葡萄不同抗霜霉病品种的生理生化指标研究

Indices of Physiology and Biochemistry of Various Grape Cultivars Resistant to Downy Mildew

筛选抗霜霉病的葡萄品种可为病害防治提供基础资料,为了探讨葡萄抗霜霉病的生理生化机制,以不同抗性的葡萄品种贝达(高抗)、红地球(感病)和无核白鸡心(高感)为材料,分别测定接种霜霉病菌前后不同时期的防御酶活性、叶绿素含量及叶绿素荧光参数,研究其动态变化规律。结果表明:未接种霜霉病菌的各葡萄品种防御酶活性差异不大;接种后,防御酶活性均高于对照且不同抗性品种间存在显著差异。接种后第1天,贝达和无核白鸡心CAT活性达到最大值,酶活性上升分别为0.79倍和0.26倍;接种后第3天,各葡萄品种POD、SOD、PPO和PAL活性达到最大值;贝达在接种后第3天PPO活性达24.7 U·g^(-1) FW·min^(-1),酶活性升高最大,为1.29倍。高抗品种贝达的酶活性一直高于感病品种红地球和高感品种无核白鸡心,表明霜霉病菌的侵染能够诱导植物体内酶活性升高,并且高抗品种酶活性提升幅度更大,能够在接种后11 d内维持较高酶活性。接种霜霉病菌后,不同品种葡萄叶片叶绿素a、叶绿素b和叶绿素总量均下降,高抗品种的叶绿素可变荧光(Fv)、光系统Ⅱ光能转化效率(Fv/Fm)、光系统Ⅱ的潜在活性(Fv/Fo)下降幅度明显小于感病和高感品种。表明霜霉病菌的侵染破坏了叶绿素的合成,高抗品种叶绿素的合成能力以及抵御致病毒素的能力强于感病品种;高抗品种具有更高的光能捕获能力和利用效率。

In order to provide basic information for the screening of grape varieties and disease control of downy mildew and to explore the physiological and biochemical mechanism of grape's resistance,five defense enzymes activities,chlorophyll content and chlorophyll fluorescence parameters were measured respectively for selecting different resistant grape varieties(the High Resistance Variety Beta,the Susceptible Variety Red Globe,the Highly Susceptible Variety Centennial Seedless)in different periods before and after inoculation.The results showed that there was little difference in the enzymes'activities of various grape varieties before inoculation;the enzymes'activities were higher than that in control and there were significant differences among different resistance varieties after inoculation.The activities of CAT in Beta and Centennial Seedless appeared peak at 1 d after inoculation,and the enzyme activities increased by 0.79 times and 0.26 times respectively.The activities of POD,SOD,PPO and PAL in various grape varieties appeared peak at 3 d after inoculation,the activities of PPO in Beta reached 24.7 U·g-1 FW·min-1 and enzyme activities increased the most(1.29 times).The enzyme activities of the High Resistance Variety(HRV)Beta had always been higher than those of the Susceptible Variety(SV)Red Globe and the Highly Susceptible Variety(HSV)Centennial Seedless.It was indicated that it could induce the increase of enzyme activities after inoculation and the increase range of the enzyme activities of HRV was larger,which could maintains high enzyme activity for 11 d.Chlorophyll a,chlorophyll b and chlorophyll content in different varieties of grape leaves decreased after inoculation.The descend range of variable fluorescence of chloroplasts(Fv),efficiency of primay conversion of light energy of PSⅡ(Fv/Fm),potential activities of PSⅡ(Fv/Fo)in the HRV were significantly less than those of the SV and HSV.It showed that the infection of Plasmopara viticola destroyed the synthesis of chlorophyll.The synthetic ability of chlorophyll and the ability to resist pathogenic toxin in the HRV were stronger than the HSV.The HRV had higher light energy capture and utilization efficiency.