First report of large-berry coffee (Coffea liberica) anthracnose caused by Colletotrichum kahawae in China.

Large-berry coffee (Coffea liberica) is one of the three cultivated coffee species and a precious breeding germplasm in China (Yan et al, 2019). Anthracnose is a damaging epidemic disease on coffee worldwide (Mohammed et al. 2015). Between June and September 2022, anthracnose was observed on coffee plants in Puer area, Yunnan, China and disease incidence (% plants diseased) of 8.5%-28.2% was recorded in the field. The disease symptoms were observed at all growth stages. Lesions on leaves were circular or oval, with a white to gray central zone outlined by a brown margin and surrounded by a chlorotic halo, Φ5.1-18.5 mm; some lesions extended and coalesced later to form large, blighted areas, leading to complete leaf senescence, defoliation and bare blighted branches on heavily infected trees. The spots on coffee berries were oval or fusiform, sunken and brown-black; diseased berries became gray-black and dried-out but remained on the tree. Leaves with typical anthracnose lesions were collected from fields in Simao ( 22.07°E,100.98°N) to isolate the pathogen. Leaf pieces (5×5mm) from the lesion margin were cut, surface-sterilized with 75% ethanol and 2% NaClO, and cultured on PDA at 25°C. Three isolates with the same colony morphology were obtained by hyphal tip purification. Detached and intact leaves of 6-month coffee seedlings were inoculated with Φ5mm mycelial discs of the isolates. Anthracnose lesions developed on the inoculated leaves, with all 3 isolates, 7d after incubation in a growth chamber (25°C, > 90% RH and lighting 8 h/d at 11000 lux). Pathogens with the same colony morphology as those of the original isolates were re-isolated from the infected tissues of inoculated leaves, thus fulfilling Koch's Postulates. The ITS sequence (PP550861) for the isolate was PCR-amplified and Blast-n analyses showed 100 % (554/554bp) identity to Colletotrichum kahawae LWTJ01; so they were the same population and coded as KFTJ02. The actin (ACT), calmodulin(CAL), glyceraldehydes-3-phosphate dehydrogenase (GAPHD) and histone 3 (HIS3) genes (Qiu et al. 2020) were amplified from one of KFTJ02 isolates, sequenced and deposited in NCBI GenBank (OR842543, OR842544, OR842545 & OR842546). A phylogenetic tree was generated based on the concatenated sequences of the four genes and those of related Colletotrichum spp. using MEGA 6.0 and KFTJ02 clustered in the same clade with C. kahawae IMI319418 on the tree (Bootstrap sup.=88%). When cultured at 25°C on PDA for 7 days, its colonies were near round or ovoid, gray-white, contoured, Φ73.2-80.1 (76.2±2.3)mm or growth rate 10.2-11.1(8.1) mm/d (n=10). The hyphae were hyaline, septated, branching at near right angles. Conidial masses formed 14 days after incubation. The conidia were elliptical, hyaline, monocellular, 10.2-15.5 (12.7±1.06)×3.8-5.2 (4.3±0.52) µm (n=50). The appressoria were black-brown, oval or irregular, 7.8-9.3 (8.5±0.81)µm (n= 50). These morphological characteristics were consistent with those of C. kahawae (Bridge et al, 2008). Therefore, KFTJ02 was identified as C. kahawae, which has been found to infect Camellia oleifera, Areca catechu and Ficus microcarpa (Wei et al, 2023; Zhang et al, 2020; Lin 2023). The coffee berry disease pathogen (C. kahawae) is a quarantine species which has not been recorded and so it is first reported on coffee crops in China. Results of the present study provide important references for further studies on this disease.

The effects of short-term, long-term, and reapplication of biochar on the remediation of heavy metal-contaminated soil.

