Inst. f. Botanik, University Innsbruck, Sternwartestr. 15, A-6020 Innsbruck, Austria.
Protoplasma. 2010 Jul;243(1-4):137-43. doi: 10.1007/s00709-009-0039-6. Epub 2009 Mar 17.
Chrysomyxa rhododendri is a rust which infects Picea abies growing near the alpine timberline. Attacked needles are normally shed, but few remain on shoots. We hypothesised that these needles increase transpiration of Picea during winter. Partly damaged, completely damaged and healthy needles of an infected tree as well as healthy needles of a resistant tree were compared in a microscopy analysis, and needle conductance of shoots was measured gravimetrically. Despite needle shedding, more than 6% of needles remaining on infected tree shoots were damaged. Partly damaged needles showed local brownish areas in the periphery and completely damaged needles necrotic parenchyma and epidermal tissues. Cuticular conductance of affected shoots was up to 25.23 +/- 2.75 mmol m(-2) s(-1) at moderate water potential and thus twofold higher than in the resistant tree. Needle shedding reduces negative effects of Chrysomyxa infections during summer, but remaining damaged needles impair tree water relations in winter.
黄杨栅锈菌是一种侵染高山林线附近云杉属植物的锈菌。受侵染的针叶通常会脱落，但仍有少数留在嫩枝上。我们假设这些针叶会增加云杉在冬季的蒸腾作用。在显微镜分析中，对受感染树木的部分受损、完全受损和健康针叶，以及抗性树木的健康针叶进行了比较，并通过重量法测量了嫩枝的蒸腾速率。尽管针叶已经脱落，但仍有超过 6%的针叶留在受感染树木的嫩枝上受损。部分受损的针叶在周边呈现局部棕色区域，完全受损的针叶则出现坏死的薄壁组织和表皮组织。在适度水势下，受感染嫩枝的角质层导度高达 25.23 +/- 2.75 mmol m(-2) s(-1)，是抗性树木的两倍。针叶脱落减少了黄杨栅锈菌感染在夏季的负面影响，但残留的受损针叶会损害树木在冬季的水分关系。
