In order to select urban greening plants with excellent dust retaining capability, seven species of shrubs, including Allamanda cathartica, Duranta erecta 'Golden Leaves', Ficus microcarpa 'Golden Leaves', Hibiscus rosa-sinensis, Ixora chinensis, Pittosporum pentandrum var. formosanum and Heptapleurum arboricola, growing in the road green belt of University Road in Nanning, were studied to observe the leaf morphology and the ultrastructure characteristics of leaf epidermis, and collected and measured the dust retaining capability per unit leaf area at the same time. The results revealed that the plant leaves had more dust retaining in winter than in summer in this section of the road studied, and that dust particles greater than PM₁₀ were accumulated more than PM₁₀ or PM_2.5. Among the species studied, D. erecta GL had the most outstanding ability of dust retaining, I. chinensis and H. rosa-sinensis were more dust retaining capability with particle diameters more than PM₁₀, while F. microcarpa GL and P. pentandrum var. formosanum had more clear advantage in dust retaining with fine particles such as PM₁₀ and PM_2.5. According quantified principal component analysis, the five characteristic including: whether the leaf blade was hairy or not, leaf margin type, the number of primary lateral veins, the netting status of the terminal lateral veins and the distribution status of the leaf veins on the leaf surface contained most of the information on the relationship between leaf morphological traits and dust retaining capability. Among the ultrastructure features of the leaf epidermis, projecting anticlinal wall of the upper epidermal cell and granular ornamentation of waxy layer contributed to stronger dust retaining than flocculent ornamentation of waxy layer. Striped ornamentation of cuticle that was too thick or too thin and neatly arranged were not benefit to dust retaining. And the cuticle of the outer edge of stomatal outer arch of the lower epidermis of the leaf had a multilayered ring structure which facilitating the adhesion of more dust particles. The findings of this study could help to provide a reference for the selection of plants for greening and air purification in different types of atmospheric pollution environments and give us a theoretical basis for the study of plant dust retaining. In the strategy of dust retaining, seven plants showed some differences in the macro-morphological characteristics of leaves and ultrastructure of epidermis. D. erecta GL had the largest dust retaining capability, various leaf colors and outstanding landscape effects, so it is worth popularizing. In the dust environment dominated by large particulate matter, I. chinensis and H. rosa-sinensis are recommended, while in the environment with fine dust particles, F. microcarpa GL and P. pentandrum var. formosanum can be planted more.

In this study, seven LysM-RLK subfamily genes were systematically identified in the whole genome of papaya using bioinformatics methods, and the chromosome distribution, gene structure, protein physical and chemical properties, and subcellular localization information were analyzed. Familial evolutionary analysis showed that papaya LysM-RLK could be further divided into three subgroups (Lym-Ⅱ, Lym-Ⅲ, Lym-Ⅳ), distributed on four chromosomes. Recent gene replication is the main driver of the evolution of the papaya LysM-RLK subfamily. The analysis of promoter sequence regulatory elements found that it contained multiple photoresponse elements and elements involved in low temperature response and stress related hormone signal response. Large-scale comparative transcriptome analysis systematically analyzed the gene expression patterns of LysM-RLK under papaya biostress and abiotic stress and different tissues, revealing its specific expression patterns and potential biological functions. The expression differentiation of replicating gene pairs, differences in domain composition, and changes in the tertiary structure of proteins suggest subfunctionalization in the process of evolution. Core co-expression network analysis under biotic and abiotic stress conditions identified 27 core genes strongly associated with LysM-RLK3, revealing the potential transcriptional regulatory patterns of LysM-RLK3. The results would provide important insights into the evolution, functional differentiation and role of the papaya LysM-RLK subfamily in adversity response and growth and development.

