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).

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.

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.

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.

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.

Exploring the characteristics of dry-wet climate change and its impacts on crop yield can provide scientific basis for agricultural production planning and meteorological disaster prevention under climate change. Based on the daily ground observation data of meteorological stations in Zhanjiang area from 1960 to 2020 and the statistical data of rice, sugarcane and peanut yields from 1990 to 2020, the aridity index calculated by reference crop evapotranspiration (ET₀) and precipitation were used as drought index to analyze the characteristics of dry-wet climate change, and the impact of dry-wet climate change on crop yield was analyzed. The results showed that the interannual variation of precipitation in Zhanjiang area fluctuated greatly, and the annual average precipitation was 1534.41 mm, showing an insignificant rising trend. The temperature rised significantly at the rate of 0.18 ℃/10 a, and the annual average ET₀ and aridity index was 1242.72 mm/a and 0.87 respectively, showing an insignificant upward trend. According to the annual variation of the dryness index, from January to April and from October to December were the drought prone periods in Zhanjiang. The yield of rice, sugarcane and peanut showed a significant growth trend in the past 31 years, the increase of aridity index in April would reduce the yield of the three crops. The increase of aridity index in May would significantly increase the yield of peanut, but had no significant impact on the yield of the other two crops. The increase of temperature and the decrease of precipitation in June were conducive to the significant increase of rice and peanut yield. Sugarcane yield was not significantly affected by the change of temperature and precipitation, while the increase of dryness index in December significantly increased sugarcane yield. The results are of great significance for Zhanjiang and its surrounding areas agriculture to cope with climate change and improve the crop potential productivity.

Mango is known as the "king of tropical fruits" for its unique flavor and rich nutrition. However, mango is extremely perishable during postharvest ripening, and the decay loss caused by anthracnose is the most serious. Therefore, how to prevent and control mango anthracnose after harvest has become a bottleneck problem restricting the healthy development of mango industry. In this paper, Tainong No.1 mango was used as the experimental material, and the green cinnamon essential oil composite chitosan lotion was used as the treatment means to study its control effect and mechanism on postharvest mango anthracnose, which would provide theoretical basis and practical reference for the development of postharvest mango storage, transportation and preservation industry in China. The results showed that the treatment of 0.5% cinnamon essential oil+0.3% chitosan had the best control effect on mango anthracnose, the treatment of 0.03% cinnamon essential oil could completely inhibit the growth and spore production of mango anthracnose in vitro, and the treatment of 0.01% and 0.02% cinnamon essential oil had obvious destructive effect on mango anthracnose mycelium. The complex treatment significantly inhibited the expansion of mango anthracnose disease spot, increased the content of disease resistance related substances lignin, total phenol (TP) and hydrogen peroxide (H₂O₂), and increased the content of disease resistance related enzymes phenylalanine ammonia lyase (PAL), peroxidase (POD),β-1,3 glucanase (β-1,3-GA) and chitinase (CHI). It can be seen that cinnamon essential oil composite chitosan lotion has a good control effect on mango anthracnose by inhibiting or destroying the growth and spore production of mango anthracnose mycelium, and inducing mango fruit to improve disease resistance. Therefore, the proper concentration of cinnamon essential oil combined with chitosan lotion treatment would provide a new green way to control mango anthracnose after harvest.

Leaf anatomy, plant growth traits and leaf ecological stoichiometry were analyzed in 8 pineapple cultivars (Gold diamond, Red skin, Red fragrant, Hand torn, Gold, Bali, Watermelon, and Mango) in a common garden in Jiangmen, Guangdong, China. The purpose was to explore the differentiation of functional traits between different pineapple cultivars, and the relationships between leaf ecological stoichiometry and plant growth as well as the plant nutrient limitation. The results showed that leaf stomatal density was the highest in the middle of leaves in most pineapple cultivars, and leaf thickness increased from the upper position to the lower position. There were significant differences in stomatal density, guard cell length, leaf thickness and anatomical proportion in different leaf positions within the same cultivar or in the same leaf position between different pineapple cultivars. Different pineapple cultivars differed in the leaf C, N, P and K content. Pineapple plants required large amount of K, as leaf K content was much higher than N and P content. Leaf N and P content in pineapples were lower than those in grassland plants in China. The leaf content of N and P of pineapple was higher than that of the plants in grasslands and in farmland ecosystems in China, while the leaf content of C, C∶N and C∶P were higher than those of the plants in grasslands and in farmland ecosystems in China, indicating that pineapple plant is reducing the dependence on nutrients through special leaf morphological or histological structure, agreement with the "Demand reduction strategy". Moreover, leaf C content, C∶P and N∶P were significantly negatively correlated with total leaf biomass, which was consistent with the growth rate hypothesis. Ranging from 6.40 to 19.07 across all pineapple cultivars, leaf N∶P values indicated that plant growth of Golden and Mango pineapples were limited by P; Golden diamond, Red skin, Hand torn and Watermelon pineapples were restricted by N, while Red fragrant and Bali pineapples were co-limited by N and P. This study twould provides a theoretical foundation for the cultivar selection and the agricultural management of pineapples.

Carica papaya L. belongs to Caricaceae, Brassicales, which is widely distributed in tropical and subtropical areas. In our previous study, the major constituent of C. papaya seeds essential oil was benzyl isothiocyanate (BITC) with a content of up to 99%. It had many advantages such as natural, non-pollution, high purity and strong antifungal activity against Candida strain. However, the application of BITC in pharmaceuticals, food industry and other fields is limited due to its poor aqueous solubility, volatility and easily degradation. In this study, in order to increase the stability and anti-Candida efficacy of BITC, nanostructured lipid carrier loaded with benzyl isothiocyanate from C. papaya seeds (BITC-NLC) was prepared by the melting emulsification ultrasonic method. The physicochemical properties such as morphology, particle size, Zeta potential, encapsulation efficiency, drug loading, etc. were evaluated and its anti-Candida activity was investigated. On the basis of single factor influence test, the orthogonal design was adopted to choose the preparation process of nanostructured lipid carrier (NLC) and formulation of BITC-NLC. The best preparation process was stirring for 20 minutes and ultrasonic dispersion for 15 minutes (amplitude 80%). The best prescription was composed of 50 mg monostearate, 50 mg octyl capric acid triglyceride, 400 mg poloxamer, 400 mg soybean lecithin, 100 mg BITC and 20 mL ultrapure water. The morphology was observed by a transmission electron microscope, the particle size and zeta potential were measured by Zetasizer Nano ZSE, and the encapsulation efficiency and drug loading were analyzed by high performance liquid chromatography. The final prepared BITC-NLC was quasi-spherical shapes and the average particle size, Zeta potential and encapsulation efficiency was 79.13 nm, -21.77 mV and 91.52%, respectively. The preliminary stability test results showed that BITC-NLC was stable for 30 d kept at 25 ℃. The minimal inhibitory concentrations (MICs) were determined using the broth dilution method. MICs of the BITC-NLC against all the selected Candida strains were 8-32 μg/mL, which were better than BITC. In addition, it could inhibit C. albicans and C. tropicalis that are resistant to the most commonly used antifungal drug - fluconazole. The new prepared formulation BITC-NLC from papaya seeds essential oil in this study has small particle size, good physical stability, high encapsulation efficiency and better antifungal effect on C. albicans and C. tropicalis. The results may provide theoretical and experimental basis for the application of papaya seeds which are abundant and typically discarded and the development of natural antifungal drugs.