Pollen morphological variation in Vanguerieae (Ixoroideae Rubiaceae)
نویسندگان
چکیده
منابع مشابه
The Epidermal Cell Structure of the Secondary Pollen Presenter in Vangueria infausta (Rubiaceae: Vanguerieae) Suggests a Functional Association with Protruding Onci in Pollen Grains
Secondary pollen presentation is a well-known phenomenon in the Rubiaceae with particularly conspicuous pollen presenters occurring in the tribe Vanguerieae. These knob-like structures are formed by a modification of the upper portion of the style and stigma, together known as the stylar head complex. In the flower bud and shortly before anthesis, the anthers surrounding the stylar head complex...
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Pollen wall ontogeny of RONDELETIA: odorata was studied with transmission electron microscopy (TEM) and scanning electron microscopy (SEM) from tetrad stage until maturity. The ontogenetic sequence of wall development in RONDELETIA: follows, to some extent, the basic scheme in the angiosperms, i.e., development starts centripetally with the pro-columellae in a plasmalemma surface coating (prime...
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The mean diameter of viable pollen grains is approximately 13 μm greater than the mean diameter of inviable grains in Mimulus guttatus. We show that this difference is large enough to be detected by particle counters and that these machines can be used to obtain a rapid estimate of pollen viability. While requiring a separate calibration, a size-based statistic is also strongly correlated with ...
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ژورنال
عنوان ژورنال: Grana
سال: 2000
ISSN: 0017-3134,1651-2049
DOI: 10.1080/001731300300045201