Calonectria leaf blight of Eucalyptus: A global review

Abstract

Calonectria (= Cylindrocladium), an internationally recognised fungal ascomycete genus, causes significant diseases on numerous crops of forestry, horticultural and agricultural interest. Eucalyptus, an economically important multipurpose plantation forestry species, is severely threatened by Calonectria leaf blight (CLB) disease in Brazil, Australia, China, Indonesia, Vietnam and India. The disease causes serious mortality in the nurseries/plantations and yield losses due to defoliation. Since the first report of Calonectria in 1867, efforts have been made for the identification and characterisation of this vastly diverse hypocrealean genus. Currently, the genus Calonectria harbours 131 species grouped within 11 species complexes, and broadly categorised into the Prolate and Sphaero‐Naviculate groups. Globally, 35 Calonectria species distributed in seven species complexes cause CLB of Eucalyptus, out of which 29 belong to the Prolate group and five to the Sphaero‐Naviculate group. Likewise, 28 Calonectria species distributed in eight species complexes have been reported in association with infected Eucalyptus tissues and plantation soil, however, their pathogenicity remains to be determined. Given the importance of CLB of Eucalyptus, this review compiles its global impact, shifts in taxonomy and nomenclature of Calonectria, pathogenesis mechanism, defence response of Eucalyptus upon infection and disease management. This study identifies and provides direction to crucial areas of future research on CLB which is severely impacting Eucalyptus plantations globally.

Diversity and Distribution of Calonectria Species in Soils from Eucalyptus urophylla × E. grandis, Pinus massoniana, and Cunninghamia lanceolata Plantations in Four Provinces in Southern China

“…These aggressive pathogens can infect approximately 335 plant species residing in 100 plant families, including important agricultural, horticultural, and forestry crops [ 1 , 2 , 3 , 4 ]. Leaf blight caused by Calonectria species is considered one of the most prominent diseases of Eucalyptus plantations in China, Brazil, Colombia, Vietnam, and other countries [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. Calonectria species also produce other disease symptoms, including stem and root rot, branch canker, and shoot blight on Eucalyptus [ 1 , 3 , 10 , 12 ].…”

A Proximal Sensor-Based Approach for Clean, Fast, and Accurate Assessment of the Eucalyptus spp. Nutritional Status and Differentiation of Clones

“…production costs. This greentech approach may be an accurate tool to distinguish symptoms caused by pathogenic agents [ 41 , 42 , 43 ] from those caused by inadequate nutrition in a very rapid way.…”

Molecular and morphological characterization of Calonectria quinqueramosa causing leaf blight on Eucalyptus urophylla in Brazil

“…In Brazil, diseases associated with Calonectria , such as root rot, cutting rot, damping‐off and Calonectria leaf blight (CLB), have been reported in nurseries and commercial plantations of Eucalyptus (Soares et al, 2018), and according to Liu and Chen (2022), CLB causes significant economic losses in Eucalyptus plantations, and it is one of the most damaging diseases worldwide. Since Eucalyptus trees are propagated clonally, the Eucalyptus plantations are genetically homogeneous, which gives an advantage for fungal pathogens to become a threat to commercial plantations (Bose, Banerjee, Pandey, et al, 2022).…”