Quick Preparation of Corolla Chromosomes from Flower Buds

Abstract

THE standard practice of obtaining somatic chromosomes from root-tips¹ for counting is often inconvenient, particularly for species in the wild and for perennials in the field. In grafted species, for example, cultivated top-fruit clones, it is impractical to use root-tips and it may be necessary to obtain counts from meioses in pollen mother cells. Several methods are available, however, for examining chromosomes from other meristematic tissues² such as young leaves from vegetative tips and stipules, but these do not always prove satisfactory. Burns³ has recently provided a useful method for making preparations of somatic chromosomes from corollas in Nicotiana spp. Her schedule is somewhat lengthy, and the prepared slides are not ready for examination for three days. We have been able to shorten this schedule, and have found the modifications satisfactory with the several genera tested. The abridged technique successfully used for rapidly preparing chromosomes in corolla tissue is given here.