In this study, the chloroplast (Cp) genome of Zanthoxylum avicennae (Lam.) DC was sequenced by high-throughput sequencing technology. The length of the Cp genome of Zanthoxylum avicennae was 158,568 bp, and the total GC content was 38.4%, including a large single-copy (LSC) region of 86,318 bp, a small single-copy (SSC) region of 18,250 bp, and 27,000 bp of inverted repeats (IRs). The Cp genome encoded 131 genes, including 88 protein-coding, 37 tRNA, and six rRNA genes. Phylogenetic analysis of the genome sequence showed that Zanthoxylum avicennae was closely related to Zanthoxylum nitidum , Zanthoxylum esquirolii and Zanthoxylum motuoense of the Rutaceae family.

Mallotus paniculatus (Lam.) Müll. Arg. 1865 ( Euphorbiaceae ) is a shrub or small tree with medicinal properties that is distributed across Southeast Asia. In this study, we sequenced the complete chloroplast genome of M. paniculatus to study phylogenetic relationships within the family Euphorbiaceae Juss. The complete chloroplast genome of M. paniculatus was 164,455 bp in length, with an overall GC content of 35.3%. It was found to consist of a long single copy region of 89,021 bp, a small single copy region of 18,524 bp, and a pair of inverted repeats of 28,455 bp. Results indicated that the chloroplast genome contains a total of 131 genes, including 78 protein-coding genes, 37 tRNA genes, eight rRNA genes, and eight pseudogenes. The phylogenetic tree showed that M. paniculatus is closely related to Mallotus japonicus and Mallotus peltatus .

Euphorbia micractina Boiss is a plant with high medicinal value. Yet, its molecular biology is not fully understood. In this study, we sequenced the whole chloroplast genome (CP) sequence of E. micractina to study its phylogenetic relationship in Euphorbiaceae. The total length of the chloroplast genome of E. micractina is 162,056 bp, including a large single-copy (LSC) region of 89,936bp bp, a small single-copy (SSC) region of 18,376 bp, and a pair of identical inverted repeat regions (IRs) of 11,367 bp. The genome has 128 genes, including 84 protein-coding genes, 36 transfer RNA (tRNA) genes, and 8 ribosomal RNA (rRNA) genes. The overall GC content of the plastome is 35.7%. The phylogenetic analysis of E. micractina with 30 related species suggested a closest taxonomical relationship with Euphorbia pekinensis in the Euphorbiaceae family.

Euonymus japonicus Thunb., an evergreen shrub, is popular for landscaping in China. In 2021, leaf spot was observed on E. japonicus (about 150 trees) leaves with 40 to 50% disease incidence in Wanzhou urban forest (30°45′N; 108°27′E) of Chongqing, the infected plants were between 5 and 6 years old. The symptoms started to occur from June to July and approximately 30 to 40% of the leaves exhibited leaf spot symptoms from August to September. Initial symptoms appeared as yellow spots of 1.2 to 4.9 mm in diameter, and then expanded to become large and irregular lesions, having white center surrounded by a brown halo. Under humid conditions, black dots appeared in the central part of the spots. In later stage, split and fall of the tissues occurred from the infected spot. To identify the causal agent, infected tissues from 20 samples (from 5 trees) were cut into small pieces (5 mm2), surface-sterilized for 30 s in 75% ethanol and 3 minutes in 3% sodium hypochlorite, rinsed three times in sterile water, placed onto potato dextrose agar (PDA) amended with streptomycin sulfate (50 μg/ml) and incubated at 25°C in dark conditions. Purified eight fungal colonies were white with undulating margins and light cream on the reverse side, measuring 85 mm diameter after 7 days, dark brown to black conidiomata were irregularly scattered and Conidia were observed in 20 days old colonies. Conidia were spindle‐shaped, 4.5 to 6.8 × 15.2 to 23.5 μm (n=50), with 4 diaphragms, the three median cells were light to dark brown and the two end cells were colorless. 1 to 3 accessory filaments (5.2 to 22.5 μm long) protrude from theapical cell while a short stalk (3.5 to 5.5 μm long) was attached to the basal cell, these morphological features suggested that the isolates were most likely Pestalotiopsis. sp. Eight colonies were confirmed to be identical based on morphological characteristics. For molecular identification, DNA was extracted from representative strains (YF‐5, YF‐13, YF‐24). The internal transcribed spacer (ITS) region, β‐tubulin (TUB2), the translation elongation factor-1 alpha gene (TEF1), genes were amplified using primers ITS5/ITS4, TUB2F/TUB2R, and EF‐526F/EF‐1567R, respectively (White et al.1990; Glass & Donaldson 1995; O’Donnell & Cigelnik 1997; Carbone &, Kohn.1999). The sequences were deposited in NCBI GenBank YF-24, [ITS; ON204233: TUB2; ON304156: TEF1; ON400075]: YF-5, [ITS; OP379570: TUB2; OP413495: TEF1; OP413496]: YF-13, [ITS; OP379589: TUB2; OP413494: TEF1; OP413497]. Which revealed a 95% similarity to the Ps. theae NTUCC 18-067 [ITS; MT322086: TUB2; MT321888: TEF1; MT321987] ex‐type sequences. Based on morphology and multilocus phylogenetic analysis, representative strains were identified as Pseudopestalotiopsis theae. For Koch's postulates, wiped the leaves of six healthy plants of E. japonicus (two-year-old) grown in pots with sterile water, 10 μL of spore suspension (106 spores/ mL) was brushed on five leaves per plant (three plants in total) with a sterile brush, and the other three plants were treated with sterile water instead of spore suspension as control, the plants were placed in a greenhouse at 28°C and 95±1% relative humidity. Seven days after inoculation, brown lesions appeared, similar to those observed in infected plants. Black dots surrounded by a brown halo reappear on the lesions after 12 days, whereas control plants remained healthy. Ps. theae culture was re-isolated from the infected leaves and identified using morphological characteristics and DNA sequence analysis. To our knowledge, Ps. theae can cause diseases on tea plants and has been found in Japan, Thailand and China, this is the first report of leaf spot infection of E. japonicus caused by Ps. theae in China. This disease is reducing the ornamental value of E. japonicus. Our results will contribute to the prevention and cure of leaf spot disease in E. japonicus.

