Fig. 1

Development of male gametes in Ranunculus plants. a. – e.) Regular meiosis of PMCs, a.) PMC at metaphase I, b.) PMC at telophase I during cell plate formation, c.) PMC at the end of anaphase II, d.) Meiotically developed tetrad of microspores, e.) Homogeneous-sized pollen grains, f. – p.) Various cytological failures in Ranunculus PMCs, f.) PMC at metaphase II showing a sticky out-of-plate chromosome (arrowhead), g. + h.) PMCs with lagging chromosomes at anaphase I (arrowhead), i. + j). PMCs with irregular spindle activity (arrowhead), resulting in abnormal chromosome segregation at anaphase II, k.) PMC at anaphase II with several lagging chromosomes, l.) A Dyad, m.) A Triad, n.) Tetrad with three normally sized microspores and one miniature microspore, o.) Polyad of five uniformly sized microspores, p. + q.) Figure of the same sporad at different levels. Polyad with seven microspores at different sizes, r.) Incompletely separated microspores. Arrowheads point to connections between the three nuclei-containing microspores, s.) Dyad pollen grain, t.) Heterogeneously-sized micropollen grains. Genotypes: a.) F3 * J6 (22); b.) J9A; c., d., g., j.) 10136 (15); e.) 10137 (08); f.) J6 * F7 (14); h., i., k.) G5A; l., m., r., s.) F10 * F7 (04); n., t.) 10136 (08); o.) 10136 (02); p., q.) G16A. Scale bars = 50 μm