In order to understand the flora characteristics of wild seed plants in Mashan county, Guangxi, the wild seed plant resources were investigated. The results showed that there were 1504 species of wild seed plants in Mashan county, Guangxi, belonging to 170 families and 740 genera. Angiosperms were dominant and gymnosperms were relatively scarce. From the perspective of family and genus composition, monospecific families and oligospecies were the main body, while the genera and species of seed plants were concentrated in medium and large families, small genera and monospecific genera. The plant distribution area was rich in types, with obvious tropical nature and certain temperate components, showing a transitional nature from tropical to subtropical. Compared with neighboring areas, Mashan county has richer plant diversity, and its flora is the closest to Binyang county, Guangxi. In general, Mashan county is rich in plant diversity, with prominent tropical components, rich in life and mainly herbaceous plants, with ancient and young flora coexisting, and the unique phenomenon is prominent, reflecting the characteristics of the flora of the Beibu Gulf as a whole.

Root exudates are one of the important sources of plant autotoxic substances. Studies have shown that phthalic acid is a well known allelopathic autotoxic substance, and it is also one of the substances with higher content in rubber tree root exudates. In order to explore whether phthalic acid has an autotoxic effect on rubber tree, the effects of different concentrations (0.05, 0.50, 1.00, 2.00 mmol/L) of phthalic acid solutions on the seed germination and seedling growth of rubber tree RRIM600 were investigated. Phthalic acid delayed the initial germination time of rubber tree seeds, and reduced the germination rate, germination speed and uniformity of seeds germination. Compared with the control, the germination rate, germination index, germination speed, and uniformity of seeds germination of 2.00 mmol/L phthalic acid trestment decreased by 23.60%, 42.75%, 37.18%, 58.69%. All concentrations of phthalic acid treatment inhibited the growth of shoot length, diameter of shoot base, root diameter, and reduced the seedling biomass accumulation. In the concentration range of 0.05-2.00 mmol/L, the shoot length, diameter of shoot base, root diameter, shoot weight and root weight reduced by 12.91% to 40.70%, 20.05% to 21.59%, 7.89% to 34.13%, 16.18% to 26.47%, 20.00% to 36.00%. The content of soluble sugar, proline and malondialdehyde (MDA) increased gradually with the increase of phthalic acid concentration, along with the degree of cell membrane lipid peroxidation gradually increased. The pigment content and catalase (CAT) activity of rubber tree seedlings increased first and then decreased with the increase of phthalic acid treatment concentration, while peroxidase (POD) and superoxide dismutase (SOD) activities decreased with the increase of phthalic acid treatment concentration. 0.05 mmol/L phthalic acid promoted the accumulation of chlorophyll b in seedlings, decreased the content of chlorophyll a, increased the activity of CAT, reduced POD and SOD activity. When the concentration reached 0.50 mmol, the content of chlorophyll a, total amount of chlorophyll, and carotenoid accumulated to the maximum, and decreased the activities of POD and SOD, at 2.00 mmol/L, the activities of POD and SOD continued to decrease. In conclusion, phthalic acid delayed the initial germination time of rubber tree RRIM600 seeds, decreased the seed germination rate and germination rate, led to the disorder of the physiological function of rubber tree seedlings, and inhibited the growth and development. The results could provide basic data support for the evaluation of the autotoxicity of phthalic acid on rubber trees.

