Powdery mildew caused by Erysiphe quercicola is one of the major diseases of rubber trees. There have been large outbreaks in rubber tree planting areas in China in recent years, seriously reducing the rubber yield. As a common protective forest species in rubber plantations, the evergreen tree Acacia mangium is one of the important host of rubber tree powdery mildew. The study of the biological interactions between E. quercicola and A. mangium could improve the understanding of the behavior of E. quercicola and provide technical guidance for effectively controlling of the primary source of the disease. In this study, cold acclimation significantly enhanced the resistance of A. mangium to rubber tree powdery mildew. The young leaves of A. mangium cultured at 23 ℃ had severe lesions when inoculated with E. quercicola, the young leaves of plants acclimated at 19 ℃ for 30 days had less lesions, and the young leaves of plants acclimated at 15 ℃ for 30 days and the mature leaves cultured at 23 ℃ had no lesion. Electron microscopy scans revealed that the surface of young leaves of A. mangium cultured at 23 ℃ was uneven. The surface of the young leaves cultured at 19 ℃ tended to be flat, with a raised and well-arranged waxy crystal structure. The raised and irregularly waxy crystal structure superimposed and entangled with each other. The surface of young leaves of plants acclimated at 15 ℃ and mature leaves of plants cultivated at 23 ℃ was flat. The surface of the waxy crystal structure was smooth and had obvious crystal-like waxes. Gas chromatography-mass spectrometer (GC-MS/MS) was used to analyze the wax content of A. mangium leaves on both the qualitative and quantitative level. Compared with the young leaves of A. mangium cultivated at 23 ℃, the wax composition of the young leaves acclimated at 15 ℃ and 19 ℃ and the mature leaves of the plants cultured at 23 ℃ were more complex. The main wax components and contents of young leaves acclimated at 15 ℃ were more consistent with those of mature leaves cultured at 23 ℃, and the relative contents of C₃₆ alkane, C₃0 ketone, C₃₂ ester, and C₃₀ alcohol were significantly decreased. In addition, cold acclimation at 15 ℃ could increase the SOD, CAT and POD oxidase activities of young leaves of A. mangium infected by E. quercicola, with SOD enzyme showing the greatest increase. In summary, cold acclimation may improve plant disease resistance by promoting the maturation of the structure and composition of the waxes of young leaves of Acacia mangium and restraining the infection of E. quercicola. This study is useful for understanding the interactions between rubber tree powdery mildew and its hosts, and provides a theoretical basis for efficient control of this disease.

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.

To clarify the adaptability of Eotetranychus sexmaculatus in different main rubber strains in rubber planting areas in China, the development and reproduction of E. sexmaculatus in six rubber strains, Reyan 73397, Reyan 72059, Reken 628, Dafeng 95, PR107 and RRIM600, were observed by biological methods, and the experimental population life table was established. The results showed that different rubber strains had significant effects on the development and reproduction of E. sexmaculatus. The whole generation duration of E. sexmaculatus was the shortest in RRIM600 strain and the longest in Reken 628, which was 10.93 d and 12.82 d, respectively, followed by Reyan 73397, Reyan 72059 and PR107, with no significant difference. The juvenile survival rate of Dafeng 95 strain was the lowest, only 65.00%, and there was no significant difference among other strains. The large number of fecundity per female was the largest when feeding on RRIM600, which were 18.38 eggs. PR107 strain was the most unfavorable to the survival and reproduction of adult mites, and its life span and spawning period were also the shortest. There was significant difference in the sex ratio of F₁ generation of E. sexmaculatus on different rubber strains and the female rate of Dafeng 95 was the highest, which was 78.67%. Through the establishment of population life table for parameter analysis, the intrinsic rate of increase and finite rate of increase of E. sexmaculatus were the largest in RRIM600, and the lowest in Reyan 73397, followed by Reyan 72059, Reken 628 and PR107, which was no significant difference among the Reyan 72059, Reken 628 and PR107. The double population time was the shortest in RRIM600, while was the longest in Reyan 73397, followed by Reyan 72059, Reken 628 and PR107. In a comprehensive view, it showed that E. sexmaculatus had a high fitness when feeding on RRIM600 and a low fitness on PR107.

In order to provide theoretical and practical basis for the effective molybdenum deficiency control measures and rational application of molybdenum fertilizer, field investigation, morphological diagnosis, leaf nutrients content determination and spraying test of ammonium molybdate were carried out in navel orange (Citrus sinensis Osbeck). Further, navel orange leaves with different degrees of chlorisis were collected to measure photosynthetic pigment concentration, photosynthesis rate, chlorophyll fluorescence parameters and photosynthetic product concentration. For normal, slight chlorisis and severe chlorisis leaves, the concentration of nitrogen, potassium, magnesium and born were all in optimum range, zinc and calcium content were no significant difference. The molybdenum content of slight chlorisis and severe chlorisis leaves were lower than that of the threshold value of molybdenum deficiency (0.10 mg/kg), and decreased significantly than the normal leaves. Spraying 0.05% ammonium molybdate significantly reduced the symptoms of chlorisis, indicating that the yellowing leaves of navel oranges in the test orchard was caused by molybdenum deficiency. Molybdenum deficiency symptoms of navel orange were with nearly round and bright yellow waterlogged spots or patches on the new leaves, and the leaves were distorted with the edge leaf rolled up or inward. Photosynthetic pigment concentration, activity of RUBP carboxylase, potential activity (F_v/F_o), maximum photochemical efficiency (F_v/F_m), electron transfer efficiency (ETo/RC) and quantum yield (ETo/CSm) of PSⅡ reaction center decreased significantly with molybdenum deficiency, while the heat dissipation coefficient (DIo/RC) increased significantly. Molybdenum deficiency significantly decreased the photosynthetic rate (P_n), soluble sugar and sucrose contents, indicating molybdenum deficiency will decrease the photosynthesis of navel orange.