Biochar, a cost-effective amendment, has been reported to play pivotal roles in improving soil fertility and immobilizing soil pollutants due to its well-developed porous structure and tunable functionality. However, the properties of biochar and soils can vary inconsistently after field application. This may affect the remediation of biochar on heavy metal (HM)-contaminated soil being altered. Therefore, we selected lettuce as a model crop to determine the effects of short-term, long-term, and reapplication of biochar on soil physicochemical properties, microbial community, HM bioavailability, and plant toxicity. Our investigation revealed that the long-term application of biochar remarkably improved soil fertility, increased the relative abundance of the phylum Proteobacteria which was highly resistant to HMs, and reduced the abundance of phylum Acidobacteria. These changes in soil properties decreased the accumulation of Cd and Pb in lettuce tissues. The short- and long-term applications of biochar had no substantial effects on biomass, quality, and photosynthesis of lettuce. Moreover, the short-term and reapplication of biochar had no significant effects on soil bacterial communities but decreased the accumulation of Cd and Pb in lettuce tissues. It showed that the changes in the physical, chemical, and biological properties of soil after long-term application of biochar promoted the remediation of HM-contaminated soil. Furthermore, microbial community compositions varied with metal stress and biochar application, while the relative abundance of the phylum Actinobacteria in HM-contaminated soil with long-term biochar application was markedly higher than in HM-contaminated soil without biochar application.

Study on the physicochemical properties changes of field aging biochar and its effects on the immobilization mechanism for Cd2+ and Pb2.

It has been widely reported that biochar can be used as a cost-effective amendment to immobilize of heavy metal contaminants in soil. While less research has been conducted on effect of biochar long-term field aging on its properties and the adsorption capability. In this study, the characteristics of aged biochar were investigated by comprehensive characterization to elucidate its mechanism transformation for heavy metal immobilization. Our results showed that, compared to fresh biochar, the relative content of C of aged biochar was reduced by 34.12%, while O was increased by 8.79%. Additionally, the specific surface area, pore volume, pore size and oxygen-containing functional groups of aged biochar were significantly increased compared to the fresh biochar. Batch adsorption experiment indicated that the maximum adsorption for Cd2+ (Qm = 32.157 mg/g) and Pb2+ (Qm = 39.216 mg/g) on aged biochar surface was much larger than that of Cd2+ (Qm = 7.573 mg/g) and Pb2+ (Qm = 8.134 mg/g) on fresh biochar. The underlying adsorption mechanisms for Cd2+ and Pb2+ on fresh biochar were dominated by coprecipitation, cation exchange and cation-π interaction, whereas surface complexation and cation exchange appeared to be more vital for aged biochar, as more active adsorption sites and Oxygen-containing functional groups were formed on its surface during aging, which was well explained by BET, XPS, FTIR and Elemental Analysis. Our study found that the physicochemical properties of biochar changed significantly during field aging. Although these changes increased the adsorption of heavy metals by biochar, the reduced stability of biochar to passivated heavy metal ions.

The genus Helionothrips (Thysanoptera, Panchaetothripinae) in China, with two new species and an identification key.

With 28 listed species Helionothrips Bagnall is the most species-rich genus within the subfamily Panchaetothripinae. Problems are discussed with several character states used for species discrimination: fore wing color; thoracic sculpture; sense cone length on antennal segment IV; male sternal pore plates. An identification key is provided to 15 species of Helionothrips known in China, including H. pallidus sp. n. and H. phragmitesi sp.n. from Southwestern China.

Complete mitochondrial genome sequence for the Thrips hawaiiensis (Thysanoptera: Thripidae).

Thrips hawaiiensis (Morgan) (Thysanoptera: Thripidae) is a common Thysanoptera insect widely distributed in Asia and the Pacific, it damages various plants. In this study the complete mitochondrial genome of T. hawaiiensis was sequenced and characterized by using next-generation sequencing technique. The total length of the complete genome is 15,357 bp and A + T content of 77.8% (GeneBank accession No. MW582621). The T. hawaiiensis mitochondrial genome consists of 13 protein-coding genes (PCGs), 2 ribosomal RNA genes, 22 transfer RNA genes (tRNAs) and 2 non-coding control regions (Dloop region). According to previous studies, only a few complete mitochondrial genomes from Order Thysanoptera have been reported. Thus, T. hawaiiensis complete mitochondrial genome sequence reported will provide molecular information for mitochondrial genome research on Thysanoptera.

