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.

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 purpose of the paper is to investigate the physiological and biochemical mechanism of drought and low temperature stress in Sophora davidii seedlings. S. davidii seedlings were used as the experimental materials to evaluate the changes of anti-oxidant protective enzyme activities, membrane injury indexes, osmotic adjustment substances in leaves under increasingly severe drought in natural conditions, and late artificial low temperature treated, with pot experiments. The results showed that the relative water content of leaves decreased significantly with the increase of drought time, and the growth could be restored 2 days after rehydration. Moderate drought was beneficial to the accumulation of photosynthetic pigments, but the content of synchromes decreased in severe drought. Superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities first increased and then decreased with prolonged drought stress. The peak activity of SOD and POD was 458.85 U/g and 5.30 U/g, respectively on the 8th day, which was 142.53% and 68.25% more than CK respectively. Malondialdehyde (MDA) showed a slow increase with the prolonged drought stress, the peak value was 6.20 mmol/g FW on the 15th day, which was 108.75% higher than that of CK. Osmotic adjustment substances such as proline increased first and then decreased with prolonged drought stress, the peak value was 459.67 mg/g on the 10th day, which was 226.45% higher than that that of CK. Under drought stress and low temperature, photosynthetic pigment content of S. davidii leaves decreased significantly, and the changes of three protective enzymes activities (SOD, POD and CAT) increased first and then decreased, which were similar to those under drought stress. Malondialdehyde (MDA) and proline (Pro) showed increase gradually when cold stress continued. Three protective enzymes could play inter-coordinating roles at different stress stages for drought resistance and cold tolerance of S. davidii. The study revealed that S. davidii positively responded to stress through improved antioxidant enzyme activity and the accumulation of osmotic adjustment substances as proline, which could help to reduce reactive oxygen to the membrane damage. Drought stress could improve the adaptability to low temperature, which may be related to the enhancement of protective enzyme system and osmotic regulation ability.

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.

In this study, potassium hydroxide (KOH), ammonia, sodium dodecyl sulfate (SDS) and potassium laurate were added to NRL to study the effects of different stabilizers on the stability of NRL. The results showed that KOH could quickly increase pH value of NRL, maintain the viscosity of fresh latex, improve the mechanical stability (MST) of fresh latex, especially when the dosage exceeds 0.3%. But KOH would increase the viscosity of concentrated natural rubber latex (CNRL), lead to the thickening of the CNRL. It had no obvious effect on improving MST and the mechanical stability (ZST) of the concentrated latex. KOH could significantly improve the thermal stability of the CNRL, significantly improve the particle size of the rubber particles. When the dosage of ammonia was low, pH value of NRL could quickly increased, but when the dosage was high, the effect of improvement was not obvious. Aammonia could stabilize the viscosity of fresh latex, increase MST of fresh latex, but when the dosage exceeded 0.2%, the increase was no longer obvious. At the same time, ammonia could maintain the fluidity of CNRL and stabilize the viscosity value. Ammonia had no obvious effect on improving MST, ZST and thermal stability of CNRL, it had no obvious effect on the particle size of latex rubber particles. SDS would increase the viscosity of the fresh latex, resulting in the thickening of the fresh latex, but it could maintain the fluidity of the CNRL and inhibit the viscosity increase. It could slowly increase MST and ZST of CNRL. Increasing the average particle size of rubber particles also had a certain effect. Potassium laurate would increase the viscosity of fresh latex, resulting in thickening of fresh latex, at the same time, it would also cause CNRL to thicken slowly. Potassium laurate could also rapidly increase MST and ZST of concentrated latex, and cause CNRL to heat up the stability decreases rapidly. It also had a certain effect on increasing the average particle size of rubber particles, but when the dosage exceeded 0.3%, the particle size would also decrease. Therefore, the type and dosage of stabilizers need to be controlled during the production of CNRL.

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.

