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      柑橘褐腐病圖片及防治防治措施視頻講解大全圖(柑橘褐腐疫病圖片)

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      Summary : How can conifers that are used, for example, as Christmas trees, keep their green needles over the boreal winter when most trees shed their leaves? Science has not provided a good answer to this question but now an international team of scientists has deciphered that a short-cut in the photosynthetic machinery allows the needles of pine trees to stay green.

      How can conifers that are used, for example, as Christmas trees, keep their green needles over the boreal winter when most trees shed their leaves? Science has not provided a good answer to this question but now an international team of scientists, including researchers from Ume? University, has deciphered that a short-cut in the photosynthetic machinery allows the needles of pine trees to stay green. The study was published in the journal Nature Communications.

      In winter, light energy is absorbed by the green chlorophyll molecules but cannot be utilized by the downstream reactions in the photosynthetic machinery as freezing temperatures stop most biochemical reactions. This is especially a problem in the early spring when temperatures can still be very low, but sunlight is already strong, and the excess light energy can damage the proteins of the photosynthetic machinery. The researchers showed that the photosynthetic apparatus is wired in a special way which allows pine needles to stay green all year long.

      Under normal conditions, the two photosystems, the two functional units where light energy is absorbed and converted into chemical energy, are kept apart from each other to prevent a short-cut and allow efficient photosynthesis. In winter, the structure of the thylakoid membrane, where the two photosystems are located, is reorganized which brings the two photosystems in physical contact. The researchers showed that photosystem II donates energy directly to photosystem I and this short-cut mode protects the green chlorophyll and the needles when conditions become harsh.

      柑橘褐腐病圖片及防治防治措施視頻講解大全圖(柑橘褐腐疫病圖片)

      "We have followed several pine trees growing in Ume? in northern Sweden over three seasons," says Pushan Bag, PhD student at Ume? University, who has collected samples all around the year and made many of the analyses. "It was essential that we could work on needles "straight from outdoors" to prevent that they adjusted to the higher temperatures in the lab environment before we analysed them for example with electron microscopy which we used to visualize the structure of the thylakoid membrane."

      All plants have safety valves to deal with the excess light energy which is either dissipated as heat or as fluorescence light. However, only conifers seem to have such powerful valves that they can keep the photosynthetic apparatus intact over the extreme boreal winter. The research team combined biochemistry and ultrafast fluorescence analysis, a very sophisticated method that can resolve chlorophyll fluorescence light at a picosecond time scale. Like this, they could demonstrate how the pine needles deal with excess light energy to protect their sensitive photosynthetic apparatus from damage.

      "We needed to adjust the equipment to study pine needles in cold temperatures in order to trap the unique mechanism," explains Volha Chukhutsina from Vrije Universiteit Amsterdam, who has performed much of the ultrafast fluorescence analysis. "We also tried spruce needles but they were hard to fit in a good way into the equipment."

      Alfred Holzwarth, who has developed the time-resolved fluorescence measurements adds: "The pine needles gave us the opportunity to study this shortcut mechanism -- also called spill-over -- as they really show an extreme adaptation."

      The study was done with pine trees, but the researchers believe that the mechanism is probably similar for other conifer species -- like the typical Christmas trees spruces and firs -- because their photosynthetic apparatus is similar.

      "This remarkable adaptation not only enjoys us during Christmas but is in fact extremely important for mankind," says professor Stefan Jansson from Ume? University. "Hadn′t conifers been able to survive in extreme harsh winter climates vast areas in the northern hemisphere may not have been colonized as conifers provided firewood, housing and other necessities. Still today they form the basis of the economy in most of the circumpolar taiga region."

      Source : Umea University

      2020年松材線蟲病防治

      國際研討會在線召開

      12月21日,由中國林科院主辦的2020年松材線蟲病防治國際研討會在線召開。中國工程院院士、中國農業科學院副院長吳孔明,北京林業大學副校長駱有慶,中國科學院沈陽分院研究員姬蘭柱,中國林科院院長、國際林聯副主席劉世榮出席會議。國家林草局科技司有關同志,中國林科院、中國科學院動物所、福建農林大學和哈爾濱市三立雅風科技開發有限公司等相關科研和企業的著名學者以及來自法國、葡萄牙、日本、韓國等國的67位代表參加了會議。會議由中國科學院動物研究所研究員孫江華主持。

      國家林草局科技司有關同志指出,國家林草局始終高度重視林業在減緩氣候變化和實現可持續發展目標方面的作用,保護森林生態系統免受外來有害生物危害是重要任務之一。松材線蟲病目前已成為許多國家森林生態系統的共同威脅,需要通過有效措施和開展國際合作來控制其危害和傳播。國家林草局已組織專題研究項目,聯合中國林科院、北京林業大學、南京林業大學及相關機構和企業的專家共同研究松材線蟲病防治相關應急技術。希望此次會議能夠成為分享不同國家和地區松材線蟲病發生危害現狀、研究成果和成功經驗的平臺,促進松材線蟲病防控和生態系統安全維護等合作。

