Pollen and Tapetum Development in Male FertileRosmarinus OfficinalisL. (Lamiaceae)

Electron-translucent angular areas in developing tapetum cell walls and pollen grains ofTilia platyphyllos

“…The stages of tapetum development are characterized by gradual modification of cell organelles (Hesse 1993a) and by stepwise disintegration of the tapetal cell walls (this paper); analogous steps in tapetum maturation occur in all taxa with a secretory tapetum, although the timing is very variable (for a review, see Ubera Jimdnez et al 1996). One stage of this stepwise disintegration may be represented by the electron-translucent areas.…”

Mitochondrial Dna Polymorphism and Gynodioecy in a Natural Population of Rosmarinus Officinalis L.

“…In Rosmarinus officina/is there have been several previous studies on the morphology and distribution of male fertile flowers in natural populations (Roiz and Dulberger, 1988;Ubera-Jimenez and Hidalgo-Femandez, 1992), and of normal (Ubera-Jimenez et al, 1996) and male sterile anther development (Hidalgo, 1997). However, no studies have addressed mitochondrial genome variability nor its relationship with male sterility.…”

Ultrastructure and ontogeny of the exine inTribulus terrestrisLinné (Zygophyllaceae)

“…This has been shown in numerous studies of pollen ontogeny, as for example, in Lavandula dentata (Suárez-Cervera & Seoane-Camba, 1986), Ulmus (Rowley & Rowley, 1986), Olea europaea (Fernández & Rodríguez-García, 1989), Calluna (Dahl & Rowley, 1990-1991, Fuchsia magellanica var. riccartonii (Horvat, 1992), Felicia muricata (Jordaan & Kruger, 1993), Platanus acerifolia (Suárez-Cervera et al, 1995), Rosmarinus officinalis (Ubera Jiménez et al, 1996). However, this lamellar structure may persist at pollen grain maturity, for example, in Compositae: Ambrosia sp.…”

“…In Tribulus terrestris the intine consists of two layers; similar cases have been described in a wide range of angiosperm families: from early evolving dicotyledons, for example, Asimina triloba (Annonaceae) by Gabarayeva (1993); and the monocotyledons, for example, Amphibolis griffithii (Cymodoceaceae) by McConchie et al (1982), Gibasis karwinskyana and G. venustula (Commelinaceae) by Owens & Dickinson (1983), and Amaryllidaceae, Liliaceae, Bromeliaceae, Dianellaceae, Dracaenaceae, Funkiaceae, Hyacinthaceae, Iridaceae, Melanthiaceae, Velloziaceae (Halbritter & Hesse, 1993); to the eudicotyledons, for example, Nelumbo nucifera and N. lutea (Nelumbonaceae) by Kreunen & Osborn (1999) and Rosmarinus officinalis (Lamiaceae) by Ubera Jiménez et al (1996). In R. officinalis the outer layer of the intine is electron lucent and thick at the aperture level, while the inner layer is electron dense and has a uniform thickness around the microspore.…”