Hypothenemus hampei (Ferrari), a newly invading pest in Hainan in 2019, is a serious threat to coffee production all over the world, posing a major threat to the healthy development of the coffee industry in Hainan and even the whole country. In order to understand the habits of this insect and provide basic data for the prevention and control of this insect in the future, this experiment observed its death-feigning, hunger tolerance ability, and discussed the lethal effect of short-term high temperature on it. The results showed that 24 h without feeding any food had no significant effect on the death-feigning of H. hampei adults. After the treatment at 45 ℃ for 2 h, the proportion and duration of death-feigning of H. hampei adults were significantly increased. The proportion of suspended death reaction was 72.0% and the duration of death-feigning was 320.33 s, which was significantly higher than 43.26 s at 26 ℃. H. hampei had a strong hunger tolerance ability, without providing any food, its longest survival time could reach 204 h, the average survival time was 90.17 h. After short-term high temperature treatment, both treatment temperature and treatment duration significantly affected the survival of adults of H. hampei. With the increase of treatment temperature and treatment duration, the mortality rate increased gradually. The corrected mortality rate was 94.92% after 6 h treatment at 45 ℃, and the mortality rate reached 100% after 12 h. Treatment at 36 ℃ and 39 ℃ for 6 h or less had little effect on the viability of H. hampei, and the mortality rate was 16.94% and 23.73% after 24 h, respectively. The Lt₅₀ of different short-term high temperature treatments decreased with the increase of treatment temperature, and the Lt₅₀ also decreased with the extension of observation time. The shortest Lt₅₀ for 24 h and 48 h after 45 ℃ treatment was 3.11 h and 2.70 h. The longest Lt₅₀ treated at 36 ℃ was 17.85 h and 11.42 h. The LT₅₀ was 39.53 ℃ and 38.66 ℃ for 24 h and 48 h after 6 h of different short-time high temperature treatments, and the LT₅₀ reduced with the extension of observation time.

Dendrobium kingianum belongs to Orchidaceae family, which is widely grown as an ornamental plant in China. In recent years, a blight disease in D. kingianum is observed in Guangdong province, China. This disease infects the stems and leaves of D. kingianum, causing brown rot and plant death. It has a serious impact on production. A fungus was isolated from the diseased plants of D. kingianum. The pathogenicity test showed that this fungus could infect healthy potted plants and cause the disease. The symptoms on inoculated plants were similar to field symptoms. Morphological characteristics of the fungus from the inoculated plants were consistent with that of the original fungus from field samples. The pathogen was identified by both morphological characteristics and β-tubulin (tub) gene sequence analysis. The morphological characteristics of the isolates were similar to Phytophthora palmivora. BLAST results showed both the sequences of two isolates in this study were 99% identical to the sequence of P. palmivora. In the maximum likelihood (ML) tree based on tub gene sequences, the strains in this study clustered with P. palmivora with 100% support. Therefore, P. palmivora was identified as the pathogen of Phytophthora blight on D. kingianum based on morphological characteristics and phylogenetic analysis. This is the first report of P. palmivora causing Phytophthora blight on D. kingianum in China and worldwide. The inhibitory effect of 10 fungicides on P. palmivora was determined using the mycelial growth rate method. The results showed that four fungicides, namely diacetylomyamide, dimethomorph, metalazepine and metalazepine · mancozeb, were the top four toxic to P. palmivora, and the EC₅₀ value was 0.000 03 μg/mL, 0.0628 μg/mL, 0.2381 μg/mL and 0.5457 μg/mL, respectively. It was followed by chlorothalonil, pyrimethole and mancozeb, the EC₅₀ was less than 10 μg/mL. However, the effect of downy mildew hydrochloride and triethylphosphonate was poor, and the EC₅₀ was more than 100 μg/mL. Carbendazim showed no inhibitory effect, the EC₅₀ was more than 1000 μg/mL. The result would provide a theoretical basis for the prevention and control of Phytophthora blight in Dendrobium.

