“环境影响番茄果实色泽变化”实验的PBL教学实践

Practice of PBL for environmental stress on uneven-colored of tomato fruit

运用问题导向学习(PBL)教学方法,以番茄果实着色不均的品质问题为教学实验切入点,引导学生查阅文献解析影响果实品质的环境因子,鼓励学生基于文献查阅结果提出合理设想。根据实验假设,教师引导学生设计不同温度及光照强度组合的多因子实验。通过果实表型观察、叶绿素/番茄红素含量测定、果实硬度分析及荧光定量PCR检测基因表达等植物生理学综合性实验,逐步引导学生发现高温通过抑制番茄红素关键基因的表达抑制番茄红素的合成,从而导致果实着色不均的机理。通过实验,学生能切实感受农业生产与科学研究的紧密联系,体会理论指导实践的重要意义。因此,PBL法结合农业生产实际问题设计的教学实践对培养学生专业知识的综合应用、训练学生的科学思维及创新研究能力具有重要作用。

The quality problem of uneven-colored of tomato fruit is taken as the breakthrough point for a teaching experiment by using the problem-based learning method.Students were guided to propose the possible environmental factors which affected fruit colour change.And then,they were encouraged to put forward a reasonable hypothesis to explain the reason of uneven-colored fruit.According to the assumption,the teacher helped students to design a comprehensive experiment,including different temperatures treatment combined with different light intensities treatment.The students were guided to confirm that high temperature inhibited the level of lycopene synthesis gene to block the lycopene accumulation,which resulting in an uneven fruit coloring,through the results of fruit phenotype observation,chlorophyll/lycopene content,fruit firmness and gene expression.Through this experiment,students could really feel the close relationship between agricultural production and scientific research,and realize the importance of theory guiding practice.Therefore,PBL combined with the agricultural production plays an important role in cultivating students’ability of integrating multi-disciplinary knowledge,students’scientific thinking,and innovative research ability.