Search for sources of wide-spectrum resistance to Fusarium oxysporum f. sp. basilici isolates in accessions of Ocimum species

Abstract

Ocimum (Lamiaceae) is an important plant genus, with many species used for food flavorings and for essential oils. Fusarium wilt (Fusarium oxysporum f. sp. basilici, FOB) is the most important disease of basil (O. basilicum L.). Twenty-five accessions of O. basilicum, five of O. americanum and two of O. campechianum were initially evaluated for resistance to one FOB isolate (named as FOB-1). Eight accessions (identified as resistant to FOB-1) and one susceptible control were reevaluated to FOB-1 and four other FOB isolates of distinct geographic origins. The FOB isolates varied in aggressiveness and interacted differentially with the Ocimum accessions. Two accessions of O. americanum, one of O. campechianum, and one of O. basilicum had high levels of resistance to all five FOB isolates. The Ocimum germplasm identified here could represent useful sources of resistance genes for developing cultivars with wide-spectrum resistance (i.e., effective against a broad range of FOB isolates). In addition, having a set of potential differential accessions might be useful for large-scale analysis of FOB isolates to demonstrate the presence of physiological races in the Ocimum-FOB pathosystem.

Cold Plasma Treatment Strategies for the Control of Fusarium oxysporum f. sp. basilici in Sweet Basil

“…To determine if the cold plasma treatment impacted pathogen virulence, at the conclusion of the experiment, inoculum was prepared separately from each treatment by washing the control and plasma-treated plates with 10 mL each of deionized water and then adjusting the spore suspension to 0.785 • 10 6 conidia/mL. Six-leaf stage seedlings of the susceptible basil cultivar DiGenova (Johnny's Selected Seeds, Winslow, ME) were inoculated using the cut and dip method described by Reis et al (2008). Plants were inoculated on 9 Sept. 2018 in the first experiment and on 10 Nov. 2018 in the second experiment.…”

“…basilici (obtained from UMass-Amherst) growing on half-strength PDA. Plants were inoculated using the cut and dip method as described by Reis et al (2008). The inoculated plants were planted into 24-cell trays containing Redi-Earth Coir Mix Sun Gro Redi-Earth Plug and Seedling Mix Series Growing Medium.…”

“…Sweet basil (Ocimum basilicum) is grown throughout the world as an economically significant culinary herb in fields and greenhouses (Biris et al, 2004;Keinath, 1994;Reis et al, 2008;Vieira and Simon, 2000). Unfortunately, two diseases of sweet basil, basil downy mildew (BDM) caused by Peronospora belbahrii and Fusarium wilt of basil (FOB) caused by Fusarium oxysporum f. sp.…”

“…Unfortunately, two diseases of sweet basil, basil downy mildew (BDM) caused by Peronospora belbahrii and Fusarium wilt of basil (FOB) caused by Fusarium oxysporum f. sp. basilici, greatly impact the success of this crop (Reis et al, 2008;Wyenandt et al, 2015). While both pathogens can result in yield and quality reduction, FOB infection of a young, susceptible sweet basil cultivar can result in plant death within 4 to 7 d after the appearance of symptoms (Garibaldi et al, 1997;Moya et al, 2004).…”

Rapid detection of Fusarium wilt in basil (Ocimum sp.) leaves by desorption electrospray ionization mass spectrometry (DESI MS) imaging

“…basilica (Fob). 14,15 Planting resistant varieties have also been challenged by new pathogenic races of Fusarium, which has resulted in recurrence of Fusarium epidemics in several crops including banana and cereals. 10 The presence of Fusarium pathogenic fungal species complex in the common environment causes diseases (like keratitis, fusariosis etc.…”