部分裸子植物叶片总蛋白分析

采用ＳＤＳ－ ＰＡＧＥ 技术, 分析了红豆杉科（Ｔａｘａｃｅａｅ） 植物南方红豆杉（ Ｔａｘｕｓ ｃｈｉｎｅｎｓｉｓｖａｒ－ ｍａｉｒｅｉ （Ｌｅｍｅｅ ｅｔ Ｌｅｖｌ－） Ｃｈｅｎｇ ｅｔ Ｌ－Ｋ－Ｆｕ） 、穗花杉（ Ａｍｅｎｔｏｔａｘｕｓ ａｒｇｏｔａｅｎｉａ （Ｈａｎｃｅ） Ｐｉｌ ｇｅｒ） 、云南穗花杉（ Ａ－ ｙｕｎｎａｎｅｎｓｉｓ Ｌｉ） 、白豆杉（ Ｐｓｅｕｄｏｔａｘｕｓｃｈｉｅｎｉｉ（Ｃｈｅｎｇ） Ｃｈｅｎｇ） 以及三尖杉科（Ｃｅｐｈａｌｏｔａｘａｃｅａｅ） 、植物三尖杉（ Ｃｅｐｈａｌｏｔａｘｕｓ ｆｏｒｔｕｎｅｉ Ｈｏｏｋ－ｆ－） 、粗榧（ Ｃ－ｓｉｎｅｎｓｉｓ （Ｒｅｈｄ－ｅｔＷｉｌｓ－） Ｌｉ） 、海南粗榧（ Ｃ－ｈａｉｎａｎｅｎｓｉｓ Ｌｉ） 、篦子三尖杉（ Ｃ－ｏｌｉｖｅｒｉ Ｍａｓｔ－） 和罗汉松科（Ｐｏｄｏｃａｒｐａｃｅａｅ） 、植 物罗汉松 （ Ｐｏｄｏｃａｒｐｕｓ ｍａｃｒｏｐｈｙｌｌｕｓ （ Ｔｈｕｎｂ－ ） Ｄ－Ｄｏｎ） 、鸡毛 松（ Ｐ－ｉｍｂｒｉｃａｔｕｓ Ｂｌ－） 、竹柏（ Ｐ－ ｎａｇｉ（Ｔｈｕｎｂ－） Ｚｏｌｌ） 、陆均松（ Ｄａｃｒｙｄｉｕｍ ｐｉｅｒｒｅｉ Ｈｉｃｋｅｌ） 共１２ 种植物的叶片蛋白, 在蛋白质水平上采用     

云衫针层孔菌化学成分的研究

从云衫针层孔菌Ｐｈｅｌｌｉｎｕｓ ｙａｍａｎｏｉ（Ｔａｍｚ．）ｓｈａｗ分离得到１２个化合物,借助光谱分析鉴定为：８,１１,１３－ａｂｉｅｔａｄｉｅｎ－１８－ｏｉｃ ａｃｉｄ（１）,１,２－ｂｅｎｚｅｎｅｄｉ－ｃａｒｂｏｘｙｌｉｃ ａｃｉｄｂｉｓ（２－ｅｔｈｙｌ－ｈｅｘｙｌ）ｅｓｔｅｒ（２）,ｅｒｇｏｓｔｅｒｏｌ ｐｅｒｏｘｉｄｅ（３）,ｅｒｇｏｓｔａ ７,２２（Ｅ）－ｉｄｅｎ－３－ｏｌ（４）,ｅｒｇｏｓｔａ ７,２２（Ｚ）－ｄｉｅｎ－３－ｏｌ（５）,ｏｃｔａｄｅｃａｎｏｉｃ ａｃｉｄ－１,３－ｐｒｏｐａｎｅｄｉｙｌ ｅｓｔｅｒ（６）,ｏｃｔａｄｅｃａｎｏｉｃ ａｃｉｄ（７）,８（１９）,１４－ｌａｂｄａｄｉｅｎ－１３－ｏｌ（８）,ｅｒｇｏｓｔａ－４,６,８（１４）,２２－ｔｅｔｒａｅｎ－３－ｏｎｅ（９）,化合     

