Susceptibility of Strawberry Cultivars and Advanced Selections to Leaf Spot Caused by Mycosphaerella fragariae

Abstract

<jats:p>Seventeen strawberry (<jats:italic>Fragaria</jats:italic> ×<jats:italic>ananassa</jats:italic> Duchesne) cultivars and six selections were tested under greenhouse conditions for susceptibility to leaf spot induced by <jats:italic>Mycosphaerella fragariae</jats:italic> (Tul.) Lindau. The level of susceptibility was evaluated based on maximum disease severity and area under the disease progress curve (AUDPC). The 23 genotypes were ranked based on AUDPC and grouped according to their susceptibility. Cluster analysis for AUDPC gave four groups corresponding to low, moderate, high, and very high susceptibility to leaf spot. `Annapolis', `Chambly', `Glooscap', `Redcoat', and `Veestar' consistently showed a low level of susceptibility. The selections SJ89700-1 and SJ8518-11 and `Tribute' showed a very high level of susceptibility, and the remaining cultivars were grouped as either moderately or highly susceptible.</jats:p>

Regulation of superoxide dismutase isoforms in resistant and susceptible strawberry cultivars subjected to leaf spot disease

“…In previous studies, significant variation in the susceptibility of 25 cultivars to M. fragariae was observed. According to these studies, the ''Joliette'' cultivar was considered resistant and the Kent cultivar displayed marked susceptibility (Delhomez et al 1995;Khanizadeh et al 1996). Some researchers (Hernández et al 1995;Foyer & Noctor 2000;Anderson 2002) reported that interactions between host plants and fungal pathogens, and defence against invasion, include a host resistance response, where the host plant produces reactive oxygen species (ROS), such as superoxide-and hydroxyl-radicals and hydrogen peroxide.…”

Superoxide dismutase responses of strawberry cultivars to infection by Mycosphaerella fragariae

“…Lindau ( ¼ Ramularia tulasnei Sacc.) has previously been reported by Delhomez et al (1995). Briefly, stock cultures were maintained on potato agar slants at 3 1C.…”

“…Joliette cv was considered resistant, Honeoye cv was defined as partially resistant and Kent cv displayed marked susceptibility (Delhomez et al, 1995;Khanizadeh et al, 1996). Initial symptoms of this disease are small, purple, circular spots that first appear on young leaves.…”

“…As the spots enlarge, the center becomes brown with distinct red borders. Lesions produced by M. fragariae differ depending on host cv and environmental conditions during infection (Delhomez et al, 1995;Carisse et al, 2000).…”

Effect of cultural methods on leaf spot (Mycosphaerella fragariae) and gray mold (Botrytis cinerea) damage in strawberries

“…is one of the most common diseases of strawberry (Fragaria · ananassa Duchesne) (Maas, 1998b). There is a wide range of susceptibility between strawberry cultivars (Delhomez et al, 1995). Three sources of primary inoculum exist: Conidia that survive the winter on lesions on living leaves, conidia produced from overwintering sclerotia, and ascospores.…”