
Timothy Baxter ◽  
Hugh A. McAllister ◽  
Björn Wiström ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Significant Relationship ◽  
Betula Pendula ◽  
Potential Evapotranspiration ◽  
Climatic Conditions ◽  
Urban Trees ◽  
Collection Site ◽  
Turgor Loss Point ◽  
Drought Tolerant ◽  
Botanical Collection

Abstract Key message The results showed a significant relationship between the potential evapotranspiration of the provenance collection site and the leaf turgor loss point and significant positive differences in drought tolerance between provenances and subspecies of B. pendula. Abstract The ecosystem services provided by urban trees make substantial contributions to the quality of urban living and securing resilience towards the challenges posed by a changing climate. Water deficits are a major abiotic stress for trees in urban environments and, in many regions, this stress is likely to be amplified under future climate scenarios. Although wide variation in drought tolerance exists at the species level, many species also show substantial intraspecific variation in drought tolerance. The aim of this study is to evaluate how drought tolerance, inferred from the water potential at leaf turgor loss point (ΨP0), varies in Betula pendula from different geographical origins and determine if the observed drought tolerance can be related to the local climate and seasonal water balance from the provenance of origin, despite the trees now being established in similar soil and climatic conditions within a single botanical collection. Six subsp. betula, five subsp. mandshurica and two subsp. szechuanica were evaluated, giving a total of 12 different provenances. The results showed a significant relationship between the potential evapotranspiration of the provenance collection site and the leaf turgor loss point and significant positive differences in drought tolerance between provenances and subspecies of B. pendula. By directing efforts towards identifying more drought-tolerant genotypes, it will be possible to diversify the palette of trees that could confidently be integrated by urban tree planners and landscape architects into the urban landscape. The results of this study on different ecotypes of B. pendula clearly show that it is possible to find more drought-tolerant plant material.

scholarly journals Tree genetics defines fungal partner communities that may confer drought tolerance

2017 ◽  
Vol 114 (42) ◽  
pp. 11169-11174 ◽  
Author(s):  
Catherine A. Gehring ◽  
Christopher M. Sthultz ◽  
Lluvia Flores-Rentería ◽  
Amy V. Whipple ◽  
Thomas G. Whitham
Keyword(s):  
Drought Tolerance ◽  
Common Garden ◽  
Interactive Effects ◽  
Plant Responses ◽  
Drought Tolerant ◽  
Fungal Partner ◽  
Dry Conditions ◽  
In The Wild ◽  
Tree Genetics ◽  
Drying Conditions

Plant genetic variation and soil microorganisms are individually known to influence plant responses to climate change, but the interactive effects of these two factors are largely unknown. Using long-term observational studies in the field and common garden and greenhouse experiments of a foundation tree species (Pinus edulis) and its mutualistic ectomycorrhizal fungal (EMF) associates, we show that EMF community composition is under strong plant genetic control. Seedlings acquire the EMF community of their seed source trees (drought tolerant vs. drought intolerant), even when exposed to inoculum from the alternate tree type. Drought-tolerant trees had 25% higher growth and a third the mortality of drought-intolerant trees over the course of 10 y of drought in the wild, traits that were also observed in their seedlings in a common garden. Inoculation experiments show that EMF communities are critical to drought tolerance. Drought-tolerant and drought-intolerant seedlings grew similarly when provided sterile EMF inoculum, but drought-tolerant seedlings grew 25% larger than drought-intolerant seedlings under dry conditions when each seedling type developed its distinct EMF community. This demonstration that particular combinations of plant genotype and mutualistic EMF communities improve the survival and growth of trees with drought is especially important, given the vulnerability of forests around the world to the warming and drying conditions predicted for the future.

