Papaya (Carica papaya L.) is a tropical fruit consumed worldwide due to its nutritional, medicinal and pharmacological properties. In China, papaya was widely planted in Guangdong, Guangxi, Hainan, Yunnan, Fujian and Taiwan provinces. From September to December in 2015-2020, fruit with internal black rot disease was observed in papaya plantation in Xuwen, Guangdong province (N20°20'9"; E110°14'45"), approximately 5% fruits on about 85% trees were infected every year. The infected fruits showed the symptom of 'false-ripening' and the pericarp color changed from green to yellow earlier than that of normal fruits. In the cavity of diseased fruits, the sarcocarp black rotted and conspicuous mycelia were observed. Mycelia and infected tissues from symptomatic fruits were picked up, placed on potato dextrose agar (PDA) with 50mg/L ampicillin and incubated at 25± 2 ℃ in the dark. The fungus was purified by spore dilution plate method. Fast-growing colonies with dense, floccose, cottony mycelium were initially white gradually becoming buff brown. Macroconidia were falcate, 3-5 septa with foot-shaped cell and 10.35-41.50 (av. 25.41±6.82) ×1.90-5.95 (av. 3.67±0.85) µm (n>140) in size after 7 days of incubation on carnation leaf agar (CLA). There were scarce microconidia. Chlamydospores were intercalary, solitary or in chains, globose or irregular, hyaline to light brown. The morphological characteristics of the fungus were similar to that of Fusarium sulawesiense (Maryani et al. 2019). The internal transcribed spacer region (ITS) (KU881904 and KY436233), translation elongation factor 1-alpha (tef1) (KU894408 and KY436232), and RNA polymerase second largest subunit (rpb2) (KU894409 and KY436231) were sequenced from two isolates to cofirm species identification. Blast analysis in the FUSARIUM-ID and the NCBI databases revealed above 99 to 100% identity match with the F. sulawesiense strains NRRL34056, NRRL34059, NRRL34004 and NRRL43730 (Xia et al 2019). Maximum likelihood (ML) analysis and Bayesian inference (BI) based on the concatenated sequences using RAxML v.1.0.0 and MrBayes v. 3.2.1 software revealed that the isolates were resolved in the same clade with the F. sulawesiense strains. Thus, the fungus was identified as F. sulawesiense based on morphological characteristics and molecular criteria. To confirm pathogenicity, five healthy fruits were injected with 200 μl of spore suspension (approximately 104 spores/ml) in the field and laboratory, and isovolumetric sterile water served as control. Each fruit was sealed with a plastic bag and kept at natural temperature (about 25-30 ℃). All the inoculated fruits developed typical symptoms after 30 days in the field and 15 days in the laboratory, whereas no symptoms were observed on the control fruits. F. sulawesiense was reisolated from inoculated fruits, but not from non-inoculated fruits. F. sulawesiense displayed a broad host which included Oryza sativa, Musa nana, Citrus reticulata, and Colocasia esculenta etc. in China (Wang et al. 2019). To our knowledge, this is the first report of F. sulawesiense causing internal black rot on papaya fruit. This work is important for papaya growers to prevent this disease in time.

Manglietia decidua, named ‘Hua manglietia’, belonging to the Magnoliaceae family, is one of the most important ornamental plant in China. In 2019 and 2020, an unknown disease caused 3- to 12-month ...

Ficus religiosa L., known as bodhi tree, is an ornamental tree and widely planted as an avenue and roadside tree due to ovate-rounded leaves with narrow, elongated tips. During 2018-2021, circular to oval-shaped leaf spots with pale white centers and brown-black edges surrounded by a chlorotic halo were observed on the leaves of more than 200 bodhi trees all year round in a park in Zhanjiang, Guangdong (N 21°15'22.29''; E110°23'1.03''). The leaf disease incidences were usually 15-80%, in severe cases, up to 100% in autumn and winter every year, and some trees shed all leaves(Fig S1). Repeated annual defoliation may weaken the tree and decrease the aesthetic value in the landscape. Diseased tissues (5 × 5 mm) of five symptomatic infected leaves were surface sterilized in 3% hydrogen peroxide solution for 3 min, rinsed thrice with sterile water, plated on potato dextrose agar (PDA) amended with ampicillin (50mg/L), and incubated at 25-28 ℃ in the dark for 3-7 days. Five strains with similar morphology were obtained by transferring hyphal tips of the colonies to fresh PDA and further isolating by single spore method. Fungal colonies were flat and spreading, with sparse, white aerial mycelium, and black pycnidial conidiomata semi-immersed in PDA after 30-days incubation at 25-28 ℃ in dark. Conidiophores were hyaline and α-conidia were single-celled, oval to fusiform, guttulate, 5.3 × 2.5 μm (n>50), similar to Diaporthe sp. (Crous et al. 2015), but no β and γ -conidia were observed. The internal transcribed spacer(ITS), large subunit ribosomal RNA gene(LSU), calmodulin (CAL) and β-tubulin(TUB) gene regions of a representative strain were amplified using specific primers reported by White et al. (1990), Gao et al (2017) and Gomes et al (2013), and submitted to GenBank (ITS: OM200852, LSU: OM228732, CAL: OM244761, TUB: OM244760). NCBI Blastn showed above 99% identity to D. tulliensis (anamorph: Phomopsis heveicola ) isolates of ITS (MT974186, MN393590 and KX457967), LSU (KR936131), CAL (MW759801), and TUB (KR936132 and MN399886), respectively (Crous et al. 2015; Huang et al. 2021; Gong et al. 2020; Bai et al. 2017). Based on the concatenated ITS, CAL, and TUB, a Maximum Likelihood phylogenetic analyses using MEGA 10.1.8 clustered the fungus with D. tulliensis in a clade with a 93% bootstrap support(Fig S2). Therefore, the fungus was identified as D. tulliensis based on morpho- molecular characteristics. Healthy detached leaves were sanitized thrice with 70% alcohol, and rinsed with sterile water. PDA plugs with actively growing 10-days-old mycelium were placed on predetermined sites, put into a sealed box with above 80% relative humidity and incubated at room temperature (25-28℃). Each isolate was inoculated at 25 needle-wounded and unwounded sites, PDA plugs without mycelium served as controls. Symptomatic spots appeared on all wounded leaves by 7 days post-inoculation (dpi) and on all unwounded leaves by 12 dpi. No symptoms appeared on controlled leaves. Pure cultures were recovered from inoculated leaves and showed identical morpho-molecular criteria to the original isolates. More than 70 pathogenic fungi are known to cause diseases on F. religiosa while there is no record of D. tulliensis infecting bodhi according to the U.S. National Fungus Collection (Farr and Rossman 2022). This report could provide basic understanding and alerting role for horticulturist in daily management.

