苹果霉心病Alternaria spp在芽中越冬的研究

用红星(starking delicious)、金冠(Golden delicious)、秦冠(Qin delicious)三个品种的短果枝顶芽(花芽)、中长枝顶芽及中长枝侧芽(叶芽)等三种芽的鳞片分层剥取后,采用组织分离法和洗涤离心法分析研究,发现这三个品种芽的鳞片均带有AIternaria spp。三个品种中红星的带菌率及所带孢子量最高,三种芽中短果枝顶芽的带菌率及带孢子量最高,同时鳞片上所带的孢子于次年春均能荫发,可作为初次侵染源。三个品种中,红星田间果实发病率最高,这与芽内带A.spp及其孢子量成正相关。以上结果表明了A.spp能以菌丝和分生孢子在芽中越冬,所以芽是霉心病的一个重要越冬场所。

A STUDY ON THE OVERWINTERING OF THE PATHOGEN OF APPLE MOLDY CORE ALTERNARIA SPP IN APPLE BUDS

Excavating the top buds (flower buds on the short fruit twigs and short middle branches and also the side buds on the short fruit twigs and short middle branches and also the side buds on middle long branches of three apple varieties golden delicious,Starking delicious and Qin-delicious, adopting the methods of organization differentiation and washing centrifuge, we discovered that there were Alternaria spp in buds scales of allthese three varieties,A.spp and its conidia carring ratio of Starking delicious was the highest in the three varieties. The A.spp carring and the quantity of conidia were the highest in the top buds on the short fruit twigs of the three varieties. All the conidia might germinate in the following spring as aninitial infecting source.The highest ratio of A.spp infecting fruits of these three varieties in the fields was of Starking delicious. This ratio had a plus interrelation to the quantity of A.spp and its conidi a carring in buds. Above results also showed that A.spp might overwinter by mycelia and conidia in buds of apple trees and then the buds of apple trees were one of the important A.spp overwintering place.