Citral(Eo)exhibits excellent fungicidal activities.However,it is difficult to maintain long-term fungicidal activity due to its strong volatility.Herein,a controlled-release strategy by using biomass-derived porous ca...Citral(Eo)exhibits excellent fungicidal activities.However,it is difficult to maintain long-term fungicidal activity due to its strong volatility.Herein,a controlled-release strategy by using biomass-derived porous carbon(BC)was developed to overcome the drawback of Eo.New composite materials were prepared by loading Eo on tea stem porous carbon(BC@Eo),and their controlled-release fungicidal activity against Exobasidium vexans was assessed.BC with a large specific surface area of 1001.6 m2/g and mesoporous structure was fabricated through carbonization tempera-ture of 700℃.The BC@Eo materials were characterized using Fourier-transform infrared spectroscopy and X-ray powder diffraction.The results suggested that chemical and physical interactions occurred in BC@Eo.The Eo release profile suggested a biphasic pattern with an initial fast release on days 1–14 and a subsequent controlled phase on days 14–30.The in vitro cumulative release percentage of Eo from BC@Eo was 51%during one month,and this result was significantly lower than that from free Eo(cumulative release percentage of Eo of 82%in one week).The anti-fungal activities of Eo and BC@Eo against E.vexans were determined using the inhibition zone method.The results indicated that Eo and BC@Eo formed large inhibition zones of 19.66±0.79 and 21.92±0.77 mm,respectively.The influence on the hyphal structure of E.vexans was observed by scanning electron microscopy on day 30.The hyphal structure of E.vexans treated with BC@Eo was more shrunken than that treated with Eo at 30 days,suggesting that BC@Eo prolongs the fungicidal activity against E.vexans.This study demonstrated that the encapsulation of Eo in BC for developing the BC@Eo materials could be a promising strategy to inhibit volatility and maintain the fungicidal activity of Eo and provide a potential alternative for the reuse of abundant tea biomass waste resources.展开更多
Mexico is the main producer,consumer and exporter of avocado in the world,being Michoacan the main producer state contributing more than 80%of the national production.There are phytopathogens that decimate the product...Mexico is the main producer,consumer and exporter of avocado in the world,being Michoacan the main producer state contributing more than 80%of the national production.There are phytopathogens that decimate the production causing the death of the tree.Root samples were collected in avocado trees that showed the characteristic symptomatology of the disease known as avocado sadness,the sampling was carried out in four of the main avocado producing towns,in the state of Michoacan,Mexico.The isolation consisted in sowing root tissue in Petri dishes with V8R-PARPH culture medium,subsequently they were identified morphologically and for species level it was determined by molecular biology,with the PCR-ITS technique.Pathogenicity tests were performed in triplicate with avocado seedlings with more than six leaves.After 24 hours,the inoculated plants expressed decay in the apical part,after 120 hours the leaves showed yellowing and after 15 days there was a generalized wilt on the stem and leaves,re-isolating the phytopathogen Phytopythium vexans.This study confirms the first report of the oomycete P.vexans affecting avocado trees in the most important producing region of the Mexican Republic.展开更多
During 2009 and 2010, 23 night-time mosquito captures were made at Kanci obora in south-eastern Moravia, Czech Republic. It was used in the Centers for Disease Control and Prevention （CDCP） miniature light traps wit...During 2009 and 2010, 23 night-time mosquito captures were made at Kanci obora in south-eastern Moravia, Czech Republic. It was used in the Centers for Disease Control and Prevention （CDCP） miniature light traps with CO2 （dry ice） and baited lard-can traps in which sentinel animals were replaced with a container filled with CO2 （dry ice）. In the observed period, a total of 31,882 female mosquitoes were captured by CDC miniature light traps with CO2. Lard-can traps baited with CO2 captured 995 females under the same conditions, which is just 3.12% of the quantity from the CDC traps. At the same time, there were significant differences in the proportional captures of various species. Compared to CDC miniature light traps, baited lard-can traps much more often captured Aedes cinereus （16.58% of total versus 1.93% in CDC traps）, Culex modestus （15.48% versus 4.62%）, and Ae. rossicus （6.13% versus 2.67%）. On the other hand, capture of female Ae. vexans was proportionally much lower （15.38% versus 36.41%）. Capture of Cx. pipiens was more or less the same 14.77% （miniature light traps） and 15.76% （baited lard-can traps）. The occurrence of the calamity species Ae. sticticus was proportionally very high in both trap types （30.05% in lard-can traps baited with CO2, 33.58% in CDC miniature light traps）. The findings prove that a trap＇s design itself significantly affects not only the overall capture of mosquitoes but also the proportional representation of individual species.展开更多
基金Supported by National Modern Agricultural Industry Technology System,Youth Science and Technology Fund of Guizhou Academy of Agricultural Sciences No.[2020]02,Guiding Project of Guizhou Academy of Agricultural Sciences No.[2018]01.
