scholarly journals Genotypic variation in root distribution changes and physiological responses of sugarcane induced by drought stress

2018 ◽  
Author(s):  
Jariya Namwongsa ◽  
Nuntawoot Jongrungklang ◽  
Patcharin Songsri

Drought is an important factor reducing yield and quality of sugarcane. Root growth and physiological traits are important for maximizing water uptake to improve drought resistance. This study compared the root, shoot and physiological traits under drought stress (DS) and well-watered (WW) conditions of various sugarcane varieties grown in rhizoboxes in a greenhouse at the Field Crops Research Station of Khon Kaen University, Khon Kaen, Thailand. Data were recorded for the root, shoot and physiological traits (relative water content, stomatal conductance, SPAD chlorophyll meter reading and chlorophyll fluorescence) at 90 days after transplanting. Root samples were recovered from 11 soil layers at 10 cm intervals from the top to the bottom of the rhizobox, for root length and root dry weight measurements. Drought was imposed on sugarcane at early growth stages altered the root distribution patterns, and differences were evident among the sugarcane genotypes. The sugarcane genotypes adapted to water stress by increasing root length into deeper soil layers. Drought led to increased total root length in KK3, MPT06-166, K88-92, CP38-22, Kps01-12 and KPK98-40. Root lengths and stomatal conductance were positively correlated under WW and DS conditions. Root distribution in the lower soil layers and the percentage of root distribution were higher than those under well-watered conditions. The knowledge gained from this study will aid parental selection in sugarcane breeding programs for drought resistance as the findings strongly suggest that the physiological modification in the root system is a useful drought-resistant mechanism.

2020 ◽  
Vol 4 (2) ◽  
pp. 78-82
Author(s):  
Mohd Syahmi Salleh ◽  
Ris Amirah Malek ◽  
Rozilawati Shahari ◽  
Mohd Shukor Nordin

Drought is regarded as one of the limiting factors in rice production nationally and globally. The present study was conducted to study morpho-physiological and biochemical responses of rice genotypes to drought stress, to identify potential traits for use as a selection criterion in breeding drought-tolerant rice at seedling stage and finally to identify rice genotype resistant to drought stress for use as parents in future breeding. The experimental design used was a split-plot design with three replications, with drought stress as the main plot and rice genotypes as the sub-plot. The main plots consisted of control (normal irrigation) and drought stress. The sub-plots consisted of twelve rice genotypes namely Apami (V1), Boewani (V2), Basmati 370 (V3), Cica- 4 (V4), Dular (V5), Jarom mas (V6), Kalarata (V7), Biris (V8), Haiboq (V9), Moroberekan (V10), MR 297 (V11) and Aerob 1 (V12). Results showed that drought stress led to a decrease in plant height, leaves size, root length, total dry weight, and number of leaves but an increment in proline content. The genotype Apami and Kalarata were found to accumulate higher proline content indicating potential resistant ability towards drought stress. Dular and Aerob1, along with tolerant control genotype, Moroberekan, on the other hand, recorded a lower SES score. Leave size, root length, and plant height could also be used as a selection criterion in breeding drought-tolerant rice due to high values of broad-sense heritability and genetic advance by percentage of mean (GAM). Nevertheless, further study on the genetics and physiological basis of tolerant ability at reproductive growth stages are necessary in order to assess grain yield potential of the potentially tolerant genotype reported in this study.


1996 ◽  
Vol 74 (12) ◽  
pp. 1988-1995 ◽  
Author(s):  
I. Van Splunder ◽  
L. A. C. J. Voesenek ◽  
X. J. A. De Vries ◽  
C. W. P. M. Blom ◽  
H. Coops

