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Adenia globosa, as an excellent indoor ornamental plant, is planted in Tropical Botanical Museum, Nanjing Zhongshan Botanical Garden, Jiangsu Province, China. In September 2022, a new stem basal rot disease was observed on A. globosa seedlings, being planted here. Stem basal rot were observed on approximately 80% of A. globosa seedlings. The basal stem of cutting seedlings appeared decayed, and stem tip eventually turned dry due to water loss (Figure S1A). To isolate the pathogen, three diseased stems were collected from three cuttings planted in different pots of the Tropical Botanical Museum. The stem sections (3 to 4 mm) were excised from the margins between healthy and diseased tissues, surface sterilized in 75% ethanol for 30 s and 1.5% NaClO for 90 s, rinsed three times in sterilized distilled water, plated on potato dextrose agar (PDA) and incubated at 25℃ in the dark. Pure cultures were obtained by monosporic isolation. Eight isolates were obtained, and all identified as Lasiodiplodia sp.. The colonies morphology of cultures, growing on PDA were cotton-like, the primary mycelia were black gray after 7 days, and the reverse sides of PDA plates were similar to front sides in color (Figure S1B). A representative isolate, QXM1-2 was selected for the further study. Conidia of QXM1-2 were oval or elliptic, with a mean size of 11.6 µm×6.6 µm (n=35). The conidia are colorless and transparent in the early stage, and become dark brown with one-septum in the later stage (Figure S1C). The conidiophores produced conidia after nearly four weeks of cultivation on PDA plate (Figure S1D). The conidiophore was a transparent cylindrical structure, with a size of (6.4-18.2) µm × (2.3-4.5) µm ( n = 35). These characteristics were consistent with the description of Lasiodiplodia sp. (Alves et al. 2008). The internal transcribed spacer regions (ITS), translation elongation factor 1-alpha (TEF1α) and β-tubulin (TUB) genes (GenBank Accession No.OP905639, No.OP921005, and No.OP921006, respectively) were amplified and sequenced with the primer pairs ITS1/ITS4 (White et al. 1990), EF1-728F/EF1-986R (Alves et al. 2008) and Bt2a/Bt2b (Glass and Donaldson 1995), respectively. They had 99.8-100% homology to the ITS (504/505 bp) of Lasiodiplodia theobromae strain NH-1 (MK696029), TEF1α (316/316 bp) of strain PaP-3 (MN840491), and TUB (459/459 bp) of isolate J4-1 (MN172230). A neighbor-joining phylogenetic tree was generated by combining all sequenced loci in MEGA7. The isolate QXM1-2 clustered in the L. theobromae clade with 100% bootstrap support (Figure S2). To test pathogenicity, three A. globosa cutting seedlings that previously had been wounded with a sterile needle were inoculated with 20 μL conidia suspension (1×106 conidia/mL) on the stem base. The seedlings inoculated with 20 µL sterile water was used as the control. All plants were covered with clear polyethylene bags to keep moisture in a greenhouse (25℃, 80% relative humidity). The experiment was repeated three times. After 7 days post-inoculation, typical stem rot were found on the treated cutting seedlings and the control seedlings did not have any symptoms (Figure S1E-F). The same fungus, identified by morphological characteristics and sequencing using ITS, TEF1α and TUB genes, was isolated from the diseased tissues of the inoculated stems to complete Koch's postulates. This pathogen has been reported infecting the branch of castor bean (Tang et al. 2021) and root of Citrus (Al-Sadi et al. 2014). For our knowledge, this is the first report of L. theobromae infecting A. globosa in China. This study provides an important reference for the biology, epidemiology of L. theobromae.

The sucrose nonfermenting 1-related protein kinase (SnRK) plays an important role in responding to abiotic stresses by phosphorylating the target protein to regulate various signaling pathways. However, little is known about the characteristics, evolutionary history, and expression patterns of the SnRK family in black raspberry (Rubus occidentalis L.) or other Rosaceae family species. In this study, a total of 209 SnRK genes were identified in 7 Rosaceae species and divided into 3 subfamilies (SnRK1, SnRK2, and SnRK3) based on phylogenetic analysis and specific motifs. Whole-genome duplication (WGD) and dispersed duplication (DSD) were considered to be major contributions to the SnRK family expansion. Purifying selection was the primary driving force in the SnRK family evolution. The spatial expression indicated that the RoSnRK genes may play important roles in different tissues. In addition, the expression models of 5 RoSnRK2 genes in response to abiotic stresses were detected by qRT-PCR. The proteins encoded by RoSnRK2 genes localize to the cytoplasm and nucleus in order to perform their respective functions. Taken together, this study provided an analysis of the SnRK gene family expansion and evolution, and contributed to the current knowledge of the function of 5 RoSnRK2 genes, which in turn expanded understanding of the molecular mechanisms of black raspberry responses to abiotic stress.

