Guangxi spans the southern subtropics and central subtropics, with the Tropic of Cancer crossing the central part of the province, and belongs to the subtropical monsoon climate zone, which breeds rich wild sugarcane germplasm resources. From 2016 to 2023, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences organized a team of researchers to carry out systematic surveys and collection of Narenga porphyrocoma germplasm resources in Guangxi. The team collected a total of 58 copies of N. porphyrocoma germplasm resources in 43 townships of 18 cities and districts in Guangxi. The results showed that the N. porphyrocoma germplasm resources in Guangxi were mainly distributed in the area of 60.0-602.5 m above sea level, longitude E: 107°08′01″-111°32′02″, latitude N: 23°08′02″-26°01′43″. The genetic diversity indices of the 20 descriptive quality traits of N. porphyrocoma germplasm resources in Guangxi ranged from 0 to 1.2044, with a mean value of 0.5557, in which the diversity of the color of the internodes after exposure was the highest, that of the cork was lower, and the diversity of the three traits of stem shape, aerial roots and water splitting was not reflected; the genetic diversity indices of N. porphyrocoma germplasm resources in Guangxi of the different collection areas ranged from 0.1040 to 0.4911, with Hezhou being the highest and Baise being the lowest. The phenotypic traits of N. porphyrocoma germplasm resources in Guangxi were rich in variation, and the coefficients of variation for six quantitative traits ranged from 17.3% to 53.6%, with an average of 34.8%; the coefficients of variation of N. porphyrocoma germplasm resources in Guangxi from different collection areas ranged from 29.4% to 36.9%, with Hechi being the largest and Guilin being the smallest. The results of cluster analysis showed that the 58 N. porphyrocoma germplasm resources in Guangxi were classified into six major groups, but were not closely related to the geographical origin, in which the materials in the first major group had better overall traits and excellent biomass and quality traits. The collection expanded the number of resources in Guangxi Sugarcane Germplasm Repository and would provide excellent genetic resources for sugarcane breeding and genetic improvement.

Luffa, a major melon vegetables in China, is a crop of gourd family and the silk gourd genus, which is rich in nutrients and favored by consumers. With the increasing number and type of luffa germplasm resources, it is increasingly difficult to screen and preserve the excellent materials of luffa. In order to construct a core germplasm bank of luffa, eliminate germplasm materials with serious homogenization, and improve the efficiency of lucerne breeding, this study investigated the genetic diversity of 244 luffa germplasm resources by using 18 phenotypic traits that are highly representative of luffa as indicators, and compared and analyzed eight different sampling ratios (5%-40%), and three different sampling methods (random cluster sampling, group cluster sampling and preferential cluster sampling) were compared to analyze the representativeness of the core germplasm of luffa candidates. The results showed that the phenotypic genetic variation of lucerne germplasm resources was relatively rich, of which the largest Shannon index was leaf width, 3.0, and the smallest was seed melon length, 1.8. The most suitable sampling ratio was 20% using the comprehensive analysis of the seven evaluation indexes, and the most suitable sampling method was group cluster sampling. Using this method for core germplasm library construction, the primary core germplasm obtained containing 51 lucerne germplasm resources, accounting for 20.90% of all the original germplasm resources, and compared with the original germplasm, 13 of the 18 agronomic traits were in full agreement with the original germplasm in terms of the maximum and minimum values, and the characteristic values of most traits were the same as those of the original germplasm or the differences were relatively small. The T-test showed that the mean values of all phenotypic traits had no significant differences with the original germplasm, indicating that the core germplasm library constructed by the method has good representativeness and rich genetic diversity. This study could provide basic support for the collection, preservation and innovative utilization of lucerne germplasm resources in the later stage, and also lays a foundation for improving the efficiency of lucerne variety improvement.

