scholarly journals Seed Antioxidants Interplay with Drought Stress Tolerance Indices in Chilli (Capsicum annuum L) Seedlings

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
U. Lakshmi Sahitya ◽  
M. S. R. Krishna ◽  
R. Sri Deepthi ◽  
G. Shiva Prasad ◽  
D. Peda Kasim

Altering climatic conditions and water stress drastically affects the chilli crop yield. In this scenario we adapted a strategic approach for screening of elite chilli genotypes, by exploring role of seed antioxidants in stress tolerance during vegetative phase. A total of 20 chilli genotypes’ seed antioxidant potential and its effect on water stress tolerance were studied at three water regimes, namely, control (100% Field Capacity), moderate (80% Field Capacity), and severe (60% Field Capacity) stress conditions. Drought tolerance traits relative water content, chlorophyll content, and activities of superoxide dismutase and catalase enzymes were measured. A strong correlation was observed between seed antioxidants and water stress tolerant traits in seedlings. Genotypes KCa-5, KCa-6, and KCa-10 showed low quantity of H2O2 and Malondialdehyde in seeds and maintained high membrane integrity and chlorophyll content in seedlings. High content of proline in KCa-5, KCa-7, and KCa-10 seeds retained high relative water content at seedling stage under severe water stress. Present work reveals genotypic differences of hot pepper to different water regimes. Based on Principal Component Analysis (PCA) of seed antioxidant variables and drought tolerance indices twenty genotypes segregated into three clusters, namely, drought tolerant and susceptible and moderately tolerant.

Author(s):  
Ramadevi Kundur ◽  
Papi Reddy Reddy T. ◽  
Manohar Rao.T.

In rice, several cultivated and upland varieties need to be assessed and analyzed for drought tolerance traits which could be used in screening and breeding programs for drought tolerance. Hence, the objectives of this study were to investigate the effects of water deficits in two rice cultivars and thereby analyze the role of several physiological traits useful in rice breeding programs for drought tolerance. The rice varieties Tellahamsa (TH) and N22 were screened for tolerance to drought. A comparative study was done subjecting them to PEG mediated water stress. Accumulation of solutes, i.e., proline, total free aminoacids and sugars; biomass production, Relative Water Content (RWC) and the levels of antioxidant enzymes, viz., Catalase (CAT), Ascorbate Peroxidase (APX), Glutathione Reductase(GR), and Superoxide Dismutase(SOD) were analyzed in response to water stress. Maximum proline accumulation was seen within 24hrs of stress, after 10 days TH decreased its proline to one-third, whereas in N22 doubled. Although amino acids doubled within 24hrs, gradually they depleted in N22. This may be due to conversion of aminoacids into proline which could be the most compatible solute. Sugars increased within 24hrs, but were depleted in 10days in both. In TH, the shoot and root biomass decreased, whereas in N22 there was a significant increase in root biomass. Shoot and root RWC of N22 was higher than TH under stress. GR increased in both TH and N22, APX and SOD increased only in N22. Proline accumulation, increase of root biomass and antioxidant enzymes such as APX or SOD during water stress are contributing to drought tolerance and could be used in screening for drought tolerance.


2016 ◽  
Vol 18 (2) ◽  
pp. 31-38
Author(s):  
JA Chowdhury ◽  
MA Karim ◽  
QA Khaliq ◽  
MSA Khan ◽  
SK Paul ◽  
...  

An experiment was conducted in a Venylhouse of Bangabandhu Sheikh Mujibur Rahman Agricultural University during September to December 2012 to determine the effect of midday drop of relative water content (RWC) on drought tolerance of soybean genotypes. Four soybean genotypes viz. Shohag, BARI Soybean-6, BD2331 and BGM2026 were used in the study. Plants were grown in pots under stress and control condition. A marked difference in RWC between morning and midday was observed both in stressed and control plants. BARI Soybean-6 showed higher RWC than rest of the genotypes and BGM2026 showed the lowest at all growth stages. The reduced RWC of BARI Soybean-6 under water stress at vegetative, flowering and pod developing stages were 11.35, 13.52 and 15.04% at 1.00 PM as compared to control, respectively. The reduced RWC of BGM2026 at vegetative, flowering and pod developing stages were 18.99, 20.64 and 23.05% at 1.00 PM, respectively. In stressed plants, midday drop of relative water content was minimal in BARI Soybean-6 (8.97%) and maximum in BGM2026 (17.89%) at 1.00 PM. Under water stress condition BARI Soybean-6 gave the highest seed yield (5.23 g plant-1) and BGM2026 the lowest (3.21 g plant-1) which might be attributed to the drastic reduction in 100-seed weight of RWC in the variety BGM2026 due to the significant reduction in RWC in this variety. Considering the midday drop of RWC and seed yield, it may be concluded that BGM2026 is susceptible and BARI Soybean-6 is drought tolerant among the genotypes.Bangladesh Agron. J. 2015, 18(2): 31-38