多荚草中的新三萜皂甙

从石竹科植物多荚草（Ｐｏｌｙｃａｒｐｏｎ ｐｒｏｓｔｒａｔｕｍ（Ｆｏｒｓｓｋ．）Ａｓｃｈｅｒｓ．ｅｔ Ｓｃｈｗｅｉｎ．ｅｘ Ａｓｃｈｅｒｓ）中分离得到３个新的柴胡皂甙类化合物：ｐｒｏｓｔｒａｔｏｓｉｄｅ Ａ￣Ｃ（１￣３）。它们的结构通过波谱方法分别鉴定为：３－Ｏ－｛β－Ｄ－ｘｙｌｏｐｙｒａｎｏｓｙｌ－（１→２）－β－Ｄ－ｇｌｕｃｏｐｙｒａｎｏｓｙｌ－（１→４）－「β－Ｄ－ｇｌｕｃｏｐｙｒａｎｏｓｙ     

荒漠沙蜥的年龄划分

荒漠沙蜥的年龄划分徐海根（国家环保局南京环境科学研究所,２１００４２）杨凤翔,宋志明（兰州大学,７３００００）（四川大学,成都６１００６４）ＡｇｅＤｉｆｆｅｒｅｎｔｉａｔｉｏｎｏｆＰｈｒｙｎｏｃｅｐｈａｌｕｓｐｒｚｅｗａｌｓｋｉｉｏｎＤｅｓｃｒｔｓ￥．ＸｕＨａｉｇｅｎ（ＮａｎｊｉｎｇＩｎｓｔｉｔｕｔｅｏｆＥｎｕｉｒｏｎ－ｍｅｎｔａｌＳｃｉｅｎｃｅｓ,２１００４２）,ＹａｎｇＦｅｎｇｘｉａｎｇ（ＬａｎｚｈｏｕＵｎｉｕｅｒｓｉｔｙ,７３００００）,ＳｏｎｇＺｈｉｍｉｎｇ（ＳｉｃｈｕａｎＵｎｉｕｅｒ－ｓｉｔｙ,Ｃｈｅｎｇｄｕ６１００６４）．ＣｈｉｎｅｓｅＪｏｕｒｎａｌｏｆＥｃｏｌｏｇｙ,１９９３,１２（４）：３０－３２．Ｕｓｉｎｇｍａｒｋ－ｒｅｃａｐｔｕｒｅｍｅｔｈｏｄａｎｄａｃｃｏｒｄｉｎｇｔｏｔｈｅｓｎｏｕｔ－ｖｅｎｔｌｅｎｇｔｈｇｒｏｗｔｈｐａｔｔｅｒｎ,ｆｉｖｅａｇｅｇｒｏｕｐｓｏｆＰｈｒｙ,ｉｏｃｅｐｈａｌｕｓｐｒｚｅｗａｌｓｋｉｉｏｎｄｅｓｅｒｔｓａｒｅｄｉｆｆｅｒｅｎｔｉａｔｅｃｄ．Ａｎｄｂａｓｅｄｏｎｔｈｅｄａｔａｏｆｌｉｚａｒｄｓｍｏｒｐｈｏｌｏ－ｇｙ,ｔｈｅｃｏｍｍｕｎｉｔｙｏｆＰｈｒｙｎｏｃ     

