糜子感染黑穗病菌后的生理变化及与抗病性关系
Study on physiological changes and correlation with resistance level to the head smut of broomcorn millet after an infection with Sphacelotheca destruen

为明确糜子对黑穗病的抗性生理机制,在大田条件下,以不同抗性水平的10个糜子品种为材料,采用种子饱和接种法人工接种黑粉菌,测定了三叶期不同糜子品种叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、β-1,3-葡聚糖酶、几丁质酶活性以及丙二醛(MDA)含量.结果表明,人工接种黑粉菌后不同抗性水平糜子品种叶片SOD、β-1,3-葡聚糖酶和几丁质酶活性有所提高,最大增幅分别达92%、16%和31%; MDA含量有所增加,最大增幅达20%;POD活性呈不同变化.人工接种条件下抗性水平较高品种的保护酶系统酶活性以及病程相关蛋白活性提升幅度较大,MDA含量增加幅度较小.各生理指标与抗病性的相关分析表明,SOD、POD、β-1,3-葡聚糖酶以及几丁质酶活性与发病率呈极显著负相关,相关系数分别为0.941、0.468、0.514和0.757;MDA含量与发病率呈显著正相关,相关系数为0.378.
In order to study the resistance mechanism of broomcorn millet to head smut,10 broomcorn millet cultivars at different resistance levels were selected as the experiment material under the field condition.Using the method of artificial inoculation of seed saturated inoculation,SOD,POD,β-1,3-glucanase and chitinase activities and MDA content were analyzed at three leaves stages in the leaves of different broomcorn millet cultivars.The results indicated that after artificial inoculation,the activities of SOD,β-1,3-glucanase and chitinase all increased in different cultivars,and the largest increase amplitudes were 92%,16% and 31% respectively.The content of MDA increased as well,and the largest increase amplitude was 20%.However,POD activity showed different trends in cultivars at different resistance levels.Under the condition of artificial inoculation,cultivars at high resistance level had a higher increase amplitude in the activities of protective enzymes and the pathogenesis proteins than the cultivars at low resistance level,while the content of MDA performed with a reversed tendency.Each physiological index had a closed correlation with the resistance level,the activities of SOD,POD,β-1,3-glucanase and chitinase had a negative correlation with the incidence,and the correlation coefficients are 0.941,0.468,0.514 and 0.757 respectively,but the content of MDA had a positive correlation with the incidence,and the correlation coefficient is 0.378.