植物细胞大小与植物倍性关系的实验探索

本实验以同种植物的不同倍性个体叶片为材料,利用市售指甲油制取植物叶片表皮细胞的复制膜,制成临时装片,通过测量比较气孔保卫细胞的密度和面积,探索植物细胞大小与植物倍性的关系。本实验方法可进一步拓展应用于多倍体植物的鉴定。     

植物学专业课教学的尝试

职业高中教学改革应突出职业高中教学特点,注重学生实际操作能力的培养,提高学生的劳动技术水平,这样才能培养出适应现代化建设需要的中初级技术人才。     

Synthetic and biological studies on a cyclopolypeptide of plant origin

Objective: A natural cyclic peptide previously isolated from Citrus medica was synthesized by coupling oftetrapep-tide units Boc-Leu-Pro-Trp-Leu-Ome and Boc-Ile-Ala-Ala-Gly-Ome after proper deprotection at carboxyl and amino terminals followed by cyclization of linear octapeptide segment.Methods: Solution phase technique was adopted for the synthesis of cyclooctapeptide--sarcodactylamide.Required tetrapeptide units were prepared by coupling of Boc-protected dipeptides viz.Boc-Leu-Pro-OH and Boc-Ile-Ala-OH with respective dipeptide methyl esters Trp-Leu-Ome and Ala-Gly-Ome.Cyclization of linear octapeptide unit was done by p-nitrophenyl ester method.The structure of synthesized cyclopolypeptide was elucidated by FTIR,1H NMR,13C NMR,FABMS spectral data and elemental analysis.The newly synthesized peptide was evaluated for dif-ferent pharmacological activities including antimicrobial,anthelmintic and cytotoxic activities.Results: Synthesis of sarcodac-tylamide was accomplished with >78% yield utilizing dicyclohexylcarbodiimide (DCC) as coupling agent.Newly synthesized peptide possessed potent cytotoxic activity against Dalton's lymphoma ascites (DLA) and Ehrlich's ascites carcinoma (EAC) cell lines,in addition to moderate anthelmintic activity against earthworms Megascoplex konkanensis,Pontoscotex corethruses and Eudrilus sp.Moreover,cyclopolypeptide displayed good antimicrobial activity against pathogenic fungi Candida albicans and Gram-negative bacteria Pseudomonas aeruginosa,in comparison to standard drugs griseofulvin and ciprofloxacin.Conclusion: Solution phase technique employing DCC and triethylamine (TEA) as base proved to be effective for the synthesis of natural cyclooctapeptide.N-methyl morpholine (NMM) was found to be a better base for the cyclization of linear octapeptide unit in comparison to TEA and pyridine.     

淮河源国家森林公园植物资源研究

淮河源国家森林公园位于河南省西南部、桐柏山腹地，共有维管植物181科，785属，1886种及变种，具有丰富的中草药植物资源、观赏植物资源和许多珍稀濒危植物。森林植被垂直分布差异明显，植物种类多方交汇，南北兼容，有许多原始或古老的科属，是一个温带性质的植物区系，而且温带成分和亚热带到暖温带过渡类型突出，其植物的进化类型、生活型具有丰富的多样性。     

植物组织培养中的玻璃化现象

本文叙述了植物组织培养过程中，出现的玻璃苗解剖学特点、生理生化变化、形成原因及预防措施。     

人工诱变在植物病原真菌研究中的应用

分别介绍了物理诱变、化学诱变和插入突变在病原真菌遗传变异规律和致病机理研究中的应用.     

从考试焦虑浅谈高中生耐挫心理的培养

本文就心理耐挫能力的含义及影响因素,探讨增强心理耐挫能力的办法:正确认识自我;制定合适的奋斗目标;树立正确的人生观和世界观;努力完善自我个性特征等。     

植物也会被淹死

发洪水之后，部分植物因受涝死亡，其主要原因在于无氧呼吸时间过长。氧气是植物正常呼吸、氧化物质不可缺少的。水淹后，氧气的不足，直接影响植物呼吸性质和呼吸速率。