The riparian distribution patterns of floodplain species are affected by fluctuations in water level. Rapidly declining water levels in river banks during the growing period of plants can result in limited availability of water, particularly on coarse substrates. Differences in drought resistance among Salix alba, Salix triandra, Salix viminalis, and Populus nigra, four species dominating river banks along the River Rhine, could explain part of the riparian distribution patterns. Mortality and growth responses of seedlings grown under well-watered and dry conditions were studied in a greenhouse experiment. Drought-induced mortality was 0% in S. alba and P. nigra, 37.5% in S. triandra, and 62.5% in S. viminalis, which correlated with differences in water-loss characteristics of the species studied: S. triandra and S. viminalis had much higher transpiration rates under well-watered conditions than S. alba and P. nigra. Decreased shoot to root ratios were observed in all species after 3 weeks of drought. The increase after drought of the root length to leaf area ratio was greatest for P. nigra, indicating that this species has a relatively efficient water economy. Specific leaf areas of draughted plants decreased in S. alba and P. nigra, reflecting smaller transpiration areas. Drought also affected root distributions, resulting for all four species in deeper rooting and increased root length in deeper soil layers. Salix viminalis and S. triandra showed the greatest increase in root length in deep soil layers. We concluded that P. nigra is most resistant to drought followed by S. alba and then S. triandra and S. viminalis, and that these differences are reflected in the distribution patterns of these species observed on the banks of the River Rhine. Keywords: drought resistance, Salix, Populus, root distribution, transpiration, leaf conductance.


2012 ◽  
Vol 151 (5) ◽  
pp. 630-647 ◽  
Author(s):  
R. SANKARAPANDIAN ◽  
S. AUDILAKSHMI ◽  
V. SHARMA ◽  
K. GANESAMURTHY ◽  
H. S. TALWAR ◽  
...  

SUMMARYRecent trends in climate change resulting in global warming and extreme dry spells during rainy seasons are having a negative impact on grain and fodder production in rain-fed crops in India. Understanding the mechanisms of drought tolerance at various growth stages will help in developing tolerant genotypes. Crosses were made between elite and drought-tolerant sorghums, and F2and F3progenies were evaluated for drought tolerance in multiple locations. Twenty-five F4/F5derivatives along with drought-tolerant check plants (two high-yielding genotypes showing moderate drought tolerance: C43 (male parent of the commercial hybrid CSH 16, tolerant to drought) and CSV 17, (a pure line commercial cultivar released for drought-prone areas) were screened for drought tolerance under a factorial randomized block design with three replications during the rain-free months of April–June in 2007 and 2008 at Tamil Nadu Agricultural University, Kovilpatti, India. In each generation/year, four trials were conducted and water stress at different phases of crop growth,viz. vegetative, flowering and post-flowering (maturity), was imposed by withholding irrigation. Observations were recorded on grain and straw yields, plant height, number of roots, root length, leaf relative water content (LRWC), chlorophyll content and stomatal conductance under all treatments. The traits, grain yield, plant height, average root length and stomatal conductance showed significant mean sums of squares (SSs) for genotype × environment (G × E), suggesting that genotypes had significant differential response to the changing environments. Significant mean SSs due to G × E (linear) were obtained for straw yield, LRWC and chlorophyll content, indicating that the variability is partly genetic and partly influenced by environment. Grain yield was correlated with chlorophyll content (r = 0·43) at the vegetative stage, with number of roots (r = 0·49), LRWC (r = 0·51), chlorophyll content (r = 0·46) and stomatal conductance (r = −0·51) at the pre-flowering stage, and with LRWC (r = 0·50) and stomatal conductance (r = −0·40) at the post-flowering stage, under water stress. Partial least square (PLS) analysis showed that different traits were important for grain yield under water stress at different growth stages. Pyramiding the genes for the traits responsible for high grain yield under stress will help in developing stable genotypes at different stages of plant growth.


Author(s):  
Saranya Chumphu ◽  
Nuntawoot Jongrungklang ◽  
Patcharin Songsri

The objective of this study was to determine the association of physiological responses and root distribution patterns on yield of the second ratoon cane and the relationships among these traits. Seventeen sugarcane genotypes were planted in a randomized complete block design with four replications. The second ratoon crop was evaluated for germination percentage, cane yield, SPAD chlorophyll meter reading (SCMR), chlorophyll fluorescence, relative water content (RWC), specific leaf area (SLA) and stomatal conductance. Root length density (RLD) was evaluated by auger method. The root samples were divided into upper soil layer and lowers soil layers to study root distribution patterns. Sugarcane genotypes were significantly different for RLD, germination percentage and cane yield. Root distribution patterns were classified into three groups based on the RLD. High RLD between plants in the upper soil layers at 90 DAH was positively correlated with high germination, whereas high RLD between rows in the lower soil layers at 90 and 270 DAH was associated with high cane yield. RWC at 90 DAH and stomatal conductance at 180 DAH were closely related to germination percentage, whereas chlorophyll fluorescence and stomatal conductance at 180 DAH were closely related to cane yield.


