Abstract: DAP (4,6.Diamidino-2-phenylindole) has been shown in this investigation to be a convenient and reliable DNA-specific nuclear stain which will exhibit pale blue fluorescence under ultraviolet irradiation. It could be employed to stain the nucleus in living plant specimens by simply immersing them in highly diluted DAPI solution (ca. 0.5 ppm) for 2–24 hours. The specimen with stained nucleus is still capable of exhibiting cyclosis. The seedling may grow steadily in such solution. Hence, the whole procedure is well suited for the preliminary survey of occurrence of nuclear extrusion in various higher plants chosen at random. As most investigations on nuclear extrusion have been intensively conducted on two monocots (wheat and Allium), special attention is paid to dicots. Free hand sections consisting of several layers of cells in thickness are taken from the various parts of a plant (flower bracts, petals and stipule) to avoid artificial indlced by injury ,and stripping. The main findings are summarized in Table, and the microscopic record illustrated in figures. The preliminary survey has adequately demonstrated that the frequency of successful detection of nuclear extrusion in plant samples taken at random is rather high although its occurrence is rare. Patient search under microscope is usually required. In general it is present in embryonic as well as in senescent tissues and in tissues of transitory existence such as the leaf hairs, but it is absent in mature normal function-organs. The results are in conformity with those of prefious observations.

Key words: DAPI, Nuclear extrusion