The islands are important pivots for the development of South China Sea, and which play an important role in ensuring the development sustainability of South China Sea and safeguarding national rights and territorial integrity. The islands in South China Sea have rich biodiversity and complex ecological functions, but they are also vulnerable to human disturbances. The paper summarizes the basic characteristics of the climate, water, soil, biology and agriculture development of the islands. It indicates that keeping ecological sustainability is the fundamental task during the development of islands, and it is important to reduce the disturbances of human factors on the islands ecology, and pay attention to the development of island agriculture and modern marine ranching, and build a comprehensive evaluation system for the ecology sustainable development of islands, that will ensure the realization of social, economic and national security services function of the South China Sea islands.

In order to explore the polymeric 2-(2-phenylethyl) chromones (PPECs) components and the structures from agarwood (Aquilaria spp.), ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass/mass spectrometry (UPLC-Q-TOF-MS) was used to acquire the spectrum of TOF-MS and TOF-MS/MS of agarwood samples. The fragmentation pathway of PPECs was analyzed. The screening and structure confirmation of PPECs from agarwood was performed. A total of 55 PPECs components were identified. According to the structural characteristics, 55 components were grouped into three types, including dimeric 2-(2-phenylethyl) chromones (DPECs), trimeric 2-(2-phenylethyl) chromones (TPECs) and sesquiterpenoid-2-(2-phenylethyl) chromones (SPECs). All identified components were consisted of 44 DPECs, 3 TPECs and 8 SPECs, of which nine DPECs, one TPECs and one SPECs were firstly identified in agarwood. Furthermore, 2-4 isomers were observed for some PPECs components from agarwood. The results showed that agarwood were rich in PPECs components and the corresponding isomers. Meanwhile, the proportion of DPECs was the highest (80%) among total PPECs. The results could provide reference for the study of material basis of pharmacodynamics effect and utilization of agarwod.

The global quality cigar tobacco planting areas are basically dominated by tropical rain forest or tropical monsoon climate. The overall quality of cigar raw materials from Chinese and overseas planting areas has the certain disparity by multiple factors. In order to study the chemical constituents, a cluster and comparative analysis was conducted on some domestic and foreign cigar tobacco. The contents of carbohydrates and the distribution of amino acids reflected the characteristics of cigar tobacco. There were large differences among cigar tobacco samples from different planting areas in the content of conventional chemical components, and the chemical components of the cigar tobacco leaves had harmonious percentage in general. The average contents of total sugar, reducing sugar, anatabine, glutamic acid, linolenic acid and linoleic acid in cigar tobacco samples from Hainan and foreign planting areas were significantly lower than those in the other three planting areas in China, but the pectin content showed the opposite pattern. In terms of aroma components, the average contents of carotenoid degradation products such as megastigmatrienone, linalool and damascenone, non-enzymatic brown-reaction products such as pyrazine and furfural, and solanone in cigar tobacco samples from other three planting areas in China were significantly higher than those from Hainan and foreign planting areas. The average contents of neophytadiene, isoamyl alcohol, pyridine, phenyl ethanol and other aroma components in cigar tobacco samples from all domestic planting areas were higher than those from foreign planting areas, and the difference was significant or most significant. These planting areas fell into four categories according to clustering results. The first group included America areas and Hainan Province in China. The second group included Indonesian areas. Hubei Province, Yunnan Province was in the third group, and Sichuan province was in the fourth group.

