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Chatara T, Musvosvi C, Houdegbe A, Tesfay SZ, Sibiya J. Morpho-physiological and biochemical characterization of African spider plant ( Gynandropsis gynandra (L.) Briq.) genotypes under drought and non-drought conditions. Front Plant Sci 2023; 14:1197462. [PMID: 37662144 PMCID: PMC10469808 DOI: 10.3389/fpls.2023.1197462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 07/13/2023] [Indexed: 09/05/2023]
Abstract
The African spider plant (Gynandropsis gynandra (L.) Briq.) is a nutrient-dense, climate-resilient indigenous vegetable with a C4 carbon fixation pathway. Understanding African spider plant drought tolerance mechanisms is essential for improving its performance in water-stressed areas. The objective of this study was to evaluate the stress tolerance potential of African spider plant accessions based on thirteen morphological, physiological, and biochemical traits under three different water treatment regimes. Eighteen accessions were evaluated over two growing seasons in the greenhouse using a split-split plot design with four replications and three water treatment-regimes namely optimum (100% field capacity), intermediate drought (50% field capacity) and, severe drought (30% field capacity). The results revealed that water regime had a significant effect (P< 0.01) on the accessions for the traits studied. A significant reduction across most of the studied traits was observed under drought conditions. However, proline content in all the accessions significantly rose under drought conditions. The principal component analysis revealed a considerable difference in the performance of the 18 African spider plant accessions under optimum and drought stress conditions. Several morphological and physiological parameters, including days to 50% flowering (r = 0.80), leaf length (r = 0.72), net photosynthesis (r = 0.76) and number of leaves per plant (r = 0.79), were positively associated with leaf yield under drought conditions. Cluster analysis categorized the 18 accessions and 13 measured parameters into 4 clusters, with cluster-1 exhibiting greater drought tolerance for most of the studied traits, and cluster-4 having the most drought-sensitive accessions. Among the accessions tested, accessions L3 and L5 demonstrated excellent drought tolerance and yield performance under both conditions. As a result, these accessions were selected as candidates for African spider plant drought tolerance breeding programs. These findings will serve as the foundation for future studies and will aid in improving food and nutrition security in the face of drought.
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Affiliation(s)
- Tinashe Chatara
- School of Agriculture, Earth and Environmental Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - Cousin Musvosvi
- School of Agricultural Sciences and Technology, Chinhoyi University of Technology, Chinhoyi, Zimbabwe
| | - Aristide Carlos Houdegbe
- School of Agriculture, Earth and Environmental Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
- Genetics, Biotechnology and Seed Science Unit (GBioS), Laboratory of Crop Production, Physiology and Plant Breeding, Faculty of Agronomic Sciences, University of Abomey-Calavi, Abomey-Calavi, Benin
| | - Samson Zeray Tesfay
- School of Agriculture, Earth and Environmental Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - Julia Sibiya
- School of Agriculture, Earth and Environmental Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
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Zheng X, Qiao L, Liu Y, Wei N, Zhao J, Wu B, Yang B, Wang J, Zheng J. Genome-Wide Association Study of Grain Number in Common Wheat From Shanxi Under Different Water Regimes. Front Plant Sci 2022; 12:806295. [PMID: 35154198 PMCID: PMC8825475 DOI: 10.3389/fpls.2021.806295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 12/08/2021] [Indexed: 06/14/2023]
Abstract
Water availability is a crucial environmental factor on grain number in wheat, which is one of the important yield-related traits. In this study, a diverse panel of 282 wheat accessions were phenotyped for grain number per spike (GNS), spikelet number (SN), basal sterile spikelet number (BSSN), and apical sterile spikelet number (ASSN) under different water regimes across two growing seasons. Correlation analysis showed that GNS is significantly correlated with both SN and BSSN under two water regimes. A total of 9,793 single nucleotide polymorphism (SNP) markers from the 15 K wheat array were employed for genome-wide association study (GWAS). A total of 77 significant marker-trait associations (MTAs) for investigated traits as well as 8 MTAs for drought tolerance coefficient (DTC) were identified using the mixed linear model. Favored alleles for breeding were inferred according to their estimated effects on GNS, based on the mean difference of varieties. Frequency changes in favored alleles associated with GNS in modern varieties indicate there is still considerable genetic potential for their use as markers for genome selection of GNS in wheat breeding.
