Über den Pollenkitt bei Galanthus nivalis L.

TAPETAL ORIGIN OF POLLEN‐COAT SUBSTANCES IN LILIUM

“…There is no evidence at any time of contacts between tapetal cytoplasm and the surface of the grains. This is in contrast with the situation in Galanthus nivalis, where the PoUenkitt is synthesized by an invasive tapetum, the cells of which are in intimate ass(jciation with the young spores (Pankow, 1957). Evidently in Galanthus, cytoplasm, or cytoplasmic products other than the PoUenkitt itself, could be transferred and trapped in ca\ ities within the exine in the mantier proposed by Pankow.…”

“…Pankow, 1957), namely, that the synthesis must be programmed by the parental genome, and not by the haploid spores themselves. Thus where the colotir of pollen is due to surface materials of the nature of Pollenkitt, it is determined by sporophyte tissues external to the spores.…”

“…Troll (1928) pointed out that the possession of this coating was related to mode of pollination, and in a series of elegant experiments Knoll (1930) showed that this Pollenkitt, as he termed it, was characteristic of many entomophilous species but lacking in those which were wind pollinated. Pankow (1957) quotes Meyen as having noted as early as 1839 that the material appears first on the inner face of the anther loculi before, or immediately following, the release of the young microspores from the tetrad, and is later transferred to the surface of the grains. Pankow himself investigated its origin in Galanthus nivalis, and found that it arose firstly in the form of droplets in the anther fluid, itself actually a plasmodium formed by the disruption of the tapetal cells, which in this species invade the loculus during the later period of pollen maturation.…”

Pollen-Pistil Interactions

“…The material is present in particular abundance in animal-pollinated grains where it has been termed Pollenkitt (PANKOW 1957) and in other cases tryphine (see review by ECHLIN 1971). Because of this cOnfusion in terminology, the term pollen-coat suggested by ZANDONELLA et al (1981) has been used in this chapter.…”

Pollen wall development in Olea europaea L.

“…Shortly after dehiscence of the mature anthers globules are deposited in the ectexine. This material, the degradation product of the tapetum, has been identified as lipidic in nature (Pacini & Casadoro, 1981) and is analogous to the so-called pollenkitt (Pankow, 1957) found in most mature pollen grains, both entomophilic and anemophilic. (1982) Figure 7.…”