Evaluation of drought tolerance and screening for drought-tolerant indicators in sweetpotato cultivars

2019 ◽  
Vol 45 (3) ◽  
pp. 419 ◽  
Author(s):  
Hai-Yan ZHANG ◽  
Bei-Tao XIE ◽  
Bao-Qing WANG ◽  
Shun-Xu DONG ◽  
Wen-Xue DUAN ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Drought Tolerant

scholarly journals Improving Drought Tolerance in Mungbean (Vigna radiata L. Wilczek): Morpho-Physiological, Biochemical and Molecular Perspectives

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1534
Author(s):  
Chandra Mohan Singh ◽  
Poornima Singh ◽  
Chandrakant Tiwari ◽  
Shalini Purwar ◽  
Mukul Kumar ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Crop Production ◽  
Mitigation Strategies ◽  
Theoretical Research ◽  
Whole Genome Sequence ◽  
Complex Nature ◽  
Drought Tolerant ◽  
Breeding Programmes ◽  
The Impact

Drought stress is considered a severe threat to crop production. It adversely affects the morpho-physiological, biochemical and molecular functions of the plants, especially in short duration crops like mungbean. In the past few decades, significant progress has been made towards enhancing climate resilience in legumes through classical and next-generation breeding coupled with omics approaches. Various defence mechanisms have been reported as key players in crop adaptation to drought stress. Many researchers have identified potential donors, QTLs/genes and candidate genes associated to drought tolerance-related traits. However, cloning and exploitation of these loci/gene(s) in breeding programmes are still limited. To bridge the gap between theoretical research and practical breeding, we need to reveal the omics-assisted genetic variations associated with drought tolerance in mungbean to tackle this stress. Furthermore, the use of wild relatives in breeding programmes for drought tolerance is also limited and needs to be focused. Even after six years of decoding the whole genome sequence of mungbean, the genome-wide characterization and expression of various gene families and transcriptional factors are still lacking. Due to the complex nature of drought tolerance, it also requires integrating high throughput multi-omics approaches to increase breeding efficiency and genomic selection for rapid genetic gains to develop drought-tolerant mungbean cultivars. This review highlights the impact of drought stress on mungbean and mitigation strategies for breeding high-yielding drought-tolerant mungbean varieties through classical and modern omics technologies.

scholarly journals Drought Tolerant near Isogenic Lines (NILs) of Pusa 44 Developed through Marker Assisted Introgression of qDTY2.1 and qDTY3.1 Enhances Yield under Reproductive Stage Drought Stress

Agriculture ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 64
Author(s):  
Priyanka Dwivedi ◽  
Naleeni Ramawat ◽  
Gaurav Dhawan ◽  
Subbaiyan Gopala Krishnan ◽  
Kunnummal Kurungara Vinod ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Grain Quality ◽  
Reproductive Stage ◽  
Recurrent Parent ◽  
Near Isogenic Lines ◽  
Improvement Project ◽  
Isogenic Lines ◽  
Drought Tolerant ◽  
Rice Improvement

Reproductive stage drought stress (RSDS) is detrimental for rice, which affects its productivity as well as grain quality. In the present study, we introgressed two major quantitative trait loci (QTLs), namely, qDTY2.1 and qDTY3.1, governing RSDS tolerance in a popular high yielding non-aromatic rice cultivar, Pusa 44, through marker-assisted backcross breeding (MABB). Pusa 44 is highly sensitive to RSDS, which restricts its cultivation across drought-prone environments. Foreground selection was carried out using markers, RM520 for qDTY3.1 and RM 521 for qDTY2.1. Background selection was achieved with 97 polymorphic SSR markers in tandem with phenotypic selection to achieve faster recurrent parent genome (RPG) recovery. Three successive backcrosses followed by three selfings aided RPG recoveries of 98.6% to 99.4% among 31 near isogenic lines (NILs). Fourteen NILs were found to be significantly superior in yield and grain quality under RSDS with higher drought tolerance efficiency (DTE) than Pusa 44. Among these, the evaluation of two promising NILs in the multilocational trial during Kharif 2019 showed that they were significantly superior to Pusa 44 under reproductive stage drought stress, while performing on par with Pusa 44 under normal irrigated conditions. These di-QTL pyramided drought-tolerant NILs are in the final stages of testing the All India Coordinated Rice Improvement Project varietal trials for cultivar release. Alternately, the elite drought-tolerant Pusa 44 NILs will serve as an invaluable source of drought tolerance in rice improvement.

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.

Sign in / Sign up

Export Citation Format

Share Document