3种黑籽南瓜对枯萎病菌胁迫的响应

为探究白皮、绿皮、花皮3种黑籽南瓜对枯萎病菌抗病能力差异,本研究测定枯萎病菌胁迫下3种黑籽南瓜的气体交换参数、叶绿素荧光参数、抗氧化系统、丙二醛(MDA)的变化。结果表明:当受到枯萎病菌侵染后,3种黑籽南瓜的气体交换参数均出现不同程度的降低,白皮黑籽南瓜呈现大幅下降;花皮黑籽南瓜的F_v′/F_m′和绿皮黑籽南瓜Φ_(PSⅡ)、q_P上升,而白皮黑籽南瓜均表现下降,同时白皮黑籽南瓜q_N和NPQ显著下降,绿皮黑籽南瓜下降幅度最小;在抗氧化系统中白皮黑籽南瓜过氧化物酶(POD)活性增大,花皮黑籽南瓜减小,但花皮黑籽南瓜超氧化物歧化酶(SOD)活性显著增大;绿皮和白皮黑籽南瓜MDA含量升高,而花皮黑籽南瓜显著下降。研究发现:正常生长的白皮黑籽南瓜具有较高的光合能力,但其对枯萎病菌的抵抗力较弱,绿皮和花皮黑籽南瓜的抗病性强于白皮黑籽南瓜。

Response of Three Cultivated Varieties of Cucurbita ficifotia to Fusarium Wilt

The disease resistance of the Fusarium wilt in three cultivated varieties of Cucurbita ficifolia Bouche named ‘WhitePpeel',‘Green Peel',‘Green Peel with White'was studied.This study measured the gas exchange parameters,chlorophyll fluorescence parameters and antioxidant system,malondialdehyde (MDA) of the three varieties by inoculating the pathogen of the Fusarium wilt.The results showed that the gas exchange parameters of the three varieties reduced with varying degrees,and ‘White Peel'fell sharply.Fv'/Fm'of‘Green Peel'with ‘White Peel'and Φpsu,qP of ‘Green Peel'increased,but ‘White Peel'decreased.qN and NPQ of ‘White Peel'dropped significantly,while ‘Green Peel'reduced least.Peroxidase (POD) activity of‘White Peel'increased,while that of ‘Green Peel with White'decreased,but the superoxide dismutase (SOD) activity of ‘Green Peel with White'increased significantly.MDA of ‘Green Peel'and ‘White Peel'increased,while that of ‘Green Peel with White'dropped significantly.The study revealed that the normal growth of‘White Peel'had a high photosynthetic capacity,but its resistance to Fusarium wilt was weak,and the resistance to Fusarium wilt of ‘Green Peel'and ‘Green Peel with White'were stronger than ‘White peel'.