Response of alfalfa and sugar beet to field dodder (Cuscuta campestris Yunck.) parasitism: a physiological and anatomical approach

The physiological and anatomical impact of field dodder (Cuscuta campestris Yunck.) on alfalfa and sugar beet was examined under controlled conditions. The following parameters were checked: physiological - content of pigments (chlorophyll a, chlorophyll b and carotenoids) and mineral nutrients: nitrogen, phosphorus, potassium, organic and mineral nutrients (%); anatomical: thickness of epidermis and cortex, diameter of stem and central cylinder of alfalfa plants; diameter of tracheids and phloem cells, area of xylem and phloem, and hydraulic conductance of petiole bundles in petiole vascular bundles of sugar beet plants. Leaf parameters were also measured on both host plants: thickness of upper and underside leaf epidermis, thickness of palisade, spongy and mesophyll tissue, and diameter of vascular bundle cells. Pigments content and anatomical parameters were measured 7, 14, 21, 28, 35 and 42 days after infestation (DAI), while mineral nutrient contents were determined 20 and 40 DAI. Field dodder caused...