Diversity of indigenous arbuscular mycorrhizal fungi in rhizosphere of upland rice (Oryza sativa L.) varieties in Southwest Nigeria

Article Details: Received: 2020-02-05      |      Accepted: 2020-05-07      |      Available online: 2020-06-30https://doi.org/10.15414/afz.2020.23.02.42-48 Arbuscular mycorrhizal fungi (AMF) have the potential to increase crop productivity and play a key role in the functioning and sustainability of most agroecosystems. However, limited information is available on the divervisity of AMF associated with upland rice varieties in Southwest Nigeria. Field survey was conducted to investigate colonization and diversity of AMF in 13 upland rice varieties commonly grown in Southwest Nigeria. Root and soil samples were collected from rice fields in 2012. The results showed natural root colonization of all the rice varieties by AMF with highest root colonization in ITA 157and Ofada. The spore densities retrieved from the different rhizospheres were relatively high, varying from 13 spores in UORW 111 to 174 spores in Ofada with a mean of 67.6 spores per 20 g dry soil. Glomus was observed to be the most abundant AMF genus. Funneliformis mosseae was the most frequently occurring AMF species (96.2%) with relative density (RD) of 32.2%, followed by Glomus intraradices, Claroideoglomus etunicatum, and Glomus clareium. This study showed that AMF naturally colonized the roots of these rice varieties and diversity of different AMF genera in rice rhizosphere. This study will help draw attention to natural colonization of AMF in rice producing areas of Nigeria that can influence future possibility of using inocula of the dominant AMF species in upland rice cultivation.Keywords: Arbuscular mycorrhizal fungi, community structure, diversity, upland rice, spore densityReferences ADEYEMI, N.O. et al. (2020). Effect of commercial arbuscular mycorrhizal fungi inoculant on growth and yield of soybean under controlled and natural field conditions. Journal of Plant Nutrition, 43(4), 487–499, DOI: https://doi.org/10.1080/019041 67.2019.1685101 ADEYEMI, N.O. et al. (2019). Identification and relative abundance of native arbuscular mycorrhizal fungi associated with oil-seed crops and maize (Zea mays L.) in derived savannah of Nigeria. Acta fytotechn zootechn, 22(3), 84–89. DOI: https://doi.org/10.15414/afz.2019.22.03.84-89 ADEYEMI, N. et al. (2017). Yield and yield attributes responses of soybean (Glycine max L. Merrill) to elevated CO2 and arbuscular mycorrhizal fungi inoculation in the humid transitory rainforest. Notulae Scientia Biologicae, 9(2), 233–241. DOI: https://doi.org/10.15835/nsb9210002 BARBER, N.A. et al. (2013). Linking agricultural practices, mycorrhizal fungi, and traits mediating plant-insect interactions. Ecol Appl, 23(7), 1519–1530.BŁASZKOWSKI, J. (2012) Glomeromycota. Kraków: W. Szafer Institute of Botany, Polish Academy of Sciences. BOUYOUCOS, G.H. (1951). A recalibration of the hydrometer method for testing mechanical analysis of soils. Agronomy Journal, 43,434–438.BRUNDRETT, M.C. and TEDERSOO, L. (2018) Evolutionary history of mycorrhizal symbioses and global host plant diversity. New Phytol, 220,1108–1115. CAMPOS-SORIANO, L. et al. (2010). Activation of basal defense mechanisms of rice plants by Glomus intraradices does not affect the arbuscular mycorrhizal symbiosis. New Phytol, 188(2), 597–614. CHEN, M. et al. (2018) Beneficial services of arbuscular mycorrhizal fungi – from ecology to application. Frontiers in Plant Science, 9. DOI: https://doi.org/10.3389/fpls.2018.01270DAVISON, J. et al. (2015). Global assessment of arbuscular mycorrhizal fungus diversity reveals very low endemism. Science, 349, 970–973. DE ANDRADE-JÚNIOR, J.A. et al. (2018) Fixação de carbono em sistemas agroecológicos na região do Vale do São Patrício, Goiás. Científica – Multidiscip J, 5, 85–98. DE MOURA, J.B. et al. (2018) Taxa de colonização micorrízica sob diferentes sistemas de cultivo no cerrado em cana-deaçúcar. Diálogos & Ciência, 2, 60–66. GIANINAZZI, S. et al. (2010). Agroecology: The