In order to explore the growth and branching genetic variation of Casuarina equisetifolia half-sib families at seedling stage, the annual seedlings of 40 half-sib C. equisetifolia families were used as the materials. Genetic analysis was carried out on seven traits: seedling height, ground diameter, dry weight, root shoot ratio, number of lateral branches, angle of lateral branch, and length of lateral branch. At the same time, cluster analysis and multi-trait comprehensive evaluation method were used to select excellent families. The results showed that the growth and branching traits of C. equisetifolia half-sib families at seedling stage varied widely, and the differences of the seven traits among families reached extremely significant level. The family heritability of the growth and branching traits ranged from 0.36 to 0.83, which were controlled by moderate or strong inheritance. Four excellent families, 3-265, 5-373, 1-266 and 2-343, were selected at a 10% selection rate. The real gains of seedling height, ground diameter, dry weight, number of lateral branches and length of lateral branches of the selected families was 21.14%, 19.10%, 41.83%, 19.97% and 18.88%, respectively. The genetic gains were 17.55%, 15.66%, 29.70%, 15.57% and 15.10%, respectively. The effect of selection work was remarkable. C. equisetifolia seedlings have great breeding potential among families. The excellent families selected in this study not only enrich the excellent germplasm resources of C. equisetifolia, but provide better germplasm materials for the subsequent genetic improvement and forest construction of C. equisetifolia.

Verticillium wilt, a soil-borne disease caused by Verticillium spp., is one of the most important diseases in eggplant production. It seriously affects the yield and quality of eggplant. At present, the control methods for eggplant verticillium wilt are limited to grafting and chemical controls, but neither of them can prevent the occurrence of verticillium wilt. The best way to control Verticillium wilt is to explore the verticillium wilt resistance genes in eggplant and to breed some resistant eggplant varieties with genetic engineering technology. Solanum symbriifolium Lam. is a wild eggplant in Yunnan, China with a high Verticillium wilt resistance. PR genes encode pathogenesis-related proteins, which are closely related to plant disease defense. Among them, PR10 protein is a nuclease-like protein, and the defense mechanism of PR10 protein in S. sisymbriifolium is still unclear. In this study, a wild eggplant S. sisymbriifolium was used as the experimental material. The pathogenesis related protein 10 (PR10) homologous gene was isolated and cloned by reverse transcription PCR (RT-PCR) technology from the previously established transcriptome database of S. sisymbriifolium and named as SsPR-10. The cloned sequence length of SsPR-10 was 645 bp, and its coding region was 480 bp long, encoding a protein of 159 amino acids residues in total. And the bioinformatics analysis showed that SsPR-10 protein was an acidic hydrophilic protein with a molecular mass of 17.71 kDa and a theoretical isoelectric point (pI) of 5.54. The prediction of transmembrane region and signal peptide showed that SsPR-10 protein had no transmembrane region and signal peptide. The prediction for subcellular localization showed that SsPR-10 was localized in the cytoplasm of plant cell. The results of conserved domain prediction showed that SsPR-10 contained a "P-LOOP" circle structure (sequence positions at 47-52 bp) and conserved sequence PATHOGENESIS_BETVI (sequence positions at 88-120 bp). The sequence alignment and phylogenetic tree analysis showed that SsPR-10 protein had the highest homology with PR10 protein from S. virginianum, followed by STH-2 protein from S. tuberosum. The expression of SsPR-10 gene was analyzed by real-time fluorescence quantitative PCR (RT-qPCR) experiments, and the expression level of SsPR-10 was the highest in the root than in other organs of S. sisymbriifolium, showing a tissue specificity. The expression level of SsPR-10 was multiplied to 8.16 times at 24 h after inoculation with V. dahliae, indicating that verticillium wilt might induce the expression of SsPR-10. In this study, SsPR-10 gene was cloned and its expression pattern was analyzed in the wild eggplant S. sisymbriifolium for the first time, which will provide a theoretical basis for further studying the mechanism of SsPR-10 responding to Verticillium wilt and other biological stresses.

