The Qinling Mountains, known for their rich vegetation and diverse pollinating insects, have seen a significant decline in bee species richness and abundance over recent decades, largely due to the introduction and sp...The Qinling Mountains, known for their rich vegetation and diverse pollinating insects, have seen a significant decline in bee species richness and abundance over recent decades, largely due to the introduction and spread of Apis mellifera. This decline has caused cascading effects on the region's community structure and ecosystem stability. To improve the protection of native bees in the natural and agricultural landscape of the Qinling Mountains and its surrounding areas, we investigated 33 sampling sites within three habitats: forest, forest-agriculture ecotones, and farmland. Using a generalized linear mixing model, t-test, and other data analysis methods, we explored the impact of Apis mellifera on local pollinator bee richness, abundance, and the pollination network in different habitats in these regional areas. The results show that(1)Apis mellifera significantly negatively affects the abundance and richness of wild pollinator bees,while Apis cerana abundance is also affected by beekeeping conditions.(2)There are significant negative effects of Apis mellifera on the community structure of pollinator bees in the Qinling Mountains and its surrounding areas: the Shannon-Wiener diversity index, Pielou evenness index, and Margalef richness index of bee communities at sites with Apis mellifera influence were significantly lower than those at sites without Apis mellifera influence.(3)The underlying driver of this effect is the monopolization of flowering resources by Apis mellifera. This species tends to visit flowering plants with large nectar sources, which constitute a significant portion of the local plant community. By maintaining a dominant role in the bee-plant pollination network, Apis mellifera competitively displaces native pollinator bees, reducing their access to floral resources. This ultimately leads to a reduction in local bee-plant interactions, decreasing the complexity and stability of the pollination network. These findings highlight the need for targeted conservation efforts to protect native pollinator species and maintain the ecological balance in the Qinling Mountains.展开更多
The chemical compositions of volatile oil from fruiting body of Armillaria luteo-virens in Qinghai Province were firstly analyzed with GC-MS and its relevant compositions were detected by calculating chromatographic p...The chemical compositions of volatile oil from fruiting body of Armillaria luteo-virens in Qinghai Province were firstly analyzed with GC-MS and its relevant compositions were detected by calculating chromatographic peak area with normalized method. 21 peaks were separated and 13 compositions were identified which were mainly unsaturated fatty acids, taking 97.1% of the total volatile oil.展开更多
[Objective] The experiment aimed to study chromatographic fingerprint in volatile components of acacia honey and provide scientific evaluation and effective control on quality of acacia honey.[Method] Using solid-phas...[Objective] The experiment aimed to study chromatographic fingerprint in volatile components of acacia honey and provide scientific evaluation and effective control on quality of acacia honey.[Method] Using solid-phase microextraction method to separate and detect volatile components and construct chromatographic fingerprint.[Result] The honey was preheated for 15 min in water bath at 40 ℃ and solid-phase microextraction 85 μmPA was used to extract in overhead air about 30 min,then put it into the injector and desorpted 3 min,which is in 230 ℃.The Supelco WaxTM10 30 m×0.25 mm×0.25 μm column and gradient heating program was the best method to separate volatile components from honey.83 fingerprint peaks were constructed,among which 17 common fingerprint peaks were comprised of chromatographic fingerprint of volatile components of acacia honey.[Conclusion] The chromatographic fingerprint could provide reference for quality control of acacia honey.展开更多
Dynamics of dry- or fresh-weight of fruit, peel photosynthetic rate and chlorophyll content, and the characteristics of translocation and distribution of radiolabelled assimilates from leaf or fruit were examined in d...Dynamics of dry- or fresh-weight of fruit, peel photosynthetic rate and chlorophyll content, and the characteristics of translocation and distribution of radiolabelled assimilates from leaf or fruit were examined in developing satsuma mandarin (Citrus unshiu Marc. cv. Miyagawa wase) fruit from primary stage of fruit enlargement up to fruit full ripe. Change in fruit photosynthetic rate was some what related to the change in the chlorophyll content of peel. Fruit photosynthetic rate markedly declined as chlorophyll degradation occurred in the peel. Before full ripe stage of the fruit, photosynthates produced by a 14C-fed leaf were mainly distributed to juice sacs even during periods when dry matter accumulation in peel was more rapid than that in juice sacs. At the full ripe stage, peel photosynthetic rate approached zero and peel became the major sink of leaf photosynthates. Most of the peel assimilates, however, remained in situ for up to 48 h after feeding 14CO 2 to the fruit, only a small portion being transported to other parts of fruit. The percentage of fruit photosynthates exported decreased with fruit development and ripening, but the peak rate of export to juice sacs amount to as high as 12%. The sugar content and dry weights of peel and juice sacs in shaded fruit were lower than that in the control fruit. These results show that peel assimilate was mainly consumed in peel respiration and growth and thus the dependence on leaf photosynthates decreased. Part of this assimiate was used in sugar accumulation in juice sacs of fruit.展开更多