Colletotrichum siamense is the main pathogen of anthracnose in many crops in tropical and subtropical regions. SSK1 is a response regulator protein of the two-component system. Studies have shown that SSK1 in pathogenic fungi is related to the morphogenesis, stress response, drug resistance and pathogenicity of pathogens, but SSK1 homologues have distinct functions in different fungi. In order to understand the function of CsSSK1 in C. siamense, the CsSSK1 gene deletion mutant ΔCsSSK1 and the complement strain ΔCsSSK1 (CsSSK1) were constructed and phenotypically observed. The results showed that the deletion mutant ΔCsSSK1 showed slightly retarded mycelial growth, shorter conidia, lower sporulation and conidial germination rate. ΔCsSSK1 significantly increased the sensitivity of C. siamense to NaCl, sorbitol, sucrose, glucose and Congo red, and the sensitivity to fluconazole and tebuconazole, but decreased the sensitivity to fludioxonil. The pathogenicity of ΔCsSSK1 was significantly reduced. The results showed that CsSSK1 gene was involved in the regulation of C. siamense morphogenesis, response to salt stress, osmotic stress, Congo red stress and fungicide stress, affecting the pathogenicity of C. siamense. The results would lay a foundation for further understanding the function of CsSSK1 gene in C. siamense and analyzing the molecular mechanism of pathogenic fungi response to stress.

The effects of different nitrogen forms on the growth, rhizosphere soil nutrients and soil enzyme activities of cassava variety Huanan 9 (SC9) were studied to provide theoretical basis for the scientific fertilization of cassava in Hunan Province. CK (no nitrogen fertilizer), T₁ (amide nitrogen-urea), T₂ (ammonium nitrogen-ammonium sulfate) and T₃ (nitrate nitrogen-calcium nitrate) were set in the study. The level of soil fertility was the same, and the application rate of nitrogen fertilizer was 180 kg/hm². Effects of different nitrogen forms on plant height, stem diameter, soil nutrients, soil enzyme activity, yield and quality of cassava were studied. Compared with CK, different nitrogen treatments improved plant height, stem diameter, yield and quality of cassava. T₂ had the highest plant height, stem diameter, yield, dry matter rate and starch content, which was significantly higher than that of CK by 13.51%, 32.24%, 61.72%, 6.44%, 19.86%. Nitrogen application changed the nutrient content of rhizosphere soil, and T₂ had the best effect on the nutrient content of cassava rhizosphere soil. The contents of soil organic matter and alkali-hydrolyzable nitrogen in T₂ were higher than those in the other treatments. The content of available potassium in T₂ was higher than that in other treatments at root formation stage and root expansion stage. Compared with CK, nitrogen application increased soil enzyme activity in cassava rhizosphere. With the passage of the growth period, urease activity increased gradually, sucrase activity decreased at first and then increased, catalase and nitrate reductase activity increased at first and then decreased. Among them, the soil sucrase activity in T₂ was the highest. Comprehensive analysis, in Hunan, the effects of different nitrogen forms on cassava growth and soil environment were different. Compared with CK, nitrogen application improved soil fertility, and then improved the growth of aboveground parts of cassava, thus improving the yield and quality of cassava. Among them, the application of ammonium nitrogen fertilizer is more beneficial to the growth and yield of cassava SC9.

The structural characteristics of the rhizosphere bacterial communities of cucumber plants under different proportions of mushroom residue and sawdust were analyzed, and it was found that mushroom residue and sawdust compound substrate could replace conventional commercial matrix peat (CK) cultivation cucumber, which providing a basis for the application of a new substrate cultivation mode. Compared with CK, cucumber cultivated with substrate composed of mushroom residue and sawdust in three different proportions significantly increased its yield, rhizosphere bacterial diversity and richness index, and also affected the metabolic function of rhizosphere bacteria, among which the ratio of mushroom residue to sawdust was 1∶1 (T₂). At the classification level, the proportion of bacterial abundance in Proteobacteria of cucumber plants under the cultivation of mushroom residue and sawdust compound substrate was lower than that of CK, but the proportion of bacterial abundance of Bacteroidota was higher than that of CK, and Bacteroidota was the dominant bacterial phylum shared by mushroom residue and sawdust compound substrate cultivation. At the taxonomic level, unclassified_c__Gammaproteobacteria, Limnobacter and Chujaibacter were the dominant bacterial genera unique to the root system of cucumber plants under CK conditions. Bradyrhizobium, Brevundimonas, and Dokdonella were the dominant bacterial genera with a 1∶3 (T₁) ratio of mushroom residue to sawdust. Under the conditions of 1∶1 (T₂) and 3∶1 (T₃) ratios of mushroom residue to sawdust, respectively, no dominant bacterial genus was found in the rhizosphere of cucumber plants. Through species Venn analysis, the ratio of mushroom residue to sawdust at the species classification level increased the number of rhizobacteria species in cucumber plants under the treatment of 1∶3 (T₁), 1∶1 (T₂) and 3∶1 (T₃), and the richness and diversity of rhizosphere bacteria were improved.

