The enlarged corm of Chinese water chestnut (Eleocharis dulcis) is the main edible part, and the related genes involved in the regulation of the corm enlargement process remain unclear. COL5 (CONSTANS-Like 5) gene is a member of COL gene family, which may play an important role in the development of plant storage organs. The transcript fragment with high homology to COL gene in other plants was screened from the Chinese water-chestnut transcriptome databases and cloned its cDNA sequence and full-length DNA, and then the bioinformatics analysis and spatiotemporal expression pattern analysis were analyzed to study the expression pattern and possible role of Chinese water-chestnut COL5 during corm enlargement. The results showed that the cloned COL5 gene related to Chinese water-chestnut enlargement had an ORF of 1017 bp, encoding 338 amino acids, and the DNA sequence was 1275 bp, containing an intron of 257 bp, which was named CwCOL5 (ON934922). Bioinformatics analysis showed that the CwCOL5 protein with the formula C₁₅₉₂H₂₅₁₅N₄₇₇O₅₀₈S₁₇, the relative molecular weight of the predicted protein was 37 010.39 Da, and a theoretical isoelectric point of 5.89. The total average hydrophilic value (gravy) was -0.462, the instability coefficient was 45.63, which was a hydrophilic unstable protein. There were 31 phosphosites, no transmembrane structure, and no signal peptide, and additionally subcellular prediction analysis showed that it was located in the nucleus. CwCOL5 contained two B-box Zinc fingers and a highly conserved CCT domain. Phylogenetic analysis showed that CwCOL5 was closely related to the COL protein of Nelumbo nucifera and Arabidopsis. The results of PCR showed that CwCOL5 had a high expression in the leaves and water-chestnut peel, and the expression of CwCOL5 increased rapidly in the early stage of corm enlargement. The CwCOL5 gene belongs to a typical transcription factor family of zinc finger protein, and the gene may be involved in the process of corm enlargement of Chinese water-chestnut. In this study, COL5 gene was cloned from the corm of Chinese water-chestnut and its expression pattern was analyzed, which would provide a theoretical basis for molecular mechanism of plant corm enlargement.

Tibet is rich in orchid plant resources, mainly distributed in the eastern Himalayas. Among them, Motuo County, Bomi County and Chayu County of Nyingchi City, Yadong County, Dingjie County, Nielamu County and Jilong County of Xigaze City are the main distribution areas of orchid plants in Tibet. With the release of Latest National Key Protected Wild Plant List, more and more orchids are listed for protection. In this paper, four species of the Subtribe Goodyerinae (Orchidaceae) found in the southeast of Tibet are reported. They are Anoectochilus, Anoectochilus brevilabris Lindl., Cheirostylis moniliformis (Griff.) Seidenf., Goodyera hispida Lindl and Goodyera yunnanensis Schltr. The voucher specimens are deposited in the Herbarium of Tibet Institute of Agriculture and Animal Husbandry (TAAHUC) and Herbarium of Wuhan Botanical Garden, CAS (WIB). Most of the plants of the Subtribe Goodyerinae have extremely high medicinal value. The report of this new record is of great significance to the introduction, propagation and domestication, biodiversity protection and development and utilization of medicinal Orchidaceae in Tibet.

A new recorded plant of Asteraceae, Porophyllum ruderale (Jacquin) Cassini was reported in Hainan which could be used as a spice. This paper introduced the biological characters, origin and distribution of P. ruderale, and evaluated the ecological invasion risks, and analyzed the value of being a spice plant, which could provide references for the prevention, control as well as the development and utilization of spice resources on the exotic species in Hainan province.

One genus and five species of vascular plants, Nepeta Linn. , Nepeta cataria Linn. , Keiskea sinensis Diels, Leptochilus ellipticus var. flexilobus (Christ) X. C. Zhang, Illigera rhodantha Hance, Scutellariafranchetiana Levl, were reported as new records to Fujian, China in this study. The voucher specimens were preserved in Museum of Fujian Bioengineering Vocational and Technical College.

