The extract from leaves of Rhododendron dauricum L. was extracted with 95% alcohol by common method for studying its insecticidal activities. The chemical components of the alcohol extract and relative contents were a...The extract from leaves of Rhododendron dauricum L. was extracted with 95% alcohol by common method for studying its insecticidal activities. The chemical components of the alcohol extract and relative contents were analyzed by GC-MS. The insecticidal activities of the alcohol extract were tested on the 2nd？3rd instar larvae of Lymantria dispar L. for five days. Five concentrations of the extract samples were designed as 50, 10, 5, 1, and 0.5 g？L？1. The results show that the alcohol extracts from leaves of R. dauricum exhibited insecticidal activities against larvae of L. dispar. The corrected mortality of larvae of L. dispar for was over 50% for both contact toxicity and stomach toxicity at the extract concentration of ≥ 5 g·L？1 after five days of application. The insecticidal activity in contact toxicity is more effect than stomach toxicity for the alcohol extract. Twenty compounds, with total GC relative contents of 93.81% in the alcohol extract from leaves of R. dauricum were identified. The main chemical components in the extract are： （1） 4,5-Dihydro-5-oxo-3-（p-tolyl） isoxazole, with a relative content of 40.03%; （2） 1,3-Benzenediol, 5-methyl-2-（3,7,11-trimethyl-2,6,10- dodecatrienyl）-, （E,E）-, the relative content 18.27%; （3） 3,6-Diphenyl- 1,2,3,4,5,6,7,8-octahydro-1,8-acridinedione, the relative content 3.89%; （4） 6H-[1,2,4]Triazolo[1,5-a]indole, 4a,5,7,8,8a,9-hexahydro-9- methylene-, the relative content 2.99%; （5） 7-Amino-4-methyl-1,8- naphthyridin-2-ol, the relative content 2.64%; （6） 4-Methyl-2,6- dihydroxyquinoline, the relative content 2.63%; （7） 2,4,6- Triaminoquinazoline, the relative content 2.27%; （8） 2（1H）-Quinolinone, 4-hydroxy-1-methyl-, the relative content 2.02%.展开更多
昭通杜鹃(Rhododendron tsaii)于2021年列入《云南省极小种群野生植物名录》,云南大山包黑颈鹤国家自然保护区为新分布记录,为掌握该保护区内昭通杜鹃的种群及分布状况,于2022年3—8月采用访问、踏查、实地调查及面积测量等方法,初步查...昭通杜鹃(Rhododendron tsaii)于2021年列入《云南省极小种群野生植物名录》,云南大山包黑颈鹤国家自然保护区为新分布记录,为掌握该保护区内昭通杜鹃的种群及分布状况,于2022年3—8月采用访问、踏查、实地调查及面积测量等方法,初步查清昭通杜鹃在该地的分布及种群状况。结果显示:昭通杜鹃空间上分布于大山包集镇南侧的4个地块;种群分布面积3022.24 m 2;种群数量共计550丛,其中健康223丛,亚健康207丛,不健康120丛,单株幼树2株;成苗率低、种群面积狭小,鼠害、干旱等是昭通杜鹃繁衍的主要威胁因子;受限于空间分布狭窄,且处于人为干扰较频繁的区域,严重威胁着昭通杜鹃的生存,急需采取相关保护措施;现有文献资料表明云南大山包黑颈鹤国家自然保护区是昭通杜鹃已知种群数量最大的分布地。基于上述结果,建议相关部门采取就地、近地保护措施,在云南大山包黑颈鹤国家自然保护区建立昭通杜鹃保护示范小区,进行严格保护,以恢复其种群。展开更多
文摘The extract from leaves of Rhododendron dauricum L. was extracted with 95% alcohol by common method for studying its insecticidal activities. The chemical components of the alcohol extract and relative contents were analyzed by GC-MS. The insecticidal activities of the alcohol extract were tested on the 2nd？3rd instar larvae of Lymantria dispar L. for five days. Five concentrations of the extract samples were designed as 50, 10, 5, 1, and 0.5 g？L？1. The results show that the alcohol extracts from leaves of R. dauricum exhibited insecticidal activities against larvae of L. dispar. The corrected mortality of larvae of L. dispar for was over 50% for both contact toxicity and stomach toxicity at the extract concentration of ≥ 5 g·L？1 after five days of application. The insecticidal activity in contact toxicity is more effect than stomach toxicity for the alcohol extract. Twenty compounds, with total GC relative contents of 93.81% in the alcohol extract from leaves of R. dauricum were identified. The main chemical components in the extract are： （1） 4,5-Dihydro-5-oxo-3-（p-tolyl） isoxazole, with a relative content of 40.03%; （2） 1,3-Benzenediol, 5-methyl-2-（3,7,11-trimethyl-2,6,10- dodecatrienyl）-, （E,E）-, the relative content 18.27%; （3） 3,6-Diphenyl- 1,2,3,4,5,6,7,8-octahydro-1,8-acridinedione, the relative content 3.89%; （4） 6H-[1,2,4]Triazolo[1,5-a]indole, 4a,5,7,8,8a,9-hexahydro-9- methylene-, the relative content 2.99%; （5） 7-Amino-4-methyl-1,8- naphthyridin-2-ol, the relative content 2.64%; （6） 4-Methyl-2,6- dihydroxyquinoline, the relative content 2.63%; （7） 2,4,6- Triaminoquinazoline, the relative content 2.27%; （8） 2（1H）-Quinolinone, 4-hydroxy-1-methyl-, the relative content 2.02%.
文摘昭通杜鹃(Rhododendron tsaii)于2021年列入《云南省极小种群野生植物名录》,云南大山包黑颈鹤国家自然保护区为新分布记录,为掌握该保护区内昭通杜鹃的种群及分布状况,于2022年3—8月采用访问、踏查、实地调查及面积测量等方法,初步查清昭通杜鹃在该地的分布及种群状况。结果显示:昭通杜鹃空间上分布于大山包集镇南侧的4个地块;种群分布面积3022.24 m 2;种群数量共计550丛,其中健康223丛,亚健康207丛,不健康120丛,单株幼树2株;成苗率低、种群面积狭小,鼠害、干旱等是昭通杜鹃繁衍的主要威胁因子;受限于空间分布狭窄,且处于人为干扰较频繁的区域,严重威胁着昭通杜鹃的生存,急需采取相关保护措施;现有文献资料表明云南大山包黑颈鹤国家自然保护区是昭通杜鹃已知种群数量最大的分布地。基于上述结果,建议相关部门采取就地、近地保护措施,在云南大山包黑颈鹤国家自然保护区建立昭通杜鹃保护示范小区,进行严格保护,以恢复其种群。
