scholarly journals Developing mathematical model for diurnal dynamics of photosynthesis in Saccharum officinarum responsive to different irrigation and silicon application

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10154
Author(s):  
Krishan K. Verma ◽  
Kai-Chao Wu ◽  
Chhedi Lal Verma ◽  
Dong-Mei Li ◽  
Mukesh Kumar Malviya ◽  
...  

In the dynamic era of climate change, agricultural farming systems are facing various unprecedented problems worldwide. Drought stress is one of the serious abiotic stresses that hinder the growth potential and crop productivity. Silicon (Si) can improve crop yield by enhancing the efficiency of inputs and reducing relevant losses. As a quasi-essential element and the 2nd most abundant element in the Earth’s crust, Si is utilized by plants and applied exogenously to combat drought stress and improve plant performance by increasing physiological, cellular and molecular responses. However, the physiological mechanisms that respond to water stress are still not well defined in Saccharum officinarum plants. To the best of our knowledge, the dynamics of photosynthesis responsive to different exogenous Si levels in Saccharum officinarum has not been reported to date. The current experiment was carried out to assess the protective role of Si in plant growth and photosynthetic responses in Saccharum officinarum under water stress conditions. Saccharum officinarum cv. ‘GT 42’ plants were subjected to drought stress conditions (80–75%, 55–50% and 35–30% of soil moisture) after ten weeks of normal growth, followed by the soil irrigation of Si (0, 100, 300 and 500 mg L−1) for 8 weeks. The results indicated that Si addition mitigated the inhibition in Saccharum officinarum growth and photosynthesis, and improved biomass accumulation during water stress. The photosynthetic responses (photosynthesis, transpiration and stomatal conductance) were found down-regulated under water stress, and it was significantly enhanced by Si application. No phytotoxic effects were monitored even at excess (500 mg L−1). Soil irrigation of 300 mg L−1 of Si was more effective as 100 and 500 mg L−1 under water stress condition. It is concluded that the stress in Saccharum officinarum plants applied with Si was alleviated by improving plant fitness, photosynthetic capacity and biomass accumulation as compared with the control. Thus, this study offers new information towards the assessment of growth, biomass accumulation and physiological changes related to water stress with Si application in plants.

2003 ◽  
Vol 128 (3) ◽  
pp. 337-342 ◽  
Author(s):  
William L. Bauerle ◽  
Jerry B. Dudley ◽  
Lawrence W. Grimes

Cultivars of red (Acer rubrum L.) and Freeman maple (Acer ×freemanii E. Murray) are popular ornamental plants which are commonly placed in a variety of landscapes. To date, little information quantifies the capacity to tolerate and recover from drought among cultivars of red and Freeman maple. The objective of this study was to compare the effects of water stress on the physiology of five different maple cultivars of marketable size including four red maple genotypes, `Summer Red', `October Glory' (October Glory), `Autumn Flame', and `Franksred' (Red Sunset), as well as one hybridized Freeman maple genotype, `Jeffersred' (Autumn Blaze). Two-year-old cloned genotypes of red and Freeman maple were subjected to two treatments: irrigated daily to container capacity or irrigation withheld for one drought and recovery cycle. Light absorption, gas exchange, and chlorophyll fluorescence measurements were conducted under well-watered and drought stress conditions that approached 0.070 m3·m-3. Compared to well-watered conditions, drought stress conditions of 0.090 m3·m-3 had a significant main effect that reduced the amount of light absorption in four of the five genotypes. Additionally, absorption among genotypes was different under both well-watered and water stress conditions. Over the course of drought stress and a recovery phase, net photosynthesis and stomatal conductance were different among genotypes. Maximum photosystem II (PSII) efficiency of dark-adapted leaves (Fv/Fm) was lowered by the water stress condition. The efficiency of excitation capture by open PSII reaction centers (Fv`/Fm') was variable among genotypes. Photochemical quenching was higher in Autumn Blaze, October Glory, and `Summer Red' under drought conditions, which corresponded with a low degree of closure of PSII centers. Additionally, the fraction of excess excitation energy was also lower. Lastly, water deficit caused an increase in PSII efficiency in all genotypes except Autumn Blaze. This research demonstrated physiological variation among commercially available red and Freeman maple genotypes that may be selected for drought tolerance based on site moisture characteristics.


