月季黑斑病生物学特性研究

 本文对月季黑斑病的危害程度、症状表现进行了调查和观察,着重对病原及生物学特性进行了研究。结果表明,月季黑斑病在北京地区主要以无性阶段Actinonema rosae(Lib)Fr.进行危害,并以分生孢子在病落叶上越冬,但尚未发现有性阶段。分生孢子需在水滴中保持16h方可萌发。其萌发最适宜的温度为20～25℃。在0～5℃及40℃孢子萌发均受抑制。在2%葡萄糖液中孢子萌发率最高(93%)。人工接种证明:病菌通过表皮直接侵入,潜育期为10天左右。

Studies on Chinese Rose Black-Spot-lts Symptoms, Damage, Pathogen and Biological Characteristics

This paper deals with the Chinese Rose black-spot-its symptoms,damage,pathogen and biological characteristics.Observations showed that the infected plant underwent serious defoliation,the plant growth was hampered,and the branches,even the whole plant withered to death.Lesions on the affected leaves appeared more or less round with a radiated edge.At the later stage of the disease,some tiny black and brown grains were scattered on the lesions.The pathogen is identified as Actinonema rosae(Lib.) Fr.and it overwintered by means ofconidium on the affected fallen leaves.The conidium is required to germinate in water drops in about 16 hours.The optimal temperature for conidium germination is 20-25℃.However,at 0-5℃ and 40℃ the spore germination is subjected to inhibition.2% glucose and 2.5% Chinese Rose juice are able to increase the germination rate of conidium,and 2% glucose is most effective(93%) Artificial inoculation proved that the fungi invade the plant directly through the epidermis.The incubation period of the disease is in general 10 days or so.