Author(s):  
R. Himaja ◽  
K. Radhika ◽  
K. Bayyapu Reddy ◽  
M. Raghavendra

Background: Drought stress at germination and early growth stages hinders the seedling establishment in chickpea which ultimately affects the economic yield. Such adverse affects of drought can be mitigated by screening and identifying the tolerant genotypes of chickpea which is commonly cultivated under rain-fed conditions during post-rainy season. Methods: Effect of drought stress on germination and early seedling growth of thirty three chickpea genotypes was studied under four different concentrations of PEG 6000 (-0.3, -0.6, -0.9 and -1.2 MPa) along with control and hydration under laboratory conditions during 2018-19. Result: Significant variation was observed among the genotypes for germination, root length, shoot length and seedling vigour index under different concentrations of PEG 6000. Complete inhibition of germination was observed in most of the genotypes at -1.2 MPa. Based on the results obtained, JG 11 and NBeG 3 were considered as tolerant since they showed comparatively higher germination, root length, shoot length and seedling vigour even at -1.2 MPa, while NBeG 723 and NBeG 833 were considered as susceptible genotypes because of their poor germination and seedling growth even at lower levels of drought stress.


Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1106
Author(s):  
Ranjit Singh Gujjar ◽  
Pennapa Banyen ◽  
Wannisa Chuekong ◽  
Phapawee Worakan ◽  
Sittiruk Roytrakul ◽  
...  

Drought susceptible rice cultivar PTT1 (Pathumthani1) was treated with drought (−72 kPa) and CPPU (N-2-(chloro-4-pyridyl)-N-phenyl urea) @ 5 mg/L at tillering and grain-filling stages. Plants were tested for the effect of synthetic cytokinin on the parameters influencing the process of photosynthesis. Exogenous spray of CPPU improved the stomatal conductance of rice leaves, which was severely reduced by drought. The abundance intensities of proteins, associated with the stomatal conductance (ZEP, NCED4, PYL9, PYL10, ABI5, SnRK4, Phot1, and Phot2), were also in agreement with the positive impact of CPPU on the stomatal conductance under drought stress. Among the photosynthetic pigments, Chl b contents were significantly reduced by drought stress, whereas CPPU treated plants retained the normal contents of Chl b under drought stress. Subsequently, we examined the abundance intensities of chlorophyll synthase and HCR proteins, implicated in the biosynthesis of chlorophyll pigments and the conversion of Chl b to Chl a, respectively. The results indicated a drought-mediated suppression of chlorophyll synthase. However, CPPU treated plants retained normal levels of chlorophyll synthase under drought stress. In addition, drought stress induced HCR proteins, which might be the cause for reduced Chl b contents in drought stressed plants. Further, CPPU treatment helped the plants sustain photosynthesis at a normal rate under drought stress, which was comparable with well-watered plants. The results were further confirmed by examining the abundance intensities of two key proteins, RAF1 and Rubisco activase, implicated in the assembly and activation of Rubisco, respectively. CPPU treatment reversed the drought mediated suppression of these proteins at both of the growth stages of rice under drought stress. Based on the results, it can be suggested that synthetic cytokinins help the plants sustain photosynthesis at a normal rate under drought stress by positively influencing the determinants of photosynthesis at a molecular level.


Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1121
Author(s):  
Idan Reingwirtz ◽  
Jake Uretsky ◽  
Italo F. Cuneo ◽  
Thorsten Knipfer ◽  
Clarissa Reyes ◽  
...  

