Morphological and Structural Characterization of Rhizospheric Endomycorrhiza Communities Associated with Rice Grown in the Sahelian Zone (Chad)

Abstract

In Chad, rice is grown for its starchy seeds or caryopses, but is also for consumption in the form of seeds pasta with soup. However, little or no work has been conducted in Chad to assess the composition of endomycorrhiza community inhabiting the plant rice rhizospheres. Hence, the main objective of this study was to investigate on native endomycorrhiza that are efficient to establish a symbiotic relationship with two rice varieties in the Sahelian zone in Chad. Two rice varieties were grown in a pot experiment on composite soils samples from Laï, Kelo, Kolobo and N’Djamena for 3 months. Parameters such as mycorrhizal frequency, intensity, specific density and richness were determined following to the standard methods. After spore extraction, species description and characterization were obtained through the informations provided by the International Vesicular Mycorrhizal fungi collection (INVAM): http://invam.caf.wv.edu/fungi/taxonomy/species ID.htm. The highest specific endomycorrhizal density (97.3%) and richness (11%) were registered respectively at kelo, Laï and Kolobo. The endomycorrhizal frequency and intensity were respectively between 4.33-7.33% and 0.8-2.9% for the two rice varieties. Eleven endomycorrhiza species belonging to six genera were identified from different soil samples. These include Septoglomus (S. constrictum, S. deserticola); Rhizophagus (R. aggregatus, R. fasciculatus, R. intraradices); Acaulospora (A. lacunosa, A. rugosa, A. trappei); Claroideoglomus lamellosum; Glomus pansihalos and Diversispora epigae. S. constrictum was the most dominant and frequent species found in all the soil sampling sites, while R. aggregatus was the less frequently encountered specimen. The lowest macorrhizal richness and frequency obtained is a proof that cultivation of rice dependent on endomycorrhiza in this zone. The multi-native endomycorhiza spores identified are the active principle to be included in the bioinoculants production in order to increase and improve the production of rice in the south of Chad.

Field Evaluation of Growth and Yield of Two Local Rice Varieties (Tox-728-1 and Madjitolngar) in Response to Indogenous Mycorrhizal Inoculation in South-Chad

“…These seeds (Figure 1) were graceously provided by the Agricultural research station in the Tandjilé region of Chad. AMF spores were isolated from soils in four regions of Chad by Nadjilom et al [22], using the two above cited rice varieties as trapping plants. Endomycorrhizal inoculants were obtained by massive multiplication of the isolated spores per rice variety and for each of the four soil sampling sites, using the modified method as described by Brundrett [23].…”

“…A previous research conducted in the Tandjile region-Chad has revealed the existence of more efficient indigenous AMF affiliated to local rice varietie than to Nerica rice varieties [21]. Therefore, these indigenous strains associated with rice rhizosphere in growing areas have recently been characterized [22], but their efficacity on the improvement of rice production has not yet been investigated.…”

Prevalence and Morpho-Anatomical Diversity of Arbuscular Mycorrhizal Fungi Spores, from Soybean (Glycine max L.) Rhizosphere in the Agro-Ecological Zone 1 of Cameroon

“…The highest mycorrhization frequency was observed in the Maroua zone in the Far North (43.66%), followed by those in the Ngaoundéré zone (26.33%) in Adamawa and Tcholiré (25 , 33%) in the North; conversely, the values recorded in the areas of Guider (1.33%) and Garoua (3%) in the North are similar and are lower (p <0.0001). Nadjilom and al. (2019) have also obtained similar results on the morphological and structural diversity of the arbuscular mycorrhiza fungi community in rice rhizosphere, grown in the sahelian zone of Chad: Mycorrhization frequency variable between 4 and 7.33%.…”

Status of endogenous endomycorrhizal fungi associated with cowpea (<i>Vigna unguiculata</i> L.) in the Sudano-Sahelian zone of Cameroon

“…These interactions can be very beneficial for plants, as is the case of the symbiotic plant-fungus endomycorrhizal association (Alabouvette andCordier, 2018, Diedhiou et al, 2022). Indeed, the fungal strains involved in this symbiosis are capable of improving the plant partner's hydro-mineral nutrition (Lambers et al, 2008), drought resistance (Leyval, 2005), yield (Ngakou et al, 2007;Ngakou et al, 2020), resistance to pathogens and pests (Elsen, 2003), and nutrition in polluted environments (Chen et al, 2007, Koffi et al, 2021. In addition, these micro-organisms stabilise soil aggregates by releasing a protein substance called glomalin (Rillig and Steinberg, 2002).…”

“…In addition, these micro-organisms stabilise soil aggregates by releasing a protein substance called glomalin (Rillig and Steinberg, 2002). Therefore, the technology of this symbiosis, which is now valued in crop production, deserves to be promoted to reduce the use of inorganic fertilisers and pesticides, in order to promote ecological and sustainable agricultural production, (Ngonkeu et al, 2013;Nadjilom et al, 2019;Koffi et al, 2019). On the other hand, leguminous crops such as cowpea, and groundnut contribute enormously to soil fertilisation through symbiotic fixation of atmospheric nitrogen (Bado, 2002).…”