2020 ◽  
Vol 48 (2) ◽  
pp. 938-953
Author(s):  
Taieb TOUNEKTI ◽  
Mosbah MAHDHI ◽  
Zarraq AL-FAIFI ◽  
Habib KHEMIRA

Seeds of three sorghum (Sorghum bicolor (L.) Moench.) varieties from Southwest Saudi Arabia were used to investigate the potential of osmopriming with polyethylene glycol (PEG 8000) to improve germination performance, seed reserve utilization and early seedling growth and drought stress tolerance. The primed (PS) and unprimed (UPS) seeds of the three sorghum varieties were germinated for 8 days under increasing PEG-induced osmotic stress. The treatments were arranged in a completely randomized design, in a factorial arrangement, with three sorghum cultivars (‘Zaydia’, ‘Shahbi’ and ‘Ahmar’) and four osmotic potentials (0.0; -0.4; -0.8 and -1.2 MPa) with four replicates of 50 seeds each. The results showed that drought stress affected seed germination and seedling emergence and establishment, but increased the activity of the antioxidant enzyme catalase (CAT). The strongest inhibition of germination and growth occurred at the highest PEG concentration and a significant difference was noticeable between the studied varieties. We confirmed also that seed osmopriming improved seed germination performance, seedling growth and enhanced the CAT activities while reduced malonyldialdehyde (MDA) accumulation and electrolyte leakage (EL) in the drought-stressed seedlings. Seed priming have enhanced also the α-amylase and total proteases activities in all varieties. The largest increase of these hydrolysing enzymes was shown in ‘Ahmar’. Furthermore, the PEG priming lead to improvement of the weight of utilized (mobilized) seed reserve (WUSR), seed reserve depletion percentage (SRDP) and total seedling dry weight (SLDW) of sorghum seedlings under water stress conditions. Still, the highest values or all three parameters were found in the ‘Ahmar’ variety. Under increasing drought stress conditions, ‘Ahmar’ showed the highest yield stability index (YSI) and the least EL and MDA contents in comparison to the other two varieties during the seedling establishment stage. Therefore, the former variety can tolerate better a rigorous water stress condition. ‘Zaydia’ appears to be the most vulnerable to drought stress. Thus, the use of species or varieties with eminent seed metabolic quality is an advantageous trait in drought-prone regions.


2021 ◽  
Vol 54 (1) ◽  
Author(s):  
Krishan K. Verma ◽  
Xiu-Peng Song ◽  
Chhedi Lal Verma ◽  
Zhong-Liang Chen ◽  
Vishnu D. Rajput ◽  
...  

Abstract Background Water stress is one of the serious abiotic stresses that negatively influences the growth, development and production of sugarcane in arid and semi-arid regions. However, silicon (Si) has been applied as an alleviation strategy subjected to environmental stresses. Methods In this experiment, Si was applied as soil irrigation in sugarcane plants to understand the mitigation effect of Si against harmful impact of water stress on photosynthetic leaf gas exchange. Results In the present study we primarily revealed the consequences of low soil moisture content, which affect overall plant performance of sugarcane significantly. Silicon application reduced the adverse effects of water stress by improving the net photosynthetic assimilation rate (Anet) 1.35–18.75%, stomatal conductance to water vapour (gs) 3.26–21.57% and rate of transpiration (E) 1.16–17.83%. The mathematical models developed from the proposed hypothesis explained the functional relationships between photosynthetic responses of Si application and water stress mitigation. Conclusions Silicon application showed high ameliorative effects on photosynthetic responses of sugarcane to water stress and could be used for mitigating environmental stresses in other crops, too, in future.


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.


Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 830 ◽  
Author(s):  
Yan Liu ◽  
Xiaoli Wei

Dark septate endophytes (DSEs) are known to help host plants survive drought stress; however, how DSEs enhance host plant drought resistance under water stress conditions remains unclear. The objective of this study was to inoculate Ormosia hosiei seedlings with a DSE strain (Acrocalymma vagum) to investigate the effects of DSE inoculation on root morphology, ultrastructure, and the endogenous hormone content under drought stress conditions and to elucidate the drought resistance mechanism involved in the DSE–host-plant association. The inoculated seedlings were grown under three different soil water conditions (well watered—75% field water capacity, moderate water—55% field water capacity, or low water—35% field water capacity) for 114 days. Fresh root weight, root volume, root surface area, root fork, and root tip number were significantly higher in inoculated seedlings than in noninoculated seedlings. Furthermore, the root architecture of the inoculated seedlings changed from herringbone branching to dichotomous branching. Mitochondria and other organelles in root cells of inoculated seedlings remained largely undamaged under water stress, whereas organelles in root cells of noninoculated seedlings were severely damaged. The abscisic acid (ABA) and indole-3-acetic acid (IAA) content and IAA/ABA ratio of inoculated seedlings were significantly higher than those of noninoculated seedlings, whereas the content of gibberellic acid (GA) and the ratios of GA/ABA, zeatin riboside (ZR)/ABA, and ZR/IAA in inoculated seedlings were lower than those of noninoculated seedlings. DSE inoculation could help plants adapt to a drought stress environment by altering root morphology, reducing ultrastructural damage, and influencing the balance of endogenous hormones, which could be of great significance for the cultivation and preservation of the O. hosiei tree.