[Objective] The aim was to observe the antibacterial effect of nano-scale Titanium dioxide on parasitic bacterium of Nanfeng Citrus in storage period.[Method] Nano-scale Titanium dioxide was prepared by dibutyl phthal...[Objective] The aim was to observe the antibacterial effect of nano-scale Titanium dioxide on parasitic bacterium of Nanfeng Citrus in storage period.[Method] Nano-scale Titanium dioxide was prepared by dibutyl phthalate through sol-gel method under anhydrous conditions,and orthogonal experiment was used to determine optimum conditions for nano-scale Titanium dioxide preparation,and structure characterization of nano-scale Titanium dioxide was carried out by X-Ray diffractometer.Oxford cup method was used to explore inhibition effect of nano-scale Titanium dioxide suspension on the activity of normal parasitic bacterium of Nanfeng Citrus.Simultaneously,the empirical preservation test was carried out.[Result] The average diameter of nano-scale Titanium dioxide powder attained to 14.6 nm,actual average yield could reach 90.83% with RSD（Relative Standard Deviation）of 0.86%.[Conclusion] Nano-scale Titanium dioxide had good antibacterial effect on the parasitic bacterium of Nanfeng Citrus in storage period.展开更多
In order to build method for measuring of elements in honey, the contents of Ba, Cu, Pb, Cd, As, Hg, Cr, Mn, Se had been determined by microwave diges- tion （MWD） and actively coupled plasma atomic emission spectrom...In order to build method for measuring of elements in honey, the contents of Ba, Cu, Pb, Cd, As, Hg, Cr, Mn, Se had been determined by microwave diges- tion （MWD） and actively coupled plasma atomic emission spectrometry （ICP-AES）. The results show that, the range of heavy metal elements were in the range of 0- 10.0 mg/L, with good linear relationship. In addition, all correlation coefficients kept higher than 0.999, and the recovery rate of ample added with standard solution was in 94.1%-110%. By comparison with the result of chemical experiment, the method was quickly accessible and convenient, widely used in the measurement of elements in honey, with satisfactory results.展开更多
基金funded by the National Key R&D Program of China (2022YFE0115200)the Biodiversity Survey and the Assessment Project of the Ministry of Ecology and Environment, China (2019HJ2096001006)the National Animal Collection Resource Center, China。
文摘The Qinling Mountains, known for their rich vegetation and diverse pollinating insects, have seen a significant decline in bee species richness and abundance over recent decades, largely due to the introduction and spread of Apis mellifera. This decline has caused cascading effects on the region's community structure and ecosystem stability. To improve the protection of native bees in the natural and agricultural landscape of the Qinling Mountains and its surrounding areas, we investigated 33 sampling sites within three habitats: forest, forest-agriculture ecotones, and farmland. Using a generalized linear mixing model, t-test, and other data analysis methods, we explored the impact of Apis mellifera on local pollinator bee richness, abundance, and the pollination network in different habitats in these regional areas. The results show that(1)Apis mellifera significantly negatively affects the abundance and richness of wild pollinator bees,while Apis cerana abundance is also affected by beekeeping conditions.(2)There are significant negative effects of Apis mellifera on the community structure of pollinator bees in the Qinling Mountains and its surrounding areas: the Shannon-Wiener diversity index, Pielou evenness index, and Margalef richness index of bee communities at sites with Apis mellifera influence were significantly lower than those at sites without Apis mellifera influence.(3)The underlying driver of this effect is the monopolization of flowering resources by Apis mellifera. This species tends to visit flowering plants with large nectar sources, which constitute a significant portion of the local plant community. By maintaining a dominant role in the bee-plant pollination network, Apis mellifera competitively displaces native pollinator bees, reducing their access to floral resources. This ultimately leads to a reduction in local bee-plant interactions, decreasing the complexity and stability of the pollination network. These findings highlight the need for targeted conservation efforts to protect native pollinator species and maintain the ecological balance in the Qinling Mountains.
