Microsporogenesis and anther development in Bromeliaceae

Structural anomalies in pollen grains of Dyckia racinae L.B.Sm. (Bromeliaceae)

“…However, the embryological analyzes on Dyckia racinae did not indicate errors during meiosis or alterations in tapetum degeneration in the anthers of this species (Dorneles 2013). Therefore, the intrinsic causes of the anomalies reported here must differ from those pointed out by Mendes et al (2016) for P. encholirioides and by Sajo et al (2005) for other bromeliads, in addition to the fact that the anomalies reported are rare and structurally very distinct. In these works, there is an evident precocity in the tapetum degeneration, which was directly related to the extensive production of sterile pollen grains in some anthers, which does not occur in D. racinae.…”

“…Mendes et al (2016) discuss the relationship of this type of sterility with premature PCD in tapetum, which generates a large amount of sterile pollen grains in some anthers of Pitcairnia encholirioides L.B.Sm. In this case, as well as in other bromeliads (Sajo et al 2005), the protoplast in the sterile pollen grains completely collapses, although they appear to have a normal exine. On the other hand, structural anomalies that do not cause the collapse of the pollen grains, especially when the tapetum develops normally, are unknown to Bromeliaceae and it can be a neglected aspect of reproductive biology in this family.…”

Evolution and diversity of the angiosperm anther: trends in function and development

“…in safflower Carthamus tinctorius , where two types of tapetal cells coexist (Yeung et al 2011 ). Additionally, Sajo et al ( 2005 ) hypothesise there might be an intermediate tapetum type, where an early-stage secretory tapetum subsequently becomes invasive. The significance of two types coexisting, working independently or transitioning from one to another is still unclear, but it suggests there are intricate adaptations and specific regulation of tapetum development.…”