2014 ◽  
Vol 68 (1) ◽  
pp. 65-75
Author(s):  
Soleiman Mohammadi ◽  
Reza Kas Nazani ◽  
Ayda Hosseinzadeh Mahootchi ◽  
Keiwan Ftohi

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.


2020 ◽  
Author(s):  
Soumya Kumar Sahoo ◽  
Goutam Kumar Dash ◽  
Arti Guhey ◽  
Mirza Jaynul Baig ◽  
Madhusmita Barik ◽  
...  

ABSTRACTRice production is severely threatened by drought stress in Eastern India. To develop drought tolerant varieties, selection of donors for breeding programme is crucial. Twenty one selected rice genotypes including both tolerant and sensitive to drought were grown under well-watered and drought stress conditions in dry seasons of two successive years of 2017 and 2018. Leaf water potential, relative water content displayed significant difference among the genotypes during vegetative screening. At reproductive stage drought screening, days to 50% flowering was delayed in all genotypes except N22 and Anjali (showed early flowering) however grain yield and other yield related traits decreased significantly compared to well watered condition. Correlation analysis of phenological and yield related traits with grain yield revealed that tiller numbers and panicle numbers are highly correlated with grain yield both under well-watered and water stress conditions and contributes maximum towards grain yield. The dendrogram grouped Mahamaya, Sahabhagidhan, Poornima, IBD 1, Hazaridhan, Samleshwari and Danteshwari into one cluster which performed better under water stress conditions and had grain yield more than 1.69 tha−1. Sahabhagidhan, Poornima, Vandana, and N22 displayed tolerance to drought both under vegetative and reproductive conditions which could be a good selection for the breeders to develop drought tolerant rice cultivars for eastern region of India.


2021 ◽  
Author(s):  
DEVENDRA SINGH ◽  
Shobit Thapa ◽  
Jagriti Yadav ◽  
Dikchha SINGH ◽  
Hillol Chakdar ◽  
...  

Abstract Drought stress adversely influences the crop plants. Herein, present research was designed to elucidate the role of plant growth promoting microbes for amelioration of water stress in wheat. A pot experiment was conducted for screening the microorganisms on the basis of plant growth, chlorophyll and proline content under water stress. Bacillus sp. BT3 and Klebsiella sp. HA9 were found more promising strains that positively influenced the plant growth, chlorophyll and proline status of seedlings under water stress condition. Further, Bacillus sp. BT-3 and Klebsiella sp. HA9 along with check strain (BioNPK) were used for elucidating their detailed effect on morphological, biochemical, physiological and molecular traits to mitigate drought stress in wheat. Microbial inoculation significantly enhanced plant growth, biomass, relative water content, chlorophyll content and root morphological parameters over the uninoculated water stressed (30% FC) control. Likewise, sugar content, protein content and antioxidant enzymes were also significantly enhanced due to microbial inoculation under water stress (30% FC). Microbial inoculation significantly decreased proline, glycine betaine, lipid peroxidation, peroxide and superoxide radicals in wheat over the uninoculated water stressed (30%FC) control. Quantitative real-time (qRT)- PCR analysis revealed that Bacillus sp. BT-3, Klebsiella sp. HA9 and BioNPK inoculation significantly upregulated stress responsive genes (DHN, DREB, L15 and TaABA-8OH) over the uninoculated water stressed (30% F.C.) control. The study reports the potential of Bacillus sp. BT3 and Klebsiella sp. HA9 along with BioNPK in water stress alleviation in wheat which could be recommended as effective biofertilizers.


2019 ◽  
Vol 99 (4) ◽  
pp. 510-524
Author(s):  
D.E.J. Wright ◽  
J.A. Cline ◽  
H.J. Earl

The use of drought-tolerant rootstocks is an important strategy in maintaining orchard productivity while meeting the increasing need to conserve water resources. The drought tolerance of two new genotypes, Vineland 1 (V.1) and Vineland 3 (V.3), was assessed along with industry standards to test the hypothesis that differences in water-use efficiency exist among these apple rootstocks. One-year-old, non-grafted nursery liners of M.9, MM.111, V.1, and V.3 were grown in a controlled-environment experiment. Plants of each genotype were maintained water-replete or were subjected to a 9-d controlled dry down and then maintained under water stress conditions for 55 d. Water stress reduced biomass accumulation and trunk cross-sectional area for all four genotypes. The two vigorous genotypes, MM.111 and V.1, increased their root-to-shoot ratios in response to water stress, whereas the root-to-shoot ratios of M.9 and V.3 remained unchanged in their water-replete controls. Genotype V.3 maintained its transpiration at a significantly lower soil water content compared to M.9, MM.111, and V.1. Of the four genotypes, V.3 demonstrated a high tolerance to water stress conditions, and therefore deserves further investigation using grafted apple trees in an orchard study.


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