Paecilomyces variotii as A Plant-Growth Promoter in Horticulture

Abstract

In the present study, P. variotii, an endophytic fungus isolated from plant roots from the Cabo de Gata Natural Park (Parque Nacional Cabo de Gata—Spain), was tested to determine the effect on the growth promotion of tomato and pepper seeds and seedlings. For these purposes, germination trials in a laboratory and two experiments in a commercial nursery and greenhouse conditions were performed. The P. variotii isolate has shown a high ability to produce siderophores and IAA, but low ability to solubilize P. High values for germination percentage, seedling vigor, root and shoot length were obtained by P. variotii on tomato and pepper against control. P. variotii applications resulted in improved most of the growth parameters evaluated, for both horticultural crops, with the best results in the development of pepper seedlings. The application of a higher dose of P. variotii improved most of the morphological parameters and the Dickson quality index (DQI) value in tomato in seedlings and plants. The establishment of the endophytic fungus at the root enabled its biostimulant effects to persist after transplantation without any additional application. Few studies have analyzed this species as a biostimulant. The positive results from the tests showed its high potential. The application of this isolate can be of enormous benefit to horticultural crops for its high reproductive and establishment capacity.

Paecilomyces and Its Importance in the Biological Control of Agricultural Pests and Diseases

“…Siderophore production limits the availability of iron for pathogens [ 75 , 99 ]. In vitro synthesis of hydroxamate and carboxylate siderophores, such as ferrirubin trihydroxamate, has been described mainly in P. lilacinus and P. variotii [ 15 , 100 , 101 , 102 , 103 , 104 ].…”

“…Some in vivo studies show a direct effect on plant growth promotion after using Paecilomyces , [ 15 ] but also an indirect effect due to fungal disease control [ 72 ]. Yang et al [ 125 ] observed inhibited S. sclerotiorum mycelial growth and sclerotia germination and a reduced disease severity after using P. lilacinus on a rapeseed crop.…”

“…Paecilomyces has high growth sporulation rates and grows over a wide range of temperatures and substrates. As a result, its rapid multiplication ensures viable and affordable development of commercial formulations [ 15 ].…”

“…It can be used directly or indirectly as a potential biostimulant. When used directly, Paecilomyces or its metabolites increases the plant morphological parameters and crop yield [ 15 , 34 , 35 , 36 , 37 ]. The plant– Paecilomyces interaction improves plant health through different mechanisms and provides protection from phytopathogens [ 38 ].…”

Role of Trichoderma aggressivum f. europaeum as Plant-Growth Promoter in Horticulture

“…A mixture of two kinds of substrates, one containing buckwheat husk (BH) and oat (O), the other containing BH and rice (R) were tested for the mass multiplication of TA and TS [31]. Different proportions of BH-O (90-10%, 80-20% and 70-30% v/v) and BH-R (90-10%, 80-20% and 70-30% v/v) were submerged in 30% v/v of water for 24 h. Each mixture was sterilised for 1 h at 125 • C twice on consecutive days.…”