Some grapevine rootstocks perform better than others during and after drought events, yet it is not clear how inherent and stress-induced differences in root morphology and anatomy along the length of fine roots are involved in these responses. Using a variety of growing conditions and plant materials, we observed significant differences in root diameter, specific root length (SRL) and root diameter distribution between two commonly used commercial grapevine rootstocks: Richter 110 (110R; drought resistant) and Millardet et de Grasset 101-14 (101-14Mgt; drought sensitive). The 110R consistently showed greater root diameters with smaller SRL and proportion of root length comprised of fine lateral roots. The 110R also exhibited significantly greater distance from tip to nearest lateral, longer white root length, and larger proportion of root length that is white under drought stress. Mapping of fine root cortical lacunae showed similar patterns between the rootstocks; mechanical failure of cortical cells was common in the maturation zone, limited near the root tip, and increased with drought stress for both genotypes; however, lacuna formed under wetter soil conditions in 110R. Results suggest that drought resistance in grapevine rootstocks is associated with thick, limitedly branched roots with a larger proportion of white-functional roots that tend to form lacuna under more mild water deficit, all of which likely favor continued resource acquisition at depth.


2016 ◽  
Vol Volume 112 (Number 9/10) ◽  
Author(s):  
Makoena J. Moloi ◽  
Obed J. Mwenye ◽  
Rouxlene van der Merwe ◽  
◽  
◽  
...  

Abstract Soybean (Glycine max L.) is a small but growing component of the agricultural economy of South Africa and is predicted to become a major crop in Africa because of its high protein content. Drought induction at flowering or early stages of pod development has detrimental effects on soybean yield. As antioxidative enzymes play a protective role in plants during various abiotic stress conditions, this study was conducted to investigate how ascorbate (Enzyme Commission (EC) number 1.11.1.1) and guaiacol (EC: 1.11.1.7) peroxidases are involved in soybean drought resistance at different maturity stages (flowering and pod development). We also investigated whether the levels of these enzymes decline with plant maturity. Three tolerant soybean genotypes (G1, G2, G3) and a susceptible genotype (G4*) were used. These cultivars were categorised according to their sensitivity to drought stress in previous studies. The activity of ascorbate peroxidase was significantly induced by drought stress at both growth stages with higher activity in the resistant than susceptible plants, strongly supporting the protective role of this enzyme against drought stress at both developmental stages. The guaiacol peroxidase activity was induced to higher levels in the resistant than in the susceptible plants at flowering only, with no significant increase observed at pod development stage, indicating its selective protective involvement against drought stress. Interestingly, the levels of these enzyme activities were induced in all cultivars at both developmental stages, irrespective of drought stress, indicating that their activities increased with maturity.


Agronomy ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 200 ◽  
Author(s):  
Saranya Chumphu ◽  
Nuntawoot Jongrungklang ◽  
Patcharin Songsri

Poor ratooning ability for sugarcane can limit crop productivity and profitability of sugarcane growers. The objective of this study was to determine the association of physiological responses and root distribution patterns on the yield of the second ratoon cane, and the relationships between these traits. Seventeen sugarcane genotypes were planted in a randomized complete block design with four replications. The second ratoon crop was evaluated for germination percentage, cane yield, Soil Plant Analysis Development (SPAD) chlorophyll meter reading (SCMR), chlorophyll fluorescence, relative water content (RWC), specific leaf area (SLA), and stomatal conductance. Root length density (RLD) was evaluated through the auger method. The root samples were divided into upper and lower soil layers in order to study root distribution patterns. Sugarcane genotypes were significantly different for RLD, germination percentage, and cane yield. Root distribution patterns were classified into three groups based on the RLD. High RLD between plants in the upper soil layers at 90 days after harvest (DAH) was positively correlated with high germination, whereas high RLD between rows in the lower soil layers at 90 and 270 DAH was associated with high cane yield. RWC at 90 DAH and stomatal conductance at 180 DAH were closely related to germination percentage, whereas chlorophyll fluorescence and stomatal conductance at 180 DAH were closely related to cane yield.


2017 ◽  
Vol 204 (2) ◽  
pp. 111-122 ◽  
Author(s):  
N. Thangthong ◽  
S. Jogloy ◽  
N. Jongrungklang ◽  
C. K. Kvien ◽  
V. Pensuk ◽  
...  

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