studies of postmeiotic chromosomes have been impeded by the thick exine of immature pollen grains. chromosome staining of immature and adult pollen grains through conven-tional acetocarmine procedure is tedious and often leads to unsatisfactory results. an acetocarmine stain, used in conjugation with carnoy’s solution as fixative for 72 hrs or until the chlorophyll-containing tissues of spike b...

weed pollen grains belonging to  the  asteraceae  family contain  a variety of  allergens inducing type i  and iv allergies in susceptible people. the  aim of this research was to compare  the  allergenic properties  of  immature  and  mature  shasta  daisy pollen  grains (chrysanthemum maximum ramond) to define the potential role of the maturation process on the allergenicity of asteraceae pol...

Studies of postmeiotic chromosomes have been impeded by the thick exine of immature pollen grains. Chromosome staining of immature and adult pollen grains through conventional acetocarmine procedure is tedious and often leads to unsatisfactory results. An acetocarmine stain, used in conjugation with Carnoy’s solution as fixative for 72 hrs or until the chlorophyll-containing tissues of spike be...

The effect of anther-derived substances on pollen function was studied using pollen produced by in vitro culture of immature pollen of tobacco (Nicotiana tabacum L.) and petunia (Petunia hybrida). Addition of conditioned medium consisting of diffusates from in situ matured pollen strongly increased pollen germination frequency and pollen tube growth, as well as seed set after in situ pollinatio...

Weed pollen grains belonging to the Asteraceae family contain a variety of allergens inducing type I and IV allergies in susceptible people. The aim of this research was to compare the allergenic properties of immature and mature Shasta daisy pollen grains (Chrysanthemum maximum Ramond) to define the potential role of the maturation process on the allergenicity of Asteraceae pollen grains. The ...

Hop latent viroid (HLVd) is not transmissible through hop generative tissues and seeds. Here we describe the process of HLVd elimination during development of hop pollen. HLVd propagates in uninucleate hop pollen, but is eliminated at stages following first pollen mitosis during pollen vacuolization and maturation. Only traces of HLVd were detected by RT-PCR in mature pollen after anthesis and ...

Pollen embryogenesis provides exciting opportunities in the areas of breeding and biotechnology as well as representing a convenient model for studying the process of plant cell proliferation in general and embryogenesis in particular. A cell culture system was devised in which immature barley pollen could be cultured as a monolayer trapped between the bottom glass-cover slip of a live-cell cha...

The pollen coat protects pollen grains from harmful environmental stresses such as drought and cold. Many compounds in the pollen coat are synthesized in the tapetum. However, the pathway by which they are transferred to the pollen surface remains obscure. We found that two Arabidopsis thaliana ATP binding cassette transporters, ABCG9 and ABCG31, were highly expressed in the tapetum and are inv...

Plants display a remarkable capacity for cellular totipotency. An intriguing and useful example is that immature pollen cultured in vitro can pass through embryogenic development to form haploid or doubled haploid plants. However, a lack of understanding the initial mechanisms of pollen embryogenesis hampers the improvement and more effective and widespread employment of haploid technology in p...