^(60)Co-γ辐照对葡萄3种病原真菌的抑制效果

Inhibition of three fungal pathogens of grape cuttings and fruits by ^(60)Co-γ ray radiation

【目的】探究不同剂量的^(60)Co-γ辐照对葡萄枝条、果实病害的防治效果,为葡萄高效安全生产和提高防霉保鲜效果提供科学依据。【方法】以葡萄灰霉病菌、白腐病菌和溃疡病菌为靶标菌,选用剂量分别为40、100、600、1000、2000 Gy的^(60)Co-γ射线进行辐照处理,就不同剂量的^(60)Co-γ辐照对3种病原真菌孢子萌发和菌丝生长的影响情况进行试验与观测分析;并在巨峰葡萄1年生嫩枝上经刺伤接种葡萄灰霉病菌、白腐病菌和溃疡病菌,然后分别用剂量为40、100、600 Gy的^(60)Co-γ射线对发病的嫩枝进行辐照处理,统计嫩枝成活率和嫩枝上的病斑扩展面积;再在巨峰葡萄果实上经刺伤接种葡萄灰霉病菌和白腐病菌,然后用剂量分别为100、600、1000 Gy的^(60)Co-γ射线对发病的葡萄果实进行辐照处理,统计葡萄果实的发病率。【结果】^(60)Co-γ辐照对葡萄3种病原真菌的孢子和菌丝都有明显的抑制甚至致死作用,且当辐照剂量大于600 Gy时才始有明显的抑制效果;不同剂量的^(60)Co-γ辐照处理对葡萄3种病菌在嫩枝上病斑的扩展都有一定的抑制作用,而且随着辐照剂量的增大,病斑的扩展面积显著减小,经600 Gy剂量的^(60)Co-γ辐照后其病斑扩展的面积最小,说明辐照的抑制效果最好,该剂量的辐照处理对3种病菌在葡萄嫩枝上病斑的抑制率均在75%以上,且该剂量的辐照处理不影响葡萄嫩枝的扦插成活;^(60)Co-γ辐照葡萄果实的适宜剂量为600 Gy,以此剂量辐照葡萄果实可使灰霉病和白腐病在其贮藏期的发病时间推迟4~6 d。【结论】^(60)Co-γ辐照葡萄嫩枝和果实的适宜剂量均为600 Gy,剂量为600 Gy的辐照能有效抑制葡萄灰霉病、白腐病和溃疡病的发生及其病斑的扩展,还可减少农药的使用量。

【Objective】The effects of different doses of 60Co-γirradiation on the prevention and control of grape branches and fruit diseases were studied for the efficient and safe production of grapes and the improvement of anti-mold and freshkeeping in grape fruits.【Method】Three fungal pathogens of grape,including Botrytis cinerea,Coniella diplodiella and Botryosphaeria sp.were irradiated with 60Co-γrays at the doses of 40 Gy,100 Gy,600 Gy,1000 Gy and 2000 Gy,and the germination of spores and mycelial growth of each pathogen were scored.One-year-old cuttings of Kyoho grape inoculated with above mentioned three fungal pathogens by stab wound were first irradiated with 60Co-γrays at the doses of 40 Gy,100 Gy and 600 Gy,and the cutting survival rates and the areas of diseased spots were determined at the onset of disease;Kyoho grapes fruits were inoculated with B.cinerea and C.diplodiella by stab wound,and were irradiated with 60Co-γrays at the doses of 100 Gy,600 Gy and 1000 Gy,and the disease spot areas on the fruits were measured at the onset of the disease.【Result】The results showed that radiation doses of 60Co-γ rays over 600 Gy had inhibitive and even lethal effects on spore germination and mycelial growth of the three fungal pathogens on grape.Different doses of 60Co-γ radiation had certain inhibitive effects on the disease spot expansion caused by the three pathogens on grape cuttings,and the expansion area decreased significantly with the increase of the irradiation doses.The expansion area of the disease spots was the smallest and the inhibition effect was the best after 600 Gy of 60Co-γradiation,and the inhibition rates were all above 75%.At the same time,this dose did not affect the survival rate of grapes cuttings.The suitable dose of 60Co-γradiation on grape fruit was 600 Gy,which could delay the disease onset time of grape fruits for 4~6 d during storage.【Conclusion】The suitable dose of 60Co-γ radiation on grape cuttings and fruits was 600 Gy,which effectively inhibited the occurrence and expansion of grape diseases and thus reduced the use of chemical fungicides.