Pecan [Carya illinoinensis (Wangenh.) K. Koch] is an important nut tree species, which has been widely planted in Jiangsu and Anhui Provinces of China in recent years (Mo et al. 2018). In May 2022, a new leaf spot disease was observed on both young and old leaves of pecan trees in the Luhe area, Nanjing, Jiangsu Province. Approximately 30% of pecan trees suffered from the disease, which affected the growth of young trees and nut production to cause economic loss. Initially, the leaf spots were grayish black and round. Then, disease spots enlarged and joined together, forming irregular lesions with uneven edges. In the last stage, the leaflets were withered. To isolate the pathogen, three symptomatic leaves were collected from each of three different pecan trees. Leaf sections (3 to 4 mm) were excised from the margin of spots, surface sterilized in 75% alcohol for 30 s, then sterilized in 1.5% NaClO for 90 s. After rinsing three times with sterile distilled water, leaf sections were placed on potato dextrose agar (PDA) medium and incubated at 25 °C in a dark environment for 5 days. Pure cultures were obtained by monosporic isolation. A total of 20 isolates were obtained, and 12 isolates were identified as Stemphylium sp. with the same morphological features and ITS sequences. A representative isolate, named LH3-3, was selected for further study. Colonies on PDA were light yellow with dense mycelium and were brownish yellow on the reverse side. Conidia were 16.3 to 34.4 × 8.1 to 16.3 µm) (n=35), muriform, brown, with transverse and longitudinal septa, lightly deformed at the transverse septa. Ascomata were not observed. The morphological characteristics were consistent with the description of Stemphylium eturmiunum (Simmons 2001). The internal transcribed spacer region (ITS) and portions of genes for calmodulin (cmdA) and glyceraldehyde-3-phosphate dehydrogenase (gpd) were amplified and sequenced with the primers ITS1/ITS4 (White et al. 1990), CALDF1/CALDR2 (Xu et al. 2022) and GPD-F/R (Xie et al. 2019), respectively. Sequences were deposited in GenBank under accessions OP482492 (ITS), OP495734 (cmdA), and OP495735 (gpd). BLAST analysis showed that the sequences had 99.67-100% homology to ITS (525/525 bp) of S. eturmiunum strain ST14 (MH843733), cmdA (694/694 bp) of strain CBS122124 (KU850832), and gpd (299/300 bp) of isolate UMSe0030 (MK336876). MEGA 7.0 was used to construct a phylogenetic analysis based on concatenated sequences of ITS, cmdA, and gpd using the neighbor-joining method. The results showed that LH3-3 clustered on the branch of S. eturmiunum, and the support rate was 100%. A spore suspension in sterile water was made from strain LH3-3 grown on PDA, and adjusted to 1×106 spores/mL with a hemocytometer. To test pathogenicity, 20 µl drops of the spore suspension were placed on the left sides of four healthy detached leaflets of mature pecan trees and leaves of three 3-month-old seedlings. The right side of each leaflet was inoculated with 20 µl drops of sterile distilled water as the control. All inoculated seedlings and detached leaflets were covered with a transparent plastic bag and cultured in a greenhouse at 25 °C, 80% relative humidity, and a 12 h light cycle until symptom appeared. The experiment was repeated three times. After 7 days of inoculation, grayish black lesions appeared on all inoculation sites with the spore suspension but not in the controls. The leaf spot symptoms were similar to those observed in orchards. The same fungus, identified by morphological characteristics and sequencing of ITS, cmdA, and gpd, was re-isolated from the diseased spots of the inoculated leaflets to complete Koch’s postulates. S. eturmiunum has been reported to infect garlic (Dumin et al. 2022) and tomato (Prencipee et al. 2021), but this is the first report of S. eturmiunum causing leaf spot of C. illinoinensis. This study provides a basis for further study on the biology, epidemiology, and management of the disease.