Susceptibility of Six Scots Pine Clones to the Pathogenic Fungus Gremmeniella abietina

Genotypic variation in susceptibility to Gremmeniella abietina, an economically important fungal pathogen of conifers, was studied by artificially inoculating 23 - yr - old grafted plants of six Scots pine (Pinus sylvestris L.) clones in a seed orchard. Two fungal isolates were used. The mycelium was inserted into the current year shoots in late winter and the length of the necrotic lesion caused by the fungus was measured the next spring. The growth and male flower production of the experimental shoots were also measured. The development of symptoms did not vary among the clones, but the location of the grafts within the orchard statistically significantly affected the length of necrosis. The clones differed significantly in regard to height and the production of male and female flowers. Differences in flowering intensity among the clones were not connected with the development of G. abietina. At the level of the single shoot, the production of male flowers correlated positively with the length of necrosis. The length of necrosis correlated negatively with the length of current and previous year shoots. The ability of the two fungal isolates to cause necrosis differed significantly.     

几种优良彩叶植物的生长节律研究

［目的］研究彩叶植物的生长节律。［方法］对红叶石楠（Phtinia×fraseri‘Red Robin’）、小丑火棘（Pyrachtha fortuntana ‘Herleguin’）、水果蓝（Teucrium fruitcans）、金叶大花六道木（Abelia grandiflora‘Francis Mason’）及北美枫香（Liquidambar styraciflua）5个彩叶树种连续3年进行株高和冠幅测量。［结果］小丑火棘、金叶大花六道木、水果蓝3个品种的冠幅生长量大于株高的生长量,其余2个品种与之相反。另外,从不同月份的生长量来看,除北美枫香的生长高峰为7月外,其余4个品种的生长高峰都在4～5月。［结论］研究结果可以为彩叶树种的栽培管理和园林应用中的植物配置提供参考。