key role of arbuscular mycorrhizas in ecosystem services. Mycorrhiza, 20(8), 519–530. INVAM (2018). International culture collection of (vesicular) arbuscular mycorrhizal fungi. Morgantown: West Virginia University. HAZARD, C. et al. (2013). The role of local environment and  geographical distance in determining community composition of arbuscular mycorrhizal fungi at the landscape scale. The ISME Journal, 7, 498–508. JIANG, Y.N. et al. (2017). Plants transfer lipids to sustain colonization by mutualistic mycorrhizal and parasitic fungi. Science, 356, 1172–1175. JOHNSON, N.C. (2010). Resource stoichiometry elucidates the structure and function of arbuscular mycorrhizas across scales. New Phytol, 185(3), 631–647. LEKBERG, Y. and KOIDE, R.T. (2005). Is plant performance limited by abundance of arbuscular mycorrhizal fungi? A metaanalysis of studies published between 1988 and 2003. New Phytol, 168(1). LIN, X. et al. (2012). Long-term balanced fertilization decreases arbuscular mycorrhizal fungal diversity in an arable soil in north China revealed by 454 pyrosequencing. Environmental Science & Technology, 46, 5764–5771. LUGINBUEHL, L.H. et al. (2017). Fatty acids in arbuscular mycorrhizal fungi are synthesized by the host plant. Science, 356, 1175–1178. LUMINI, E. et al. (2011). Different farming and water regimes in Italian rice fields affect arbuscular mycorrhizal fungal soil communities. Ecol Appl, 21(5), 1696–1707.OEHL, F. et al. (2010). Soil type and land use intensity determine the composition of arbuscular mycorrhizal fungal communities. Soil Biology and Biochemistry, 42, 724–738. OEHL, F. et al. (2017) Diversity and biogeography of arbuscular mycorrhizal fungi in agricultural soils. Biol Fertil Soils, (53), 777–797. PEYRET-GUZZON, M. et al. (2016). Arbuscular mycorrhizal fungal communities and Rhizophagus irregularis populations shift in response to short term ploughing and fertilisation in a buffer strip. Mycorrhiza, 26, 33–46. PHILLIPS, J.M. and HAYMAN, D.S. (1970). Improved procedures for clearing roots and staining parasitic and vesicular-arbuscular mycorrhizal fungi for rapid assessment of infection. Trans Br Mycol Soc., 55,158–IN18. PIVATO, B. et al. (2007). Medicago species affect the community composition of arbuscular myccorhizal fungi associated with roots. New Phytologist 176, 197–210. RILLIG, M.C. and MUMMEY, D.L. (2006). Mycorrhizas and soil structure. New Phytol, 171(1), 41–53. SILVA-FLORES, P. et al. (2019) Factors affecting arbuscular mycorrhizal fungi spore density in the Chilean Mediterraneantype ecosystem. J Soil Sci Plant Nutr, 19, 42–50. SMITH, S.E. and READ, D.J. (2008). Mycorrhizal symbiosis. 3rd ed., New York: Academic Press. SNOECK, D. et al. (2010). Temporal changes in VAM fungi in the cocoa agroforestry systems of central Cameroon. Agroforestry Syst., 78, 323–328. SOUZA, B.R. et al. (2016) Arbuscular mycorrhizal fungi as indicative of soil quality in conservation systems in the region of vale do São Patrício, Goiás. Int J Curr Res, 8, 43307–43311.VALLINO, et al. (2014). Rice flooding negatively impacts root branching and arbuscular mycorrhizal colonization, but not fungal viability. Plant Cell Environ, 37(3), 557–572. VAN Der HEIJDEN, M.G. et al. (2015) Mycorrhizal ecology and evolution: the past, the present, and the future. New Phytol 205, 1406–1423. VENTURA, M.V.A, et al. (2018) Influence of arbuscular mycorrhizal fungi in the establishment of pre-broken sugar cane. Poljoprivreda i Sumarstvo, 64,149–157. WALKLEY, A., and BLACK, I.A. (1934). An examination of Degtjareff method for determining soil organic matter and proposed modification of the chromic acid in soil analysis.1. Experimental soil science, 79, 459–465. WANG, Y.T. et al. (2015). Community dynamics of arbuscular mycorrhizal fungi in high-input and intensively irrigated rice cultivation systems. Appl Environ Microbiol, 81(8), 2958–2965. ZHANG, S.J. et al. (2015). Is resource allocation and grain yield of rice altered by inoculation with arbuscular mycorrhizal fungi? J Plant Ecol, 8(4), 436–448

