柱花草接种炭疽菌后防御酶活性反应的品种间差异

Responses of defense enzyme activities to inoculation with Colletotrichum gloeosporioides in four cultivars of Stylosanthes spp.differing in resistance

以4个抗病性不同的柱花草品种为材料,研究了接种胶胞炭疽菌后过氧化物酶(POD)、草酸氧化酶(OXO)、多酚氧化酶(PPO)、抗坏血酸氧化酶(AAO)、几丁质酶和β-1,3-葡聚糖酶活性的变化。高抗品种Tarido、中抗品种CIAT184和TPRC90087在接种后能较快和较大幅度诱导POD活性,在48 h分别为对照的2.69,1.48和2.27倍。而高感品种Graham需较长时间才诱导POD活性,且诱导幅度较低,在48 h与对照相比没有增加。高抗品种Tar-ido接种炭疽菌后PPO活性持续升高,96 h达到最大值时,处理是对照的2.22倍,中抗品种和高感品种Graham的PPO活性在接种后与对照间差异不大。Tarido的β-1,3-葡聚糖酶在接种后诱导幅度和持续时间均大于CIAT184和TPRC90087,最大增幅依次为对照的1.72,1.46和1.45倍。而高感品种Graham的酶活性无变化。4个品种的总几丁质酶、AAO和OXO活性在接种后与对照相差不大。结果表明,柱花草接种后POD、PPO和β-1,3-葡聚糖酶活性被诱导的时间及程度可能与品种的抗病性大小有关。

The activities of peroxidase （POD）, oxalase oxidase （OXO）, polyphenol oxidase （PPO）, ascorbic acid oxidase （AAO）, chitinase and β-1,3-glucanase were measured by spectrophotometer in four cultivars of Stylosanthes differing in disease resistance, Tardio, CIAT184, TPRCg0087 and Graham, following inoculation with conidiospore suspension of C. gloeosporioides. POD activity was highly and rapidly induced in the high and medium resistant cultivars following the inoculation, while that in the disease sensitive cultivar was induced slowly. The PPO activity was induced and maintained at a high level in comparison to the unaltered level in the other three cultivars. β-1,3-glucanase activity was also induced and maintained at a high level for 72 h in the highly resistance cultivar, Tardio, but it was only maintained for 48 h in the medium resistant cultivars, CIAT184 and TPRCg0087, compared with the unaltered activity in the sensitive cultivar, Graham. The chitinase, AAO and OXO activity were not changed by inoculation of the four cultivars. It is suggested that the induction of POD, PPO and β-1,3-glucanase activity is associated with the disease resistance to C. gloeosporioides in Stylosanthes spp.