Species of Astrothrips from China, with one new species and a list of plant associations (Thysanoptera, Panchaetothripinae).

Seven species of the Panchaetothripinae genus Astrothrips are recorded from China, and an illustrated key provided for their identification. One new species is described, A. glanduculus sp.n., and the following three species are newly recorded from China, A. asiaticus, A. globiceps, and A. tumiceps. The male of A. aucubae is described for the first time, and plants from which Astrothrips have been taken are listed.

Montmorillonite-supported nanoscale zero-valent iron for thiamethoxam removal: response surface optimization and degradation pathway.

As a highly efficient insecticide, thiamethoxam was widely used in the world. However, it was bioaccumulative and toxic to aquatic organisms that must be removed from water. In this work, nanoscale zero-valent iron particles loaded on montmorillonite (nZVI/Mt) were successfully synthesized for effective removal of thiamethoxam. The properties of nZVI/Mt for the removal of thiamethoxam were investigated, and the reaction conditions were optimized through response surface methodology. Furthermore, the degradation products were analyzed by liquid chromatography-mass spectrometry (LC/MS). The results demonstrated that the reaction activity of nZVI was enhanced because the agglomeration and oxidation of nZVI particles were effectively inhibited by using montmorillonite as a support. The significance of the effects of each factor on the removal of thiamethoxam was determined to be in the order of pH Ëƒ temperature Ëƒ reaction time Ëƒ nZVI/Mt dosage. The optimal conditions were as follows: a dosage of nZVI/Mt of 2 g/L, a reaction time of 2 h, a reaction temperature of 35 °C, and a solution pH of 3. The removal efficiency of thiamethoxam (C0 = 20 mg/L) was observed to be as high as 94.29% under the optimal conditions, which was close to the value of 94.47% that was predicted using the mathematical model, indicating that the model could accurately predict the removal efficiency of thiamethoxam. The degradation mechanism involved the -NO2 group on the thiamethoxam molecule was reduced and eliminated by nZVI/Mt.

A new species of Heliothrips (Thysanoptera, Panchaetothripinae), based on morphological and molecular data.

Heliothrips longisensibilis sp. n. is described from the tropical regions of southern China, Yunnan and Hainan, based on morphology and data from mitochondrial and nuclear genes. However, specimens that are identical in colour and structure are reported from northern Brazil, and this is presumably the area of origin of this new species. The area of origin within South America of the Greenhouse Thrips, Heliothrips haemorrhoidalis, is discussed and remains in doubt. An identification key to the four species of Heliothrips is provided.

Two genera of Panchaetothripinae newly recorded from China, with first description of males of Opimothrips tubulatus (Thysanoptera, Thripidae).

The subfamily Panchaetothripinae comprises 40 extant genera worldwide (ThripsWiki 2019), although only 15 genera are previously recorded from China (Mirab-balou et al. 2016; Li et al. 2018). Panchaetothripinae thrips are characterized by the strong reticulations on the body and leg. Wilson (1975) recognized three tribes in this subfamily, Panchaetothripini, Monilothripini and Tryphactothripini, but only tribe Tryphactothripini was relatively supported based on morphological characters (Mound et al. 2001). Species in this Tribe have abdominal segment II constricted at the base and bearing laterally patches of strong ridges, wart-like tubercles or stoutly recurved microtrichia, and abdominal segment X tends to be asymmetrical. Recently, two further genera of Tryphactothripini were found in Southern China, Noathrips and Opimothrips. These two monotypic genera are reported only from the Old World tropics, Noathrips from India and Sri Lanka, and Opimothrips only from Thailand (Bhatti 1967; Kudô 1979; Nonaka Okajima 1992). The purpose of this paper is to record these two genera from China, together with the first description of the male of Opimothrips tubulatus.