Ardisia gigantifolia Stapf is native to Hekou county, Yunnan province, with few wild individuals, and is listed as a critically endangered species. It has important protection value and good prospect of garden development and application. The stem segments of aseptic seedlings of A. gigantifolia were used as the explants to establish a propagation in vitro. The results showed that the optimal medium for callus induction was WPM+0.50 mg/L TDZ+0.10 mg/L NAA, and the induction rate of callus was 96.67%. The optional medium for callus proliferation was WPM+0.50 mg/L TDZ and the multiplication coefficient was 4.42. The optimal medium for callus differentiation was WPM+2.00 mg/L 6-BA+0.20 mg/L NAA, and the induction rate reached 100%. The optional medium for adventitious bud proliferation culture was WPM+4.00 mg/L 6-BA, the multiplication coefficient was 3.90, and the cluster buds grew well. The optional rooting medium was WPM+10% coconut water+0.20 mg/L NAA, the rooting rate reached 100%, the root system developed well and the test-tube plantlets grew vigorously. Plantlets were transplanted into the mixture substrate with the volume ratio of perlite and peat soil of 1∶3, the survival rate was 96.67% after 60 days and plants grew well. This study can provide technical support for the large-scale seedling production of A. gigantifolia, as well as theoretical basis and technical support for the protection, seedling breeding, and molecular biology research of this species.

Self-incompatibility is a genetic mechanism to prevent self-fertilization and the consequent inbreeding and fitness decay in plant populations. In the gametophyte self-incompatibility mechanism represented by Solanaceae, Rosaceae and Plantaginaceae, the self/non-self recognition between pollen and pistil is determined by the polymorphic S locus. SLF (S-locus F-box)/SFB (S-haplotype-specific F-box) gene is the pollen S determinant of gametophyte self-incompatibility. In this study, 21 SLF/SFB family genes were screened and identified based on the genome-wide of the pineapple. Each AcSLF gene had an F-box conserved domain at the N-terminal. There were great differences in amino acid length, theoretical isoelectric point and molecular weight. The size range of the encoded amino acid sequence was 242-612 aa, and the molecular weight was 27.778-69.070 kDa. The isoelectric point ranged from 5.70 to 9.57. 18 AcSLF proteins were alkaline and most proteins were unstability, only AcSLF19, AcSLF21 were stability. It was predicted that 18 AcSLF proteins were located in the nucleus, one AcSLF protein in chloroplast, two AcSLF protein in both chloroplast and nucleus, and more than 60% of the secondary structure of the protein was composed of alpha helix and random coil. Bioinformatics analysis showed that the pineapple SLF/SFB family genes, which were unevenly distributed on 14 chromosomes, and the chromosome location of AcSLF21 was undetermined. Furthermore, AcSLF4, AcSLF5, AcSLF6, AcSLF8, AcSLF14 and AcSLF15 were linked with RNase T2 family genes, this was one of the main characteristics of pollen SLF gene. AcSLF genes contained different numbers of introns, most of which contained 1~2 introns, and AcSLF3 contained 4 introns. Based on the above analysis results, it showed that AcSLF proteins had different characteristics. Phylogenetic analysis indicated that the evolutionary relationship of AcSLFs in pineapple was far away from the SLF/SFB in Rosaceae, Plantaginaceae and Solanaceae, the degree of clustering was low on the branches of evolutionary tree. The expression levels of the AcSLF genes in pistil, stamen, leaf, sarcocarp, stem and root were analyzed by qRT-PCR. The results showed that AcSLFs had obvious expression differences in different tissues of pineapple. AcSLF1, AcSLF2, AcSLF4, AcSLF9, AcSLF10, AcSLF11, AcSLF15, AcSLF19, AcSLF20 and AcSLF21 genes were highly expressed in pineapple stamens. The expression of AcSLF3 and AcSLF7 in sarcocarp was higher than that of other tissue, and AcSLF5, AcSLF12, AcSLF18 were higher expression in root than other tissues. In general, most pineapple AcSLF genes are mainly expressed in pineapple stamens or leaves. It was found that the expression of AcSLF1, AcSLF2, AcSLF15 genes in pollinated pistil were significantly up-regulated than that in non-pollinated pistil. Especially at 6 h after cross-pollination, the expression level was significantly higher than that of non-pollinated pistils. With the extension of the pollen tube in the pistil, the expression level decreased, but it still had a high expression at 24 h after pollination. And the expression trend of AcSLF1, AcSLF2 and AcSLF15 in cross-pollination was consistent with the growth of pollen tube in the pistil. Therefore, it is speculated that AcSLF1, AcSLF2 and AcSLF15 play an important role in pineapple self-incompatibility. This is the first time to analyze the expression pattern of SLF/SFB family genes in pineapple. This study would provide a reference for the cloning of pineapple SLF/SFB family genes, and basis for the study of pineapple self-incompatibility mechanism.