In order to understand the C, N and P eco-chemometric characteristics of different tree age groups, the coffee from the Manxieba Xiaoaozi Nanpingzhen a Coffee Estate in Pu'er Simao District was studied in four tree age groups: 1 a, 7 a, 10 a and 20 a, the C, N, and P levels in coffee leaves and soil were determined, as well as the chemometric ratio between them. The N and P content of coffee leaves was proportional to the age of the tree, gradually increasing with the age of the tree, inversely proportional to the C content, gradually decreasing with the age of the tree. The differences in N and P content of coffee reached significant levels (P<0.05), and the chemometric ratios C∶N and C∶P decreased with tree age, among which C∶P was significantly different in different tree ages (P<0.01). Leaf N∶P threshold analysis found that the leaf N∶P ratio was less than 14 in all four tree age segments, indicating that the growth of coffee was mainly limited by N elements. There was significant variability (P<0.05) in SOC content between tree age groups, with 7 a coffee having the highest C, N and P content. The mean values of C, N and P content were slightly higher for 0-10 cm soils than for 10-30 cm soils and 9.79 for 0-10 cm soils than 6.87 for 10-30 cm soils. The range of C∶P variation for coffee was 11.51-46.80 for 0-10 cm soils and 4.53-20.82 for 10-30 cm soils, with large inter-soil variations. The range of N∶P variation was 1.00-5.12 and 0.81-2.08 for different soil layers, respectively. The correlation showed that N∶P and P elements were significantly correlated and P element was the main cause of C∶N variation. From the correlation analysis, coffee leaf C was significantly negatively correlated with N, P (P<0.05), leaf N was extremely significantly positively correlated with C∶N, C∶P (P<0.01) and leaf P was extremely significantly negatively correlated with C∶P (P<0.01). The SOC and TN of different soil layers were positively correlated (P<0.05), and the C, N, and P of the blade were not correlated with the TOC, TN, and TP of the soil, and the ratio of measurements was rarely correlated. It can be seen from the above that the SOC, TN and TP of coffee soil were relatively low, the soil was mainly limited by N nutrients. In addition, the absorption of N and P by coffee leaves had a synergistic effect, and there was a broad quantitative coupling relationship between coffee leaves and soil elements.

The proteins on rubber particles of Hevea brasiliensis play key roles in a series of reactions of rubber biosynthesis. They directly determine the number and size of rubber molecules, thus affecting the yield and quality of natural rubber. Small rubber particle protein (SRPP) is the second highest abundance protein in rubber particles following after the rubber elongation factor (REF), which is closely related to rubber particle development and rubber biosynthesis. At present, it is known that there are many SRPP family proteins on rubber particles, but the functions of most SRPP family proteins have not been identified. SRPP may function by interacting with other rubber particle proteins. To screen the interaction protein of HbSRPP7, a normalized H. brasiliensis latex cDNA library was constructed based on the membrane yeast two-hybrid (MYTH) system. The capacity of the cDNA library was 1.5×10⁷ CFU, the average library recombination rate was about 100%, and the average amplification sizes of insert fragments in the cDNA library were above 1500 bp. The pBT3STE-SRPP7 and pBT3SUC-SRPP7 bait vectors were constructed and confirmed that they could be correctly expressed in the NMY32 yeast strain without self-activating activity. The latex MYTH cDNA library was screened using the bait plasmid pBT3STE-SRPP7, and 21 candidate proteins of HbSRPP7 were obtained, including three REF family proteins (HbREF1, HbREF3, and HbREF8), two SRPP family proteins (HbSRPP1 and HbSRPP2), two reactive oxygen species scavenging-related proteins (thioredoxin H-type-like and L-ascorbate peroxidase 2), and five stress-related proteins (high mobility group B protein 2-like, RPM1-interacting protein 4-like, stress-related protein-like, salt stress-induced hydrophobic peptide ESI3-like and F-box/kelch-repeat protein). It is shown that HbSRPP7 may participate in rubber biosynthesis through interaction with the rubber particle proteins related to rubber biosynthesis. In addition, HbSRPP7 may also participate in the regulation of rubber biosynthesis on rubber particles by interacting with biotic and abiotic stress-related proteins and responding to biotic and abiotic stress signals in laticiferous cells of H. brasiliensis. The research results are helpful to understand the function of SRPP family proteins and lay a foundation for revealing the composition of protein complexes involved in rubber biosynthesis on rubber particles and elucidating the molecular mechanism of rubber biosynthesis and its regulation.

