Mayr Stefan, Siller Christian, Kriss Michaela, Oberhuber Walter, Bauer Helmut
Institut f. Botanik, Universität Innsbruck, Sternwartestr. 15, A-6020 Innsbruck, Austria.
New Phytol. 2001 Sep;151(3):683-689. doi: 10.1046/j.0028-646x.2001.00222.x.
• Norway spruce (Picea abies) has been infected by the needle rust Chrysomyxa rhododendri in many regions of the Central Alps with increasing intensities in recent years. Basidiospores formed on leaves of the main host, Rhododendron sp., only penetrate into developing current-year needles of Norway spruce, which leads to shedding of infected needles in the autumn. • Net photosynthesis at ambient CO , net photosynthesis vs internal CO , pigment and nitrogen concentration were compared, as well as annual radial growth of severely infected and healthy adult Norway spruce under field conditions. • Net photosynthesis at ambient CO was significantly decreased (-47%) in infected current-year needles. However, net photosynethesis in uninfected, older (1-yr-old) needles increased, expressed per needle area, per gram of chlorophyll a + b as well as per gram of nitrogen. Annual ring width analysis revealed growth reductions (-25%) of the infected tree in periods of repeated C. rhododendri infections. • Although adult Norway spruce trees dispose of compensatory photosynthetic potentials of older needle age classes, C. rhododendri infections cause a substantial decrease in annual radial growth. If high infection intensities persist we predict serious damage to the subalpine spruce forest.
• 近年来，欧洲云杉（Picea abies）在阿尔卑斯山中部的许多地区受到叶锈病（Chrysomyxa rhododendri）的感染，且感染强度不断增加。主要寄主杜鹃属植物叶片上形成的担孢子仅侵入欧洲云杉当年生的发育中的针叶，这导致受感染的针叶在秋季脱落。
• 比较了环境CO₂下的净光合作用、净光合作用与内部CO₂的关系、色素和氮浓度，以及田间条件下重度感染和健康的成年欧洲云杉的年径向生长。
• 受感染的当年生针叶在环境CO₂下的净光合作用显著下降（-47%）。然而，未受感染的较老（1年生）针叶的净光合作用增加，以每针叶面积、每克叶绿素a + b以及每克氮来表示。年轮宽度分析显示，在反复感染叶锈病期间，受感染树木的生长减少（-25%）。
• 虽然成年欧洲云杉树具有较老针叶龄级的补偿性光合潜力，但叶锈病感染会导致年径向生长大幅下降。如果高感染强度持续存在，我们预测亚高山云杉林将受到严重损害。
