Effects of Boron on Spore Germination and Integrity of Colletotrictum gloeosporioides （Penz） Saec

摘要

Litchi anthracnose caused by Colletotrictum gloeosporioides( Penz) Saec. is an extremely destructive and widely distributed disease,which results in poor market value. Borate,an essential plant micronutrient that helps plant growth and has been used extensively in industry and agriculture as a safe method for control of fungi,was effective in the form of potassium tetraborate for control of C. gloeosporioides( Penz). In this study,boron strongly inhibited spore germination,germ tube elongation,and mycelial spread of C. gloeosporioides( Penz) in the culture medium. Application of boron at 1% caused the appearance of abnormal spores( disrupted) in some cases. On the basis of propidium iodide fluorescent staining,the loss of membrane integrity in C. gloeosporioides( Penz) was observed after boron treatment. Furthermore,Boron led to the leakage of cellular constituents( soluble proteins and carbohydrates) from hyphae of C. gloeosporioides( Penz). These data suggest that the mechanisms may be directly related with the disruption effect of boron on cell membrane of the fungal pathogen,resulting in the breakdown of cell membrane structure and loss of cytoplasmic materials from the hyphae.