      劉世榮指出,中國是受松材線蟲病影響最嚴重的國家,該病害已經成為危及中國生態安全的重要挑戰。該病具有危害性強、適生區廣、防治和根除困難等特點,且其危害可能受全球氣候變化影響而加劇,目前迫切需要開展國際合作以加強相關認識,促進監測方法及防控措施的分享。一要逐步建立起由科學家、政策制定者、森林從業人員及相關企業共同參與的專門性合作網絡,定期舉辦分享交流會議。二要持續分享各國松材線蟲病相關政策、技術規范和指南。三要著手建立專門網站作為信息共享平臺,匯集松材線蟲病防治信息與方法,為林業從業人員提供實際幫助。

      柑橘褐腐病圖片及防治防治措施視頻講解大全圖(柑橘褐腐疫病圖片)

      聯合國糧農組織森林健康與保護官員Shiroma Sathyapala博士通過主旨報告分享了聯合國糧農組織森林健康和保護項目的情況,并從貿易、監管、經濟社會影響的角度分析了松材線蟲病研究的重要性和防治措施的必要性,提出在全球尺度應對松材線蟲病的措施建議。

      法國農業食品環境研究院Géaldine Roux博士、日本森林綜合研究所Katsunori Nakamura-Matori博士、韓國林科院Hyerim Han博士、中國科學院動物所趙莉藺博士和中國林科院新技術所張星耀研究員通過報告分享了松材線蟲病分布情況及防治技術研究成果。

      柑橘褐腐病圖片及防治防治措施視頻講解大全圖(柑橘褐腐疫病圖片)

      與會者就開展相關國際合作進行了深入討論。

      來源:中國林科院

      “十三五”我國珍稀瀕危物種實現恢復性增長

      五年來,我國通過系統實施瀕危物種拯救工程,建立了占國土面積18%的各類自然保護地,有效保護了90%的植被類型和陸地生態系統、65%的高等植物群落,85%的重點保護野生動物種群,大熊貓、朱鹮、亞洲象、藏羚羊、蘇鐵、西藏巨柏等珍稀瀕危野生動植物種群實現恢復性增長。大熊貓野生種群增至1864只,朱鹮野外種群和人工繁育種群總數超過4000只,亞洲象野外種群增至300頭,藏羚羊野外種群恢復到30萬只以上。

      “十三五”期間我國通過加強野生動物棲息地保護和拯救繁育,不斷強化瀕危野生動物保護,為300多種珍稀瀕危野生動物建立了穩定的人工繁育種群。其中,人工繁育大熊貓數量實現快速優質增長,“十三五”期間繁育成活大熊貓258只,人工圈養種群總數達到633只。對大熊貓、麋鹿、朱鹮、林麝、白頸長尾雉、黑葉猴等一大批野生動物實現放歸自然,并不斷擴大放歸區域和范圍,特別是曾在我國野外消失的野馬、麋鹿,已重新建立起野外種群,9只人工繁育大熊貓放歸自然,并成功融入野生種群。

      柑橘褐腐病圖片及防治防治措施視頻講解大全圖(柑橘褐腐疫病圖片)

      我國還采取就地保護、遷地保護、回歸自然等措施,持續開展珍稀瀕危野生植物保護。通過對德保蘇鐵、華蓋木、百山祖冷杉、天臺鵝耳櫪、普陀鵝耳櫪等近百種極小種群野生植物實施搶救性保護,部分瀕危物種種群數量逐步恢復。目前,我國建有近200個各級各類植物園,收集保存了2萬多個物種,占我國植物區系的2/3?;就瓿闪颂K鐵、棕櫚和原產我國的重點蘭科、木蘭科植物等珍稀野生植物的種質資源收集保存。野外回歸約120個物種,其中多為我國特有種。

      五年來,我國不斷完善野生動植物保護管理制度,嚴厲打擊非法貿易。兩次修訂野生動物保護法,加快推進《國家重點保護野生動物名錄》和《國家重點保護野生植物名錄》調整,制定并實施相關配套管理制度。建立了打擊野生動植物非法貿易部際聯席會議制度,合力打擊破壞野生動植物違法犯罪活動。開展打擊整治破壞野生植物專項行動,嚴厲打擊亂采濫挖野生植物、破壞野生植物生長環境和違法經營利用野生植物行為。

      同時,加快構建野生動物疫源疫病主動預警和監測體系,建成以742處國家級監測站為主體,一大批?。ㄊ?、縣)監測站為補充的野生動物疫源疫病監測防控網絡,啟用“陸生野生動物疫源疫病監測防控信息管理系統”,持續開展禽流感、非洲豬瘟等重點野生動物疫病主動監測預警,構建野生動物病原體庫。成功控制陜西大熊貓犬瘟熱、寧夏巖羊小反芻獸疫、吉林野豬非洲豬瘟、新疆H5N6亞型高致病禽流感等79起突發野生動物疫情,未發生擴散蔓延等重大風險。為維護野生動物種群安全和生物安全,有效防范重大公共衛生風險,切實保障人民群眾生命健康安全,發揮了前沿哨卡和屏障作用。

      我國還進一步強化野生動植物保護國際合作,切實履行有關國際公約義務,與18個國家和11個國際保護組織建立了合作關系,積極落實野生動物保護援外項目,牽頭組織或參與開展“牙刃”等系列全球打擊行動,提升我國國際影響力,為推進全球生物多樣性保護貢獻了中國智慧和中國力量。

      來源:科技日報

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