文摘Citral(Eo)exhibits excellent fungicidal activities.However,it is difficult to maintain long-term fungicidal activity due to its strong volatility.Herein,a controlled-release strategy by using biomass-derived porous carbon(BC)was developed to overcome the drawback of Eo.New composite materials were prepared by loading Eo on tea stem porous carbon(BC@Eo),and their controlled-release fungicidal activity against Exobasidium vexans was assessed.BC with a large specific surface area of 1001.6 m2/g and mesoporous structure was fabricated through carbonization tempera-ture of 700℃.The BC@Eo materials were characterized using Fourier-transform infrared spectroscopy and X-ray powder diffraction.The results suggested that chemical and physical interactions occurred in BC@Eo.The Eo release profile suggested a biphasic pattern with an initial fast release on days 1–14 and a subsequent controlled phase on days 14–30.The in vitro cumulative release percentage of Eo from BC@Eo was 51%during one month,and this result was significantly lower than that from free Eo(cumulative release percentage of Eo of 82%in one week).The anti-fungal activities of Eo and BC@Eo against E.vexans were determined using the inhibition zone method.The results indicated that Eo and BC@Eo formed large inhibition zones of 19.66±0.79 and 21.92±0.77 mm,respectively.The influence on the hyphal structure of E.vexans was observed by scanning electron microscopy on day 30.The hyphal structure of E.vexans treated with BC@Eo was more shrunken than that treated with Eo at 30 days,suggesting that BC@Eo prolongs the fungicidal activity against E.vexans.This study demonstrated that the encapsulation of Eo in BC for developing the BC@Eo materials could be a promising strategy to inhibit volatility and maintain the fungicidal activity of Eo and provide a potential alternative for the reuse of abundant tea biomass waste resources.
文摘Mexico is the main producer,consumer and exporter of avocado in the world,being Michoacan the main producer state contributing more than 80%of the national production.There are phytopathogens that decimate the production causing the death of the tree.Root samples were collected in avocado trees that showed the characteristic symptomatology of the disease known as avocado sadness,the sampling was carried out in four of the main avocado producing towns,in the state of Michoacan,Mexico.The isolation consisted in sowing root tissue in Petri dishes with V8R-PARPH culture medium,subsequently they were identified morphologically and for species level it was determined by molecular biology,with the PCR-ITS technique.Pathogenicity tests were performed in triplicate with avocado seedlings with more than six leaves.After 24 hours,the inoculated plants expressed decay in the apical part,after 120 hours the leaves showed yellowing and after 15 days there was a generalized wilt on the stem and leaves,re-isolating the phytopathogen Phytopythium vexans.This study confirms the first report of the oomycete P.vexans affecting avocado trees in the most important producing region of the Mexican Republic.
文摘During 2009 and 2010, 23 night-time mosquito captures were made at Kanci obora in south-eastern Moravia, Czech Republic. It was used in the Centers for Disease Control and Prevention （CDCP） miniature light traps with CO2 （dry ice） and baited lard-can traps in which sentinel animals were replaced with a container filled with CO2 （dry ice）. In the observed period, a total of 31,882 female mosquitoes were captured by CDC miniature light traps with CO2. Lard-can traps baited with CO2 captured 995 females under the same conditions, which is just 3.12% of the quantity from the CDC traps. At the same time, there were significant differences in the proportional captures of various species. Compared to CDC miniature light traps, baited lard-can traps much more often captured Aedes cinereus （16.58% of total versus 1.93% in CDC traps）, Culex modestus （15.48% versus 4.62%）, and Ae. rossicus （6.13% versus 2.67%）. On the other hand, capture of female Ae. vexans was proportionally much lower （15.38% versus 36.41%）. Capture of Cx. pipiens was more or less the same 14.77% （miniature light traps） and 15.76% （baited lard-can traps）. The occurrence of the calamity species Ae. sticticus was proportionally very high in both trap types （30.05% in lard-can traps baited with CO2, 33.58% in CDC miniature light traps）. The findings prove that a trap＇s design itself significantly affects not only the overall capture of mosquitoes but also the proportional representation of individual species.
