Novel species of <I>Calonectria </I> associated with <I>Eucalyptus</I> leaf blight in Southeast China

Abstract

Leaf blight caused by Calonectria spp. is an important disease occurring on Eucalyptus trees grown in plantations of Southeast Asia. Symptoms of leaf blight caused by Calonectria spp. have recently been observed in commercial Eucalyptus plantations in FuJian Province in Southeast China. The aim of this study was to identify these Calonectria spp. employing morphological characteristics, DNA sequence comparisons for the β-tubulin, histone H3 and translation elongation factor-1α gene regions and sexual compatibility. Four Calonectria spp. were identified, including Ca. pauciramosa and three novel taxa described here as Ca. crousiana, Ca. fujianensis and Ca. pseudocolhounii. Inoculation tests showed that all four Calonectria spp. found in this study were pathogenic on two different E. urophylla × E. grandis hybrid clones, commercially utilised in eucalypt plantations in China.

Two novel species of Calonectria isolated from soil in a natural forest in China

“…paracolhounii and Ca. pseudocolhounii (Crous 2002, Lombard et al 2010b, 2016, Chen et al 2011. The macroconidia of Ca.…”

“…To date 27 Calonectria species have been isolated from Eucalyptus tissues with CLB/leaf rot symptoms or from soils originating from Eucalyptus plantations in tropical or subtropical areas in FuJian, GuangDong, GuangXi and HaiNan Provinces (Crous et al 2004, Lombard et al 2010a, Chen et al 2011. However, little information is known about the species diversity of Calonectria in natural forests.…”

“…Based on previous studies, Calonectria species have been reported in nine provinces and one Special Administrative Region (SAR), which with the exception of LiaoNing and ShanDong Provinces belong to temperate regions (Luan et al 2006, Li et al 2010. Most Calonectria have been isolated from agronomic crops or forestry plantations in subtropical and tropical regions, including FuJian, GuangDong, GuangXi, GuiZhou, HaiNan, JiangXi and YunNan Provinces, as well as Hong Kong SAR (Crous et al 2004, Lombard et al 2010a, Chen et al 2011, Gai et al 2012, Pei et al 2015.…”

“…As an important fast-growing tree species, Eucalyptus plays a significant role in the global pulpwood supply. Previous research showed that Calonectria leaf blight (CLB), associated with several species of Calonectria, is considered to be one of the most prominent Eucalyptus leaf diseases that has occurred in numerous countries such as Brazil (Alfenas et al 2015, Lombard et al 2016, China (Zhou et al 2008, Chen et al 2011), Colombia (Rodas et al 2005), India (Sharma et al 1984) and Vietnam (Old et al 1999). Other fungal diseases of Eucalyptus spp.…”

“…Species of Calonectria are also rapidly dispersed via aerial dissemination and water movement, which leads to the transmission of Calonectria disease . Based on previous studies, at least 145 Calonectria species have been identified using molecular data and have been described worldwide (Crous 2002, Crous et al 2004, Lombard et al 2010a, b, c, 2011, 2016, Chen et al 2011, Alfenas et al 2013a, Gehesquière et al 2015. Sixty species were isolated from soil samples collected in subtropical or tropical regions (Crous 2002, Crous et al 2004, Lombard et al 2010a, b, c, 2015, 2016, Chen et al 2011, Alfenas et al 2015.…”