Effect of inoculation method and plant growth medium on endophytic colonization of sorghum by the entomopathogenic fungus Beauveria bassiana

Abstract

A study was conducted to determine the effect of inoculation method and plant growth medium on colonization of sorghum by an endophytic Beauveria bassiana. Colonization of leaves, stems, and roots by B. bassiana was assessed 20-days after application of the fungus. Although B. bassiana established as an endophyte in sorghum leaves, stems, and roots regardless of inoculation method (leaf, seed, or soil inoculation), plant growth medium (sterile soil, non-sterile soil, or vermiculite) apparently influenced colonization rates. Seed inoculation with conidia caused no stem or leaf colonization by the fungus in non-sterile soil but did result in substantial endophytic colonization in vermiculite and sterile soil. Leaf inoculation did not result in root colonization, regardless of plant growth medium. Endophytic colonization was greater in leaves and stems than roots. Endophytic colonization by B. bassiana had no adverse effects on the growth of sorghum plants. Leaf inoculation with a conidial suspension proved to be the best method to introduce B. bassiana into sorghum leaves for plants growing in either sterile or nonsterile soil. Further research should focus on the virulence of endophytic B. bassiana against sorghum stem borers.

Establishing Fungal Entomopathogens as Endophytes: Towards Endophytic Biological Control

“…It would be ideal for an inoculation method to result in systemic plant colonization by a fungal entomopathogen 14,17,18,21 .…”

“…Beauveria bassiana (Balsamo) Vullemin (Ascomycota: Hypocreales) is the best-studied endophytic fungal entomopathogen [5][6][7][8][9][11][12][13][14][15][16][17][18][19] , and it is available as a commercial mycopesticide. Inoculation methods tested to establish B. bassiana as an endophyte include soil drenches 14,17 , seed coatings 18 and immersions 14 , radicle dressings 13,15 , root and rhizome immersions 11,16,18 , .…”

“…Inoculation methods tested to establish B. bassiana as an endophyte include soil drenches 14,17 , seed coatings 18 and immersions 14 , radicle dressings 13,15 , root and rhizome immersions 11,16,18 , . Recent evidence suggests that endophytic B. bassiana has the potential to protect plants not only from arthropod pests [5][6][7][22][23][24][25][26][27] , but also from some plant pathogens 9 .…”

Survey on Natural Occurrence of Endophytes in Maize (Zea mays L.) Ecosystem

“…To check the efficacy of the surface sterilization, 20 ml of water which is used to rinse the tissue after sterilization was taken and 20 µl of aliquots of 10 -3 dilutions were plated on the PDAY media and spread with a sterile glass rod, incubated at 20-23 0 C for colony forming units. However the sterilization resulted in no growth of fungus inferred that fungus has originated from internal plant tissues (Tefera and Vidal, 2009). The presence or absence of naturally occurring endophytic growth on the samples were recorded after 7 days based on the colony characters, colour and morphology of the reproductive structures.…”

Innovative Method to Control Dubas Bug, Ommatissus lybicus (Deberg) (Homoptera: Tropiduchidae) in Date Palm Orchards Using Endophytic Beauveria bassiana Isolates

“…In addition, since 1990s of the last century, B. bassiana was reported to be isolated from many plants as an endophyte, including maize, coffee, sorghum, banana tissue cultures, Theobroma gileri, Carpinus caroliniana, seeds and needles of Pinus monticola, Opium poppies, potato, cotton, cocklebur and jimsonweed [3][4][5][6][7][8][9][10][11][12]. The endophyte B. bassiana isolates were applied to manage many insect pests, such as European corn borer, Ostrinia nubilalis, stem borers, specifically Chilo partellus, Busseola fusca Innovative Method to Control Dubas Bug, Ommatissus lybicus (Deberg) (Homoptera: Tropiduchidae) in Date Palm Orchards Using Endophytic Beauveria bassiana Isolates 395 reaching around 50% of crop production under sever infestation [18][19][20].…”