| 摘要: |
| 为鉴定‘GR891’和‘新选048’2个木薯(Manihot esculenta Crantz)品种抗细菌性枯萎病等级，分析木薯叶片侵染病原菌后PAL(苯丙氨酸解氨酶)、SOD(超氧化物歧化酶)、POD(过氧化物酶)、PPO(多酚氧化酶)和CAT(过氧化氢酶)5种酶活性，并研究细菌性枯萎病与酶活性关系。利用喷雾法接种木薯叶片评价抗细菌性枯萎病等级，分光光度法测定POD、SOD、CAT和PAL酶活性，采用碘滴定法测定PPO酶活性。结果表明:感病的‘新选048’木薯叶片的病斑长度为(0.3±0.1)cm，病情指数为29.4，而‘GR891’的病斑长度为(0.6±0.2)cm，病情指数为43.7；侵染12 d后的2个木薯品种叶片的CAT、PPO、POD3 种酶的活性均有一定程度的上升，其中‘新选048’接种病原菌后CAT、PPO、POD分别上升了72.31%、9.55%、94.78%，‘GR891’接种病原菌后CAT、PPO、POD分别上升了34.2%、20.05%、91.63%，均与抗性呈正相关；‘新选048’的POD和CAT活性水平显著高于‘GR891’酶活性水平，2 个木薯品种PAL活性表现各异，‘新选048’PAL活性与抗性呈正相关，而‘GR891’与抗性呈负相关；SOD活性与抗病性不相关。综合各个酶活性变化和木薯的病情指数来看，‘新选048’比‘GR891’对细菌性枯萎病的抗病性更强。 |
| 关键词: 木薯叶片 防御酶活性 细菌性枯萎病 抗性 |
| DOI：10.11841/j.issn.1007-4333.2022.01.10 |
| 投稿时间：2021-03-19 |
| 基金项目:广西科技计划项目(桂科AB18221127)；亚热带农业生物资源保护与利用国家重点实验室开放课题(SKLCUSA-b201609)；亚热带农业生物资源保护与利用国家重点实验室自主研究课题(SKLCUSA-a201802) |
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| Relationship between the activities of five defense enzymes in cassava leaves and bacterial blight resistance |
|
WU Meiyan1,LUO Xinglu1,2*,LIU Shanting1,FAN Zhupeng1,HUANG Tangwei1,YANG Yanni1
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| (1.Agricultural College, Guangxi University, Nanning 530005, China;2.State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Nanning 530004, China) |
| Abstract: |
| In order to investigate the level of resistance of two cassava(Manihot esculenta Crantz)varieties, ‘GR891' and‘Xinxuan 048', to bacterial blight, the activities of five resistantce enzymes, PAL(phenylalanine aminolytic enzyme), SOD(superoxide dismutase), POD(peroxidase), PPO(polyphenol oxidase)and CAT(catalase), were analyzed after cassava leaves were infected with pathogenic bacteria. The relationship between bacterial blight and enzyme activity was investigated. The resistance levels of the two cassava vaireties to bacterial blight were evaluated using spray inoculation. POD, SOD, CAT and PAL enzyme activities were determined by spectrophotometric, and PPO enzyme activity was determined by iodine titration. The results showed that: The lesion length of the susceptible cassava leaves of ‘XinXuan 048' was(0. 3±0. 1)cm and its disease index was 33. 4, while the lesion length of ‘GR891'was(0. 6±0. 2)cm and its disease index was 43. 7; The activities of CAT, PPO and POD in the leaves of both cassava varieties increased to a certain level 12 days after infestation, and respectively increased by 72. 31%, 9. 55% and 94. 78% after inoculation with the pathogen in ‘Xinxuan 048'. The activities of CAT, PPO and POD in cassava leaves respectively increased by 34. 2%, 20. 05% and 91. 63% after inoculation with the pathogen in ‘GR891'. The levels of POD and CAT activity of ‘Xinxuan 048' were significantly higher than those of ‘GR891'; The PAL activity in leaves of the two varieties showed different performance, the PAL activity of the ‘Xinxuan 048' was positively correlated with resistance, while ‘GR891' was negatively correlated with resistance; SOD activity was not correlated with disease resistance. In condlusion according to the changes of each enzyme activity and the disease index of cassava, ‘Xinxuan 048'variety was more resistant to bacterial blight than ‘GR891'. |
| Key words: cassava leaves defense enzyme activity bacterial blight resistance |