Banana (Musa spp.) is one of the most popular fruits in the world and is widely loved for its sweet taste and nutritious value, it is usually eaten after ripened. Bananas are rich in more than 90% resistant starch before they are unripe, and the effective use of resistant starch in green bananas can significantly increase the added value of the banana planting industry. In addition, green bananas are prone to producing a large number of defective fruits during the harvesting process, resulting in a serious waste of starch resources. In order to study the effect of autoclaving treatment on the digestion and structure properties of flour, three different banana cultivars: Dajiao, Fenjiao, and Gongjiao were chosen. By using scanning electron microscopy, dynamic light scattering, rapid paste viscometer, differential scanning calorimetry, Fourier transform near infrared spectroscopy, and X-ray diffraction analysis. To investigate the relationship between the structural changes and digestion properties of the three green banana flours before and after an autoclaving treatment was applied to them. The content of resistant starch in green banana flour decreased from 91.50%-93.33%(RS2 type) to 39.17%-44.63% (RS3 type) after autoclaving treatment. The scanning electron microscope results showed that powder granules were completely pasted and disintegrated, with variable particle size distribution and irregular shape. The amylose starch content increased from 23.3%-28.3% to 32.7%-37.0%, so that the thermal stability and gel enthalpy of green banana flour were significantly decreased (P<0.05) while the peak viscosity and breakdown was increased. The relative crystallinity of the green banana flour decreased from 28.98%-32.56% to 20.66%-22.26% after the autoclaving treatment. Despite this, the B-type crystalline structure was still preserved after the treatment. The new chemical bonds or functional groups were not found after the autoclaving treatment compared with green banana flour, and the short-range order R_1047/1022 was decreased from 1.031-1.166 to 1.016-1.122. The findings revealed that although the content of the resistant starch was reduced after autoclaving treatment, the type of resistant starch was changed from RS2 to RS3. This suggests that the stability of the resistant starch is greatly enhanced after autoclaving treatment. This research could offer a theoretical foundation for the production of heat-stable banana resistant starch, support the development of naturally starch-based materials, and is crucial for resolving the disparity between banana industry production and sales.

Starch branching enzyme (SBE) play a key role in amylopectin biosynthesis and directly influence the content and structure of starch. Taro is a major tuber crop, widely cultivated in tropical and subtropical regions of the world. At present, there are few studies on SBE in taro, and the number, molecular structural characteristics and expression patterns of SBE genes in taro are not clear. In this study, a comprehensive analysis of taro SBE genes was conducted for the first time, and three SBE genes (CeSBE1, CeSBE2 and CeSBE3) were identified. The amino acid numbers of CeSBE1, CeSBE2 and CeSBE3 proteins was 828, 845 and 598, respectively, with molecular mass of 92 956.71 Da, 95 625.13 Da and 69 169.16 Da, and isoelectric point of 5.22, 5.41 and 7.36, respectively. Phylogenetic analysis showed that the three CeSBE proteins were divided into three different subgroups. Gene structure analysis showed that the number of CeSBE1, CeSBE2 and CeSBE3 exons was 16, 22 and 10, respectively. Conservative structural domain analysis showed that both CeSBE1 and CeSBE2 proteins had α-amylase_C and α-amylase structural domains and 7 motifs, while CeSBE3 protein had α-amylase and CBM_48 structural domains and 3 motifs. Analysis of cis-acting elements in the promoter region of CeSBE gene showed that a total of 55 cis-acting elements were predicted, 29 of which were functionally annotated, involving elements related to light response, hormone response, plant growth and development, and environmental stress. The three CeSBE genes were expressed in all tissues, with CeSBE2 being significantly expressed in corms and leaves (P<0.05). At different developmental stages of the corm, CeSBE2 had high expression at all developmental stages, showing a trend of increasing and then decreasing expression, with peak expression at 120 d of corm development. The increase in total starch and amylopectin content at different developmental stages of the corm was consistent with the trend of CeSBE2 expression, suggesting that CeSBE2 may be a key gene for amylopectin biosynthesis in taro. The study would enhance the understanding of CeSBE gene family members and provide the basis for genetic improvement of yield, quality and nutritional traits in taro.