Iron (Fe) is one of the essential trace mineral elements in plants to maintain normal growth and development that plays an important role in various life processes. Researches towards molecular mechanism of Fe uptake, transport and distribution are mainly focused on the annual model plants. Biological functions of genes towards Fe uptake and transport in fruit trees are still unknown. In this study, 11 ferric reduction oxidase encoding genes (FROs) were isolated and identified from diploid mango Guire 82, named by MiFRO1–MiFRO11. All mango FRO had ten typical motifs except for MiFRO1 lacking Motif2–Motif5. All mango FRO possessed similar tertiary structure, with the exception that MiFRO3 exhibited distinct tertiary structure. The amino acid sequences of FRO from 11 plants shared an overall identity of 42.07%, while mango FRO shared an overall identity of 62.43%. Phylogenetic tree analysis showed that mango FRO were prone to be closely clustered together lonely, which was far away from the homologs of the other ten plants in genetic distance. Quantitative real-time PCR (qRT-PCR) analysis showed that MiFRO3 was the most abundant expressed gene during different parts of Guire 82 mango on the whole. In particular, MiFRO4, MiFRO5, MiFRO8 and MiFRO11 were highly expressed in the leaves of both mature trees and grafted seedlings. MiFRO6 and MiFRO7 were highly expressed in phloem or stem, MiFRO1 and MiFRO10 were highly expressed in young fruits, MiFRO2 and Mi-FRO9 were highly expressed in seedling roots, while MiFRO3 was highly expressed in full bloom flowers. In addition, expression of FRO in mango roots were mainly induced under iron depletion and NaCl stress, respectively, while Mi-FRO3, MiFRO5 and MiFRO8 were significantly reduced under iron toxicity. Expression of MiFRO2, MiFRO5 and Mi-FRO7 were increased under ABA treatment, and MiFRO1 and MiFRO5 were enhanced under PEG treatment. Expression of MiFRO2, MiFRO6 and MiFRO7 were decreased under low temperature (4 ℃). However, FRO changed little under heat stress (45 ℃) in mango roots. This study would provide gene resources to elucidate the molecular mechanisms of Fe uptake and transport in mango, and lay a theoretical foundation to reveal Fe nutrition and high utilization in tropical fruit crops.

Oil Palm (Elaeis guineensis Jacq.) is the most efficient oil-producing plant in the world. Fruit development is the basis of yield formation, but rancidity occurs after 24 h of harvesting, which seriously affecting the quality of palm oil. At present, the key regulatory genes and pathways for the differences in the synthesis of free fatty acid metabolism in pulp development and postharvest fruits have not been identified. In this study, oil palm fruits were collected from 95 days (MS1), 125 days (MS2), 185 days (MS3), 24 h (MS4) and 36 h (MS5) after pollination. The second generation high-throughput transcriptomics (RNA-Seq) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were used to analyze the transcriptomes and metabolomes of the fruits during the development and postharvest storage. The unsaturated fat of oil palm was significantly higher than that of fatty acid during the middle and late stages of fatty acid accumulation, LACS4, LACS4-X1, FATA, FATB, KASⅠ, KASII, SAD1 were highly expressed in pulp and were positively correlated with oleic acid, linoleic acid, palmitic acid, palmitoleic acid acid, stearic acid and linolenic acid, DGAT and PDAT were over-expressed in the pulp and negatively correlated with the content of the six fatty acids, indicating that the expression of the above-mentioned genes may promote and inhibit the synthesis and accumulation of the fatty acids in oil palm fruit, respectively, suggesting that LACS4, LACS4-A1, FATA, FATB, KASⅠ, KASII and SAD1 may be the key genes with high content of unsaturated fat during postharvest storage. GDSL2, GDSL7, SAD2, LACS9 genes and GDSL1, KAT were positively and negatively correlated with oleic acid, and negatively and positively correlated with palmitic acid, palmitoleic acid acid, stearic acid, linoleic acid and linolenic acid, respectively, suggesting that GDSL2, GDSL7, SAD2 and LACS9 might promote oleic acid production and inhibit palmitic acid, palmitoleic acid acid, stearic acid, linoleic acid and linolenic acid production during rancidity, while GDSL1 and KAT might inhibit linolenic acid production, suggesting that GDSL2, GDSL7, SAD2 and LACS9 are the key genes causing oil palm rancidity after harvest. The aim of this study is to provide candidate genes for improving unsaturated fat content and altering fatty acid composition by using molecular biotechnology, and to provide theoretical reference for screening unsaturated fat and storability varieties.

