| Abstract: | A device was designed to mark the growth zones of elongating seedling stems rapidly and accurately without exposing the tissue to mechanical stress. The device consists of a spring-loaded clamp, two plastic, grooved holders attached to either side of the open end of the clamp, a narrow foam pad to cushion and support the plant tissue, and a narrow nylon marking head. The marking head contains flat-topped ridges, 0·5 mm in width, machined such that the ridges are 2 mm (± 0·1) apart. Marking is accomplished using India ink. The procedure is rapid, precise, relatively inexpensive to build and operate, and does not require sophisticated or expensive instrumentation to obtain meaningful data. With practice, up to 100 seedlings may be uniformly marked in one hour. Tests using dark-grown soybean (Glycine max), sunflower (Helianthus annuus), and pea (Pisum sativum) show that the device does not itself cause a reduction in growth. |