HortScience ◽  
1996 ◽  
Vol 31 (6) ◽  
pp. 915A-915 ◽  
Author(s):  
Rajeev Arora ◽  
Dharmalingam S. Pitchay ◽  
Bradford C. Bearce

This study evaluated the effect of reversible water stress on heat stress tolerance (HST) in greenhouse-grown geraniums. Water stress was imposed by withholding irrigation until pots reached ≈30% (by weight) of well-watered (control) plant pots, and maintaining this weight for 7 days. Control plants were watered to just below field capacity, every other day. Leaf xylem water potential (LXWP, MPa), leaf-relative water content (LRWC,%), media water content (MWC, % fresh weight), and heat stress tolerance (HST, LT50) were determined for control and stressed plants. HST (LT50), defined as temperature causing half-maximal percent injury, was based on electrolyte leakage from leaf disks subjected to 25 to 60C. Control-watering was restored in stressed plants and above measurements made after 7 days of recovery. Data indicate: 1) LXWP, LRWC, and MWC in control and stressed plants were –0.378 and –0.804 MPa, 92.31% and 78.69% and 82.86% and 15.5%, respectively; 2) HST increased significantly in stressed as compared to control plants (LT50 of 55C vs. 51C); 3) control plants were near maximally injured by 53C treatment and sustained more than 3-fold greater injury than stressed plants at 53C. In recovered plants, LXWP and RWC reversed back to control levels, paralleled by loss of higher HST.


2015 ◽  
Vol 10 (4) ◽  
pp. 208 ◽  
Author(s):  
Lorenzo Barbanti ◽  
Ahmad Sher ◽  
Giuseppe Di Girolamo ◽  
Elio Cirillo ◽  
Muhammad Ansar

A better understanding of plant mechanisms in response to drought is a strong premise to achieving high yields while saving unnecessary water. This is especially true in the case of biomass crops for non-food uses (energy, fibre and forage), grown with limited water supply. In this frame, we investigated growth and physiological response of two genotypes of biomass sorghum (<em>Sorghum bicolor</em> (L.) Moench) to contrasting levels of soil moisture in a pot experiment carried out in a greenhouse. Two water regimes (high and low water, corresponding to 70% and 30% field capacity) were applied to JS-2002 and Trudan-8 sorghum genotypes, respectively bred for dry sub-tropical and mild temperate conditions. Two harvests were carried out at 73 and 105 days after seeding. Physiological traits (transpiration, photosynthesis and stomatal conductance) were assessed in four dates during growth. Leaf water potential, its components and relative water content were determined at the two harvests. Low watering curbed plant height and aboveground biomass to a similar extent (ca. 􀀀70%) in both genotypes. JS-2002 exhibited a higher proportion of belowground to aboveground biomass, <em>i.e</em>., a morphology better suited to withstand drought. Despite this, JS-2002 was more affected by low water in terms of physiology: during the growing season, the average ratio in transpiration, photosynthesis and stomatal conductance between droughty and well watered plants was, respectively, 0.82, 0.80 and 0.79 in JS-2002; 1.05, 1.08 and 1.03 in Trudan-8. Hence Trudan-8 evidenced a ca. 20% advantage in the three traits. In addition, Trudan-8 could better exploit abundant moisture (70% field capacity), increasing aboveground biomass and water use efficiency. In both genotypes, drought led to very low levels of leaf water potential and relative water content, still supporting photosynthesis. Hence, both morphological and physiological characteristics of sorghum were involved in plant adaptation to drought, in accordance with previous results. Conversely, the common assumption that genotypes best performing under wet conditions are less suited to face drought was contradicted by the results of the two genotypes in our experiment. This discloses a potential to be further exploited in programmes of biomass utilization for various end uses, although further evidence at greenhouse and field level is needed to corroborate this finding.


2017 ◽  
Vol 9 (2) ◽  
pp. 1036-1041 ◽  
Author(s):  
Priyanka Kumari ◽  
H. K. Jaiswal

Cold stress at seedling stage is a major constraint in boro rice production. Nine boro rice lines were crossed in diallel fashion excluding reciprocals to obtain 36 crosses. All the 36 crosses along with parents were grown in nursery in three seasons (boro-2014, kharif-2015 and boro-2015). Performance of seedlings for survival per cent, chlorophyll content, relative water content, membrane stability index was recorded just before transplanting in all the three seasons. Scoring for cold tolerance was done in both boro seasons. Gautam showed highest survival rate over three seasons. Among crosses, IR 64 x Krishna Hamsa showed highest survival (84%) in boro-2014, MTU 1010 x Jaya (86.33%) in boro-2015 and MTU 1010 x Krishna Hamsa (95.67%) in kharif-2015. Jaya x Krishna Hamsa was most cold tolerant cross over both boro seasons. Significant positive correlation was observed among survival per cent, chlorophyll content, relative water content and membrane stability index over seasons.