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.

This study aimed to investigate the mineral nutrient composition, improve the economic benefits of Ficus hirta Vahl (FH) planting and increase the feed source for the animal farming. The biomass and mineral elements content in leaf, stem and fruit of one-year and two-year-old FH plants intercropped with rubber tree and monoculture was analyzed in the study. The results showed that the aboveground biomass of FH ranged from 3.06 to 9.22 t/hm², which showing monoculture>intercropping, biennial>annual. Intercropping increased the leaf biomass of FH and decreased the stem biomass. Two-year-old intercropping FH plant was mainly fruit development and the fruit biomass was significantly increased by 99.64%. Aboveground plants of FH was rich in mineral elements. The content of mineral elements in leaves and fruits was higher than that in stems. Intercropping under the rubber plantation increased the contents of N, K, Mg, Mn, Cu and Zn, and reduced the contents of Ca and Fe. In the macroelements, the content of K was the highest and P content was the lowest. The ratio of Ca to P in leaves, stems and fruits was between 1.52 and 4.84. In the microelements, the content of Mn was the highest and Cu content was the lowest. The content of mineral elements in leaves and fruits of FH was higher than that in stems. The mineral nutrition of two-year plants was better than that of one-year plants. Intercropping under forests would change the mineral nutrition composition of plants. The FH plant was not suitable for feeding alone according to its mineral nutrient composition. But it could be used as a feed additive to replace part of roughage and save feed cost.

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.

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.

As one of the most prominent spices in the world, pepper (Piper nigrum L.) is extremely popular due to its aroma and flavor. Current study focuses mostly on the production of piperine in pepper, although starch, the primary component of pepper granules, has been researched infrequently and nothing is known about it. The potential for pepper starch to interact with pepper's active components is crucial to pepper production and industrial development. This study separated the starch in black pepper and white pepper using the sodium thiosulfate method and analyzed the two types of pepper starch using various characterization techniques to investigate the characteristics of starch in pepper (black pepper and white pepper) produced by different processing methods. The results indicated that the purity of black pepper starch and white pepper starch was 96.38 and 97.70%, respectively, with low protein, fat, and ash content, and that they belonged to the high-purity starch; SEM and particle size distribution analyses revealed that both black pepper starch and white pepper starch contained exceptionally small starch granules (volume-weighted average diameters of 3.44 μm and 4.80 μm, respectively), although the particle size distribution of black pepper starch was more irregular and broader. Both types of pepper starch had an A-shaped structure; White pepper starch contained more amylose (24.21%), relative crystallinity (34.21%), gelatinization temperature (90.42 ℃), gel strength (1466.72 g), tackiness (157.53), chewiness (87.55), gel enthalpy (15.80 J/g), and retrogradation value (1294.00 cP) when compared to black pepper starch. However, white pepper starch's molecular short-range order (0.67), peak viscosity (3074.00 cP), trough viscosity (2615.67 cP), breakdown viscosity (458.33 cP), and final viscosity (3909.67 cP) were significantly lower than those of black pepper starch (P<0.05), indicating that there are variations in the structure and physicochemical properties of pepper produced by various processing methods. In conclusion, the morphologies of the two types of pepper granules are comparable, and white pepper starch has more amylose concentration and molecular short-range order, as well as better gel qualities and retrogradation characteristics. The primary distinction between white pepper and black pepper is the presence or absence of exocarp; this distinction may be attributable to the presence of a small amount of starch in the exocarp of black pepper. The results of this study would lay a theoretical foundation for the application of pepper starch as a novel unconventional crop small-granular starch in the food and non-food industries and promote the sustainable growth of the pepper business.

In this paper, on the basis of potato sucrose agar medium, the single factor and L₁₆(4⁵) orthogonal optimization experiments were used to study the effects of 5 environmental factors on the mycelial growth and coremium formation of P. cystidiosus. The results showed that the mycelium of P. cystidiosus could grow in the range of temperature 10-30 ℃, agar concentration 0.5%-3.0%, pH 4.00-10.00, petri dish diameter 60-100 mm, and light time 0-24 h. The mycelium grew the fastest under the conditions of temperature 25 ℃, agar concentration 3.0%, pH 5.80, petri dish diameter 100 mm and dark conditions. The coremium of P. cystidiosus can be formed in the range of temperature 15-30 ℃, and the other environmental conditions were the same as that of its mycelium. The number of coremium formation was the largest under pH 8.00, petri dish diameter 100 mm and light duration of 24 h. The orthogonal optimization test showed that the optimum environmental conditions for mycelium growth of P. cystidiosus were temperature 25 ℃, agar concentration 3.0%, pH 5.80, petri dish diameter 100 mm, and dark conditions. The optimum environmental conditions for its coremium formation were temperature 25 ℃, agar concentration 2.0%, pH 8.00, petri dish diameter 100 mm, and light duration 14 h. In a word, the environmental conditions had a great influence on the mycelium growth and coremium formation of P. cystidiosus, and there was an interaction.