苹果炭疽病菌对苹果果实致病机制初探

对活体内外苹果炭疽菌产生的细胞壁降解酶进行活性分析,初步明确了聚甲基半乳糖醛酸酶(PMG)和羧甲基纤维素酶(Cx)在该菌侵染苹果过程中的作用.结果表明,活体外PMG活性随培养时间增加呈上升趋势,Cx活性则先升后降.活体内,无论抗感品种接种后,均先出现PMG活性高峰,后出现Cx活性高峰;抗病品种的细胞壁降解酶活性要低于中感和感病品种,但酶活高峰出现较早.此外,未接种的健康苹果果实中也检测到细胞壁降解酶,但活性较低.

Pathogenesis of the cell wall degrading enzymes produced by Colletotrichum gloeosporioides

Activities of the cell wall degrading enzymes(CWDEs) produced by Colletotrichum gloeosporioides both in vitro and in vivo were studied.The results primarily demonstrated that PMG and Cx played pathogenic roles during the infection.In vitro,PMG activity showed an increase trend during culture days,and Cx activity firstly increased then decreased,while PMG activity was always higher than Cx activity.In vivo,the peak of PMG activity appeared early and the peak of Cx activity appeared later whether in resistant variety or in susceptible ones after inoculation.The enzyme activities of CWDEs in resistant variety were lower than those in mid-susceptible one and in susceptible one,but the peak in resistant variety showed earlier.In addition,CWDEs could also be detected in healthy apple fruits without inoculation,however,the activities were low.