Knowledge on germplasm resource information is the foundation for the genetic improvement of Aquilaria sinensis, and genome resequencing is a powerful tool for analyzing the genetic diversity of germplasm resources. However, there is no research on the genetic diversity of A. sinensis using genome resequencing. Based on the collection of A. sinensis germplasm resources in the early stages, this study utilized genome resequencing to obtain 1284 Gb of resequencing data from 60 samples of A. sinensis. Using the agarwood genome, 6 716 166 high-quality variation sites were detected, including 6 284 344 SNP sites and 428 658 Indel sites. Principal component analysis, phylogenetic analysis, and genetic structure analysis all indicated that A. sinensis could be divided into three distinct groups (Pop1, Pop2 and Pop3), with two of the groups further subdivided into multiple subgroups. Population selection signals were detected in all the groups, with Pop3 showing the highest frequency of selection signals. However, nucleotide polymorphism calculations indicated that Pop3 had the lowest nucleotide polymorphism. This study would provide valuable information for exploring the genetic resource diversity of A. sinensis and lay a theoretical foundation for genome-based genetic breeding of A. sinensis.

Broomcorn millet (Panicum miliaceum L.) is a traditional grain crop in China. Currently, there is still limited research on the genetic transformation methods for P. miliaceum. This study aimed to establish an efficient genetic transformation method for P. miliaceum mediated by Agrobacterium. Mature seeds of the millet variety Jishu 5 were used as the explants to induce embryogenic callus of millet on CIM and MSD induction media, respectively. They were used as the transformation receptor materials and infected with Agrobacterium containing plant expression vectors for 60 minutes and co-cultured for 6 days. The calli were then transferred to a screening medium containing 0.025 g/L of hygromycin to screen for resistant calli. Then, they differentiated on a differentiation medium containing 0.015 g/L of hygromycin. Finally, they rooted into seedlings on a rooting medium containing 0.015 g/L of hygromycin. PCR detection was performed on the regenerated plants using vector specific primers to identify whether they were positive transgenic plants. Based on the multiple batches of transformation experiments, the screening efficiency and transformation efficiency of resistant regenerated plants of broomcorn millet were statistically analyzed. The results showed that both CIM and MSD media could induce embryogenic callus of broomcorn millet, but CIM medium had a better effect on inducing embryogenic callus of broomcorn millet. After being infected by Agrobacterium and co-cultured with Agrobacterium, the multiple resistant regenerated plants were obtained through screening, differentiation, and rooting on a medium containing hygromycin. The PCR identification positive rate of the resistant regenerated plants obtained from three experiments was 100%, and the average transformation efficiency was over 30%. This study successfully established an Agrobacterium mediated genetic transformation method for broomcorn millet, which is simple to operate, efficient, cost-effective, and not limited by seasons. It could be carried out on a large scale, providing an effective technical means for genetic improvement of broomcorn millet.

Based on the panel data of 18 cities (counties) in Hainan, China from 2012 to 2022, combining the non-expected output super efficiency SBM model and Tobit regression mode, this paper analyzed the spatial and temporal evolution characteristics of agricultural eco-efficiency and influencing factors of agricultural ecological efficiency in cities (counties) of Hainan. From 2012 to 2022, the average agricultural eco-efficiency in Hainan showed obvious grading characteristics of central region>western region>eastern region. The agricultural eco-efficiency at the county scale of Hainan improved significantly year by year. The average agricultural eco-efficiency was 0.541, and the number of cities (counties) above the average value was 7. In terms of spatial change, the overall distribution characteristics of agricultural eco-efficiency were “spreading from the middle to the east and west”, and the distribution characteristics of full efficiency and high efficiency were block and chain. The cities (counties) with medium efficiency were distributed around the cities and counties with full efficiency and high efficiency. The trend lines in the north-south direction and the east-west direction showed the characteristics of inverted U-shape. The temporal and spatial evolution of agricultural eco-efficiency in Hainan at the provincial scale was influenced by several key factors, including the level of farmers’ income, intensity of agricultural mechanization, use of agricultural chemicals, and urbanization rate. At different regional scales, farmers’ income level was the main factor affecting agricultural eco-efficiency in the eastern region, while urbanization rate, intensity of agricultural chemical input use and farmland irrigation rate were the main factors affecting agricultural eco-efficiency in the central region. Urbanization rate, farmers’ income level, agricultural industrial structure, intensity of use of agricultural chemical inputs and farmland irrigation rate were the main factors affecting agricultural eco-efficiency in the western region. On the whole, the agricultural eco-efficiency of all cities (counties) in Hainan showed an upward trend, and there were some differences in the agricultural eco-efficiency among different regions. In the future, we should explore the priorities of agricultural development in different regions according to local conditions to effectively improve agricultural eco-efficiency.

