Anthracnose is recognized as a significant agricultural disease. This study investigates the disease symptoms characterized by black dots on walnut fruits observed in the walnut orchards of Longnan City, Gansu Province, China, in June 2022. These symptoms resemble those of anthracnose reported in previous studies. A strain designated Ht-10 was initially isolated and identified as belonging to the Colletotrichum species based on its morphological features. Pathogenicity tests confirmed that this strain induced pronounced anthracnose symptoms in walnuts, consistent with those originally observed in the field. Subsequently, multilocus phylogenetic analysis, which included partial sequences of the internal transcribed spacer (ITS), actin (ACT), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), β-tubulin2 (TUB2), and chitin synthase (CHS-1) genes of Ht-10, indicated that it most likely clustered with Colletotrichum fioriniae. The determination of biological characteristics revealed that the optimal temperature for the growth of Ht-10 was 25 °C in full light at a pH of 6, with soluble starch and yeast paste serving as the optimal carbon and nitrogen sources, respectively. To our knowledge, this is the first report of C. fioriniae as a causal agent of anthracnose in walnut fruits in China.

Tomato spotted wilt disease, caused by Tomato spotted wilt virus (TSWV), poses a severe, widespread threat to commercial crop production. Triggering endogenous plant defense capacity serves as a promising tactic for sustainable disease control. Environmental factors, such as temperature, can modulate plant metabolic activities to suppress disease development. To characterize how sub-low temperatures shape tomato responses to TSWV, we maintained tomato seedlings under three regimens: room temperature (25 °C) and two sub-low temperatures (15 °C and 10 °C). Subsequent viral inoculation and phenotypic monitoring revealed that 15 °C pretreatment was associated with markedly reduced TSWV disease severity. RT-qPCR quantification further demonstrated that this 15 °C priming correlated with diminished accumulation of the viral NSs gene. Transcriptome profiling indicated that the 15 °C regime was linked to coordinated activation of cold acclimation pathways, hormone signaling cascades, and antiviral defense programs, which correlated with reduced TSWV accumulation. Specifically, 15 °C conditioning was correlated with the induction of a cold-responsive transcriptional network that overlaps with plant antiviral immune responses. This activated transcriptional signature is putatively associated with the stimulation of defensive cascades, maintenance of cellular homeostasis, and lowered viral accumulation, which collectively align with alleviated spotted wilt symptoms. To our knowledge, this work presents the first correlative evidence associating 15 °C sub-low temperature preconditioning with reduced TSWV accumulation in tomato. Collectively, these observations highlight the potential of temperature manipulation as a chemical-free disease mitigation approach and provide a valuable reference for sustainable crop protection strategies.