苹果霉心病菌的侵染过程

 苹果霉心病致病菌链格孢(Alternaria alternata)经花柱侵入,自花朵开放时开始侵染。自初花至落花期,70%花柱被链格孢定殖。元帅系品种,从落花后3周至果实采收,定殖于花柱的病菌通过萼筒心室间组织陆续进入心室。采收以后,在常温贮藏条件下,继续向心室蔓延。

INFECTION PROCESS OF PATHOGENIC FUNGI CONTRIBUTING TO MOULDY CORE AND CORE ROT OF STARKING APPLE FRUITS

An investigation program of apple mouldy core and core rot was conducted in Tianshui, Gansu Prov. , from 1988 to 1992. More than 10 genera of fungi were isolated from core region and tested for determining their pathogenicity. Alternaria alternata was the predominant resident in carpel cavities and the main pathogen inducing mouldy core, while the major pathogens inducing core rot included Trickothecium roseum, Truncatella angustata, Fusarium arthrosparioides, Coryneum sp. and others. Parts of flowers and fruits were cut and isolated at various stages in succession. Incidence of fungal colonies revealed that fungal colonization on styles started from apple blossoming and followed by ingression into core region through the opening or loose tissue between the end of calyx tube and carpel cavity. More than 3 weeks after petal fall later, the causal fungi colonized on styles grew into carpel cavities progressivel. Later on, fungal invasion into core region increased continuously during fruit development and postharvest period.