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Affiliation(s)
- Xingwei Zheng
- State Key Laboratory of Sustainable Dryland Agriculture, Institute of Wheat Research, Shanxi Agricultural University, Linfen, China
| | - Ling Qiao
- State Key Laboratory of Sustainable Dryland Agriculture, Institute of Wheat Research, Shanxi Agricultural University, Linfen, China
| | - Ye Liu
- College of Life Science, Shanxi University, Taiyuan, China
| | - Naicui Wei
- College of Life Science, Shanxi University, Taiyuan, China
| | - Jiajia Zhao
- State Key Laboratory of Sustainable Dryland Agriculture, Institute of Wheat Research, Shanxi Agricultural University, Linfen, China
| | - Bangbang Wu
- State Key Laboratory of Sustainable Dryland Agriculture, Institute of Wheat Research, Shanxi Agricultural University, Linfen, China
| | - Bin Yang
- State Key Laboratory of Sustainable Dryland Agriculture, Institute of Wheat Research, Shanxi Agricultural University, Linfen, China
| | - Juanling Wang
- State Key Laboratory of Sustainable Dryland Agriculture, Institute of Wheat Research, Shanxi Agricultural University, Linfen, China
| | - Jun Zheng
- State Key Laboratory of Sustainable Dryland Agriculture, Institute of Wheat Research, Shanxi Agricultural University, Linfen, China
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Zhang P, Guo Z, Monikh FA, Lynch I, Valsami-Jones E, Zhang Z. Growing Rice ( Oryza sativa) Aerobically Reduces Phytotoxicity, Uptake, and Transformation of CeO 2 Nanoparticles. Environ Sci Technol 2021; 55:8654-8664. [PMID: 34156836 DOI: 10.1021/acs.est.0c08813] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
This study compared the impact and uptake of root-administered CeO2 nanoparticles (NPs) in rice growing under flooded and aerobic soil conditions, which are two water regimes commonly used for rice cultivation. CeO2 NPs at 100 mg/kg improved photosynthesis and plant growth by reducing the oxidative damage and enhancing plant tolerance to stress, while a higher concentration (500 mg/kg) of CeO2 NPs negatively affected plant growth. More significant effects were observed under the flooded condition than under the aerobic condition. CeO2 NPs of 100 and 500 mg/kg resulted in 78% and 70% higher accumulation of Ce in shoots under the flooded condition compared to the aerobic condition. CeO2 NPs partially transformed to Ce(III) species in soils and plants under both conditions. A higher extent of transformation under the flooded condition, which was partly attributed to the lower soil pH and redox potential under the flooded condition, leads to higher plant uptake of Ce. A higher extent of transformation in rhizosphere soil was observed. A higher plant transpiration rate (TR) under flooded conditions resulted in a higher accumulation of CeO2 species in shoots. This study, for the first time, reported that water regimes influenced the biotransformation of CeO2 NPs and their uptake and impact in rice plants.
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Affiliation(s)
- Peng Zhang
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K
| | - Zhiling Guo
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K
| | - Fazel Abdolahpur Monikh
- Department of Environmental & Biological Sciences, University of Eastern Finland, P.O. Box 111, Joensuu FI-80101, Finland
| | - Iseult Lynch
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K
| | - Eugenia Valsami-Jones
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K
| | - Zhiyong Zhang
- Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
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Majumder S, Biswas PK, Banik P. Impact of Water Regimes and Amendments on Inorganic Arsenic Exposure to Rice. Int J Environ Res Public Health 2021; 18:4643. [PMID: 33925610 PMCID: PMC8123884 DOI: 10.3390/ijerph18094643] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/19/2021] [Accepted: 04/23/2021] [Indexed: 12/04/2022]
Abstract
Rice-based diet faces an important public health concern due to arsenic (As) accumulation in rice grain, which is toxic to humans. Rice crops are prone to assimilate As due to continuously flooded cultivation. In this study, the objective was to determine how water regimes (flooded and aerobic) in rice cultivation impact total As and inorganic As speciation in rice on the basis of a field-scale trial in the post-monsoon season. Iron and silicon with NPK/organic manure were amended in each regime. We hypothesised that aerobic practice receiving amendments would reduce As uptake in rice grain with a subsequent decrease in accumulation of inorganic As species relative to flooded conditions (control). Continuously flooded conditions enhanced soil As availability by 32% compared to aerobic conditions. Under aerobic conditions, total As concentrations in rice decreased by 62% compared to flooded conditions. Speciation analyses revealed that aerobic conditions significantly reduced (p < 0.05) arsenite (68%) and arsenate (61%) accumulation in rice grains. Iron and silicon exhibited significant impact on reducing arsenate and arsenite uptake in rice, respectively. The study indicates that aerobic rice cultivation with minimum use of irrigation water can lead to lower risk of inorganic As exposure to rice relative to flooded practice.
