Exine Development, Structure, and Resistance in Pollen ofCinnamomum(Lauraceae)
作者:
JohnR. Rowley,
George Vasanthy,
期刊:
Grana
(Taylor Available online 1993)
卷期:
Volume 32,
issue sup2
页码: 49-53
ISSN:0017-3134
年代: 1993
DOI:10.1080/00173139309428979
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
We report features of sporoderm development ofCinnamomum verumPresl. from the vacuolated stage of microspores through pollen grain maturity. Before microspore mitosis the sporoderm consists of spinules and gemmae separated from the cytoplasm by a channeled onciform zone. When the intine forms, after microspore mitosis, it is highly fimbriated in profile. The surface of the exine, (spinules and gemmae) is covered by a thick (200–300 nm) surface coating. Elements of the surface coating are glycoprotein and connect with filamentous material within the anther loculus. The gemmae may be assumed to increase in number between the microspore period and pollen grain maturity since their frequency per unit area and the surface area of the grains increase. The implication is that sporopollenin is added late as well as early in development. Spinules, gemmae, and straps between gemmae resist acetolysis, but special handling (no rehydration and minimal mechanical flexure) is required in order to retain the spheroidal configuration of exines; otherwise exines are compacted into knot-like masses that are then unidentifiable.
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