Botryosphaeria Ces. & De Not., Comm. Soc. crittog. Ital. 1(fasc. 4): 211 (1863)
Dothideomycetes, order incertae sedis, Botryosphaeriales, Botryosphaeriaceae
Saprobic or parasitic on the host plant. Sexual morph: Ascomata black, eustromatic, solitary to gregarious, sometimes forming botryose clusters, semi-immersed to partly erumpent, globose to subglobose, unilocular or multilocular, glabrous, thick-walled, papillate, ostiolate. Peridium composed of thick-walled, black to dark brown cells arranged in a textura angularis or textura globosa with cells becoming hyaline from outer layers to inner layers. Pseudoparaphyses hyaline, septate, constricted at septa, thin-walled, deliquescing from the basal parts when asci mature. Asci 8-spored, bitunicate, clavate or cylindric-clavate, pedicellate, with a prominent apical chamber, developing on a broad basal hymenial layer. Ascospores hyaline or sometimes becoming pale brown with age, irregularly biseriate in the ascus, ovoid or fusoid or fusoid-ellipsoid, usually widest in the middle, straight or inequilateral, thin- and smooth-walled, 0–2-septate, guttulate (description of sexual morph adapted from Liu et al. 2012, Phillips et al. 2013). Asexual morph: Conidiomata black, stromatic, pycnidial, solitary to gregarious or confluent, immersed in origin, becoming erumpent, unilocular or multi-locular, globose or ovoid to subglobose, thick-walled, glabrous, smooth, papillate, ostiolate. Ostiole circular to subcylindrical, centrally located. Conidiomatal wall composed of thick-walled, brown to hyaline cells of textura angularis to textura prismatica or textura globosa. Paraphyses hyaline, filiform, septate, unbranched. Conidiophores sometimes reduced to conidiogenous cells, when present, hyaline, subcylindrical, septate, straight or slightly curved, formed from the most inner wall of the conidiomata. Conidiogenous cells hyaline, holoblastic or enteroblastic, phialidic or annellidic, ampulliform to subcylindrical or lageniform, determinate or indeterminate, discrete or integrated, smooth-walled, with moderate periclinal thickenings at above or percurrently proliferating several times. Conidia hyaline or sometimes becoming olivaceous or darker with age, variable in shape, elliptical to fusiform or clavate, straight or slightly curved, unicellular or 1–4-septate, thick-walled, smooth, bearing irregular mucoid sheath at both ends or apex only. Synasexual morphs present or absent. Spermatophores hyaline, cylindrical to subcylindrical, septate, occasionally branched, smooth-walled. Spermatogenous cells hyaline, cylindrical, discrete or integrated, smooth-walled, holoblastic or proliferating via phialides with periclinal thickenings. Spermatia hyaline, allantoid to rod-shaped, aseptate (the description of synasexual morph from Phillips et al. 2013).
Type species: Botryosphaeria dothidea (Moug.) Ces. & De Not., Comm. Soc. crittog. Ital. 1(fasc. 4): 212 (1863)
Notes: Botryosphaeria was introduced by Cesati & De Notaris in 1863 to accommodate nine species, but the type species was not designated. Botryosphaeria berengeriana De Not., B. dothidea (Moug.) Ces. & De Not. and B. quercuum (Schwein.) Sacc. have been suggested as type species by different authors (von Höhnel 1909, Theissen and Sydow 1915, von Arx and Müller 1954, Barr 1972). However, B. berengeriana and B. quercuum were not one of the original species. Thus, B. dothidea was designated as type species (Barr 1972) and this proposal was followed by later authors (Barr 1972, Crous et al. 2006a, Liu et al. 2012, Phillips et al. 2013). Slippers et al. (2004) epitypified B. dothidea on the basis of both morphology and phylogenetic study and confirmed the placement of the genus.
Botryosphaeria is characterized by sexual morph having hyaline, aseptate ascospores and bitunicate asci. The asexual morphs have been assigned to diplodia-like and fusicoccum-like conidial states (Denman et al. 2000, Crous et al. 2006a, Liu et al. 2012). However, Phillips et al. (2013), restricted its asexual morph in Fusicoccum only and synonymized Fusicoccum under Botryosphaeria on the basis of multi-locus of LSU, ITS, tef-α and tub2 sequences data. In addition, they accepted seven species in Botryosphaeria. Dissanayake et al. (2016) included ten species in the genus. Four additional species have since been recognized, B. pseudoramosa G.Q. Li & S.F. Chen, B. qingyuanensis G.Q. Li & S.F. Chen, B. rosaceae Y.P. Zhou & Ying Zhang, and B. wangensis G.Q. Li & S.F. Chen (Zhou et al. 2017, Li et al. 2018).
Li WJ, McKenZie EHC, Liu JK, Bhat DJ, Dai DQ, Caporesi E, Tian Q, Maharachcikumbura SSN, Luo ZL, Shang QJ, Zhang JF, Tangthirasunun N, Karunarathna SC, Xu JC, Hyde KD (2020) Taxonomy and phylogeny of hyaline-spored coelomycetes. Fungal Diversity 100: pages279–801.