Bottle palm (Hyophorbe lagenicaulis) is a picturesque evergreen plant in the family Aceraceae, ubiquitously cultivated as an ornamental tree throughout the tropics and subtropics due its attractive shape and small stature. During 2016-2022, brown spots were observed on the leaves of bottle palm on both sides of a campus road in Mazhang, Zhanjiang, Guangdong province (N21°8' 59.9" E110°17' 51.4"). Symptoms appeared as circular, light yellow to brownish red, slightly sunken spots, and brown to black in the center (Fig 1 A-C). The spots expanded to big irregular blotches, which finally led leaves to wither. 0ne hundred percent of 50 plants were infected and 90% of the leaves each plant were covered with brown patches of different sizes. Tissues (5 × 5 mm) from the diseased-healthy junction of the leaf spots were surface disinfected with 75% ethanol for 30 s and 3.5% hydrogen peroxide solution for 5 min, rinsed three times with sterile water and placed on potato dextrose agar (PDA) at 25-28℃ in the dark for 3 days. Fungi with the similar morphology grew from 100% of these inoculated tissues. Hyphal tips from the colony edges were transferred to PDA. Single isolates were obtained by plate dilution method after sporogenesis. Colonies with sparse aerial mycelium were flat, grey. Conidiomata were superficial, black, solitary, scattered. Conidiophores were cylindrical, densely aggregated. Alpha conidia with bi-multiguttulate were hyaline, smooth, ellipsoidal, aseptate, 4.7-7.9×1.6-3.4 µm (Av. 6.4×2.3µm, n>50). Beta conidia were filiform, slightly curved, 15.9-28.3× 0.7-1.1 μm (20.1 × 0.9 μm, n>50) (Fig 1 E-H). Gamma conidia were not observed. The internal transcribed spacer (ITS) regions, large subunit (LSU) rRNA sequence, translation elongation factor (TEF), actin (ACT), calmodulin (CAL), histone H3 (HIS), and beta tubulin (TUB2) genes were amplified using the primers ITS4/ITS1 (White et al. 1990), LR0R/LR5, EF1-728F/EF-2, ACT-512F/ACT-783R, CAL228F/ CAL737R, CYLH3F/ H3-1b, and TUB2Fd /TUB4Rd (Aveskamp et al. 2009; Carbone and Kohn 1999; Crous et al. 2004; O'Donnell et al. 2000), respectively. All seven sequences of the isolate CCAS-JPYZ-4B (ACCC 35493) were submitted to NCBI (OR430112-3, OR451702-6). BLAST search result showed high sequence identity with several Diaporthe ueckeri isolates (Tab1). Phylogenetic analysis of the concatenated data of CAL, HIS, ITS, TEF and TUB genes using Maximum Likelihood method placed CCAS-JPYZ-4B in the D. ueckeri clade. Thus, the isolate was identified as D. ueckeri (Udayanga et al. 2015). Pathogenicity tests were performed on three 5-year-old plants, one healthy new leaf per plant and 10 sites on per leaf were slightly wounded and inoculated with 5-mm mycelial plugs from 10-day-old culture on PDA. The control sites were treated with PDA plugs. Each inoculated leaf was covered with a plastic bag to maintain high humidity and kept at natural temperatures (25-28 ℃). The experiment was repeated once. Symptoms appeared as those described as above 5 to 10 days after inoculation (Fig 1 D). Controls were asymptomatic. The fungus was reisolated from diseased leaves and identified as D. ueckeri. D. ueckeri may infect Arachis hypogaea, Cucumis melo, Camellia sinensis, Glycine max, Mangifera indica and Michelia shiluensis, and this is first report causing brown blotch on bottle palm in China. This disease occurred all year round, which seriously affected plants growth and ornamental value; it is necessary to develop an effective management strategy.