1. The interactions between ragweed pollen and the saliva from ragweed-sensitive and non-sensitive humans have been examined. A number of morphological changes of the pollen grains take place under the conditions of the incubation. Of these changes, two occur only with incubation in allergic saliva and one occurs with the use of ‘inflammatory’ saliva, allergic or non-allergic. 2. The two change...

their allotetraploid hybrid, B. napus (Nasrallah and Nas-Plant Cell Biology Research Centre rallah, 1993). Flowers of these plants have dry stigmas School of Botany covered by a waxy cuticle, and successful pollinations University of Melbourne begin when a hydraulic connection is established be-Parkville, VIC 3052 tween a pollen grain and a stigmatic papillar cell, Australia allowing the pollen...

In this article, we propose an automatic method for the segmentation of pollen grains from microscope images, followed by the automatic segmentation of their exine. The objective of exine segmentation is to separate the pollen grain in two regions of interest: exine and inner part. A coarse-to-fine approach ensures a smooth and accurate segmentation of both structures. As a rough stage, grain s...

High quality of bee pollen for commercial purpose is required. In order to attend the consumer with the best identification of the botanical and floral origin of the product, 25 bee pollen batches were investigated using two techniques of pollen grain preparation. The first started to identify pollen loads of different colors in two grams of each well mixed batch, and the second to identify pol...

pollen grains of five olive cultivars (olea europaea l .) were examined, using scanning electron microscopy (sem) for identification purposes. four measurments, polar axis (p), equatorial diameter (e), p/e ratio and exine patterns were made. forty pollen grains of each cultivar were viewed before finally selecting a representative pollen grain. polar diameter ranged between 22.76 μm for the...

In an ongoing research, 24 cultivated and wild cultivars of barley were evaluated for morphological characteristics of grain, pollen, and stomata. Traits of interest included length, width, and area. Results of variance analysis showed that all samples were differed in traits of stomata, grain, and pollen at probability levels of 1 and 5%, suggesting remarkable genetic variation among studied s...

A novel mitogen-activated protein (MAP) kinase signaling pathway has been identified in tobacco. This pathway is developmentally regulated during pollen maturation and is activated by hydration during pollen germination. Analysis of different stages of pollen development showed that transcriptional and translational induction of MAP kinase synthesis occurs at the mid-bicellular stage of pollen ...

In plant organs and tissues, the neutral storage lipids are confined to discrete spherical organelles called oil bodies. Oil bodies from plant seeds contain 0.6-3% proteins, including oleosins, steroleosins, and caleosins. In this study, a caleosin isoform of approximately 30 kDa was identified in the olive pollen grain. The protein was mainly located at the boundaries of the oil bodies in the ...

Drought stress induced pollen sterility is a detrimental factor reducing grain number in wheat. Exploring the mechanisms underlying pollen fertility under drought conditions could assist breeding high-yielding wheat cultivars with stress tolerance. Here, by using two Chinese wheat cultivars subjected to different levels of polyethylene glycol (PEG)-induced drought stress, possible links between...

The mean volume of pollen grains and total pollen production varied both within and among plants of Erythronium grandiflorum. The second flowers of two-flowered plants tended to produce smaller and fewer grains than first flowers, but there was no overall relationship between mean pollen grain size and production per flower. I evaluated the effects of pollen size differences within and among pl...