2019 ◽  
Vol 18 (6) ◽  
pp. 75-84
Author(s):  
Alireza Motallebi-Azar ◽  
István Papp ◽  
Anita Szegő

Dehydrins are proteins that play a role in the mechanism of drought tolerance. This study aimed at establishing dehydrin profile and accumulation in four local melon varieties of Iran: Mino, Dargazi, Saveii, and Semsori, as well as in a commercial variety Honeydew. Plants were treated with drought stress by adjusting the soil water content to 75, 50, 40, 30 and 20% of field capacity (FC) by withholding water. Water status of plants was monitored based on the seedling fresh weight (FW) and relative water content of leaves (RWC). Total protein content was extracted, then heat-stable protein (HSP) fraction was isolated for each variety and water stress treatment. After SDS-PAGE of HSP, Western blotting analysis was carried out with Anti-dehydrin rabbit (primary) and Goat anti rabbit (secondary) antibodies. ANOVA results showed that with decreasing FC below 75%, FW and RWC decreased, but these changes significantly varied among genotypes. On the basis of FW and RWC data under different drought stress treatments, the following drought-tolerant ranking was established: Mino > Dargazi > Saveii and Honeydew > Semsori, from tolerant to sensitive order. Results of Western blot analysis showed that expression of some proteins with molecular weights of 19–52 kDa was induced in the studied varieties under drought stress (% FC). Expression level of the dehydrin proteins in different varieties was variable and also depending on the drought stress level applied. However, dehydrin proteins (45 and 50 kDa) showed strong expression levels in all varieties under severe drought stress (20% FC). The abundance of dehydrin proteins was higher in tolerant varieties (Mino and Dargazi) than in moderate and drought sensitive genotypes. Consequently, dehydrins represent a potential marker for selection of genotypes with enhanced drought tolerance.


2020 ◽  
Vol 41 (4) ◽  
pp. 1093
Author(s):  
Suerlani Aparecida Ferreira Moreira ◽  
Pablo Fernando Santos Alves ◽  
Carlos Eduardo Corsato ◽  
Alcinei Mistico Azevedo

Maize hybrids contrasting for drought tolerance differ during the vegetative stage. Drought is the main constraint on maize production in developing nations. Differences during development between genetic materials of maize grown under water restriction suggest that the plant can be improved with a view to its adaptation. In maize, sensitivity to water stress can occur at any stage of its phenological development. However, few studies report its effects on the vegetative phase of the cycle. On this basis, this study was conducted to examine how shoot and root-system indices are expressed in cultivation under water deficit as well as determine which indicators best explain the difference between hybrids in the evaluated water regimes. Commercial seeds of hybrids BR1055 and DKB-390 (drought-tolerant) and BRS1010 (drought-sensitive) were germinated in PVC tubes (1.0 m × 0.1 m) in a randomized complete block design, in a 3 × 2 factorial arrangement. The experiment was developed in a greenhouse where two water regimes were tested: no water stress and with water stress from the VE stage. The soil consisted of quartz sand mixed with a commercial fertilizer. Stem and root traits were evaluated up to the V5 growth stage. Relative chlorophyll content, leaf temperature, stem length, phenology, shoot dry biomass, root length, root dry biomass, root surface area, root volume and D95 were responsive to water deficit. The parameters that allowed the distinction between the hybrids in water the regimes were relative chlorophyll content, leaf temperature, phenology and average root diameter.


2016 ◽  
Vol 27 (2) ◽  
pp. 128-135 ◽  
Author(s):  
J Akte ◽  
S Yasmin ◽  
MJH Bhuiyan ◽  
F Khatun ◽  
J Roy ◽  
...  

Five rice varieties viz. Binadhan-4, Binadhan-5, Binadhan-6, Binadhan-10 and Iratom-24 were evaluated in vitro under different water stress conditions. Several parameters such as germination percentage, shoot length, root length, shoot-root ratio, fresh weight, dry weight, turgid weight, relative water content and proline accumulation were studied. Drought condition was created by MS medium supplemented with five treatments of PEG, with a control such as 0%, 1%, 2%, 3% and 4% of PEG. The highest germination (100%) was found in the variety Binadhan-10 under low water stress conditions induced by 1% PEG. Similarly, the highest percentage of germination was found in all varieties under control condition (0% PEG). The lowest percentage of germination was obtained in the variety Iratom-24. But under severe stress (4% PEG), the highest percentage of germination was found only in the variety Binadhan-10. Moreover, the variety Binadhan-10 was found to be the best at 4% PEG for shoot length, root length, shoot-root ratio, relative water content and also the best at 1% PEG for fresh weight, dry weight, turgid weight. Water stress decreased relative water content and increased proline accumulation in rice. The highest relative water content was recorded in the variety Binadhan-10 and the lowest value recorded in the variety Binadhan-5. The highest proline content was obtained from the binadhan-6 at the highest treatment (4% PEG). Binadhan-10 showed the best performance almost in all the parameters under drought stress because of its own nature of tolerancy.Progressive Agriculture 27 (2): 128-135, 2016


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