Effects of antagonistic fungi, plant growth-promoting rhizobacteria, and arbuscular mycorrhizal fungi alone and in combination on the reproduction of Meloidogyne incognita and growth of tomato

Abstract

Antagonistic fungi (Aspergillus niger CA and Penicillium chrysogenum CA1), plant growth-promoting rhizobacteria (PGPR) (Burkholderia cepacia 4684 and Bacillus subtilis 7612) and AM fungi (Glomus intraradices KA and Gigaspora margarita AA) were assessed alone and in combination for their effects on the growth of tomato and on the reproduction of Meloidogyne incognita in glasshouse experiments. Application of antagonistic fungus, PGPR, or AM fungus alone or in combination significantly increased the length and shoot dry mass of plants both with and without nematodes. The increase in shoot dry mass caused by Gl. intraradices KA in plants without nematodes was greater than that caused by PGPR or antagonistic fungi. Similarly, the increase in shoot dry mass caused by Bu. cepacia 4684 in plants with nematodes was greater than that caused by P. chrysogenum CA1. Application of Bu. cepacia 4684 caused a 36.1% increase in shoot dry mass of nematode-inoculated plants followed by Ba. subtilis 7612 (32.4%), A. niger CA (31.7%), Gl. intraradices KA (30.9%), Gi. margarita AA (29.9%) and P. chrysogenum CA1 (28.8%). Use of Bu. cepacia 4684 with A. niger CA caused a highest (65.7%) increase in shoot dry mass in nematode-inoculated plants followed by Ba. subtilis 7612 plus A. niger CA (60.9%). Burkholderia cepacia 4684 greatly reduced (39%) galling and nematode multiplication, and the reduction was even greater (73%) when applied with A. niger CA. Antagonistic fungi had no significant effect on root colonization caused by AM fungi. Applying Bu. cepacia 4684 with A. niger CA may be useful in the biocontrol of M. incognita on tomato.

Suppression of the root-knot nematode [Meloidogyne incognita (Kofoid & White) Chitwood] on tomato by dual inoculation with arbuscular mycorrhizal fungi and plant growth-promoting rhizobacteria

“…AM fungi and PGPR are well recognized as microorganisms that can improve plant nutrition and growth and also reduce plant disease, and they are usually more effective when added together than alone (Miroslav and Milan 2000;Attia and Awad 2003;Akhtar and Siddiqui 2008;Siddiqui and Akhtar 2009). For instance, dual inoculation with the AM fungus Glomus fasciculatum and the bacterium Azospirillum brasilense enhanced nitrogen acquisition and growth of Medicago sativa L. (Biró et al 2000).…”

Plant-Growth-Promoting Rhizobacteria (PGPR) and Medicinal Plants

“…Rhizobia provide an initial barrier to fungal pathogens; however, through the use of AM fungus species, the potential for remediating pathogenesis while promoting growth is possible (Siddiqui and Akhtar 2009;Ozgonen and Erkilic 2007;Akkopru and Demir 2005). Akhtar and Siddiqui (2010) studied the influence of four AM fungi species, Glomus intraradices, G. aggregatum, G. claroideum, and Glomus sp., for the biocontrol of M. phaseolina on Cicer arietinum pod growth, nodulation, chlorophyll, nitrogen, phosphorus, potassium concentrations, and effectiveness of controlling root rot.…”

Activity of the desert truffle Terfezia boudieri Chatin, against associated soil microflora

“…Some Aspergillus species have specialized enzymes to solubilize complex substances (Dommergues and Mangenot, 1970;Souchie et al, 2006;Richardson et al, 2009). Others species are used as biological control agents against nematodes (Siddiqui and Akhtar, 2009) and against some phytopathogenic fungi such as Fusarium oxysporum f.sp. melonis (Suarez -Estrella et al, 2007).…”