尖孢镰刀菌侵染对香蕉幼苗叶片细胞结构的作用研究

Effect of Fusarium oxysporum Infection on Leaf Structure of Banana Seedlings

研究病原菌侵染对香蕉植株叶片结构的作用,以期为香蕉枯萎病防治提供理论依据。利用温室溶液培养植株接种病原菌的方法,测定了病原菌侵染之后香蕉叶片结构及成分含量的变化。结果表明:(1)叶片纤维素含量在轻病株和重病株中分别降低了16.5%和37.4%,质外体汁液电导率分别增加了4倍和19倍。(2)叶片氮素含量在轻病株和重病株中分别降低了5%和12%,羧化效率也显著降低。(3)显微镜观察发现发病叶片呈颜色不均一、水渍状镂空症状。(4)透射电镜观察表明发病叶片细胞膜和叶绿体均遭到严重破坏。综上所述,病原菌侵染使得香蕉植株叶片细胞壁、细胞膜和叶绿体均遭到破坏,继而影响叶片对CO_2的同化能力。

By studying the effect of pathogen infection on leaf structure, the authors aim to provide a theoreticalbasis for preventing banana wilt disease. The changes of the structure and composition of banana leaves afterinfection were determined by means of greenhouse solution culturing plant pathogenic bacteria. The resultsshowed as follows：（1） the cellulose content was decreased by 16.5% and 37.4% in lightly and heavily diseaseplants, respectively, and electrical conductivity of apoplastic sap was increased by 4 times and 19 times,respectively;（2） leaf nitrogen content was decreased by 5% and 12% in lightly and heavily disease plants,respectively, and the carboxylation efficiency was also decreased obviously;（3） uneven leaf color andhygrophanous hollow symptoms were observed in the micrographs;（4） through the observation of transmissionelectron micrographs, cell membrane and chloraplast were both seriously injured. It was concluded that leafcell wall, cell membrane and chloroplast were damaged, and then decreased the CO2 assimilation rate.