Fungal root endophytes of tomato from Kenya and their nematode biocontrol potential

Abstract

The significance of fungal endophytes in African agriculture, particularly Kenya, has not been well investigated. Therefore, the objective of the present work was isolation, multi-gene phylogenetic characterization and biocontrol assessment of endophytic fungi harbored in tomato roots for nematode infection management. A survey was conducted in five different counties along the central and coastal regions of Kenya to determine the culturable endophytic mycobiota. A total of 76 fungal isolates were obtained and characterized into 40 operational taxonomic units based on the analysis of ITS, β-tubulin and tef1α gene sequence data. Among the fungal isolates recovered, the most prevalent species associated with tomato roots were members of the Fusarium oxysporum and F. solani species complexes. Of the three genes utilized for endophyte characterization, tef1α provided the best resolution. A combination of ITS, β-tubulin and tef1α resulted in a better resolution as compared to single gene analysis. Biotests demonstrated the ability of selected non-pathogenic fungal isolates to successfully reduce nematode penetration and subsequent galling as well as reproduction of the root-knot nematode Meloidogyne incognita. Most Trichoderma asperellum and F. oxysporum species complex isolates reduced root-knot nematode egg densities by 35-46 % as compared to the nonfungal control and other isolates. This study provides first insights into the culturable endophytic mycobiota of tomato roots in Kenya and the potential of some isolates for use against the root-knot nematode M. incognita. The data can serve as a framework for fingerprinting potential beneficial endophytic fungal isolates which are optimized for abiotic and biotic environments and are useful in biocontrol strategies -016-1169-9 against nematode pests in Kenyan tomato cultivars. This information would therefore provide an alternative or complementary crop protection component.

Bioactive secondary metabolites with multiple activities from a fungal endophyte

“…The non‐pathogenic fungal endophyte Fo162 that was isolated from healthy tomato roots cv. Moneymaker was identified during our previous study (Bogner et al ., ) based on a multigene DNA sequence analysis. The GenBank Accession numbers of ITS, ß‐tubulin and TEF1α gene regions are , and respectively.…”

“…M. incognita was reared on the susceptible tomato cultivar Moneymaker for 2 months in a glasshouse at 25 ± 3°C with 16‐h diurnal light and a relative humidity of 70%. Nematode eggs were extracted according to our previous work (Bogner et al ., ) and collected on a 25‐μm sieve. Surface sterilization of the extracted eggs was carried out by incubating for 5 min in 0.6% (w/v) sodium hypochlorite solution under constant shaking in a rotary shaker (Edmund Bühler, Hechingen, Germany) at 100 rpm.…”

Evaluation of Biocontrol Efficacy of Herbal and Bioformulations against Root Rot Pathogen Fusarium Solani in Tomato

“…Expanding temperatures have expanded infection frequency in tomato [15]. Tomato plants are affected by a soil borne fungal pathogen Fusarium solani that causes major diseases like root rot and crown rot [1]. Fusarium sp.…”

Investigation on biosuppression of Fusarium crown and root rot of tomato (Solanum lycopersicum L.) and growth promotion using fungi naturally associated to Solanum linnaeanum L.

“…Several investigations dealing with fungal endophytes have evidenced their plant growth-promoting potential (PGP) and biocontrol potency (Mahmoud and Narisawa, 2013;Bogner et al, 2016) due to their capacity to release growth hormones, abscisic acid (You et al, 2012) and plant-growth regulatory substances (Wiyakrutta et al, 2004).…”