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

Five new recessive male-sterile mutants of Arabidopsis thaliana were i solated following see mutagenesis X-rays an ethyl methanesulfonate. Th e cytology of plants homozygous for the msY and msW mutations suggeste d that pollen development in these lines became abnormal at or before meiosis. The msK mutation caused faulty timing of synthesis or turnove r and distribution of callose. In plants homozygous for the msZ mutati on, pollen development failed at a late stage. In wild-type plants, th e stamen filament elongated just prior to anther dehiscence. In contra st, in the msZ mutant stamen elongation did not occur. Pollen in msH h omozygotes 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 inc luded in the present study. Pollen development in this mutant failed s hortly after microspore release from tetrads. Complementation tests co nfirmed that the ms mutations were at different loci. Reduced transmis sion of certain ms genes was observed.