云木香化学成分研究Ⅱ

从丽江产云木香（ＳａｕｓｒｅａｌａｐｐａＣ．Ｂ．Ｃｌａｒｋｅ）根中分离得到的另外７个化合物,它们分别是＿孕甾烯醇酮（ｐｒｅｇｎｅｎｏｌｏｎｅ）（１）,β－谷甾醇（β－ｓｉｔｏｓｔｅｒｏｌ）（２）,葫萝卜甙（ｄａｕｃｏｓｔｅｒｏｌ）（３）,苯丙素甙（ｓｙｒｉｎｇｉｎ）（４）,木质素甙（１－ｈｙｄｒｏｘｙｐｉｎｏｒｅｓｉｎｏｌ－１－β－Ｄ－ｇｌｕｃｏｐｙｒａｎｏｓｉｄｅ）（５）,油酸［（ｚ,ｚ）－９,１２－ｏｃｔａｄｅｃａｄｉｅｎｏｉｃａｃｉｄ］（６）和油酸－１,３－甘油二酯［（ｚ,ｚ）－９,１２－ｏｃｔａｄｅｃａｄｉｅｎｏｉｃａｃｉｄ－２－ｈｙｄｒｏｘｙ－１,３－ｐｒｏｐａｎｅｄｉｎｙｌｅｓｔｅｒ］（７）．它们的结构通过波谱和化学的方法得到鉴定。其中化合物１作为天然产物首次从植物中分离得到,化合物３,４,５和７为首次从该植物中分离得到。     

90年代农村发展与农业生态研究

９０年代农村发展与农业生态研究彭廷柏（中国科学院长沙农业现代化研究所,４１０１２５）ＲｕｒａｌＤｅｖｅｌｏｐｍｅｎｔａｎｄＡｇｒｏ－ｅｃｏｌｏｇｉｃａｌＲｅｓｅａｒｃｈｉｎ１９９０ｓ￥．ＰｅｎｇＴｉｎｇｂａｉ（ＣｈａｎｇｓｈａＩｎｓｔｉｔｕｔｅｏｆＡｇｒｉ－ｃｕｌｔｕｒａｌＭｏｄｅｒｎｉｚａｔｉｏｎ,ＡｃａｄｅｍｉａＳｉｎｉｃａ,４１０１２５）．ＣｈｉｎｅｓｅＪｏｕｒｎａｌｏｆＥｃｏｌｅｇｙ,１９９３,１２（２）：２－３．ＩｎｏｒｄｅｒｔｏａｐｐｒｏａｃｈｔｈｅｒｅｌａｔｅｄｐｒｏｂｌｅｍｓｏｆＣｈｉｎａ’ｓａｇｒｏ－ｅｃｏｌｏｇｉｃａｌｒｅｓｅａｒｃｈｉｎ１９９０ｓ,ｔｈｉｓｐａｐｅｒａｎａ－ｌｙｚｅｄｔｈｅｎｅｗｔｒｅｎｄｓｏｆｓｔｒｕｃｔｕｒａｌｃｈａｎｇｅｓｉｎｒｕｒａｌｅｃｏｎｏｍｙａｎｄａｇｒｏ－ｅｃｏｌｏｇｙ．ｕｎｄｅｒｃｏｎｄｉｔｉｏｎｏｆｓｏｃｉａｌｉｓｔｍａｒｋｅｔｅｃｏｎｏｍｙｅｘｐｏｕｎｄｅｄｓｏｍｅｖｉｅｗｐｏｉｎｔｓｏｎｔｈｅｃｏｏｒｄｉｎａｔｉｖｅｄｅｖｅｌｏｐｍｅｎｔｏｆａｇｒｏ－ｅｃｏｌｏｇｙａｎｄａｇｒｏ－ｅｃｏｎｏｍｙ,ｔｈｅｓｔｒｅｎｇｔｈｅｎｉｎｇｏｆａｂｓｏｒｂｉ     