To lay a foundation for the scientific evaluation of the ornamental traits of Primulina, 40 species of the Primulina were used as the experimental materials. The analytical hierarchy process was applied and four first-level indicators including foliage traits, flower traits, plant characteristics and cultivation performance to construct the constraint hierarchy were selected, then 14 secondary indexes including leaf shape, leaf pattern, leaf color, flower color and pattern, corolla size, flower quantity, flowering period, leaf arrangement, plant type compactness, peduncle shape, cultivation difficulty, pest and disease were selected to construct a comprehensive evaluation system for the ornamental traits of Primulina. The results showed that among the four first-level indexes, the weight of cultivation performance was 34.0%, which is the highest, followed by plant characteristics (26.6%), flower traits (24.0%), and foliag traits (15.4%). Among the 14 second-level indexes, the weight of cultivation difficulty, peduncle shape, leaf pattern and leaf arrangement on the ornamental value of Primulina all exceeded 10.0%. The weight of cultivation difficulty was 17.2%, which is a key indicator affecting the ornamental value of Primulina. According to the established scoring criteria, 40 species of Primulina were assigned, combined with the weight to calculate the scores, and divided into three grades: Grade Ⅰ (score over 3.5), 10 species with high ornamental value; Grade Ⅱ (score 3.0-3.5), 20 species with medium ornamental value; Grade Ⅲ (score below 3.0), 10 species with low ornamental value. Among them, the species rated as high ornamental value (Grade Ⅰ) are: P. Cleopatra, P. Snow Angel, P. guizhongensis, P. Stardust, P. qintangensis, P. Blue Mood, P. liujiangensis, P. hochiensis var. rosulata, P. Flying Wings and P. macrorhiza, these 10 species of Primulina are easy to cultivate and have outstanding performance in flower viewing, foliage and plant types, which can be used as excellent hybrid parents to participate in breeding, and can also be directly promoted to the market; the species classified as low ornamental value (Grade Ⅲ) are often difficult to cultivate, with poor stress resistance, and peduncle shape are poor, lack of characteristic flower color and pattern. The 40 species of Primulina are divided into 5 categories according to their ornamental values by cluster analysis, and the species with complementary traits can be selected as parents to produce better hybrid varieties.

Tropical crop germplasm resources are an important basis for the development of tropical agricultural science and technology in China. In order to fully implement the protection and utilization of tropical crop germplasm resources, and promote the high-quality development of the tropical crop industry. This study elaborates in detail on the collection and preservation of tropical crop germplasm resources, the construction of germplasm resource nurseries (libraries), and the innovative utilization of germplasm resources in China. According to the development status and long-term positioning, the problems at the current stage were point out, and corresponding opinions and development suggestions were put forward.

Information management of germplasm resources is the only way to improve the efficiency of germplasm resource management, sharing is an important means to activate the utilization value of preserved germplasm resources and realize the multiplier effect of seed industry, benefit distribution in sharing activities is the original incentive to promote germplasm resource sharing, and benefit ownership certificate is the key basis for benefit distribution. At present, the management of tropical crop germplasm resources is faced with the following problems: decentralized management of resource flow business chain; distortion of information data of resources and business chain; lack of evidence chain of credible benefit distribution of resources. To solve these problems, based on block chain technology, we put forward a kind of block chain system for tropical crop germplasm resources management to solve the problem of information asymmetry, by using decentralization, tamper-resistant, marks keeping in whole process, traceability, collective maintenance, and transparency, so as to realize the many relevant institutions of tropical crop germplasm resources and link collaboration trust and consistent action, effectively address the above issues and challenges. The system can keep marks processed and trace back to source, in full life cycle of tropical germplasm resources, laid the foundation for the combination of agriculture and computer agriculture, and resource traceability issues research. It is of great significance to the efficient management of tropical crop germplasm resources and the mining of potential value.

Rubber tree is the most important cultivated rubber-producing plant, and the tapping of trunk is the only way to obtain natural rubber from the laticifer in the bark currently. The characteristics of latex flow after tapping determine the latex yield, but the mechanism of latex flow is not yet completely clear. The turgor pressure of bark is the main initial driving force for latex flow, and the content of lignin, as the main component of cell wall, is closely related to the turgor pressure. At present, the study on the lignin content in bark of rubber tree is deficiency, among which the analysis of lignin content by morphological structure is lack. Using the bark of RY8-79 and PR107 mature tree as the research materials, paraffin sections were prepared, and the lignin in the bark was stained and localized by Wiesner reaction, Mäule reaction, and safranin staining combined with fluorescence, respectively. The results showed that both Wiesner reaction and Mäule reaction could stain the lignin component of the parenchyma cell wall, but difficult to distinguish different strains and tissues for the light color. The light purplish red of lignin in the parenchyma cell could be observed after safranin staining, but it was also difficult to distinguish different tissues and strains. The obvious red fluorescence of lignin tissue could be observed after safranin staining combined with 546 nm green light excitation, and there was significant difference among different cell types and strains. The lignin fluorescence of parenchyma cell in RY8-79 was significantly weaker than that in PR107, indicating that the content of lignin in RY8-79 was lower than that in PR107. Iodine-bromine staining showed that the distribution of secondary laticifer was consistent with the distribution of lignin with strong fluorescence, indicating that the lignin content of secondary laticifer and its surrounding parenchyma cells increased significantly, especially in PR107. In addition, Wiesner and Mäule reaction needed dangerous chemical reagents such as phloroglucinol, hydrochloric acid and potassium permanganate (KMnO₄), respectively, and the reaction time was not easy to control for slices falling off from slides and cell wall damage. By comparison, the reagents used for safranin staining combined with fluorescence observation were safe and non-toxic, and the structure of cell in bark could maintain intact easily. According to the comprehensive analysis of different methods, for the excellent clarity of lignin as well as safety and simplicity of operation, safranin staining combined with fluorescence observation is the most suitable method for lignin location in parenchyma cell of rubber tree bark.

