地被菊品种对镰孢菌侵染的响应差异及抗性综合评定

 地被菊枯萎病由镰孢菌引起,是一种土传性病害,严重威胁地被菊生产。本试验用2个强致病力镰孢菌菌株,即尖孢镰孢菌(Fusarium oxysporum)、茄镰孢菌(F. solani)接种5个地被菊品种的幼苗,测定了病菌侵染下不同品种的形态、生理和生化响应的差异,以建立抗病品种筛选的生理和生化指标。地被菊品种间抗性水平可根据病情指数划分;受病菌侵染后,叶片叶绿素含量下降,抗病品种‘俏粉阁'叶绿素含量相对较高;丙二醛含量增加,抗病品种‘乳荷'和‘俏粉阁'的丙二醛含量显著低于感病品种‘玲珑';在病菌侵染早期,脯氨酸含量、超氧化物歧化酶和过氧化物酶活性在抗病品种受到迅速诱导增加,随后下降。运用隶属函数对其抗病能力进行综合评定,地被菊品种对尖孢镰孢菌(F. oxysporum)抗病性从强到弱依次为:‘俏粉阁'＞‘乳荷'＞‘火焰'＞‘鲜红'＞‘玲珑',地被菊品种对茄镰孢菌(F. solani)抗病性从强到弱依次为:‘俏粉阁'＞‘乳荷'＞‘鲜红'＞‘火焰'＞‘玲珑',为地被菊生产和开展菊花抗病机理研究提供了依据。

Differential responses of Chrysanthemum morifolium varieties to Fusarium infection and synthetic evaluation of resistance

Soilborne disease Fusarium wilt, caused by Fusarium oxysporum and F. solani threatens chrysanthemum production seriously. However, there was no report on the difference of physiological and biochemical responses between the resistant and susceptible varieties. To establish the physiological and biochemical indexes for the selection of resistant varieties, two Fusarium strains with strong pathogenicity were inoculated into the seedlings of five Chrysanthemum morifolium varieties, and the morphological, physiological and biochemical responses of different varieties infected with the pathogen were measured in this study. The results showed that the disease index of C.morifolium was negaticely correlated with disease resistance after infection . With the development of the disease, the content of leaf chlorophyll (Chl) content increased slightly and then decreased, and the content of Chl in resistant variety ‘Qiaofenge' was higher than the other varieties tested. The content of malondialdehyde (MDA) increased after infection. The MDA content was significantly higher in susceptible variety ‘Linglong' than those in resistant varieties, and it was negatively correlated with disease resistance of varieties. The proline content increased rapidly in resistant varieties, showing that the higher the content of peoline, the stronger the disease resistance of varieties, The content of soluble protein (SPC) increased firstly and then decreased during infection and it was higher in resistant varieties than that in susceptible ones. The activities of leaf superoxide dismutase (SOD) and peroxidase (POD) increased first and then decreased following infection. SOD and POD activities in resistant varieties increased rapidly and they were higher than susceptible ones.In summary, through evaluation of resistance and measurement of various physiological indicators and disease index after inoculation,the resistance of five Ground cover chrysanthemum varieties to F. oxysporum from high to low was ‘Qiaofenge' > ‘Ruhe'>‘ Huoyan '> ‘Xianhong' > ‘Lingnong', while the disease resistance to F. solani from high to low was ‘Qiaofenge'> ‘Ruhe' > ‘Xianhong'> ‘ Huoyan' > ‘Lingnong'. This provides basis for deployment of chrysanthemum cultivars in production and molecular bree-ding of disease resistant .