杨树护田林带疏透度模型及应用

杨树护田林带疏透度模型及应用张纪林,吕祥生（江苏省林业科学研究所,南京２１１１５３）（江苏省农林厅林业局,南京２１１１５３）ＰｏｒｏｓｉｔｙＭｏｄｅｌｏｆＰｏｐｌａｒＦａｒｍｌａｎｄＳｈｅｌｔｅｒｂｅｌｔａｎｄＩｔｓＡｐｐｌｉｃａｔｉｏｎ￥ＺｈａｎｇＪｉｌｉｎ（Ｆｏｒｅｓｔｒｙｓｃｉｅｎｃｅａｎｄｔｅｃｈ－ｎｏｌｏｇｙｒｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅｏｆＪｉａｎｇｓｕ）,ＬｕＸｉａｎｇｓｈｅｎｇ（ＦｏｒｅｓｔｒｙＢｕｒｅａｕ“ｏｆＪｉａｎｇｓｕＰｒｏｖｉｎｃｅ）．ＣｈｉｎｅｓｅＪｏｕｒｎａｌｏｆＥｃｏｌｏｇｙ,１９９３,１２（５）：５６－６０。Ｉｎｔｈｉｓａｒｔｉｃｌｅ,ｔｈｅａｕｔｈｏｒｓａｔｆｉｒｓｔｍａｄｅｔｈｒｅｅ－ｐｒｉｎｃｉｐｌｅｄｓｅｌｅｃｔｉｏｎ,ｐａｒｔｉａｌｃｏｒｒｅｌａｔｉｏｎ,ｂｅｓｔｍｕｌｔｉ－ｐｒｉｎ－ｃｉｐｌｅｒｅｇｒｅｓｓｉｏｎｓｅｌｅｃｔｌｏｎｉｎｓｅｑｕｅｎｃｅ,Ｓｅｃｏｎｄｌｙｏｎｔｈｅｂａｓｉｓｏｆｒｅｓｉｄｕａｌａｎａｌｙｓｉｓ,ｔｈｅａｕｔｈｏｒｓｍａｄｅｔｅｓｔｏｆｈｉｇｈｌｅｖｅｒａｇｅｃａｓｅ,ｉｎｆｌｕｅｎｃｅｃａｓｅａｎｄｏｕｔｌｉｅｒｏｎｓａｍｐｌｅ     

有机体之间化学相互作用的研究及其应用

有机体之间化学相互作用的研究及其应用宋启示（中国科学院昆明生态研究所,６５０２２３）ＣｈｅｍｉｃａｌＩｎｔｅｒａｃｔｉｏｎＡｍｏｎｇＯｒｇａｎｉｓｍｓａｎｄＴｈｅｉｒＡｐｐｌｉｃａｔｉｏｎ￥ＳｏｎｇＱｉｓｈｉ（ＫｕｎｍｉｎｇＩｎｓｔｉｔｕｔｅｏｆＥｃｏｌｏ－ｇｙ,ＡｃａｄｅｍｉａＳｉｎｉｃａ６５０２２３）．ＣｈｉｎｅｓｅＪｏｕｒｎａｌｏｆＥｃｏｌｏｇｙ,１９９３,１２（１）：４５－４８。Ｔｈｉｓｐａｐｅｒｒｅｖｉｅｗｓｔｈｅｍｏｓｔａｃｔｉｖｅｒｅｓｅａｒｃｈｆｉｅｌｄｓｏｎｃｈｅｍｉｃａｌｉｎｔｅｒａｃｔｉｏｎａｍｏｎｇｏｒｇａｎｉｓｍｓ：（１）ａｌｌｅｌｏｐａ－ｔｈｙａｍｏｎｇｐｌａｎｔｓ,ｗｈｉｃｈｉｓｗｉｄｅｌｙａｐｐｌｉｅｄｉｎａｇｒｉｃｕｌｔｕｒｅａｎｄｈｏｒｔｉｃｕｌｔｕｒｅ,（２）ｂｉｏｃｈｅｍｉｃａｌｉｎｔｅｒａｃｔｉｏｎｂｅ－ｔｗｅｅｎｐｌａｎｔｓａｎｄｉｎｓｅｃｔｓ,（３）ｂｉｏｃｈｅｍｉｃａｌｉｎｔｅｒａｃｔｉｏｎａｍｏｎｇｉｎｓｅｃｔｓａｎｄ（４）ｂｉｏｃｈｅｍｉｃａｌｉｎｔｅｒａｃｔｉｏｎａｍｏｎｇｍａｍｍａｌｓａｎｄｂｅｔｗｅｅｎｍａｍｍａｌｓａｎｄｐｌａｎｔｓ．Ｉｎａｄｄｉｔ     