To confirm the characteristics and difference of the chloroplast (cp) genome of Colocasia esculenta var. Redbud and Colocasia esculenta var. Lipu, the two taros were taken as experimental materials in the study, their genomic DNA were first extracted form fresh leaves using an improved CTAB method and the two complete cp genomes were obtained using high-throughput sequencing technology and bioinformatics analysis, simple sequence repeat (SSR) identification, multiple sequence alignment, sliding window analysis on DNA polymorphism and phylogenetic tree analysis were then conducted on two complete cp genomes. The results showed that the length of the complete cp genomes of Redbud and Lipu was 162 478 bp and 162 453 bp, respectively, exhibiting the typical cyclic quadripartite structure. A total of 131 genes were annotated both in the two, including 86 protein-coding genes, 37 tRNA genes and 8 rRNA genes, of which 18 genes had two copies and 23 genes had introns. A total of 130 and 124 SSR sites were identified in Redbud and Lipu respectively, the content of A/T in the SSR repeats was 63.08% and 61.29% respectively. 15 SSR polymorphic primers were identified. A total of 236 cp single nucleotide polymorphism (SNP) sites were detected between Redbud and Lipu, of which 26.7% were in the gene coding region, which leading to 25 missense variant genes, the variation of the genes may promote the difference between the two varieties. Compared with the representative species from 13 genus of Aroideae showed that the structure, types, and numbers of gene were relatively conservative. The trnS-trnG and ndhF-rpl32 were the highest variation sites in SSC and LSC region, respectively. The phylogenetics analysis using maximum likelihood method (ML) showed that the genus Colocasia had the closest relationship with the genus Steudnera, but the farthest relationship with the genus Sauromatum in the Ariodeae. The results would provide a theoretical basis for the germplasm resource exploitation, genetic diversity evaluation and phylogenetic analysis of C. esculenta.

Cyperus esculentus is a special oil crop, with its underground tuber accumulating a large amount of oil, and also having the advantages of wide adaptability and strong stress resistance. This crop is a superior germplasm material for studying plant stress resistance and oil enrichment in the underground vegetative organs. Transport inhibitor response protein 1 (TIR1) can regulate plant growth and development and abiotic stress response as an auxin receptor. However, few reports on CeTIR1 have been reported. In this study, four TIR1 genes, namely CeTIR1-1, CeTIR1-2, CeTIR1-3 and CeTIR1-4, were identified from C. esculentus transcriptome data and the ORFs were further cloned by RT-PCR. All the four CeTIR1 proteins contained a typical F-box protein domain, AMN1 superdomain and Transp_inhibit domain, revealed by bioinformatics analysis. No significant difference was detected among the four CeTIR1 proteins in regarding sequence length, relative molecular weight, isoelectric point and other physicochemical properties. The four CeTIR1s were closely related to TIR1s derived from plants of Cyperaceae, Oleaceae and Cruciferae in the evolution. Gene expression profiling showed that the expression levels of CeTIR1 family genes were significantly different in different tissues of C. esculentus, with the highest expression in tuber tissues and lower expression in root and leaf tissues. The antioxidant enzyme activity and MDA content of C. esculentus seedlings increased under salt stress. After adding exogenous IBA treatment, the antioxidant enzyme activity of C. esculentus seedlings under salt stress further increased whereas the MDA content decreased. This indicated that IBA could alleviate the adverse effects of salt stress on the growth of C. esculentus seedlings. qRT-PCR results showed that expression levels of the four CeTIR1 genes increased in C. esculentus seedlings treated with salt stress, and exogenous addition of IBA could significantly up-regulate the expression of CeTIR1-2 gene. Comprehensive analysis demonstrates that CeTIR1-2 may be an important gene involved in regulating the response of C. esculentus seedlings to salt stress. Together, the results would provide the scientific basis and important reference for exploring the related function genes involved in auxin regulating the growth and development and stress resistance of C. esculentus, as well as the C. esculentus cultivation in the saline-alkali land.

In order to reveal the genome characteristics of HNU24, which has excellent antagonistic ability to Ralstonia solanacearum, its complete genome was sequenced by the BGISEQ-500 and ONT PromethION technology, and the genome assembly, gene prediction, function annotation, and protein homology analysis also were conducted. Phylogenetic analysis results demonstrated that HNU24 belonged to Bacillus velezensis. Its completed genomic sequence length was 3 932 768 bp, GC content was 46.48%, and had 3822 genes. A total of 43 carbohydrate active enzyme gene families were identified in the genome, and the cellulase activity experiment further confirmed that the strain HNU24 had the ability to degrade cellulose. Thirteen clusters of secondary metabolite biosynthesis genes were predicted in genome, including eight compounds: surfactin, fengycin, plantazolicin, butirosin A/butirosin B, macrolactin, bacillaene, difficidin, bacillibactin and bacilysin, which have been reported as the antibacterial components. Five unknown components, which were found no homologous genes or were less similar to the known database sequences, may be new compounds that have not been identified and reported. In addition, greenhouse experiment demonstrated that HNU24 had significant growth promoting effect on tomato plants. Thus, HNU24 may antagonize R. solanacearum and promote tomato growth by secreting active compounds, and it is a potential biofertilizer strain. The relevant results would lay a foundation for further research and application of HNU24 in biological control.

Two genuses and species of Orchidaceae, Taeniophyllum glandulosum Blume and Tainia dunnii Rolfe, together with other two species, Bulbophyllum henanense J. L. Lu and Goodyera yangmeishanensis T. P. Lin, were reported as new records to Hubei province. The morphological characteristics were briefly described, and color photos were provided. The new records enrich the wild orchid resources and are of great significance for further study of orchid plants and biodiversity conservation in Hubei province.

