Njiru, D. M. | bioRxiv Science

bioRxiv2020

FUNGI DIVERSITY IN THE RHIZOSPHERE OF Aspilia pruliseta Schweif . ext Schweif IN THE SEMI-ARID EASTERN KENYA

Semi-arid eastern Kenya is a fragile ecosystem with continuous cultivation of dryland pulses and grains. Farmers use artificial fertilizers most of which are deleterious to the environment. Previous studies have shown that soil microbes in the rhizosphere could be used to sustainably enhance levels of soil mineral nutrients and soil health. However, few studies have examined fungal diversity in the rhizosphere of wild and native Aspilia pruliseta shrub. In this study, amplicons of Internal Transcribed Spacer (ITS) region on Total Community DNA using Illumina sequencing were used to explore the fungal community composition within the rhizosphere. Operational taxonomic units (OTUs) were analyzed using QIIME 1.8.0, taxonomy assigned via BLASTn against SILVA 119 database. Hierarchical clustering was done using R programming software. 72,093, 50,539 and 43,506 sequence reads were obtained from samples MC1a, MC2a and MC3a respectively representing rhizosphere depth 0-20 cm, 21-40 cm and 41-60 cm. A total of 373 OTUs were realized at 3% genetic distance. Taxonomic analysis revealed that the genera Glomus was most prevalent in all soil depths with 85.60 % of the OTUs in depth 0-20 cm, 69.04 % in depth 21-40 cm and 48.45 % in depth 41-60 cm. The results revealed high levels of obligate arbuscular mycorrhiza fungi that if commercially cultured could enhance phosphates uptake in crops.

ecology↗

bioRxiv2019

MYCORRHIZA CO-ASSOCIATION WITH Aspilia pruliseta Schweif AND PHOSPHORUS UPTAKE EFFECTS ON GROWTH ATTRIBUTES OF GADAM SORGHUM IN SELECTED SITES IN KENYA

Mycorrhiza fungi are important components of soil microbiota in the rhizosphere and greatly influence uptake of mineral elements to plants. A green house experiment was conducted at the University of Embu. The experiment involved use of sterilized polythene potting material sized 30 cm by 40 cm. The pots were filled two thirds the height of the potting material with soil from a predetermined source in Gakurungu, Tunyai and Kanyuombora in the upper eastern region in Kenya. The soil used in the pots was collected from the rhizosphere of Aspilia pruliseta Schweif vegetation as well as adjacent areas without this vegetation as a control at 0-20 cm, 21-40 cm and 41-60 cm for each of the soil types (silty clay, silt loam and sandy loam) used in the experiment. Two sorghum seeds inoculated with mycorrhiza fungi were planted in each pot and a similar number of pots planted with un inoculated sorghum seeds as a control. Each of the 4 treatments mentioned above, was replicated four times giving n=144. Each pot was watered after every two days using a two-litre watering can for the first one week. Thereafter, watering regime was reduced to once a week but ensuring the pots remained moist. Watering was done uniformly to all the pots. This was maintained for a period of thirty five days. Data was analysed using SAS edition 8.2. Seed emergence, hypocotyl development and stand count were enhanced at P[≤]0.05 in both mycorrhiza fungi inoculated gadam sorghum seeds and in pots whose soils were taken from the rhizosphere of Aspilia pruliseta plants. The growth attributes had a positive correlation to yield at 95% confidence. Soil phosphate level was enhanced in both cases of gadam seed inoculation with mycorrhiza and in soils previously grown Aspilia pruliseta vegetation.

microbiology↗