title: Production of Haploid Saccharum spontaneum L. - Comparison of Media for Cold Incubation of Panicle Branches and for Float Culture of Anthers.
abstract: Means were sought to increase the frequency of haploid production from anther cultures of Saccharum spontaneum L. Excised preemerged panicle branches were incubated in modified Murashige-Skoog (MS), Nitsch (H), Gamborg (B5), and Chu (N6) media at 10 °C for 4 to 10 weeks prior to removal of the anthers for culturing at 27 °C. Anthers, either continuously cultured on liquid media or floated on liquid media 1 to 8 weeks prior to nurse culture, produced visible calli in 30 days. Nearly 1% of the anthers in one clone, SES 208, produced calli. The calli increased in mass on nurse medium containing 0.25 to 0.50 mg · l(-1) picloram as the auxin source and differentiated into green calli when the picloram was reduced to 0.05 to 0.125 mg · l(-1). The green calli developed into plants on lowered-picloram or picloram-free media. Calli and green plants were obtained from all three clones studied. Plants were regenerated from 100 out of 276 callus lines. Seventeen plant lines have been transferred to greenhouse culture. Four of seven plant lines checked for ploidy were haploid, two were diploid. A method utilizing stomate guard cell lengths was developed as a means to estimate ploidy level. The increased success in haploid callus and plant production is thought to be the result of long cold treatment of panicle branches, use of low salt media for panicle treatment in the cold, use of picloram in place of 2,4-D in the nurse culture, and use of a high nitrate/ammonium ratio in the liquid culture.
authors.affiliation: U.S. Department of Agriculture, ARS, Experiment Station Hawaiian Sugar Planters' Association, P.O. Box 1057, Aiea, Hawaii 96701, USA.
authors.forename: M M
authors.initials: MM
authors.lastname: Fitch
authors.forename: P H
authors.initials: PH
authors.lastname: Moore