Diaporthe rosae Samarak. & K. D. Hyde

Fallahi, Maryam, Armand, Alireza, Al-Otibi, Fatimah, Hyde, Kevin D. & Jayawardena, Ruvishika S., 2025, Pathogenic fungi (Sordariomycetes) associated with annual and perennial crops in Northern Thailand, MycoKeys 117, pp. 191-265 : 191-265

Diaporthe rosae Samarak. & K. D. Hyde , Fungal Diversity: 185 (2018)

Fig. 17

Description.

Pathogenic to makhuea kheun ( Solanum xanthocarpum ) and causes dark brown to black stem lesions, circular to irregular necrotic leaf spots with dark margins, and water-soaked fruit lesions that enlarge over time. Sexual morph not observed. Conidiomata pycnidial, multiloculate, scattered, globose, or asymmetrical, black. Peridium consists of brown cells with angular texture on the surface. Conidiophores hyaline, smooth-walled, two-septate, branched, compactly aggregated, cylindrical, straight to sinuous, occasionally reduced to conidiogenous cells. Conidiogenous cells phialidic, subcylindrical, or ampulliform, slightly tapering towards the apex. Beta conidia aseptate, hyaline, smooth-walled, 13–23 × 0.8–1.4 μm (mean = 19 × 1.3 μm, n = 30). Gamma and alpha conidia are absent.

Culture characteristics.

Colonies on PDA reach 35–40 mm in diameter after 7 days of growth at 25 ° C in the dark, felted, white clots of mycelium arranged outward, becoming pale yellow with age. The reverse is whitish and ozonate.

Material examined.

Thailand • Chiang Rai Province, Phan District, Sai Khao , on the stem of makhuea kheun ( Solanum xanthocarpum ). February 2023, Maryam Fallahi, dried culture MF 101-1 ( MFLU 24-0245 ), living culture, MFLUCC 24-0243 .

Notes.

Based on phylogenetic analysis of combined ITS, tef 1, tub 2, cal, and his 3 sequence data, the strain MFLUCC 24-0243 clustered with the ex-type strain of Diaporthe rosae ( MFLUCC 17-2658 ) by 87 % ML bootstrap support (Fig. 16 ). The base pair differences between D. rosae strains MFLUCC 24-0243 and MFLUCC 17-2658 revealed a 2.07 % (10 / 481 bp) difference in cal, and no difference in ITS and tub 2. The sequence data for tef 1 and his 3 are not available for the ex-type strain of D. rosae ( MFLUCC 17-2658 ). Diaporhe rosae ( MFLUCC 24-0243 ) and the ex-type of D. rosae ( MFLU 17-2658 ) are similar. However, D. rosae ( MFLUCC 24-0243 ) produced slightly larger beta conidia with an L / W ratio = 14.6 (19 × 1.3 μm in D. rosae ( MFLUCC 24-0243 ) vs. 17.5 × 1 μm in D. rosae ( MFLUCC 17-2658 )). Diaporthe rosae was erected by Wanasinghe et al. (2018) as a saprobic taxon that was isolated from a dead pedicel of Rosa sp. in Chiang Rai Province, Thailand. Based on the phylogenetic tree of Norphanphoun et al. (2022), D. rosae clustered in the D. sojae species complex. This study reports D. rosae ( MFLUCC 24-0243 ) from makhuea kheun ( Solanum xanthocarpum ), identifying this plant as a new host.

Figures

Figure 16. Phylogenetic tree of the Diaporthe sojae species complex generated by maximum likelihood of combined ITS, tef 1, tub 2, cal, and his 3 sequence data. The ultrafast maximum likelihood (ML) bootstrap support values ≥ 50 % (BT) and Bayesian posterior probabilities ≥ 0.90 (BYPP) are shown, respectively, near the nodes. The ex-type strains are marked with an asterisk. The tree is rooted in D. amygdali (CBS 126679) and D. amygdali (CBS 115620).

Figure 17. Diaporthe rosae (MFLUCC 24-0243) a stem lesion on makhuea kheun b front, and c back view of the colony on PDA after 10 days d front and e back view of the colony on PDA after 60 days f – h conidiomata I section view of conidiomata j, k conidiogenous cells m beta conidia. Scale bars: 50 μm (i); 10 μm (j – n).