Origin, Cytology, and Reproductive Characteristics of Haploids in Pearl Millet1

Abstract

AbstractPearl millet [Pennisetum americanum (L.) K. Schum.] is an important introduced forage species in the U.S. Thirteen haploid plants with seven chromosomes in somatic cells were studied. Two plants resulted from a twinembryo caryopsis, whereas the others were discovered in field plantings. The rate of spontaneous haploid occurrence was 1 per 10,000 plants in the inbred ‘Tift 23A.’ Seed set on individual haploid plants ranged from 502 to none. No haploids were recovered from progeny of seeds harvested from haploid plants. Spontaneous chromosome doubling occurred in several plants. The doubled sectors in the inflorescences were characterized by good exsertion and good dehiscence of anthers. Haploids were conspicuous because of their small inflorescence diameters, narrow leaves, and poor exsertion and dehiscence of anthers. Meiotic chromosomes of haploids were mostly univalents, but occasional pairing of two or more chromosomes was observed at metaphase I.