Plant Cell Biology Research Group, Institute of General Botany, Justus-Liebig-University, Senckenbergstraße 17-21, D-35390 Gießen, Germany.
J Exp Biol. 2010 Dec 1;213(Pt 23):4030-42. doi: 10.1242/jeb.046326.
The ability of aphids to detect and find sieve tubes suggests that aphids receive cues for sieve-tube recognition by taking samples. Specific natural conditions such as pH value, sugar species and concentration, viscosity, and oxygen pressure may enable sieve-tube detection. We tested the preference of Megoura viciae and Myzus persicae for potential plant-borne orientation parameters in artificial choice-chamber systems. Both species preferred sucrose (in comparison with fructose, glucose, raffinose or sorbitol) at concentrations of 15-22.5% (over a tested range of 0-22.5%) and at approximately pH 7 (over a tested range of pH 5-8). This preference matches the composition of the sieve-tube sap of their host plants. Likewise, Rhopalosiphum padi (normally found on barley plants with sucrose in the phloem sap) and Macrosiphum euphorbiae (normally found on pumpkin plants with raffinose-family oligosaccharides in the phloem sap) showed a significant preference for sucrose. In the absence of sucrose, however, M. euphorbiae strongly preferred raffinose. No clear preference for any carbohydrate was observed for Macrosiphum rosae and Aphis pomi (both normally found on plants with various amounts of sorbitol in the phloem sap). Electrical penetration graph (EPG) measurements of M. persicae feeding on artificial diets confirmed that sieve tubes are recognized solely by a combination of carbohydrate abundance and a neutral to slightly alkaline pH.
蚜虫探测和寻找筛管的能力表明，蚜虫通过取样来接收用于识别筛管的线索。特定的自然条件，如 pH 值、糖的种类和浓度、粘度和氧压，可能使筛管能够被检测到。我们在人工选择室系统中测试了桃蚜和烟粉虱对潜在植物传播导向参数的偏好。两种蚜虫都喜欢蔗糖（与果糖、葡萄糖、棉子糖或山梨糖醇相比），浓度为 15-22.5%（在 0-22.5%的测试范围内），pH 值约为 7（在 pH 值 5-8 的测试范围内）。这种偏好与它们的宿主植物筛管汁液的成分相匹配。同样，禾谷缢管蚜（通常在含有蔗糖的韧皮汁液中发现于大麦植株上）和榆长额蚜（通常在含有棉子糖家族低聚糖的韧皮汁液中发现于南瓜植株上）对蔗糖表现出明显的偏好。然而，在没有蔗糖的情况下，榆长额蚜强烈偏好棉子糖。而在韧皮汁液中含有不同量山梨糖醇的桃蚜和苹果绵蚜（通常在这些植物上发现）对任何碳水化合物都没有明显的偏好。对烟粉虱在人工饮食上进行的电穿透图（EPG）测量证实，筛管仅通过碳水化合物的丰富度和中性到略碱性的 pH 值的组合来识别。
