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.

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.

For the study of Hainan Island typical farmland soil fertility conditions, the forest land, cultivated land, garden land and grass land of Hainan, China under the type of soil pH, mechanical composition, organic matter, cation exchange capacity, total nitrogen, alkali solution nitrogen, total phosphorus, effective phosphorus, total potassium were determined and statistically analyzed. Based on "the second soil census nutrient classification standard", the Nemerow Index Method was used to evaluate the comprehensive soil fertility of each land use type. The results showed that nitrogen content was deficient in different land use types. The phosphorus content was abundant or very abundant. Potassium content was abundant in woodland and cultivated land, moderate in garden land, and deficient in grassland. In the four types of farmland, and cation exchange capacity of soil organic matter, total nitrogen, hydrolyze nitrogen were significantly correlated (P<0.05) or extremely significant correlation (P<0.01), soil cation exchange capacity and total nitrogen and hydrolysis nitrogen showed strong correlation, and other soil nutrient showed virtually no correlation or weak correlation. The corresponding comprehensive soil fertility of the four land types was in the order of garden land (1.164)>forest land (1.058)>arable land (0.879)>grassland (0.784). The comprehensive soil fertility of garden land and forest land was average, while that of arable land and grassland was poor. Therefore, we should strengthen land management, rational use of land, improve soil nutrient structure, and finally improve land productivity.

In order to screen out the key metabolites that control the fragrance of areca nut, enhance the fragrance of areca nut, attract more pollinators, and then increase the yield of areca nut. In this study, Headspace Solid Phase Microextraction Gas Chromatography-Mass Spectrometry Combined Analysis Technology was used for non-targeted metabolomic detection of areca nut flowers in different periods. 236 metabolites were detected in the study. 75 differential metabolites were screened by combining VIP value and differential fold. Main metabolites were terpenes, ketones, alcohols. Among them, the volatile compounds of female flowers of Areca accumulated a lot from the female flower unopened stage to the initial blooming stage, and decreased slightly in the full bloom stage, so the initial blooming stage of female flowers of Areca may be the key period for the formation of female flower fragrance. The volatile compounds in the male flowers of Areca accumulated a lot from the initial blooming stage to the blooming stage, so the blooming stage of male flowers may be the key period for the formation of flower fragrance of male flowers of Areca. KEGG database was used to analyze the metabolic pathways of differential metabolites. The fatty acid biosynthesis was the metabolic pathway that was significantly enriched in the female flowers of areca nut and related to flower aroma synthesis, and the substance enriched in this pathway was capric acid. Capric acid is a fatty acid, which is mostly used in plant physiology and signal transmission and other functions. The capric acid content in the female flowers of betel nut increased from the unopened stage to the early flowering stage, and the release of floral fragrance also increased correspondingly. This may be because areca nut starts pollination at the beginning of female flower, and more chemical signals are needed to be transmitted to attract pollinators. So capric acid may be a chemical signal released by betel nut female flowers for pollination. Metabolic pathways significantly enriched in male areca nut flowers and related to flower aroma synthesis are diterpenoid biosynthesis and fatty acid degradation. Palmitaldehyde and (4aR,6aS,9R,11aR,11bR)-4,4,11b-trimethyl-8-methylene tetrahydro-6a and 9-methylcycloheptyl [a] naphthalene were enriched in two pathways. (4aR, 6aS,9R,11aR,11bR)-4,4,11b-trimethyl-8-methylenetetrahydro-6a,9-methylcyclohept[a]naphthalene is a terpenoid. Its enantiomer, ent-kaurene, is synthesized by ring-opening of trans-geranylgeranyl pyrophosphate with the use of kaurine synthase and is a precursor ofgibberellin. The content of this substance was down-regulated from the early flowering period to the full bloom period of male flowers, which may be due to the decrease of the required gibberellin content in male flowers during the full bloom period. Palmitaldehyde is an aldehyde substance, which is a metabolite released by the biodegradation of fatty acids. The release of the fragrance of areca nut male flowers increased from the early blooming stage to the blooming stage, and the content of palmitaldehyde also increased. There is a positive correlation between these two situations. In conclusion, the above three metabolites may be the key metabolites that affect the fragrance of areca nut.

