松梢枯病及其病原的研究(一)

Studies on Die-back of Pine and Its Pathogen( I)

松梢枯病在江苏省分布普遍,不少场圃的松林严重受害,有数百公顷成片松林被毁的记录。主要受害树种是火炬松和湿地松,黑松亦有严重受害的情况,马尾松较抗病。主要症状是枯梢,其次是芽腐和2年生针叶基部坏死。比较了江苏、福建和黑龙江省松梢枯病菌的形态、培养性状、孢子萌发特征、产孢能力和致病力,未发现明显差异。病菌在经过高压蒸汽消毒的松针上于黑光灯下,2周内产生大量子实体。孢子在5～35℃均可萌发,以25℃最适宜;相对湿度98％～100％时孢子萌发最好,在水中由于供气不足萌发极差;加1％糖水或松针煮出液能提高发芽率。菌丝在pH4～10之间均生长,以pH6最好;菌丝生长所需氮源以天冬酰胺为最好,不能利用尿素。

The die-back of pines caused by Sphaeropsis sapinca (Fr.) Dyko & Sutton widely spread in Jiangsu Province. Pine stands were infected severely in many farms and several hundred ha of pine stands were killed. It is one of the most serious forest diseases in China. Among those pines, P. taeda and P. elliottii are infected severely, P. thunbcrgii is also severely infected sometimes. P. massoniana is more resistant. The most prominent symptoms of the diease are die-back, necrosis of buds and base of the two year's needles in Jiangsu Province. Morphology, culture characteristics, germination characteristics, sporogenous capacity, pathogenicity of the isolates from Jiangsu, Fujian and Heilongjiang Province were compared, and no difference was found among them. The pathogen of die-back of pine produced abundant sporocarps on steam sterilized needles under black light within two weeks. The temperature range for conidia germination is 5~35℃ and the optimun temperature 25℃.Spore germination needs 1 % sugar solution or needle juice. Spore germination is no so good in water because air is too little in water. The pH range for myceliae growth is pH 4~10 and the optimum pH 6. Sphaeropsis sapinea is capable of utilizing para-gine as nitrogen source but is not capable of utilizing urinate.