Development and Feasibility Testing of Video Home Based Telerehabilitation for Stroke Survivors in Resource Limited Settings

Tele-physiotherapy has been shown to be valuable to improve clinical outcomes after stroke. Yet, home-based interventions for stroke survivors (SSVs) who speak indigenous African languages are sparse. This study developed a video-based home exercise programme (VHEP) for SSV speakers of Yoruba.  A qualitative descriptive pilot study was conducted in two phases: development and feasibility testing. VHEP development followed the American Stroke Association’s recommendations to include demonstrations of task-specific mobility-task and postural training; trunk exercises, and overground walking. The exercise instructions were presented in the Yoruba language. Each exercise was demonstrated for five minutes on video for a total of 30 minutes. The feasibility testing involved ten consenting chronic SSVs.  Each imitated the VHEP twice per week for two weeks and thereafter completed a feasibility questionnaire. Criteria for feasibility were: cost of using VHEP, recruitment rate, retention of participants, adherence to the exercises, and intervention delivery. The ten SSVs were recruited within one week, had prior home access to a video player at no-cost, adhered to the exercises as recorded, completed the 30 minute-duration for two weeks, and confirmed intervention delivery of VHEP. Most participants liked the novel use of Yoruba as the language of instruction on VHEP. The VHEP was feasible and acceptable among the studied sample of SSVs. Video based home telerehabilitation for SSVs therefore has the potential to meet the growing need for tele-physiotherapy in resource limited settings. 

Good immune restitution but unsatisfactory viral suppression in children on ART in a remote Western Kenya area

Mexico AIDS Conference 200

PHYSIOLOGICAL AND YIELD RESPONSE OF SOME UPLAND RICE VARIETIES TO RE-WATERING AFTER IMPOSED SOIL MOISTURE STRESS

A pot experiment was conducted in the Screen house of Federal University of Agriculture, Abeokuta, October, 2011 (late dry season) to study drought recovery ability of 13 upland rice varieties exposed to soil moisture stress (20 days) at three growth stages (vegetative, reproductive and grain filling stage). The experiment was in completely randomized design, with three replicates. Under moisture stress significantly higher growth recovery, more erect canopy and flatter leaf surface were obtained in all the rice varieties at vegetative growth stage than other growth stages with increasing duration of re-watering. Under stress condition NERICA 4 maintained a significantly higher leaf area (27.50 cm2 and 40.18 cm2), plant height (53.45 cm and 67.62 cm) and number of tillers (1.67 and 1.67), but with a depressed number of leaf, slanted leaf posture and curved leaf especially during the later stage of its growth (Reproductive and grain filling stage respectively). It could be concluded that NERICA 4 had higher recovery ability than other rice varieties in drought prone upland ecology

ROOT RESPONSE OF SOME SELECTED RICE VARIETIES TO SOIL MOISTURE STRESS AT DIFFERENT PHENOLOGICAL STAGES

Physiological adjustment in plant root system is a determinant for survival and crop productivity in situation of moisture stress. A screen house experiment was conducted to access response of rice roots to moisture stress. Thirteen  varieties of rice comprising six NERICAs, WAB 56-104, CG 14, ART26-3-1-B, AC 103549, MOROBEREKAN, ART19-25-1-B and a local check (OFADA) were subjected to twenty-day moisture stress once at  each phenological stage. Results indicated that root growth generally showed preference over shoot growth. Moisture stress did not affect root volume (RV), deep root numbers (DRN), root dry weight (RDW) and root depth (RD) of all the rice varieties at reproductive stage. CG14 however recorded 67.6% increase in RD at this stage while NERICA 3, CG14 and OFADA recorded an increase in root depth: shoot length. At vegetative and grain filling stages, RV, DRN, RDW, RD, and RMC were significantly (p< 0.05) increased by moisture stress in most rice varieties. NERICA2, NERICA7, ART26-3-1-B, MOROBEREKAN and WAB56-104 however recorded 54%, 76.5%, 72.7%, 57.1%, and 56.3% significant reduction in DRN respectively at vegetative stage. Correlation analysis showed that plant height, leaf area, and number of tillers depend highly on, RD, RV, RDW and deep root weight. Therefore, attention should be focused on these parameters in selection for moisture stress tolerance in rice

Low levels of viral suppression among refugees and host nationals accessing antiretroviral therapy in a Kenyan refugee camp.

