Radermachera sinica (China doll) is a popular evergreen horticultural crop worldwide. However, little information has been provided to describe the anthracnose disease of R. sinica. In 2018, symptoms suspected of leaf anthracnose were observed on R. sinica in gardens and commercial greenhouses in Guangzhou, China. Lesions on diseased leaves showed thinned and grayish white centers, dark-brown to black borders, and raised black spots. Twenty-seven single-conidia isolates were obtained from symptomatic leaf lesions. Based on morphological characteristics and multilocus phylogenetic analysis, 19 isolates were identified as Colletotrichum siamense and six and two isolates were identified as C. fructicola and C. karstii, respectively. An in vivo pathogenicity test was conducted on leaves of R. sinica plants, and it was discovered that C. siamense was more aggressive under wounded conditions than under unwounded conditions, and caused symptomatic necrotic lesions on the leaf. Afterward, the same pathogen was reisolated from lesions of inoculated leaves to fulfill Koch’s postulates. However, neither C. fructicola nor C. karstii caused visible lesions on leaves of R. sinica under wounded or unwounded conditions, indicating that they may be asymptomatic endophytes or opportunistic pathogens on R. sinica. To our knowledge, this study is the first report of Colletotrichum spp. associated with anthracnose disease on R. sinica in China.

Blue light with a wavelength of 400-470 nm is the composition of the visible light. However, in recent years, blue light contributed the most significance to light pollution due to the artificial light at night. Previously, we have demonstrated that the Asian citrus psyllid (ACP), Diaphorina citri, an important pest in citrus production, has significant positive phototaxis with a light-emitting diode light of 400 nm. In this study, ACP with positive phototactic behavior to 400 nm light (PH) and non-phototactic behavior to 400 nm light (NP) were collected, individually. Transcriptome dynamics of head tissues of PH and NP groups were captured by using RNA-sequencing technology, respectively. Forty-three to 46 million clean reads with high-quality values were ob-tained, and 1773 differential expressed genes (DEGs) were detected. Compared with the NP group, there were 841 up-regulated DEGs and 932 down-regulated DEGs in the PH group. Eight pathways were significantly enriched in the PH group in the KEGG database, while 43 up-regulated pathways and 25 down-regulated pathways were significantly enriched in the PH group in the GO database. The DGE approach was reliable validated by real time quantitative PCR. Results indicated that the blue light acted as an abiotic stress causing physiological and biochemical responses such as oxidative stress, protein denaturation, inflammation and tumor development in ACPs. Additionally, the light was absorbed by photoreceptors of ACPs, and converted into electrical signal to regulate neuromodulation. This study provides basic information for understanding the molecular mechanisms of ACP in response to blue light and provides a reference for further studies to elucidate phototactic behavior.

Papaya leaf curl China virus (PaLCCNV), a monopartite begomovirus (genus Begomovirus, family Geminiviridae), was originally reported on Carica papaya in Guangxi province of China(Wang et al., 2004). The virus has been reported to infect C. papaya, Solanum lycopersicum, Nicotiana tabacum, Corchoropsis timentosa, Siegesbeckia orientalis and Ageratum conyzoides. In January 2015, plants of Acalypha australis, a common and widespread weed species, were found exhibiting yellow vein symptoms in fields of Nanning city, Guangxi province. Five symptomatic leaf samples were collected from each of five diseased plants. Total DNA was extracted from the five samples with the EasyPure Plant DNA kit (TransGen Biotech, Beijing, China), and used as a template for PCR with the degenerate begomovirus primers pair AV494 (5′-gccyatrtayagraagccmag-3′) and CoPR (5′-gangsatghgtrcadgccatata-3′). The expected-size ~570 bp fragment was detected from all five samples, indicating that A. australis plants showing yellow vein symptoms w...

Luffa acutangula and Momordica charantia, known for their edible and medicinal value, are economically important cucurbitaceous vegetable crops cultivated globally. Gummy stem blight, primarily caused by Stagonosporopsis species, is a devastating disease on cucurbits, resulting in significant economic losses. Although occurrence of gummy stem blight on L. acutangula and M. charantia has been reported previously, the pathogen responsible for the disease on these two crops has not been clearly identified because of the taxonomical nomenclature changes. During the period from 2018 to 2024, diseases resembling gummy stem blight were commonly observed on L. acutangula and M. charantia in Guangdong Province of China, with a disease incidence for L. acutangula of 13.5 to 21.7% in Guangzhou and 13.5 to 25.0% in Huizhou and a disease incidence for M. charantia of 20.0 to 30.0% in Guangzhou and 16.7 to 26.7% in Huizhou. Samples of symptomatic leaves, stems, and fruits were collected, and 52 fungal isolates with similar colony morphology were obtained. The initial identification of these isolates was based on cultural and morphological characteristics, which placed them in Stagonosporopsis. Subsequently, they were identified as S. citrulli with multilocus phylogenetic analyses using the ribosomal DNA internal transcribed spacer and portions of the β-tubulin, chitin synthase I, and calmodulin genes. Pathogenicity tests were conducted on leaves and fruits of L. acutangula, M. charantia, and Cucumis sativus with representative isolates of S. citrulli. These isolates produced lesion symptoms on L. acutangula and M. charantia similar to the disease symptoms in the field. Furthermore, they were also pathogenic to C. sativus. The same pathogen was reisolated from lesions of inoculated plants to fulfill Koch’s postulates. To our knowledge, this study is the first report identifying S. citrulli as the causal agent of gummy stem blight on L. acutangula and M. charantia in China.

Mycoviruses are ubiquitous in fungi, and some of these viruses induce hypovirulence, making them potential biocontrol agents. However, the effect of host genetic background at the pathogen population level on the performance of mycoviruses has not been fully investigated. Here, five diverse species of mycoviruses in Botrytis cinerea were used as a model to investigate the effect of population variation on mycovirus-induced phenotypes. The five mycoviruses were fully sequenced, including two hypoviruses (dsRNA1 and dsRNA2), one victorivirus (dsRNA3), and one partitivirus (dsRNA7 and dsRNA8), while one virus (dsRNA4, dsRNA5, and dsRNA6) remained unclassified. These viruses were readily transmitted to three B . cinerea strains, resulting in several derivative strains infected by different combinations of the five viruses. Notably, infection by some of these five viruses generally increased sporulation. However, the symptoms induced by the viruses varied, ranging from no significant effects to reduced virulence among different B . cinerea strains with the same viral profile. Therefore, we propose that the B . cinerea population can be broadly categorized into sensitive and insensitive groups regarding viral infection. These findings suggest that variation within the B . cinerea population may affect mycovirus-mediated phenotypic changes in their hosts. The presence of the insensitive group within the fungal population could also complicate the application of mycoviruses for fungal disease control.