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Affiliation(s)
- Supriya Majumder
- Department of Soil Science and Agricultural Chemistry, Institute of Agriculture, Visva Bharati 731236, Sriniketan, India; (S.M.); (P.K.B.)
| | - Pabitra Kumar Biswas
- Department of Soil Science and Agricultural Chemistry, Institute of Agriculture, Visva Bharati 731236, Sriniketan, India; (S.M.); (P.K.B.)
| | - Pabitra Banik
- Agricultural and Ecological Research Unit, Indian Statistical Institute, Kolkata 700108, India
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Huang F, Yan B, Zhang X, Zhao D, Guo L, Wang Y, Xia Z. Water Regime Evolution of Large Seasonal Lakes: Indicators for Characterization and an Application in Poyang Lake, China. Int J Environ Res Public Health 2018; 15:E2598. [PMID: 30469345 DOI: 10.3390/ijerph15112598] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 11/06/2018] [Accepted: 11/18/2018] [Indexed: 12/02/2022]
Abstract
Impacted by ongoing climate change and anthropogenic activities, large seasonal lakes experience water regime evolution, which raises challenges for the management of water resources and environment. The water regime evolution refers to the spatial and temporal alterations in the hydrological features of lakes. Characterizing the lake water regime and its alteration may help policymakers design effective adaption strategies. Therefore, total 47 hydrological indicators were proposed, considering intra-annual fluctuations, flood and drought features, and rate and frequency of water level variations. Combined with Mann-Kendall algorithm and Sen’s slope, the indicators were applied in Poyang Lake, a typically large seasonal lake in China, as a case study. The results revealed temporal and spatial variations in different hydrological indicators. The most dramatic alteration was the water level decline in October and November over the entire study phase, especially over the past 30 years. This was an urgent environmental problem that Poyang Lake faced, partially caused by the increased hydraulic gradient between southern and northern lake. It could trigger the drought occurring earlier, prolong the drought duration, and impair the wetland ecosystem. Environmental water requirements of both Poyang Lake and Yangtze River were suggested for regional sustainable development. The application in Poyang Lake showed the practicability and reliability of the indicators, which are applicable in international seasonal lakes. The series of indicators can be used in whole or in part, determined by the ecohydrological characters of a specific lake and the research objectives.
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Hu JY, Xie YH, Tang Y, Li F, Zou YA. Changes of Vegetation Distribution in the East Dongting Lake After the Operation of the Three Gorges Dam, China. Front Plant Sci 2018; 9:582. [PMID: 29765388 PMCID: PMC5938568 DOI: 10.3389/fpls.2018.00582] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Accepted: 04/13/2018] [Indexed: 05/29/2023]
Abstract
Water regime is regarded as the primary factor influencing the vegetation distribution in natural wetland ecosystems. However, the effect of water regime change induced by large-scale hydraulic engineering on vegetation distribution is still unclear. In this study, multi-temporal TM/ETM+/OLI images and hydrological data from 1995 to 2015 were used to elucidate how the change in water regime influenced the vegetation distribution in the East Dongting Lake (EDTL), especially after the operation of the Three Gorges Dam (TGD) in 2003. Using unsupervised and supervised classification methods, three types of land cover were identified in the study area: Water and Mudflat, Grass, and Reed and Forest. Results showed that the total vegetation area in EDTL increased by approximately 78 km2 during 1995-2015. The areas of Reed and Forest and Grass exhibited a contrasting trend, dramatic increase in Reed and Forest but sharp decrease in Grass, particularly after the operation of TGD. The lowest distribution elevations of Grass and Reed and Forest decreased by 0.61 and 0.52 m, respectively. As a result of water level variation, submergence duration increased at 20-21 m and 28 m elevations (1-13 days), but significantly decreased at 22-27 m and 29-30 m elevations (-3 to -31 days). The submergence duration of Grass and Reed and Forest was 246 and 177 days, respectively. This study indicated that wetland vegetation pattern significantly changed after the operation of TGD, mainly as a result of changes in submergence condition. Submergence duration might be an effective indicator to predict the shift of vegetation distribution in EDTL, and which could provide scientific guidance for vegetation restoration and wetland management in this lake.
