【作者】 张荣； 陈厚彬； 刘爱媛； 姜子德；

【机构】 华南农业大学园艺学院； 华南农业大学资源环境学院；

【摘要】 荔枝霜疫霉病是发生在荔枝园的主要病害之一,该病害降低了荔枝产量,影响荔枝采后贮运和品质。本文通过植物病理学方法研究了环境因素对荔枝霜疫霉游动孢子释放、萌发及卵孢子萌发的影响。结果表明温度是调控孢子囊萌发和萌发方式的主要因素。在荔枝果肉培养基中,孢子囊萌发的温度低于孢子囊形成的温度时,孢子囊主要以释放游动孢子的方式萌发,28℃是荔枝霜疫霉孢子囊释放游动孢子的临界温度。荔枝霜疫霉在荔枝果肉培养基中,于26℃下培养7 d后,游动孢子释放最适温度范围为12～20℃,最适pH值为5～7;游动孢子萌发的最适温度为20～24℃,最适pH值为7～9;水是游动孢子释放和萌发的必要因素。荔枝霜疫霉在荔枝果皮和叶片煎汁培养基中均可产生卵孢子,卵孢子存在3种萌发方式。当温度为28℃,pH值为5,12 h交替光照时,卵孢子的萌发率最高,可达到49.68%。本文为探索荔枝霜疫霉的发生发展规律和利用农业措施控制该病害提供理论依据,并为研究荔枝霜疫霉有性生殖生物学和遗传变异奠定基础。更多还原

【Abstract】 Downy blight of litchi is one of the most serious diseases in litchi orchard,which decreased the litchi’s production and quality.Effects on which environmental factors influenced zoospores release and germination,oospores germination were studied in the paper by plant pathology methods.Temperature was the main factor in regulation modes of sporangium germination.On 20%litchi flesh agar,more sporangia germinated by zoospores when temperature of sporangium germination was lower than the temperature at which Peronophythora litchi was cultured and no zoospores were released if Peronophythora litchi was treated at 28℃or higher.The optimum temperature of zoospore release was 12～20℃and the optimum pH was 5～7 when Peronophythora litchi was cultured at 26℃on 20%litchi flesh agar.The optimum temperature of zoospore germination was 20～24℃and the optimum pH was 7～9.It was necessary for zoospore release and germination to be immersed in liquid.Oospores were observed on litchi peels and leaves cultural media,which germinated by producing 1-3 sporangia on each germ tube through oogonium stalk,antheridium and oogonium wall,or emerging 8 germ tubes from a single oospore.The highest percentage of oospores germination was 49.68%when the pH was 5 at 28℃in 12 h-light,12 h-dark cycles.更多还原