In Situ Preservation of Dna in Plant Specimens

Summary Twenty‐seven treatments of plant specimens were examined to determine their effects on the quantity and quality of DNA obtained from spinach leaves. Treatments included various drying methods, cold storage, and chemical preservatives. Good yields of quality genomic DNA (30–50 kbp) were obtained from fresh, frozen, and dried leaves, but none of the chemical preservatives yielded high molecular weight DNA, even after only three to seven days of storage. The application of the hot CTAB procedure to fresh and dried leaves of Ginkgo biloba, Juniperus ashei, J. virginiana, Magnolia grandiflora, Phoradendron tomentosum. Pinus ponderosa, Quercus virginiana and Thuja orientalis , species that possess considerable tannins, yielded high molecular weight DNA from all the fresh leaves with some degradation. The dried leaves of Juniperus ashei, Quercus virginiana and Magnolia grandiflora yielded only small amounts of high molecular weight DNA with the hot CTAB extraction procedure.