Evaluation of Some Assays Techniques for Determination of Susceptibility of Garlic Cultivars to the Pink Root Disease

Abstract

Biological and physiological assays have been used to evaluate garlic cultivars for their resistance to the pink root disease. Biological methods using artificial media amended with Pyrenochaeta terrestris and/or its toxins or using soil infested with the pathogen P. terrestris were tested to evaluate the resistance of seedlings of various garlic cultivars against the pink root disease. Results showed that the assay using the fungus-free Pyrenochaeta toxins was more reliable than using the fungus itself, in which determination of the disease resistance of garlic seedlings was possible in 7 days without the problems of contaminations. Physiological assays indicated that histones and RNA contents in garlic plants play a role in their resistance to the pink root disease.

Factors affecting the infection by Fusarium oxysporum and F. proliferatum and the progress of garlic clove rot disease during storage

“…These findings could be interpreted in light of similar other results previously reported by Shalaby et al (2012), Moharam et al (2013), El-Marzoky, Hanan and Shaban (2014), Elshahawy et al (2017), andAhmed, Naglaa et al (2022). In addition, several investigators worldwide have reported other resistant and susceptible garlic cultivars and varieties to clove/bulb rot disease caused by F. oxysporum and F. proliferatum and/or other garlic diseases caused by pathogenic fungi (Shalaby et al, 2012;Palmero et al, 2013;Ignjatov et al, 2018;Jannatun et al, 2020;Filyushin et al, 2021;Anisimova, Olga et al, 2021). Thus, a closely established relationship exists between the presence of the pathogen F. oxysporum and F. proliferatum in the garlic bulb at harvest and the incidence and progress of cloves rot disease in storage.…”

“…has exhibited the lowest disease progress of cloves rot of stored bulbs after 30, 60, and 90 days of storage, followed by American cv. These findings could be interpreted in light of similar other results previously reported by Shalaby et al (2012), Moharam et al (2013), El-Marzoky, Hanan and Shaban (2014), Elshahawy et al (2017), andAhmed, Naglaa et al (2022). In addition, several investigators worldwide have reported other resistant and susceptible garlic cultivars and varieties to clove/bulb rot disease caused by F. oxysporum and F. proliferatum and/or other garlic diseases caused by pathogenic fungi (Shalaby et al, 2012;Palmero et al, 2013;Ignjatov et al, 2018;Jannatun et al, 2020;Filyushin et al, 2021;Anisimova, Olga et al, 2021).…”

“…Thus, a closely established relationship exists between the presence of the pathogen F. oxysporum and F. proliferatum in the garlic bulb at harvest and the incidence and progress of cloves rot disease in storage. Differences in susceptibility of garlic cultivars to F. oxysporum and F. proliferatum mainly due to genetic factors (Shalaby et al, 2012;Palmero et al, 2013;El-Marzoky, Hanan and Shaban, 2014;Elshahawy et al, 2017;Ignjatov et al, 2018;Jannatun et al, 2020;Filyushin et al, 2021;Anisimova, Olga et al, 2021). In this study, out of storage temperatures affecting the development of cloves rot disease of garlic Balady (the highest susceptible) and Seds 40 (the least susceptible) cultivars after 30, 60, and 90 days of storage, 30 °C was the most affecting ones and gradually increased disease severity index of cloves rot caused by both fungi on stored bulbs of both garlic cultivars after 90 days of storage, followed by 25 °C.…”