Cymbidium ‘Shuangyi Jinlong’ is a new variety selected and bred from the clonal variation of the hybrid orchid cultivar ‘Golden dragon’ by Fujian Bainong Ecological Technology Co. Ltd.. It integrates flower and leaf art, has good germination, easy flowering and strong resistance, and has a high market demand. The rhizome and tissue culture seedlings of Cymbidium ‘Shuangyi Jinlong’ were used as experimental materials, and the orthogonal experiment was conducted to optimize the influencing factors of rhizome proliferation and differentiation, rooting and seedling growth, seedling cultivation and transplanting, in order to improve the seedling reproductive efficiency and seedling quality of hybrid orchid, and establish a standardized production system. The most suitable medium for rhizome proliferation and growth was MS medium supplemented with 1.00 mg/L NAA, 0.10 mg/L 6-BA, 20.00 g/L sucrose, 1.00 g/L activated carbon, 6.30 g/L agar, and 1.00 g/L peptone; the quantity value-added coefficient was determined to be 3.57 while the quality value-added coefficient was found to be 4.63. The optimal medium for rhizome differentiation was 1/2MS,1.50 mg/L NAA, 0.90 mg/L TDZ, 100.00 g/L banana homogenate, 25.00 g/L sucrose 6.30g/L; the leaf bud differentiation rate reached up to 97.78%, with a differentiation coefficient of 6.87. The best-performing medium for rooting and seedlings strengthening was 1/2MS, l.00 mg/L IBA, 100.00 g/L banana homogenate, 0.17 g/L KH₂PO₄, 30.00 g/L sucrose, agar and l.00 g/L activated carbon. After 90 days of cultivation, the average number of roots per plant was five, with a root length of 5.40 cm, a pseudobulb thickness of 4.35 mm, a plant height of 12.95 cm, and a fresh quality of 2.42 g. The recommended method for transplanting tissue culture seedlings involves using water hyacinth∶pine bark (V∶V=1∶1) as the transplantation substrate after 21 days in vitro culture. The survival rate after 60 days post-transplantation reached 83.33%. Taking into account the impact of various factors, this study ultimately identified the optimal medium compositions at each stage and refined transplanting schemes. This provides a reference for establishing a standardized production system.

The study was aimed to clarify the changes in moisture content, fiber microstructure, and metabolites during the hot air drying process of areca nut, and to precisely regulate the drying time. This study focuses on areca nut and five models were used to fit the hot air drying curves of areca nut at different temperatures, and a betel nut drying kinetics model was established. At the same time, scanning electron microscopy, LC-MS were used to explore the changes in the microstructure and metabolites of areca nut during the drying process. The results showed that the drying curve of betel nut showed an exponential decrease, and the drying rate curve was divided into two stages: acceleration and deceleration. Temperature had a significant impact on the drying rate. The Page model fit the hot air drying curve of areca nut well, with a coefficient of determination R² above 0.98 and a RMSE in the range of 0.02-0.06. The difference between the predicted and true values of the model was not significant, and it could better reflect the water changes during the areca nut drying process. Microstructure analysis shows that the fiber layer of areca nut became dense and compact with increasing drying time, and the whitening treatment caused the fiber structure of areca nut to become loose. The texture results indicated that with the increase of drying time, the hardness and chewiness of areca nut increased, while the elasticity decreased. The differential metabolite results showed that the drying process affected organic acids, lipids, and lipid molecules by affecting the metabolism of amino acid, linoleic acid, central carbon, flavonoid biosynthesis, and phenylpropanoid biosynthesis. This study would enrich the basic research on areca nut processing and provide a theoretical basis for the selection of hot air drying time for areca nut.