Podocarpus macrophyllus is a common garden ornamental and greening tree species in southern China, with high economic and medicinal value. To study the physiological response of nitrogen addition under different phosphorus environments to P. macrophyllus seedlings, two-year-old P. macrophyllus seedlings were used as the material, two soil phosphorus conditions including low additional phosphorous (0.26 g/plant), high phosphorus addition (1.08 g/plant), three nitrogen addition levels including low nitrogen addition (0.53 g/plant), medium nitrogen addition (1.06 g/plant) and high nitrogen addition (2.12 g/plant) were set up and analyzed the differences of physiological characteristics, chlorophyll content, gas exchange parameters and leaf nutrient content of P. macrophyllus seedlings in each treatment group. Nitrogen addition increased the activity of POD, and high concentration nitrogen fertilizer decreased the activity of SOD. The application of nitrogen fertilizer in a low phosphorus environment increased soluble sugars and soluble proteins, decreased MDA and Pro. Soluble protein and soluble sugar accumulation decreased in high nitrogen and phosphorus environment, but MDA and Pro increased. The chlorophyll content of P. macrophyllus seedlings was the highest under medium concentration nitrogen treatment. The addition of nitrogen in low phosphorus environment increased the P_n, T_r and G_s of P. macrophyllus seedlings, while C_i (intercellular CO₂ concentration) of P. macrophyllus seedlings decreased. The P_n, T_r and G_s were the highest and C_i was the lowest in the medium nitrogen treatment group in high phosphorus environment. P_n, T_r and G_s decreased, and the C_i increased in the high nitrogen concentration and high phosphorus environment. The same change trend of P_n and T_r and correlation analysis showed that P_n of P. macrophyllus seedlings was mainly limited by stoma factors. Nitrogen addition promoted the increase of leaf nitrogen content in low phosphorus environment, but decreased the leaf nitrogen content in high phosphorus environment. Nitrogen addition limited the accumulation of phosphorus in the leaves of P. macrophyllus seedlings, but the increase of soil phosphorus content promoted the accumulation of phosphorus content in leaves. The increase of phosphorus fertilizer concentration increased the enzyme activity of P. macrophyllus seedlings under different nitrogen treatments. The increase of nitrogen fertilizer concentration decreased the content of MDA and Pro, and the content of soluble sugar and soluble protein increased in the low nitrogen and high nitrogen treatment groups. The increase of phosphorus fertilizer concentration increased the content of MDA and Pro, and the content of soluble sugar and soluble protein decreased in the high nitrogen treatment groups. Increasing the concentration of phosphate fertilizer promoted the chlorophyll content and photosynthetic efficiency of low and medium nitrogen treatment groups, while increasing the concentration of phosphate fertilizer decreased the chlorophyll and photosynthetic efficiency.

Quickly obtain embryogenic callus is the key step to successfully establish the regeneration system in the somatic embryogenesis regeneration system of rubber tree. Rubber tree anthers were used as explants in the study. The effects of different concentrations of picloram, KT, 6-BA, and IAA on the induction of rubber tree anther embryogenic callus were studied through an orthogonal experimental design. The results showed that the optimal combination medium for rubber tree anther callus induction was MS basic medium, 0.4 mg/L thiamine, asparagine 300 mg/L, hydrolyzed casein 100 mg/L, proline 100 mg/L, arginine 100 mg/L, glutathione amino amide 100 mg/L, L-cysteine-hydrochloride 50 mg/L, sucrose 70 g/L, coconut water 50 mL/L, vegetable gel 2.2 g/L, picloram 20 mg/L, KT 2 mg/L and KT 2 mg/L and 6-BA 1 mg/L, and the callus induction rate reached 73.3%-100%. In all treatments, the callus was induced for about 25-28 days, and the callus reached the stage of rapid proliferation. The main effect of the induction of embryogenic callus was the concentration of picloram. It could promote the induction of embryogenic callus. Although low concentrations of picloram could also induce callus production, the callus were basically non-embryogenic potential-ie non-embryogenic callus. At the same time, 11 somatic embryos were used for plant regeneration. Among them, two plants emerged, seven only had roots without sprouting, and two had neither buds nor roots. The plant regeneration rate was 18%. By observing the leaf morphology and plant height of the plants, there was no significant difference with the rubber tree tissue culture seedlings and seedlings in production. In the future, on the basis of the research, the formulation of the callus induction medium would be further optimized, so that it could induce embryogenic callus from anthers more quickly, shorten the induction time of embryogenic callus, and reduce variation. Probability, it could provide callus with better conditions for RITA bioreactors as starting material.

Using the in vitro axillary bud of Anthurium (Anthurium andraeanum Lind.) as the materials, this article reports the influence of the droplet vitrification on Anthurium after cryopreservation, and plants regenerated tissues genetic stability were assessment. The results showed the highest survival rate of Anthurium (63.70%) was achieved after preculture for 4 days on MS solid medium containing 0.4 mmol/L sucrose and 2 mmol/L glycerol, dehydration with 80%PVS₂ at 0 ℃ for 50 min, cooling in droplets of PVS₂ placed on aluminum foil strips, after immersing in liquid nitrogen for 2 s, directly transferred it to a cryotube filled with liquid nitrogen, and kept it in liquid nitrogen for at least 30 min after rewarming them with MS liquid medium containing 1.2 mmol/L sucrose at room temperature for 20 minutes, transferred to recovery medium. Through ISSR and SSR molecular marker detection, the genetic stability of regenerated plants did not changed. The results would provide an effective way for long-term preservation of Anthurium andraeanum germplasm resources.