The biological activity of loquat exosomes and cytosol on human skin cells in vitro was explored to provide a scientific basis for the development of skin care products. The loquat exosomes and cytosol were obtained by ultra-high-speed centrifugation and mechanical disruption, respectively. Firstly, the effect of different concentrations of loquat leaf-derived exosomes (loquat leaf-exo), loquat cell suspension culture-derived exosomes (loquat suspension-exo) and loquat cell suspension culture-derived cytosol (loquat suspension-cytosol) on cell viability of human skin fibroblasts (HSF) was detected by the CCK8 method. And then, HSF cells were treated with LPS (lipopolysaccharide) for inflammation modeling, and the concentration that significantly promoted the cell survival rate was selected, followed by adding exosomes or cytosolic treatment to detect cell apoptosis and migration ability. Secondly, the melanoma cells (A375) were subsequently treated with exosomes or cytosol, and the melanin content and tyrosinase activity were detected. The concentration of exosomes per gram of loquat leaves was 8.54×10⁹ particles, and the particle size was 86.78 nm; each milliliter (approximately equal to 1 g) of loquat suspension cells contained exosomes with a concentration of 8.67×10⁸ particles, with a particle size of 80.39 nm. At the concentration level of 20 μg/mL, loquat leaf-exo, loquat suspension-exo, and loquat suspension-cytosol all significantly increased the survival rate of HSF cells in vitro (P<0.05). Compared with the positive control (LPS treatment group), loquat leaf-exo at 20 μg/mL, loquat suspension-exo at 20 μg/mL and loquat suspension-cytosol at 10 μg/mL significantly reduced the apoptosis induced by LPS treatment (P<0.01), both significantly promoted cell migration (P<0.05). 5 μg/mL loquat suspension-exo and loquat suspension-cytosol could significantly reduce the melanin content of A375 cells in vitro, and loquat suspension-cytosol could also significantly reduce the tyrosinase activity (P<0.05).

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.

To study the physiological characteristics of high light efficiency in cassava cultivar Ku50, W14, a wild type, wild relatives of A4047 and cultivated species of Ku50 were used as the materials to investigate the character of photosynthetic physiology during different varieties of cassava by measuring the photosynthetic pigment content on functional leaves, net photosynthetic rate (including the photosynthetic rate curve under different light intensity and photosynthetic daily variation) and chlorophyll fluorescence parameters (including mainly the actual photosynthetic efficiency of PSⅡ-Y(Ⅱ), and non-photochemical quenching-NPQ). The result showed that the content of various photosynthetic pigments in Ku50 was significantly higher than that in W14, but no significant difference with that in A4047, suggesting that Ku50 and A4047 may have higher photosynthetic carbon fixation capacity. The net photosynthetic rate of Ku50 was slightly higher than that of A4047 and much higher than that of W14 on the photosynthetic daily variation and Ku50 and A4047 had no obvious midday photoinhibition phenomenon while W14 had, suggesting that Ku50 and A4047 may have higher light conversion efficiency and stronger resistance to high light. The photosynthetic rate curve under different light intensity showed that three varieties of cassava all did not arrive the light saturation point up to the maximum light intensity of 2500 μmol/(m²·s), and the net photosynthetic rate also showed Ku50>A4047>W14. Among them, Ku50 was about 40 μmol/(m²·s), A4047 was about 34 μmol/(m²·s), but W14 was only about 15 μmol/(m²·s). This result was consistent with photosynthetic daily variation and also suggested that Ku50 had stronger resistance to high light and higher light energy conversion efficiency. In addition, the chlorophyll fluorescence parameters were measured to analyze the absorption, distribution and utilization of light energy in different varieties cassava. The result showed that under high light the Y(II) of Ku50 was significantly higher than that of W14, but slightly higher than that of A4047 which had no significant difference (P>0.05). And the NPQ of Ku50 was significantly lower than those of W14 and A4047, indicating that the light energy dissipated into heat on Ku50 was lower than those of W14 and A4047, which in turn proved that the light energy conversion efficiency of Ku50 was higher than those of W14 and A4047, and which was consistent with the results of photosynthetic pigments content and net photosynthetic rate. In conclusion, this research proved that high light efficiency in cassava cultivar Ku50 was induced by high light, and had higher tolerance and utilization rate to high light than wild type of W14 and wild relatives of A4047.