辽宁省灾害区划初探

辽宁省灾害区划初探尹功成,梁文举（辽宁省农业区划研究所,沈阳１１００３１）（中国科学院沈阳应用生态研究所,１１００１５）ＡｎＡｐｐｒｏａｃｈｔｏＣａｌａｍｉｔｙＤｉｖｉｓｉｏｎｉｎｇｏｆＬｉａｏｎｉｎｇＰｒｏｖｉｎｃｅ￥．ＹｉｎＧｏｎｇｃｈｅｎｇ（ＬｉａｏｎｉｎｇＩｎｓｌｉｔｕｔｅｏｆＡｇｒｉ－ｃｕｌｔｕｒａｌＤｉｖｉｓｉｏｎｉｎｇ,Ｓｈｅｎｙａｎｇ１１００３１）,ＬｉａｎｇＷｅｎｊｕ（ＩｎｓｌｉｌｕｔｅｏｆＡｐｐｌｉｅｄＥｃｏｌｏｇｙ,ＡｃａｄｅｍｉａＳｉｎｉｃａ,Ｓｈｅｎｙａｎｇ１１００１５）．ＣｈｉｎｅｓｅＪｏｕｒｎａｌｏｆＥｃｏｌｏｇｙ,１９９３,１２（４）：６１－６５．ＮａｔｕｒａｌｃａｌａｍｉｔｉｅｓｏｃｃｕｒｗｈｅｎｖａｒｉＯｕｓｎａｔｕｒａｌｐｈｅｎｏｍｎａｅｎｄａｎｇｅｒｌｉｆｅ,ｍｉｎｄｓａｎｄｐｒｏｐｅｒｔｉｅｓ,ｂｕｔｓｏｍｅｐｏｔｅｎｔｉａｌｅｎｖｉｒｏｎｍｅｎｔａｌｄｉｓａｓｔｅｒｓｓｕｃｈａｓｒｎａｎ－ｍａｄｅａｎｄａｎｔｈｒｏｐｏｇｅｎｏｕｓｎａｔｕｒａｌｄｉｓａｓｔｅｒｓｄｅｖｅｌｏｐｓｌｏｗ－ｌｙａｎｄｐｒｏｆｏｕｎｄｌｙ,ｗｈｌｃｈａｒｅｕｎｏｂｖｉｏｕｓａｎｄｎｏｔｒ     

兴安盟山杏灌木草原的排序

兴安盟山杏灌木草原的排序王晓江,章中,刘永军,章海波（内蒙古林业科学研究院,呼和浩特０１００１０）ＯｒｄｉｎａｔｉｏｎｏｆＰｒｕｎｕｓｓｉｂｉｒｉｃａＳｈｒｕｂ－ＳｔｅｐｐｅｓｉｎＸｉｎｇａｎＬｅａｇｕｅ,ＩｎｎｅｒＭｏｎｇｏｌｉａ￥ＷａｎｇＸｉａｏｊｉａｎｇ;ＺｈａｎｇＺｏｎｇ;ＬｉｕＹｏｎｇｊｕｎ;ＺｈａｎｇＨａｉｂｏ（ＩｎｎｅｒＭｏｎｇｏｌｉａＡｃａｄｅｍｙｏｆＦｏｒｅｓｔｒｙＳｃｉｅｎｃｅｓ,Ｈｕｈｈｏｔ０１００１０）．Ｃｈｉ－ｎｅｓｅＪｏｕｒｎａｌｏｆＥｃｏｌｏｇｙ,１９９３,１２（１）：２９－３２。ＴｈｅＰｒｕｎｕｓｓｉｂｉｒｉｃａｓｈｒｕｂ－ｓｔｅｐｐｅｓｉｎＸｉｎｇａｎＬｅａｇｕｅｏｆＩｎｎｅｒＭｏｎｇｏｌｉａａｒｅｓｔｕｄｉｅｄｕｓｉｎｇａｎｕｍｂｅｒｏｆｏｒ－ｄｉｎａｔｉｏｎｍｅｔｈｏｄｓ,ｉｎｃｌｕｄｉｎｇｐｏｌａｒｏｒｄｉｎａｔｉｏｎ（ＰＯ）,ｐｒｉｎｃｉｐａｌｃｏｍｐｏｎｅｎｔａｎａｌｙｓｉｓ（ＰＣＡ）ｏｒｄｉｎａｔｉｏｎａｎｄｃｏｒｒｅｓｐｏｎｄｅｎｃｅａｎａｌｙｓｉｓ（ＣＯＡ）ｏｒｄｉｎａｔｉｏｎ,２２ｐｏｌｔｓｏｆＰｒｕｎｕｓｓｉｂｉｒｉｃａｓｈｒｕｂ－ｓｔｅｐｐｅｓａｒｅｃ     