BACKGROUND: Refugees and host nationals who accessed antiretroviral therapy (ART) in a remote refugee camp in Kakuma, Kenya (2011-2013) were compared on outcome measures that included viral suppression and adherence to ART. METHODS: This study used a repeated cross-sectional design (Round One and Round Two). All adults (≥18 years) receiving care from the refugee camp clinic and taking antiretroviral therapy (ART) for ≥30 days were invited to participate. Adherence was measured by self-report and monthly pharmacy refills. Whole blood was measured on dried blood spots. HIV-1 RNA was quantified and treatment failures were submitted for drug resistance testing. A remedial intervention was implemented in response to baseline testing. The primary outcome was viral load <5000 copies/mL. The two study rounds took place in 2011-2013. RESULTS: Among eligible adults, 86% (73/85) of refugees and 84% (86/102) of Kenyan host nationals participated in the Round One survey; 60% (44/73) and 58% (50/86) of Round One participants were recruited for Round Two follow-up viral load testing. In Round One, refugees were older than host nationals (median age 36 years, interquartile range, IQR 31, 41 vs 32 years, IQR 27, 38); the groups had similar time on ART (median 147 weeks, IQR 38, 64 vs 139 weeks, IQR 39, 225). There was weak evidence for a difference between proportions of refugees and host nationals who were virologically suppressed (<5000 copies/mL) after 25 weeks on ART (58% vs 43%, p = 0.10) and no difference in the proportions suppressed at Round Two (74% vs 70%, p = 0.66). Mean adherence within each group in Round One was similar. Refugee status was not associated with viral suppression in multivariable analysis (adjusted odds ratio: 1.69, 95% CI 0.79, 3.57; p = 0.17). Among those not suppressed at either timepoint, 69% (9/13) exhibited resistance mutations. CONCLUSIONS: Virologic outcomes among refugees and host nationals were similar but unacceptably low. Slight improvements were observed after a remedial intervention. Virologic monitoring was important for identifying an underperforming ART program in a remote facility that serves refugees alongside host nationals. This work highlights the importance of careful laboratory monitoring of vulnerable populations accessing ART in remote settings

ISOLATION, CHARACTERIZATION AND IMMUNOCHEMICAL STUDIES ON FIBROUS PROTEINS FROM COWRY SHELL (CYPRAEA MONETA, LINNAEUS)

Background: Biomaterials are non-drug substances used to treat, enhance or replace functions of body tissues or organs. Natural sources of biomaterials have recently become the focus of several research activities. Cowry shell constitutes one of the most promising natural sources of biomaterials because of its chemical stability, biodegradability and biocompatibility in the body. However, its applications may be limited due to immunogenic and toxic responses that may occur following implantation, hence this study. Materials and Methods: Crude fibrous protein extracted with citrate buffer from pulverised cowry shells (Cypraea moneta (L)), was resolved into two components (CSP1 and CSP2) by gel filtration. Immunological studies were performed with antisera obtained from rabbits by double immunodiffusion and immunoelectrophoresis techniques. Mice treated with the proteins were observed for signs of toxicity and their liver, kidney, lungs and spleen were processed histologically. Results: The native molecular weight of CSP1 and CSP2 determined by gel filtration were 91kDa and 33kDa respectively. CSP1 and CSP2 displayed single bands on SDS-PAGE with subunit molecular weight values of 19kDa and 19.5kDa respectively. Antisera obtained from rabbits immunised with the crude citrate buffer extracts precipitated the antigen in double immunodiffusion tests. Histopathological examinations revealed a dose-dependent damaging effect of the shell proteins on liver, kidney, lung and spleen tissues of the treated mice. Conclusion: This study showed that cowry shells contain fibrous proteins which are immunogenic and toxic in mice at relatively high concentrations, causing visible organ damage without concurrent physical manifestations

HIV-1 Drug Resistance Emergence among Breastfeeding Infants Born to HIV-Infected Mothers during a Single-Arm Trial of Triple-Antiretroviral Prophylaxis for Prevention of Mother-To-Child Transmission: A Secondary Analysis

Analysis of a substudy of the Kisumu breastfeeding trial by Clement Zeh and colleagues reveals the emergence of HIV drug resistance in HIV-positive infants born to HIV-infected mothers treated with antiretroviral drugs