To explore the effect of the extract from Camellia oleifera cake on the postharvest disease resistance of pitaya, pitaya Zihonglong was sprayed with different concentrations of C. oleifera cake extract before harvest. The fruits were stored at (10±0.5)℃ and 90%-95% RH after harvest. The changes of physical and chemical properties, nutritional components, reactive oxygen species (ROS) metabolism and defense-related enzyme activities of pitaya fruits after harvest were analyzed, and the correlation between each index and comprehensively scores were analyzed. The results indicated that the preharvest spraying extract from C. oleifera cake could effectively reduce the decay index (DI) of pitaya fruit. The respiratory rate (RR) and ethylene release rate (ERR) of pitaya fruit were effectively inhibited by C. oleifera cake extract at the later storage period. Pitaya fruit treated with C. oleifera cake extract effectively delayed the decrease of ascorbic acid (AsA) content, and increased the activities of catalase (CAT), superoxide dismutase (SOD) and other antioxidant enzymes, effectively promoted the metabolism of hydrogen peroxide (H₂O₂) in fruit, reduced the H₂O₂ content, and effectively removed the ROS accumulation during the fruit physiological metabolism. Meanwhile, the C. oleifera cake extract effectively increased the activities of defense-related enzymes such as phenylalanine ammonialyase (PAL), peroxidase (POD), polyphenol oxidase (PPO), β-1,3-glucanase (GLU) and chitinase (CHI) in pitaya fruit, thus improving its disease resistance. Correlation analysis founded that pitaya fruit DI was closely related to the ROS accumulation and membrane lipid peroxidation. Decreasing oxidative stress and maintaining the integrity of cell membrane were the basis for improving the disease resistance of pitaya fruit, and enhancing the disease resistance of pitaya fruit was helpful to reduce decay. Comprehensive evaluation showed that the comprehensive score of pitaya fruit preharvest spraying with 1.00% C. oleifera cake extract was the highest, indicating that its treatment effect was the best. In conclusion, preharvest spraying with 1.00% C. oleifera cake extract could maintain quality of pitaya fruit by improving the antioxidant and disease resistance. The results provide a theoretical reference for the application of C. oleifera cake extract in the postharvest storage and preservation of pitaya.

This paper reported the density, pH value, starch content, soluble protein content, anatomical structure and volatile components of the wood of Humbertia madagascariensis Lam. (HM), which is an endemic species in Madagascar. Methods for determination of wood density (GB/T 1933—2009), determination of wood pH (GB/T 6043—2009), anthrone colorimetric method, coomassie brilliant blue method, wood anatomy method and gas chromatography mass spectrometry (GC-MS) were used to determine the above contents. The results would provide a basis for the research on the wood identification, plant conservation, processing and utilization. The wood basic density of HM was 1.684 g/cm³, and it sank in water test. The wood pH value, starch content and soluble protein content of HM was 6.78, 10.953 mg/g and 0.271 mg/g respectively. The macroscopic structure of HM wood was yellowish-brown, glossy, with the smell of "citrus and sandalwood", diffuse-porous wood with large pore, with white to golden yellow tyloses inside and at the edge especially obvious on the tangential section, wood ray with clear, uniform and fine on the cross section, stripes obviously and densely distributed on the radial section, threadlike, ripple marks slightly visible on the tangential section. The microscopic structure of HM wood was elliptic or round pores, with 3-5 pores per square millimeter, dispersed and solitary vessels containing golden gum inside and at the edges of the pores, non overlapping and homogeneous uniseriate wood rays, with 7-9 wood rays per millimeter, large, mostly elliptic or oblong wood ray cells usually without gum, square cell ray recumbent with 3-7 layers, obvious numerous and regular longitudinal arrangement elliptic crystalson the outside of vessels and in the fibrous tissue on the three sections. GC-MS analysis indicated that the main components were fatty acids (88.81%), followed by lipids (8.12%) and terpenes (0.94%). The highest content of the compound was n-hexadecanoic acid (47.32%), followed by octadecanoic acid (38.79%). It also contained a small amount of unsaturated fatty acids, such as (Z,Z)-9,12-octadecadienoic acid (0.23%) and oleic acid (0.61%), which be speculated may related to "citrus and sandalwood" smell from the wood of HM.

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.

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.