嫁接茄子根系分泌物的化感效应

采用室内生物测定的方法,研究了不同砧木、不同浓度和不同生育期嫁接茄子根系分泌物的化感效应.结果表明,嫁接茄根系分泌物与自根茄相比,促进了茄子种子的萌发和幼苗生长.各砧木品种嫁接茄根系分泌物的化感效应显著或极显著高于对照,其中发芽率和苗高最高,增加29.1％和37.1％;不同浓度试验结果呈现“低促高抑”的规律,当浓度为0.04 g·ml^-1时发芽率最高,比对照增加50％,当浓度增加到0.24 g·ml^-1时,根长比对照降低了30.3％;在生长后期嫁接茄的根系分泌物对种子萌发的促进作用小于前中期,而自根茄抑制作用增强.因此,生产中使用嫁接技术是缓解由自毒作用引起的连作障碍的有效方法之一.     

拟南芥prr5突变体对ABA的响应

以拟南芥为材料,统计PRRs （pseudo-response regulators）突变体 prr5及其野生型经ABA处理后的萌发率、根长和NaCl处理后的萌发率,并采用实时定量PCR方法,对不同浓度ABA处理的拟南芥幼苗中的PRR5基因表达进行分析.结果表明：prr5突变体对ABA弱敏感,其种子萌发率比野生型显著或极显著增高,主根比野生型长,且PRR5基因表达受ABA抑制.同时,NaCl处理后,prr5的萌发率比野生型极显著增高.因此,推测prr5可能为ABA信号通路相关基因.     

Inhibition of seed germination by extracts of bitter Hawkesbury watermelon containing cucurbitacin, a feeding stimulant for corn rootworm (Coleoptera: Chrysomelidae)

Cucurbitacins are feeding stimulants for corn rootworm used in baits to control the adults of this insect pest. Corn rootworm larvae also feed compulsively on cucurbitacins. Cucurbitacins are reported to be gibberellin antagonists that may preclude their use as seed treatments for these soil-dwelling insects. The crude extract of a bitter Hawkesbury watermelon containing cucurbitacin E-glycoside significantly inhibited germination of watermelon, squash, and tomato seeds. Although the germination of corn seed was not significantly inhibited, root elongation was inhibited by crude extracts, but not by high-performance liquid chromatography-purified cucurbitacin E-glycoside. Therefore, the effects of the major components in the bitter watermelon extract (e.g., sugars) on seed germination and root elongation were determined. Pure sugars (glucose and fructose), at concentrations found in watermelon extract, mimicked the inhibition of seed germination and root elongation seen with the crude bitter Hawkesbury watermelon extract. Removal of these sugars may be necessary to use this extract as a bait for corn rootworm larvae as a seed or root treatment.     