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Affiliation(s)
- Jia-Yu Hu
- Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, China
- Dongting Lake Station for Wetland Ecosystem Research, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yong-Hong Xie
- Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, China
- Dongting Lake Station for Wetland Ecosystem Research, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, China
| | - Yue Tang
- Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, China
- Dongting Lake Station for Wetland Ecosystem Research, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, China
| | - Feng Li
- Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, China
- Dongting Lake Station for Wetland Ecosystem Research, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, China
| | - Ye-Ai Zou
- Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, China
- Dongting Lake Station for Wetland Ecosystem Research, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, China
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Deane DC, Nicol JM, Gehrig SL, Harding C, Aldridge KT, Goodman AM, Brookes JD. Hydrological-niche models predict water plant functional group distributions in diverse wetland types. Ecol Appl 2017; 27:1351-1364. [PMID: 28263423 DOI: 10.1002/eap.1529] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 01/21/2017] [Accepted: 02/08/2017] [Indexed: 06/06/2023]
Abstract
Human use of water resources threatens environmental water supplies. If resource managers are to develop policies that avoid unacceptable ecological impacts, some means to predict ecosystem response to changes in water availability is necessary. This is difficult to achieve at spatial scales relevant for water resource management because of the high natural variability in ecosystem hydrology and ecology. Water plant functional groups classify species with similar hydrological niche preferences together, allowing a qualitative means to generalize community responses to changes in hydrology. We tested the potential for functional groups in making quantitative prediction of water plant functional group distributions across diverse wetland types over a large geographical extent. We sampled wetlands covering a broad range of hydrogeomorphic and salinity conditions in South Australia, collecting both hydrological and floristic data from 687 quadrats across 28 wetland hydrological gradients. We built hydrological-niche models for eight water plant functional groups using a range of candidate models combining different surface inundation metrics. We then tested the predictive performance of top-ranked individual and averaged models for each functional group. Cross validation showed that models achieved acceptable predictive performance, with correct classification rates in the range 0.68-0.95. Model predictions can be made at any spatial scale that hydrological data are available and could be implemented in a geographical information system. We show the response of water plant functional groups to inundation is consistent enough across diverse wetland types to quantify the probability of hydrological impacts over regional spatial scales.
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Affiliation(s)
- David C Deane
- School of Biological Sciences, University of Adelaide, Adelaide, South Australia, 5005, Australia
| | - Jason M Nicol
- South Australian Research and Development Institute, West Beach, Adelaide, South Australia, Australia
| | - Susan L Gehrig
- South Australian Research and Development Institute, West Beach, Adelaide, South Australia, Australia
| | - Claire Harding
- Department of Environment, Water and Natural Resources, Mount Gambier, South Australia, Australia
| | - Kane T Aldridge
- School of Biological Sciences, University of Adelaide, Adelaide, South Australia, 5005, Australia
| | - Abigail M Goodman
- Department of Environment, Water and Natural Resources, Mount Gambier, South Australia, Australia
| | - Justin D Brookes
- School of Biological Sciences, University of Adelaide, Adelaide, South Australia, 5005, Australia
