Susceptibility of Almond (Prunus dulcis) Cultivars to Twig Canker and Shoot Blight Caused byDiaporthe amygdali

Abstract

Twenty-five almond cultivars were assessed for susceptibility to Diaporthe amygdali, causal agent of twig canker and shoot blight disease. In laboratory experiments, growing twigs were inoculated with four D. amygdali isolates. Moreover, growing shoots of almond cultivars grafted onto INRA ‘GF-677’ rootstock were used in four-year field inoculations with one D. amygdali isolate. In both type of experiments, inoculum consisted of agar plugs with mycelium, which were inserted underneath the bark and the lesion lengths caused by the fungus were measured. Necrotic lesions were observed in the inoculated almond cultivars both in laboratory and field tests, confirming the susceptibility of all the evaluated cultivars to all the inoculated isolates of D. amygdali. Cultivars were grouped as susceptible or very susceptible according to a cluster analysis. The relationship between some agronomic traits and cultivar susceptibility was also investigated. Blooming and ripening times were found relevant variables to explain cultivars performance related to D. amygdali susceptibility. Late and very late blooming, and early and medium ripening cultivars were highly susceptible to D. amygdali. Our results may provide valuable information that could assist in ongoing breeding programs of this crop and additionally in the selection of cultivars for new almond plantations.

An emerging disease on young apple trees associated with crown and collar canker and necrosis caused by Cytospora balanejica sp. nov. in Iran

“…Fourteen accessions were evaluated as resistant and the highest level of resistance was identi ed in Malus sieboldii Rehder, which was effective against different isolates of the tested fungus 40 . Similar results were also found in pathogenicity studies using different fungal species and host plants [41][42][43][44][45][46] . The virulence of the tested fungal isolates as measured by lesion length was varied and this could be attributed to the genetic diversity among the isolates.…”

Fungal trunk diseases of fruit trees in Europe: pathogens, spread and future directions

“…the Diatrypaceae E. lata; the Togniniaceae Phaeoacremonium amygdalinum and P. iranianum, confirmed by Raimondo et al (2021); and the Diaporthaceae Diaporthe amygdali, later confirmed by Varjas et al (2017), León et al (2020), andBeluzán et al (2022). Almond wood is also invaded by Pleurostoma richardsiae (Olmo et al, 2015) and Calosphaeria pulchella (Arzanlou et al, 2013).…”