皮孔组织结构及密度与苹果枝干粗皮病发生的关系

Study on the Relationship Between Lenticel Tissue Structure and Density and the Occurrence of Apple Rough Bark Disease

通过对轮纹病菌(Botryosphaeria berengriana f.piricola)引起的枝干粗皮病不同感病程度的3个苹果品种富士、国光、鸡冠的树皮皮孔组织结构和密度的研究,发现高感品种富土、中感品种国光和免疫品种鸡冠在皮孔组织结构及密度上存在显著的差异。富士和国光的皮孔结构基本相似,均是先期开口,皮孔下无木栓组织,中后期开口加大,其下形成木栓组织。而鸡冠则是先期不开口,其下有木栓组织,中后期逐渐开口。鸡冠皮孔组织结构的这种特异性是其对枝干粗皮病免疫的主要原因。富士皮孔密度最大,国光次之,鸡冠最低。相关分析表明树皮皮孔密度与枝干粗皮病的病情指数间存在明显的正相关关系。

Study was conducted with 3 apple cultivars, including Fuji, Rails Janet and Jiguan, in order to work out the relationship between the lenticel structure and density and the occurrence of apple rough bark disease, caused by Botrysphaeria berengriana f. piricola. The first one is a high sensitive cultivar, the second is a mid-resistant cultivar and the last one is an immune cultivar. It was revealed that their lenticel tissue structure and density were quite different. The lenticel structure of Fuji and Rails were very similar, opening and no phellem beneath lenticel at early stage, enlarged opening and phellem appearing beneath lenticel at mid-stage, but the lenticel structure of Jiguan is closed and having phellem beneath lenticel at early stage and then opening. Observation showed that the immunity of Jiguan to rough bark disease attributes to the characteristic of its lenticel tissue structure. The lenticel density showed Fuji>Ralls>Jiguan. All the observation results indicated that there was remarkable correlative relation between lenticel density and disease incidence.