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Světlíková P, Hájek T, Těšitel J. Hydathode trichomes actively secreting water from leaves play a key role in the physiology and evolution of root-parasitic rhinanthoid Orobanchaceae. Ann Bot 2015; 116:61-8. [PMID: 25987711 PMCID: PMC4479752 DOI: 10.1093/aob/mcv065] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 03/16/2015] [Accepted: 04/10/2015] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND AIMS Root hemiparasites from the rhinanthoid clade of Orobanchaceae possess metabolically active glandular trichomes that have been suggested to function as hydathode trichomes actively secreting water, a process that may facilitate resource acquisition from the host plant's root xylem. However, no direct evidence relating the trichomes to water secretion exists, and carbon budgets associated with this energy-demanding process have not been determined. METHODS Macro- and microscopic observations of the leaves of hemiparasitic Rhinanthus alectorolophus were conducted and night-time gas exchange was measured. Correlations were examined among the intensity of guttation, respiration and transpiration, and analysis of these correlations allowed the carbon budget of the trichome activity to be quantified. We examined the intensity of guttation, respiration and transpiration, correlations among which indicate active water secretion. KEY RESULTS Guttation was observed on the leaves of 50 % of the young, non-flowering plants that were examined, and microscopic observations revealed water secretion from the glandular trichomes present on the abaxial leaf side. Night-time rates of respiration and transpiration and the presence of guttation drops were positively correlated, which is a clear indicator of hydathode trichome activity. Subsequent physiological measurements on older, flowering plants indicated neither intense guttation nor the presence of correlations, which suggests that the peak activity of hydathodes is in the juvenile stage. CONCLUSIONS This study provides the first unequivocal evidence for the physiological role of the hydathode trichomes in active water secretion in the rhinanthoid Orobanchaceae. Depending on the concentration of organic elements calculated to be in the host xylem sap, the direct effect of water secretion on carbon balance ranges from close to neutral to positive. However, it is likely to be positive in the xylem-only feeding holoparasites of the genus Lathraea, which is closely related to Rhinanthus. Thus, water secretion by the hydathodes might be viewed as a physiological pre-adaptation in the evolution of holoparasitism in the rhinanthoid lineage of Orobanchaceae.
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Affiliation(s)
- Petra Světlíková
- Faculty of Science, University of South Bohemia, Branišovská 1760, České Budějovice 370 05, Czech Republic and Institute of Botany, Academy of Sciences of the Czech Republic, Dukelská 135, Třeboň 379 82, Czech Republic
| | - Tomáš Hájek
- Faculty of Science, University of South Bohemia, Branišovská 1760, České Budějovice 370 05, Czech Republic and Institute of Botany, Academy of Sciences of the Czech Republic, Dukelská 135, Třeboň 379 82, Czech Republic Faculty of Science, University of South Bohemia, Branišovská 1760, České Budějovice 370 05, Czech Republic and Institute of Botany, Academy of Sciences of the Czech Republic, Dukelská 135, Třeboň 379 82, Czech Republic
| | - Jakub Těšitel
- Faculty of Science, University of South Bohemia, Branišovská 1760, České Budějovice 370 05, Czech Republic and Institute of Botany, Academy of Sciences of the Czech Republic, Dukelská 135, Třeboň 379 82, Czech Republic
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Vallino M, Fiorilli V, Bonfante P. Rice flooding negatively impacts root branching and arbuscular mycorrhizal colonization, but not fungal viability. Plant Cell Environ 2014; 37:557-72. [PMID: 23927052 DOI: 10.1111/pce.12177] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 07/19/2013] [Accepted: 07/24/2013] [Indexed: 05/06/2023]
Abstract
Rice is mostly cultivated in wetlands, where arbuscular mycorrhization (AM) is reported to decrease. The mechanisms regulating such events are largely unknown. Rice uninoculated and inoculated with Rhizophagus irregularis were grown in dry and flooded conditions, allowing also for the transfer of plants from one water regime to the other. Roots were sampled at different times, from 7 to 35 d post-inoculation (dpi). The morphological and molecular parameters (root branching, aerenchyma formation, mycorrhizal colonization, AM marker gene expression) were evaluated. Root branching was more pronounced in dry conditions, and such phenotype was enhanced by the fungus. In wetlands, the colonization level was comparable till 21 dpi, when the mycorrhization then decreased, paralleled by an increase in aerenchyma. Expression of the fungal transporters was comparable under the two conditions. The root apparatus, when shifted from one water regime to the other, rapidly adapted to the new condition, revealing a marked plasticity. The reversibility of the AM rice symbiosis was also mirrored by expression changes of plant marker genes. The results demonstrate that the water regime is the driving force that regulates AM colonization under flooding conditions, by directly influencing root architecture and anatomy, but without impacting the basic AM functionality.