In order to clarify the differences and similarities in climate conditions between major cigar producing areas in China and dominant cigar producing areas in foreign countries, this study selected 17 major cigar production areas in Hainan province, Yunnan province, Sichuan province and Hubei province of China, as well as the dominant major cigar production areas in foreign countries, including Pinar del Rio in Cuba, Santiago in Dominica, Jember in Indonesia and Bahia in Brazil. General statistical analysis and cluster analysis were used. The differences of six key meteorological factors including monthly average temperature, maximum temperature, minimum temperature, rainfall, relative humidity and difference in temperature in the field period, the drying period as well as the whole growing season of cigar production in the 17 production areas were studied. There was no significant difference in the overall climate conditions of the field period, drying period and the whole growing season between domestic and foreign major cigar producing areas, while the differences in the four meteorological factors of the maximum temperature, minimum temperature, rainfall and difference in temperature in the whole growing season between domestic and foreign major producing areas reached the significant level (P<0.05). Among them, the differences of the three meteorological factors of maximum temperature, minimum temperature and difference in temperature reached the level of extremely significant (P<0.01). Taking the Euclidean distance of 15 as the critical value, the 17 major cigar producing areas in the field period could cluster into four categories, the 17 major cigar producing areas in the drying period could cluster into three categories, and the 17 major cigar producing areas in the whole growing season could cluster into two categories. The results of this study would provide a scientific basis for major cigar producing areas in China to learn from dominant cigar producing areas in foreign countries in planting layout, variety selection and quality improvement, and also provide a data basis for climate assessment and variety optimization of cigar growing areas in China.

Cellulose is one of the main components of plant roots, and plays a key role in lodging resistance. CesA7 is for cellulose synthesis, but its function is unknown in sugarcane. Rice OsCesA7 gene was used as the reference sequence to conduct homology analysis and functional prediction in the genomes of Sacchrum spontaneum, S. hybrid and S. officinarum. Phylogenetic analysis showed that CesA7 in S. hybrid was closer to that in S. officinarum, and grasses were clustered together, but herbs and woody plants could not be separated clearly. The promoter region of the sugarcane CesA7 genes had abundant light-responsive elements and methyl jasmonate element, indicating that the gene may be involved in the photomorphogenesis and the stress resistance response in sugarcane. Interaction prediction of the protein and analysis of the promoter indicated that CesA7 had interaction with MYB transcription factor, suggesting that CesA7 played a role in crop growth and development and stress response. In addition, functional predictions of CesA proteins in rice and sorghum showed involvement in regulating cellulose synthesis and lignin degradation processes. Transcriptomic analysis of roots and leaves of seven representative species of sugarcane at seedling stage revealed that CesA7 expression level in roots was much higher than that in leaves, suggesting that CesA7 might regulate sugarcane root development. The SNP variation of the gene was detected in the germplasm of sugarcane, and the nucleotide diversity was the highest in S. spontaneum. The nucleotide diversity in the exon region was significantly higher than that in the intron region, and the highest diversity was found in the region of exon 4 (about 2000 bp) of the gene. It is speculated that the functional differentiation of different alleles are caused by the balancing selection of this locus. After multiple sequence alignment combined with resequencing data analysis, two potential molecular markers were identified, which could distinguish S. spontaneum and S. officinarum samples. The study would provide theoretical guidance for subsequent research and use of CesA7 gene to improve sugarcane variety.