The heterozygosity, population structure and genetic diversity of Moringa oleifera and its progeny were analyzed using the SNP markers. The characteristics of genetic variation of M. oleifera and its progeny were studied. Simplified genome sequencing of 96 M. oleifera materials was performed by AFSM technology. The obtained sequencing filtering data were compared to the reference genome. SNP and Indel loci were detected and counted by using VCFtools and BCFtools. In order to analyze the reproduction types of M. oleifera, AWK language was used to analyze heterozygous loci, and compare the different loci of the progeny with the parents. The mutation sites were filtered by Plink software, and the high-quality mutation sites were reserved. The population structure was analyzed by ADMIXTURE software, and the optimal K value was determined according to the cross validation error rate. At the same time, GCTA software was used for principal component analysis, and the phylogenetic tree was constructed to analyze the population structure of the materials. VCFtools was used to calculate the genetic diversity index and population differentiation index for analyzing the genetic polymorphism of the population. LDBlockShow software was used for linkage imbalance analysis, and the linkage imbalance degree between loci was obtained. The result showed that a total of 1 187 831 SNP sites and 150 861 Indel sites were detected in this paper. We compared M. oleifera progeny genes with parents, which found that among the heterozygous genes in Moringa progeny, about 4.89% of the genes are self-heterozygous genes, and 19.96% of the heterozygous genes caused by foreign genetic materia. It indicates that M. oleifera produce offspring by the ways of self-pollination and cross-flowering. M. oleifera samples were divided into 3 subgroups by population structure and principal component analysis. The cluster analysis is roughly consistent with the above results. The subgroups can be clustered together, and there is a little crossover between the samples. The low genetic differentiation index (0.0049-0.0110) and genetic diversity index (0.001) among different populations of M. oleifera indicated that the level of genetic diversity was low and genetic differentiation was weak. The SNPS of 136 scaffolds which detected were counted and linkage imbalance analysis was performed, we found that scaffold 1 had the most SNPS (62 225), there was strong linkage imbalance between 6 748 044 and 6 748 185 loci. This study analyzed the genetic diversity of M. oleifera and its progeny. It would provide genetic basis for the cross breeding of M. oleifera.

Neonicotinoids (NEOs) contain imidacloprid (IMI) and acetamiprid (ACE), which are widely used in the world. In this study, earthworms (Eisenia foetida) were used as soil animal. Through high-throughput sequencing and measurement of soil physical and chemical properties, the changes of bacterial communities between IMI and ACE contaminated red soil (BCK, DCK) and soil after earthworm introduction (B, D), and the relationship with environmental factors were analyzed to explore the animal remediation mechanism of contaminated red soil. The introduction of IMI and ACE reduced the diversity of microbial population, significantly changed the composition of soil bacterial community structure, and decreased the content of soil organic matter (SOM) and total nitrogen (TN), compared with the natural red soil (CK). The addition of earthworms increased the relative abundance of Actinobacteriota, Proteobacteria and Bacteroidota, which have the ability of insecticide resistance and degrading. pH value, TN, total phosphorus (TP) and total potassium (TK) contents of contaminated soil increased. Combined with the correlation analysis of soil physiochemical properties, it was found that pH, TN, TK and SOM had a great influence on the bacterial community structure among the treatment groups at the genus level. The study showed that IMI and ACE pollution reduced the contents of SOM and soil TN, and destructed the original bacterial community structure in the soil. Earthworm activity improved soil fertility of contaminated red soil, alleviated the adverse effects of IMI and ACE on soil microbial flora, restored and enriched the diversity of microbial species in NEOs-contaminated soil to a certain extent, and then accelerated the degradation of NEOs in soil. This study showed the feasibility to screen the efficiently IMI and ACE-degrading bacteria from drilosphere, and would provide theoretical basis for the earthworm remediation of IMI and ACE-contaminated soil.