The pepper is a widely cultivated vegetable and its domestication and dissemination history have received significant attention from the academic community. This article summarizes the pathways of pepper's dissemination worldwide. The wild pepper species originated in the northwestern part of the Andes Mountains in South America and expanded, spread, and evolved in South and Central America. The Capsicum cultivars migrated outward from Mexico and underwent parallel domestication in multiple regions. After Christopher Columbus brought peppers back to Spain from South America, they began to spread to other European countries and eventually spread throughout Central Europe by the mid-16th century. Simultaneously, a large number of pepper varieties introduced into Asia, Africa, and Eastern Europe via the "Eurasian Trade Route" and the "Galleon Trade Route". The prevalent slave trade in the 17th century further facilitated the comprehensive dissemination of peppers in Africa and North America. With the development of global trade, the Capsicum cultivars from different regions were exchanged more extensively. Among them, C. annuum spread to Asia, Africa, North America, Oceania, and Eastern Europe, becoming the most widely cultivated peppers worldwide. C. frutescens and C. chinense were introduced to Eastern Europe, tropical regions of Africa, and Asia, while C. baccatum and C. pubescens are mainly grown in Central and South America, Indonesia, and South Africa. Genomic research results have provided important genetic evidence for the global dissemination history of pepper, while also offering a new perspective for the study of pepper evolution.

Trichoderma spp. is an important biocontrol microorganism in the fungal disease prevention and control of green agriculture. Which is widely developed as Trichoderma agent for biological control, biofertilizer and soil amendment. The development of traditional Trichoderma fungicide is limited to the screening of Trichoderma strains and the optimization of fermentation conditions. Therefore, it is necessary to explore a new application mode of Trichoderma. Due to intolerance to storage and high costs of transportation and development, coconut water is often directly discarded as waste in the production of coconut industry. In this study, coconut water was compounded with Trichoderma spores and medium elements as water-soluble fertilizers to explore the effects on seed germination and seedling physiological indexes of cucumber. The results showed that adding medium element to coconut water and adjusting pH to 7 had the best effect on the production of Trichoderma spore, and the sporulation reached 2.32×10⁷ CFU/mL. The treatment group A of water-soluble fertilizer compounded with medium element in Trichoderma spp. and coconut water and treatment group B of water-soluble fertilizer compounded with Trichoderma spp. and coconut water significantly promoted the germination of cucumber seeds, and the germination rates of cucumber seeds was 94.44%and 87.50%, respectively, compared with sterile water (CK), which increased by 28.30% and 18.87%, respectively. Pot experiment showed that the plant height and root length of treatment group A was 24.01 cm and 27.76 cm, respectively, which was 48.03% and 47.27% higher than those of CK, which significantly promoted the growth of cucumber seedlings. At the same time, the fresh weight and dry weight of stem and root of cucumber seedlings in treatment group A were also significantly higher than those of CK. Further, we determined the content of total chlorophyll, reducing sugar and soluble protein, the activity of peroxidase (POD) and catalase (CAT) of cucumber seedlings in treatment group A, compared with CK, which increased by 97.46%, 66.32%, 58.85%, 32.67%, and 40.31%, respectively; and the content of malondialdehyde (MDA) was significantly decreased, which was 79.96% lower than that of CK. In summary, the treatment group of water-soluble fertilizer compounded with medium element in Trichoderma spp. and coconut water could significantly promote cucumber seed germination and seedling growth, improve the contents of total chlorophyll, reducing sugar, soluble protein, POD and CAT activity, decrease MDA content of seedlings, and enhance the ability of cucumber to resist stress.

Noni fruit is a characteristic fruit of Hainan with a variety of medicinal effects, but there are few studies on its plant proteins. In the present study, two-dimensional gel electrophoresis (2-DE gel) technology based on the BPP+phenol extraction method was used to extract and separate the proteins of noni fruits at different ripening stages including bud stage, half ripe stage, and mature stage by optimizing the experimental conditions to obtain the fingerprint of plant proteins. The gel images were analyzed by Image Master 5.0 software and some proteins with high expression were screened out. The enzymatic hydrolysates of the proteins were further identified by using MALDI-TOF-MS technology. The functional analysis of the highly expressed proteins of three kinds of noni fruits were preliminarily carried out by bioinformatics methods. The results indicated that there were respectively forty four, forty nine, and forty highly expressed proteins at three maturites noni fruits. Among the proteins, there were respectively thirty three, twenty two and thirty nine proteins by mass spectrum identification, which subordinated to various types of protein with different plant functions. Moreover, significant difference existed in the highly expressed proteins of different maturity stages, which involved in a variety of proteins such as chloroplastic ligase, cysteine proteinase, protein kinase, ubiquitin ligase, and auxin response factors. It could provided a scientific and reasonable theoretical guidance for the further development and utilization of the plant protein of noni fruits.