Trachoma Garay, originally described from northern India, was recently collected from Motuo, Tibet Autonomous Region, China. The flowers are similar to those of Tuberolabium Yamamoto, but in that genus the flowers open simultaneously along an elongate rachis and with deeply cleft separated by a hyaline flange poliionia, whereas in Trachoma they open in successive clusters on an abbreviated rachis and with entire or obscurely sulcate pollinia.

In three Camellia vietnamensis producing areas of southwest tropical rainforest in Hainan Province, Baomeiling Ecological Protection Reserve (JB), Bawangling Gibbon Reserve (QS), and Jiangpai Village (XS), Baisha Li Autonomous County, 22 high-yielding single strains were selected, for primary screening and comparison. Observe fruit yield per unit area, oil content rate of fresh fruit, grude oil yield per unit of crown area, peroxide value, iodine value, acid value, saponification value and the contents of palmitic acid, stearic acid, oleic acid, linoleic acid, myristic acid, palmitoleic acid, linolenic acid, arachidic acid, eiconsenoic acid in seed oil for 3 years, after the data was treated with the methods of ANOVA, gray association analysis, and cluster analysis, then screen out the more superior single strains. There existed significant difference in grude oil yield per unit of crown area, oil content rate of fresh fruit and fruit yield per unit area, among them, fruit yield per unit area might be the key indicator of high-yield screening. The physicochemical nature and fatty acid content of camellia seed oil both meet the requirements of "oil-tea camellia seed oil" (GB/T 11765—2018), but there existed some significant difference in some indicators, and there existed the linear correlations between some saturated and unsaturated fatty acids, then there existed the phenomena of the saturated acids changed into unsaturated acids, indicating that the camellia seed oil has no quality problems, and the different tree had its specific characteristic, so the breeding target should be mainly high yield and stable yield, and iodine value, saponification value and the contents of oleic acid might be the effective indicators for selection. Known from the grey association analysis data, the single strains with superior integrated traits were successively JB2, JB7, QS6, JB1, QS5, XS2, JB4, XS4, JB9 and XS5 respectively; Known from the clustering results, it is better to gather all the individual strains into 9 categories (r=0.904), among them, the top seven single strains of comprehensive traits were clustered in Ⅰ, Ⅸ,Ⅶ and Ⅵ respectively, indicating it was expected to screen out the characteristic diverse varieties. JB2, JB7, QS5, XS2 and XS4 belonged to the expected individual strains whose comprehensive behaviors in economic traits were excellent, and JB2 among them was the best one and rare.

In this paper, a combination of traditional morphological features and modern molecular phylogenetic analysis was used to identify and describe a gasteroid fungus collected from Guangdong. The studied specimens is Asperosporus subterraneus Karlsen-Ayala, Gazis & M.E. Sm., a member of the new genus Asperosporus Karlsen-Ayala, Gazis & M.E. Sm. of Agaricaceae which newly reported from Florida, USA, and firstly reported from China. A. subterraneus was mainly characterized by its irregular spherical basidiomata, white to grayish white at first, then becoming brownish when mature, rapidly stain pinkish-red when cut or bruised, earthy smell, Basidiospores, 14-18 μm×11-16 μm, broadly elliptical to subglobose and thick-walled basidiospores ornamented with larger pyramidal to irregular warts, turn to orange brown in 5% KOH solution and dark brown when added to Melzer solution, and the spores were often attached with sterigma remnants. Specimens were deposited in the Fungarium of Guangdong Institute of Microbiology (GDGM).

Three tapping time during the daytime of six rubber cultivars was set to explore the rubber yield, latex quality and raw rubber properties of different rubber varieties. The two-way analysis of variance showed that rubber production was significantly affected by the interaction between tapping time and rubber variety, and the response of each physiological parameter to the variety was significantly different, but there was no significant difference to the tapping time. The most suitable time for daytime rubber tapping is 6:00 am in the three daytime rubber tapping time treatment. Reken 524 and Reken 525 were the most suitable daytime rubber tapping variety judged by latex volume, dry rubber yield and physiological parameters. 7-33-97 and Reken 501 were the most suitable daytime rubber tapping variety judged by common raw latex properties. Considering the purpose of improving labor efficiency and increasing the income of rubber workers, Reken 524 and Reken 525 could be used for daytime rubber tapping at 6:00 am during the peak rubber production period in Maoming Reclamation Area, Guangdong, China.