New Cowpea Pathogens Discovered in China's Hainan

Alternaria, a globally distributed genus of fungi that includes saprobic, endophytic and pathogenic species, has been found on cowpea leaves in Hainan Province, China. Four isolates were collected from symptomatic foliage and subjected to detailed morphological examination and phylogenetic analysis using multiple gene loci—GAPDH, RPB2, Alt a 1, EndoPG and OPA10-2—to determine their relationships within the genus.¹.net]

The study was conducted by researchers Shen-Xian Zhou, Jia-Hui Huang, Shi-Qiang Chen, Qian Deng, Cai-Hua Shi, Quan-Zhou Wen, Pian-Pian Yan and Jian-Xin Deng, who reported the findings in MycoKeys volume 138 (pages 329–344). The authors noted that these isolates could not be matched with any known Alternaria species based on both morphology and multi‑locus sequence data. Consequently they described two novel taxa: A. unguiculatae sp. nov. and A. hainanensis sp. nov., each exhibiting distinct conidial shapes, sizes and ornamentation patterns characteristic of the newly defined species.¹.net]

A. unguiculatae is distinguished by elongated, narrowly ellipsoid conidia with a smooth surface and a specific set of septate structures, while A. hainanensis shows shorter, more globose conidia bearing fine wart-like projections. Both species possess unique combinations of genetic markers across the five loci examined, which placed them firmly apart from previously described cowpea-associated Alternaria spp. in phylogenetic trees derived from concatenated datasets.¹.net]

The discovery expands the known diversity of Alternaria associated with Fabaceae plants—particularly cowpeas—in China. By identifying these pathogens at the species level, researchers can now better monitor disease spread, develop targeted management strategies and inform breeding programs aimed at enhancing crop resistance to Alternaria infections.¹.net]

This work underscores how detailed morphological and molecular analyses are essential for accurately cataloguing fungal biodiversity, especially when new isolates emerge from economically important crops. The findings also highlight that even well‑studied genera like Alternaria still harbor undiscovered species awaiting identification through comprehensive sampling and advanced sequencing techniques.¹.net]