Germination and development of the soma in Boschniakia hookeri (Orobanchaceae)

Germination of the holoparasitic angiosperm Boschniakia hookeri differs from the usual pattern among the Orobanchaceae. In most members of the family, the germinating seed develops a radix which establishes contact with the host root; in contrast, in B. hookeri the host root makes contact with the parasite seed, penetrates its testa, and association between host root and parasite embryo tissues is then established inside the testa.
The germination and development of the perennial vegetative body, the soma, can be divided into ten stages, with characteristic changes from stage to stage. The first four stages range from the pre–germination through the germination proper, including physical contact between parasite and host root; formation of the soma, through development of the first stem bud, occurs in stages five to ten. The processes for the first six stages occur completely within the testa.
The mature soma apparently produces flowers when it reaches a size around 15 mm in diameter and continues to grow. Maximum seems to be around 50–60 mm, where dense clusters of 10–12 inflorescences can occur.     

Colonization of cucumber seeds by bacteria during germination

Detailed analysis revealed fundamental differences between bacterial association with cucumber (Cucumis sativus) seeds and seedlings roots. Seed colonization by bacteria seems to result from passive encounter between bacteria, conveyed by imbibed soil solution, and the germinating seed. In accordance, the seed-associated bacterial community composition directly reflected that of the germination medium and was characterized by low dominance. Transition from seed to root was marked by a shift in bacterial community composition and in an increase in dominance values. Furthermore, settlement of bacteria on roots was tightly controlled by the specific properties of each root segment. Size and richness of the seed-associated bacterial community were clearly determinate by the community in the germination medium. In contrast, for fully developed and active roots, the medium effect on these parameters was negligible. Perturbation of the seed environment by a pathogen (Pythium aphanidermatum) had major consequences on the seed bacterial community. However, those were mostly related to direct pathogen-bacteria rather than seed-bacteria interactions. In conclusion, simple, even passive processes may determine the initial stage of plant-microbe association during seed germination, prior to extension of the primary root. Therefore, seed germination is a unique phase in the plant life cycle, with respect to its interaction with the below-ground microbiome.     

Effects of waterlogging on seed germination of three Mediterranean oak species: Ecological implications

Soil water saturation during prolonged periods of time generates a negative impact on nearly all terrestrial plants. In Mediterranean woodlands, precipitation can be very abundant during the wet season, inducing temporary soil waterlogging, coinciding with the seed dispersal and germination time of many species. We investigated the effects of waterlogging on seed germination and early root growth of three coexisting oak species (Quercus canariensis, Q. suber and Q. pyrenaica), by completely flooding of seeds for various periods of time. The three oak species showed a certain level of tolerance to waterlogging, only being affected those seeds subjected for long periods of submersion (over 30 days). Waterlogging during prolonged periods of time decreased the probability of seed germination in the three oak species, lengthened the time to germination, and hampered root development in two of the studied species. The main differences between oak species occurred in terms of root growth (Q. canariensis being the less affected, and Q. suber the most); these differential responses could be related to a species rank of waterlogging tolerance. Thus inter-specific differences in germination responses to waterlogging could contribute to explain, at least partially, species habitat and distribution patterns across landscapes. Seed mass also played an important role on different aspects of germination, though its relative importance varied as function of species and waterlogging treatment. The tolerance to stress induced by waterlogging increased with seed mass, but only in the case of Q. canariensis.     

SeedQuant: a deep learning-based tool for assessing stimulant and inhibitor activity on root parasitic seeds

Witchweeds (Striga spp.) and broomrapes (Orobanchaceae and Phelipanche spp.) are root parasitic plants that infest many crops in warm and temperate zones, causing enormous yield losses and endangering global food security. Seeds of these obligate parasites require rhizospheric, host-released stimulants to germinate, which opens up possibilities for controlling them by applying specific germination inhibitors or synthetic stimulants that induce lethal germination in the host’s absence. To determine their effect on germination, root exudates or synthetic stimulants/inhibitors are usually applied to parasitic seeds in in vitro bioassays, followed by assessment of germination ratios. Although these protocols are very sensitive, the germination recording process is laborious, representing a challenge for researchers and impeding high-throughput screens. Here, we developed an automatic seed census tool to count and discriminate germinated seeds (GS) from non-GS. We combined deep learning, a powerful data-driven framework that can accelerate the procedure and increase its accuracy, for object detection with computer vision latest development based on the Faster Region-based Convolutional Neural Network algorithm. Our method showed an accuracy of 94% in counting seeds of Striga hermonthica and reduced the required time from approximately 5 min to 5 s per image. Our proposed software, SeedQuant, will be of great help for seed germination bioassays and enable high-throughput screening for germination stimulants/inhibitors. SeedQuant is an open-source software that can be further trained to count different types of seeds for research purposes.     

