Abstract:
Apples are widely consumed by people all over the world due to their taste and
nutritional value. However, apple trees are prone to various environmental stresses, including fungal diseases. Among them, Cytospora canker (or Valsa canker) can cause dieback of
branches and twigs. Although Kazakhstan is well known as an origin of apples, very little
is known about canker diseases that spread across all commercial orchards. Therefore, an
accurate identification of the causal agents of those diseases is needed for further application of informed disease management strategies. In this study, eleven isolates belonging to
four Cytospora species were isolated from multiple cultivars, grown in six different orchards
within the Almaty region, Kazakhstan. As a result of a multilocus phylogenetic analysis
using ITS, LSU and tef1-α marker genes and morphological characterization, these isolates
were described as Cytospora parasitica, Cytospora sorbina, Cytospora pruinopsis and Cytospora
chrysosperma. Moreover, a pathogenicity test was conducted on detached twigs, and it
demonstrated that two of these fungi were highly virulent. Overall, this paper is a first
report of the causal agents of apple canker disease in Kazakhstan and could be a trigger for
conducting future studies to better understand the disease epidemiology, as well as build
management strategies.