In order to study the changes of cassava yield, quality, photosynthetic performance and soil enzyme activities under cassava intercropping mode of muskmelon, and to provide theoretical basis for improving the cultivation technology of cassava intercropping muskmelon in Changsha, cassava (Nanzhi 199) and muskmelon (Xiangtian thin crisp) were used as the experimental materials, cassava monoculture (CK) was used as the control, and three planting densities (T₁, T₂, T₃, plant spacing of 0.5, 0.7, 0.9 m) of muskmelon in cassava intercropping were used as treatments. Compared with monoculture cassava, the number of tuber per plant, dry matter percentage and starch content of cassava were not significantly changed under intercropping treatment, but the yield per plant, economic yield, soluble protein and vitamin C content of cassava increased under intercropping treatment. The effects of each treatment on cassava yield and quality were in the order of T₂>T₃>T₁>CK. The photosynthetic capacity of cassava leaves in intercropping mode significantly increased, and the net photosynthetic rate (P_n) of cassava leaves in root tuber formation and expansion stage was significantly higher than that of monoculture treatment. The P_n of cassava leaves under T₂ treatment was significantly higher than that under other treatments, and the intercropping treatment had significantly higher intercellular CO₂ concentration (C_i), stomatal conductance (G_s) and transpiration rate (T_r) than those under monoculture treatment. With the growth of cassava plants, the activity of sucrase in soil showed a trend of decreasing first and then increasing, urease showed a trend of increasing first and then decreasing, while acid phosphatase and catalase showed a trend of decreasing gradually. The activity of sucrase, acid phosphatase and catalase in soil was significantly promoted by intercropping at different stages, but had little effect on urease activity. The activity of sucrase, acid phosphatase and catalase in soil of T₂ treatment was significantly higher than those of monoculture treatment at the expansion and maturity stages of cassava roots. In conclusion: Compared with cassava monoculture, cassava intercropping model improved cassava photosynthetic performance and soil fertility level, so as to improve the economic yield and quality of cassava. The optimal cultivation model with two rows of cassava intercropping and one row of melon with a distance of 0.7 m was suitable for the cassava intercropping model in Changsha.

The effects of soil compaction caused by the mechanical harvesting of sugarcane variety Guitang 42 on growth and the content of endogenous hormones of roots were studied. The results showed that at the seedling stage, the compaction of 0-50 cm soil layer in the planting row and in the inter-row space increased greatly in mechanically harvested plots compared to the manual harvesting (control), with the highest compaction occurring in the top 0-10 cm layer. There was no significant difference in the compactness of 0-30 cm soil layer in the planting row between mechanically and manually harvested plots, but the compactness of 30-50 cm layer in the inter-row space was significantly higher in the mechanically harvested plots than that in the control. Mechanical harvesting significantly reduced the plant growth rate, plant height, millable stalk number and cane yield by 42.0%, 19.4%, 26.1% and 36.9%, respectively, compared to the control. However, sucrose content in the mechanised crop increased by 1.40, 0.75 and 0.58 % compared with the control. There was no significant difference in plant height, stem diameter, millable stalk number and yield between RCC and control Rootmorphology, root dry weight and root length decreased by 9.12% and 10.72%, respectively, and total root surface area and total root volume significantly decreased, while there was no significant difference between mechanized compaction and control. The endogenous content of hormone IAA, GA₃ and ZR and the levels in relation to that of ABA (IAA/ABA, GA₃/ABA and ZR/ABA) in sugarcane roots grown in compacted soil decreased to varying degrees, compared to that of the control. The root ABA content significantly increased in compacted soil IAA, GA₃, IAA/ABA and GA₃/ABA were positively correlated with root dry weight, root length, plant height and millable stalk number, while ZR and ABA were negatively correlated. In conclusion, mechanical compaction significantly increased soil compactness of sugarcane field, and greatly decreased the growth and yield composition of sugarcane root system.