Changes in Germination and Seedling Traits of Sesame under Simulated Drought

Drought is considered one of the leading abiotic constraints to agricultural crop production globally. Present study was conducted to assess the effects of different drought treatments (viz. Control, 10% PEG, and 20% PEG) on seed germination, germination indices, seedling traits, and drought tolerance indices of sesame. Our results showed that maximum reduction in the studied parameters was observed at higher PEG concentration (i.e., 20% PEG). As compared to control, the drought treatments viz. 10% and 20% PEG decreased the values for germination indices, such as germination percentage, coefficient of variation of germination time, germination index, and seedling vigor index. Similarly, for seedling traits, the values were decreased for root length, shoot length, root shoot ratio, root fresh weight, shoot fresh weight, root dry weight and shoot dry weight under 10% and 20% PEG treatments significantly in comparison with control. Furthermore, relative to control, the values for drought tolerance indices, such as germination drought tolerance index, root length drought tolerance index, shoot length drought tolerance index, total seedling length drought tolerance index, root fresh weight drought tolerance index, shoot fresh weight drought tolerance index, total fresh weight drought tolerance index, root dry weight drought tolerance index, shoot dry weight drought tolerance index and total dry weight drought tolerance index were also reduced under 10% and 20% PEG treatments, respectively. Our results confirms that drought impact on seed germination and seedling traits could be quantified by using different indices which can further help to design drought adaptation and mitigation strategies. Based on these results it can be concluded that germination indices, seedling traits, and drought tolerance indices have great potential to simulate drought stress impacts on different crop traits thus they should be used in all kinds of stress related studies.     

干旱胁迫下华北驼绒藜种子大小及苞片对萌发和幼苗生长的影响

干旱是影响荒漠区植物种子萌发和幼苗生长的关键因素。以多年生强旱生半灌木华北驼绒藜为对象,研究了不同干旱程度(0、100、200、300和400 g·L^-1 PEG6000)下,种子大小及苞片有无对种子萌发及幼苗生长的影响。结果表明: 干旱胁迫显著抑制了种子萌发和幼苗地上部的生长。100和200 g·L^-1 PEG6000处理显著增加了幼苗根长,而300和400 g·L^-1 PEG6000处理显著降低了幼苗根长。与无苞片相比,有苞片使种子的发芽率显著降低12%,发芽指数显著降低50.5%,幼苗的地上部长度显著增加20.8%,幼苗根长显著增加6.3%。种子大小对种子发芽指数无显著影响,但与小种子相比,大种子发芽率显著提高3%,幼苗的地上部长度显著增加20.5%,幼苗根长显著增加33.0%。在干旱条件下,苞片能延缓种子的萌发速度,种子大小能影响后代的存活几率,二者共同影响华北驼绒藜对极端干旱环境的适应性。     

山茶科濒危植物猪血木的生态与繁殖特性

在广东省阳春市八甲镇地区发现濒危和特有植物猪血木（Euryodendron excelsum)80余株个体及其自然居群,通过其生境条件,分布格局,群落组成,物候,种子散布和种子萌发实验等研究。结果显示该植物生长繁殖正常;其种子散布以黄臀鹎（Pycnonotus xanthorrhous)等鸟类散布为主,但鸟类消化处理不是其种子萌发的必要条件,湿度保持是其种子保持活力的重要条件;其种子无休眠期,同时探讨了该植物的濒危状况的原因。提出了相应的保护建议和方案。