Nervilia plicata is a rare southern Chinese herb. The study on the plant at molecular level is hardly seen. Real-time quantitative PCR (qRT-PCR) has been widely used in plant gene expression analysis, but there is a lack of research on it in N. plicata, which limits the progress of related work. Based on the previous researches, nine candidate reference genes, including Actin, GAPDH, TUA, UBC, UBQ, EF-1α, EF-1β, CYP and RPL, were screened out from the transcriptomic sequencing data. In order to select suitable reference gene in N. plicata, qRT-PCR technique was employed to detect the expression levels of the candidate reference genes in leaf, petiole and corm tissues of the plant. After analyzing the expression levels, the stability and comprehensive analysis of nine genes in different tissues, the most suitable reference gene was obtained. Finally, the most suitable reference gene was validated using NpDFR, Np3GT that related to anthocyanin synthesis. Results showed that the expression stability of EF-1 α and CYP was similar, with the best overall stability. When using either EF-1α or CYP, or the combination of them, as reference, the expression patterns of NpDFR and Np3GT in different tissues were consistent with the transcriptome sequencing results. This indicates that both EF-1 α and CYP can be used as reference genes in N. plicata for qRT-PCR. This study would provide a basis for further research on the molecular mechanism of genes related to the pharmacological effects of N. plicata.

Bougainvillea is an important woody ornamental plant in southern China. There are a large number of varieties, but the classification is relatively chaotic. This study took 133 Bougainvillea varieties introduced and preserved in Yunnan as the research object, and conducted frequency distribution statistical analysis, coefficient of variation calculation, and diversity index calculation for 10 quantitative characters and 41 discrete characters. Q-type clustering analysis was also conducted. The results showed that the 133 Bougainvillea varieties had rich diversity in many characters, and the coefficient of variation of quantitative characters ranged from 19.61%–32.59%, with an average of 26.64%. The coefficient of variation of the total flower stem length, calyx tube width, petiole length, and flower length was the highest, and the diversity index ranged from 1.69–2.09, with an average of 1.92. The diversity index of leaf length, bract width, leaf width, and bract length was the highest. The diversity index of discrete characters ranged from 0.17–2.19. There were 11 discrete characters with H′ values greater than 1, and the diversity index of bract color and calyx tube color was both greater than 2. The diversity was rich. Among the four species of Bougainvillea, the diversity index of Bougainvillea×buttiana was the highest, with the richest diversity, followed by B. peruviana, B. glabra, and B. spectabilis, whose diversity index was the lowest, with less diversity. However, each species has its own advantageous characters. Among the 51 characters, 22 characters showed significant difference among species, which were of great reference value for identifying and classifying the varieties of Bougainvillea. Based on the types of bracts, the number of spines, and the size of leaves, 133 B. varieties could be grouped into four categories: double spiny less, double spiny more, single spiny less leaflet, and single spiny large leaflet. The research results show that the phenotypic characters of the 133 B. varieties tested have high diversity, and the quantitative trait variation types are rich. This study could provide scientific basis for systematic evaluation of B. germplasm resources, variety classification, and germplasm innovation.

The study of the distribution characteristics of crown biomass of Dalbergia odorifera plantation can provide theoretical basis for reasonable evaluation of stand biomass and adjustment of crown structure. In this paper, D. odorifera plantation aged 10-12 a in Dongfang, Hainan, China was taken as the research object. Two sample plots (S₁ and S₂) with different site conditions were set up, and the crown of the sample trees over 4.5 m was cut off. The biomass of each organ in the canopy was obtained by layered cutting method and total weighing method, and the optimal biomass fitting equation of each organ was established. (1) The order of biomass in each organ was bare branch>branch bark>leaf. The total biomass of bare branches, branch bark and canopy was S₁>S₂, while the leaf biomass was S₁<S₂. (2) With the increase of canopy class, the biomass of bare branches and branch bark of S₁ and S₂ showed a wave-like change, in which S₁ increased first and then decreased, while S₂ was the opposite. As a whole, the leaf biomass increased first and then decreased, in which S₁ was mainly distributed in the middle and upper layers of the crown, while S₂ was mainly distributed in the lower layers. The upper layer of the canopy of S₁ was more competitive than that of S₂, there has been serious natural thinning of canopy, the leaf biomass gradually shifted from the lower layer to the middle and upper layers.(3) The optimal fitting model of biomass was power function, which was the total biomass of crown [y=3.904(D²H)^1.247], canopy bare branches [y=1.901(D²H)^1.28], canopy branch bark [y=0.734(D²H)^1.276], and canopy leaves (y=3.86D^2.791).