Polygonatum cyrtonema Hua., is one of the cultivated varieties of Polygonatum sibiricum Redouté., which also an important cash crop in China (Chen, J., et al. 2021). From 2021 to 2022, symptoms resembling gray mold were observed on P. cyrtonema leaves with 30 to 45% disease incidence in Wanzhou District (30°38′1″N, 108°42′27″E) of Chongqing. The symptoms started to occur from April to June and more than 39% of leaves were infected from July to September. Symptoms started as irregular brown spots and progressed to the leaf edges or tips and stems. In dry conditions, the infected tissue appeared dry and thin, light brown in color, and became dry and cracked in the later stages of disease development. When the relative humidity was high, infected leaves developed water-soaked decay with a brown stripe around the lesion, and a gray mold layer appeared. To identify the causal agent, 8 typical diseased leaves were collected, leaf tissues were chopped into small pieces (3×5 mm), surface sterilized for 1 min in 70% ethanol and 5 minutes in 3% sodium hypochlorite, rinsed three times using sterile water, placed onto potato dextrose agar (PDA) amended with streptomycin sulfate (50 μg/ml) and incubated at 25°C for 3 days in dark conditions. Then 6 colonies (3.5 to 4 cm diameter) with similar morphology were transferred onto new plates. In the initial stage of growth of isolates, all hyphal colonies were white, dense, and clustered, and dispersed in all directions. After 21 days, brown to black-colored sclerotia (2.3 to 5.8 mm diameter) were observed embedded on the bottom of the medium. The six colonies were confirmed to be Botrytis sp. based on the morphological characteristics. The conidia were attached in branches on the conidiophores in grape-like clusters. Conidiophores were straight and 150 to 500 μm in length, and the conidia were single-celled, long ellipsoidal, or oval-like, with no septa and 7.5 to 20 × 3.5 to 14 μm (n=50). For molecular identification, DNA was extracted from representative strains 4-2 and 1-5. The internal transcribed spacer (ITS) region and sequences from the RNA polymerase II second largest subunit (RPB2), and the heat-shock protein 60 (HSP60) genes were amplified using primers ITS1/ITS4, RPB2for/RPB2rev, and HSP60for/HSP60rev, respectively (White T.J., et al.1990; Staats, M., et al. 2005). The sequences were deposited in GenBank: 4-2 [ITS; OM655229: RPB2; OM960678: HSP60; OM960679] and 1-5 [ITS; OQ160236: RPB2; OQ164790: HSP60; OQ164791]. These sequences from isolates 4-2 and 1-5 had 100% similarity to the B. deweyae CBS 134649/ MK-2013 [ITS; HG799538.1: RPB2; HG799518.1: HSP60; HG799519.1] ex‐type sequences, and phylogenetic analyses based on multi-locus alignment demonstrated strains 4-2 and 1-5 as B. deweyae. Isolate 4-2 was used to verify whether B. deweyae can cause gray mold on P. cyrtonema, by conducting Koch’s postulates experiments (Gradmann, C., 2014). The leaves of P. cyrtonema planted in pots were washed with sterile water, and brushed with 10 mL of hyphal tissue in 55% glycerin. Leaves of another plant were brushed with 10 mL 55% glycerin as control, and Kochs’ postulates experiments were conducted three times. Inoculated plants were kept in a chamber with 80% relative humidity at 20 ± 1°C. Seven days after inoculation, disease symptoms similar to those in the field were observed on leaves, whereas control plants remained asymptomatic. The fungus was reisolated from inoculated plants and identified as B. deweyae based on multi-locus phylogenetic analysis. To our knowledge, B. deweyae is mostly found on Hemerocallis, is likely to be an important contributor to the development of ‘spring sickness’ symptoms (Grant-Downton, R.T., et al. 2014.), and this is the first report of B. deweyae causing gray mold on P. cyrtonema in China. Although B. deweyae has a limited host range, it might also become a potential threat to P. cyrtonema. This work will provide a basis for the prevention and treatment of the disease in the future.