MICROSPORE AND POLLEN DEVELOPMENT IN 6 MALE-STERILE MUTANTS OF ARABIDOPSIS-THALIANA

Five new recessive male-sterile mutants of Arabidopsis thaliana were isolated following see mutagenesis X-rays an ethyl methanesulfonate. The cytology of plants homozygous for the msY and msW mutations suggested that pollen development in these lines became abnormal at or before meiosis. The msK mutation caused faulty timing of synthesis or turnover and distribution of callose. In plants homozygous for the msZ mutation, pollen development failed at a late stage. In wild-type plants, the stamen filament elongated just prior to anther dehiscence. In contrast, in the msZ mutant stamen elongation did not occur. Pollen in msH homozygotes was fertile, but anthers failed to dehisce. The ms1 mutant of J.H. Van der Ween and P. Wirtz (1968. Euphytica 17:371-377) was included in the present study. Pollen development in this mutant failed shortly after microspore release from tetrads. Complementation tests confirmed that the ms mutations were at different loci. Reduced transmission of certain ms genes was observed.