Camellia oleifera is a unique oil plant of Theaceae, which has important ornamental value and economic value. With the intensive planting of Camellia, many diseases and pests occur. In addition, the delayed breeding of improved varieties seriously restricts the development of the Camellia industry. INDETERMINATE DOMAIN (IDD) family is a kind of conservative transcription factors in higher plants, which regulate the basic immune response of plants by mediating plant endogenous hormones. In order to identify the members of IDD gene family in C. oleifera, 29 members of CoIDD gene family were identified through the conserved domain of IDD gene family with reference to the whole genome information of C. oleifera, and further clarified the structure, physical and chemical properties, phylogenetic relationship, and sub cell localization of each gene. The CoIDD4 gene homologous to AtIDD4/5/6 was cloned by RT-PCR, and its physicochemical properties, expression mode and nuclear localization signal were clarified. At the same time, the types of cis acting elements in its promoter region were analyzed. The results showed that 29 CoIDD gene family members were divided into 4 subgroups, with average hydrophilicity coefficients less than 0, belonging to hydrophilic proteins, and subcellular localization was located in the nucleus; The full-length ORF frame cloned into CoIDD4 gene contained 1620 bp base and encoded 539 amino acids, which were mainly expressed in leaf and flower organs; The cis acting elements in the promoter region of the gene were mainly involved in light response and plant hormone response elements. In conclusion, this study identified 29 IDD gene family members in C. oleifera, among which CoIDD4 gene was closely related to AtIDD4/5/6. It is speculated that CoIDD4 gene may be involved in the process of hormone signal transduction and basic immune response regulation of C. oleifera, which would provide a theoretical basis for the functional analysis of IDD transcription factors in C. oleifera and provide a reference basis for the selection and molecular breeding of superior resistant varieties of C. oleifera.

In the current study, one newly recorded genera of wild orchids, Neuwiedia Blume, as well as five newly recorded species, including Goodyera brachystegia Hand. -Mazz, Neuwiedia zollingeri var. singapureana (Baker) E. F. de Vogel, Odontochilus drymoglossifolius (Hayata) T. Yukawa, O. saprophyticus (Aver.) Ormerod and O. yakushimensis (Yamam.) T. Yukawa in Fujian province were illustrated. The voucher specimens of the plants are preserved in the Herbarium of Fujian Normal University (FNU). The discovery of the newly recorded orchids has great significance for further studies on the diversity and conservation of Orchidaceae in Fujian, China.

In recent field survey and specimen examination, eight species of pteridophytes belonging to seven genera in five families are reported as new records in Fujian province, Gymnocarpium oyamense (Baker) Ching, Pronephrium parishii (Beddome) Holttum, Athyrium drepanopterum (Kunze) A. Braun ex Milde, Diplazium okinawaensis Tagawa, D. hainanense Ching, Hymenasplenium excisum (C. Presl) S. Lindsay, Asplenium ensiforme Wallich ex Hooker & Greville and Microsorum membranaceum (D. Don) Ching. Among them, G. oyamense is a newly recorded genus in Fujian province, and P. parishii, A. drepanopterum, D. okinawaensis, D. hainanense and M. membranaceum are newly recorded species in East China.