Home • Choanephora cucurbitarum NRRL2744 (50) v1.0
Fig 1) Fruit rot of yellow straight neck squash caused by C. cucurbitarum. Image courtesy of G.J. Holmes. Unispored sporangiola produced on terminal vesicles (Fig 2), and multispored sporangia that dehisce longitudinally at maturity (Fig 3). Figs 2 and 3 courtesy of Kerry O'Donnell.
Fig 1) Fruit rot of yellow straight neck squash caused by C. cucurbitarum. Image courtesy of G.J. Holmes. Unispored sporangiola produced on terminal vesicles (Fig 2), and multispored sporangia that dehisce longitudinally at maturity (Fig 3). Figs 2 and 3 courtesy of Kerry O'Donnell.

Choanephora cucurbitarum NRRL 2744 is a necrotrophic plant pathogen best known for fruit and blossom rot of cucurbits (Fig. 1, fruit rot of yellow straight neck squash), and several other vegetable crops (e.g., peas, beans and eggplant).  Disease outbreaks are typically associated with extended periods of warm, wet weather.  This species is classified in the family Choanephoraceae within the order Mucorales (Spatafora et al. 2016).  Multilocus molecular phylogenetic analyses have resolved the Choanephoraceae as monophyletic (O’Donnell et al. 2001; Walther et al. 2013).  Choanephora cucurbitarum reproduces asexually via unispored sporangiola that are produced on terminal vesicles in the aerial mycelium (Fig. 2) and by multispored sporangia that dehisce longitudinally at maturity (Fig. 3).  Whole-genome sequence analysis of a strain that was isolated from squash in Korea identified a number of secreted protein-encoding genes that might function as host-specific effectors (Min et al. 2017).  Sequencing of C. cucurbitarum NRRL 2744 will advance the 1000 Fungal Genome Project by providing additional insight into the evolution of early diverging fungi.

References:

Min B, Park J-H, Park H, Shin H-D, Choi I-G. 2017.  Genome analysis of a zygomycete fungus Choanephora cucurbitarum elucidates necrotrophic features including bacterial genes related to plant colonization. Scientific Reports 7:40432 | DOI: 10.1038/srep40432.

O’Donnell K, Lutzoni F, Ward TJ, Benny GL. 2001. Evolutionary relationships among mucoralean fungi (Zygomycota): Evidence for family polyphyly on a large scale. Mycologia 93:286─296.

Spatafora JW, Chang Y, Benny GL, Lazarus K, Smith ME, Berbee ML, Bonito G, Corradi N, Grigoriev I, Gryganskyi A, James TY, O’Donnell K, Roberson RW, Taylor TN, Uehling J, Vilgalys R, White MM, Stajich JE. 2016. A phylum-level phylogenetic classification of zygomycete fungi based on genome-scale data. Mycologia 108:1028─1046.