基金the National Natural Science Foundation of China (30460083)the Key Science and Technology Project of Chinese Ministry of Education (205164)~~
文摘The chemical compositions of volatile oil from fruiting body of Armillaria luteo-virens in Qinghai Province were firstly analyzed with GC-MS and its relevant compositions were detected by calculating chromatographic peak area with normalized method. 21 peaks were separated and 13 compositions were identified which were mainly unsaturated fatty acids, taking 97.1% of the total volatile oil.
基金Support by Department of Education Science and Technology Research Projects of Hebei Province(2008310)the National Special Fund for the Commonweal Industry(200810345)~~
文摘[Objective] The experiment aimed to study chromatographic fingerprint in volatile components of acacia honey and provide scientific evaluation and effective control on quality of acacia honey.[Method] Using solid-phase microextraction method to separate and detect volatile components and construct chromatographic fingerprint.[Result] The honey was preheated for 15 min in water bath at 40 ℃ and solid-phase microextraction 85 μmPA was used to extract in overhead air about 30 min,then put it into the injector and desorpted 3 min,which is in 230 ℃.The Supelco WaxTM10 30 m×0.25 mm×0.25 μm column and gradient heating program was the best method to separate volatile components from honey.83 fingerprint peaks were constructed,among which 17 common fingerprint peaks were comprised of chromatographic fingerprint of volatile components of acacia honey.[Conclusion] The chromatographic fingerprint could provide reference for quality control of acacia honey.
文摘Dynamics of dry- or fresh-weight of fruit, peel photosynthetic rate and chlorophyll content, and the characteristics of translocation and distribution of radiolabelled assimilates from leaf or fruit were examined in developing satsuma mandarin (Citrus unshiu Marc. cv. Miyagawa wase) fruit from primary stage of fruit enlargement up to fruit full ripe. Change in fruit photosynthetic rate was some what related to the change in the chlorophyll content of peel. Fruit photosynthetic rate markedly declined as chlorophyll degradation occurred in the peel. Before full ripe stage of the fruit, photosynthates produced by a 14C-fed leaf were mainly distributed to juice sacs even during periods when dry matter accumulation in peel was more rapid than that in juice sacs. At the full ripe stage, peel photosynthetic rate approached zero and peel became the major sink of leaf photosynthates. Most of the peel assimilates, however, remained in situ for up to 48 h after feeding 14CO 2 to the fruit, only a small portion being transported to other parts of fruit. The percentage of fruit photosynthates exported decreased with fruit development and ripening, but the peak rate of export to juice sacs amount to as high as 12%. The sugar content and dry weights of peel and juice sacs in shaded fruit were lower than that in the control fruit. These results show that peel assimilate was mainly consumed in peel respiration and growth and thus the dependence on leaf photosynthates decreased. Part of this assimiate was used in sugar accumulation in juice sacs of fruit.
文摘[Objective] The aim was to observe the antibacterial effect of nano-scale Titanium dioxide on parasitic bacterium of Nanfeng Citrus in storage period.[Method] Nano-scale Titanium dioxide was prepared by dibutyl phthalate through sol-gel method under anhydrous conditions,and orthogonal experiment was used to determine optimum conditions for nano-scale Titanium dioxide preparation,and structure characterization of nano-scale Titanium dioxide was carried out by X-Ray diffractometer.Oxford cup method was used to explore inhibition effect of nano-scale Titanium dioxide suspension on the activity of normal parasitic bacterium of Nanfeng Citrus.Simultaneously,the empirical preservation test was carried out.[Result] The average diameter of nano-scale Titanium dioxide powder attained to 14.6 nm,actual average yield could reach 90.83% with RSD（Relative Standard Deviation）of 0.86%.[Conclusion] Nano-scale Titanium dioxide had good antibacterial effect on the parasitic bacterium of Nanfeng Citrus in storage period.
文摘In order to build method for measuring of elements in honey, the contents of Ba, Cu, Pb, Cd, As, Hg, Cr, Mn, Se had been determined by microwave diges- tion （MWD） and actively coupled plasma atomic emission spectrometry （ICP-AES）. The results show that, the range of heavy metal elements were in the range of 0- 10.0 mg/L, with good linear relationship. In addition, all correlation coefficients kept higher than 0.999, and the recovery rate of ample added with standard solution was in 94.1%-110%. By comparison with the result of chemical experiment, the method was quickly accessible and convenient, widely used in the measurement of elements in honey, with satisfactory results.