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Affiliation(s)
- Marta Vallino
- Institute for Plant Protection - National Research Council, Viale Mattioli 25, 10125, Turin, Italy
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Soriano IR, Prot JC, Matias DM. Expression of Tolerance for Meloidogyne graminicola in Rice Cultivars as Affected by Soil Type and Flooding. J Nematol 2000; 32:309-317. [PMID: 19270982 PMCID: PMC2620461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
The effects of different water regimes on the pathogenicity of Meloidogyne graminicola on six rice cultivars were determined in two soil types in three greenhouse experiments. Two water regimes, simulating continuous flooding and intermittent flooding, were used with five of the cultivars. All cultivars were susceptible to the nematode, but IR72 and IR74 were more tolerant than IR20 and IR29 under intermittent flooding. All were tolerant under continuous flooding. UPLRi-5 was grown under multiple water regimes: no flooding; continuous flooding; flooding starting at maximum tillering, panicle initiation, or booting stage; and flooding from sowing until maximum tillering or booting. In sandy loam soil, M. graminicola reduced stem and leaf dry weight, root dry weight, and grain weight under all water regimes. In clay loam soil, the nematode reduced root weight when the soil was not flooded or flooded only for a short time, from panicle initiation, or booting to maturity, and from sowing to maximum tillering. In clay loam soil, stem and leaf dry weight, as well as grain weight, were reduced by the nematode under all water regimes except continuous flooding or when the soil was flooded from sowing to booting stage. These results indicate that rice cultivar tolerance of M. graminicola varies with water regime and that yield losses due to M. graminicola may be prevented or minimized when the rice crop is flooded early and kept flooded until a late stage of development.
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Blanch SJ, Walker KF, Ganf GG. Water regimes and littoral plants in four weir pools of the River Murray, Australia. REGULATED RIVERS: RESEARCH & MANAGEMENT 2000. [PMCID: PMC7169220 DOI: 10.1002/1099-1646(200009/10)16:5<445::aid-rrr596>3.0.co;2-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
The composition and distribution of littoral vegetation in four weir pools of the lower Murray were surveyed in summer 1994. Between‐weir gradients in the amplitude of water level fluctuations were reflected in the typical distributions of plants, with a 4–6 m elevational range in upper‐pool sites, where levels fluctuate most, and a 1–1.5 m band in the lower‐pool sites, where levels are more stable. Forty‐one of 48 species occurred across much of the longitudinal×elevational site matrix within this cone‐shaped distribution, indicating considerable tolerance to flooding and exposure; this was especially apparent for Phragmites australis, Cyperus spp. and Centipeda spp. The 41 species were represented in seven of nine water‐regime groups identified by cluster analysis. The remainder, found within ±1 m of the water surface in lower‐pool reaches, were aquatic macrophytes such as Vallisneria americana and Typha spp. and amphibious ‘mudmats’ such as Glossostigma elatinoides. Water regimes at given sites were measured by the number of days in 2 years flooded to any depth (>0 cm), or to 0–30 cm, and by days exposed by >100 cm. Inter‐pool differences in the median number of days flooded to >0 cm and 0–30 cm were 3–30% and <8%, respectively, for all species except Typha spp. but an order of magnitude for the number of days exposed by >100 cm. However, eight of 14 common or representative species analysed showed significant inter‐pool differences in the number of days flooded to >0 cm, indicating that sufficient variation exists to necessitate considerable intra‐pool replication to allow for the detection of statistical differences in a multi‐pool experiment. The practice of maintaining stable weir pool levels limits vegetation processes, e.g. germination, recruitment, decomposition. An increase in the amplitude of river level fluctuations during low flows, from the current 10–20 cm range to 20–50 cm, would reinstate water regimes suitable to the majority of species surveyed. Copyright © 2000 John Wiley & Sons, Ltd.
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Affiliation(s)
- Stuart J. Blanch
- Department of Environmental Biology, University of Adelaide, Adelaide, South Australia 5005, Australia,Cooperative Research Centre for Freshwater Ecology, Albury, NSW, Australia
| | - Keith F. Walker
- Department of Environmental Biology, University of Adelaide, Adelaide, South Australia 5005, Australia,Cooperative Research Centre for Freshwater Ecology, Albury, NSW, Australia
| | - George G. Ganf
- Department of Environmental Biology, University of Adelaide, Adelaide, South Australia 5005, Australia
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