the present research was conducted to determine the percent self-incompatibility in some asian pear (pyrus serotina rehd.) as well in european pear (pyrus communis l.) cultivars. the experiment was carried out during 2006 and 2007 growing seasons. pollen grains were collected and tested for viability using in-vitro pollen culture. for microscopic examination of pollen tube growth in the style, ...

in the present paper, the cytogenetic study including meiotic chromosome number and behavior along with pollen viability were performed in 4 populations of trigonella spruneriana boiss. this is the first cytogenetic report of the taxon. all populations are diploid and possess 2n = 2x = 16 chromosome number, which is consistent with the proposed basic number of x = 8. in addition, some meiotic i...

investigations were initiated this year to develop field and laboratory viability assays for stored walnut pollen, indentify conditions suitable for in vitro pollen germination and pollen tube growth, and determine pollen tube growth rates in pistillate flowers. Results of this project will provide background information for future investigations of transmission of pollen-borne virus, factors i...

Although pollen viability promises to be a very sensitive indicator of environmental mutagenesis, its utility in this regard is confounded by the fact that it is influenced also by nonmutagenic environmental stress. However, with appropriately homozygous material, we may discriminate between mutagenic and nonmutagenic influences on pollen viability. Pollen inviability resulting from mutagenesis...

Organic producers, particularly dairy and sweet corn growers, fear losing their organic certification if genetically engineered (GE) proteins are found in their corn (Zea mays L.). Although corn pollen grains are among the largest and heaviest of wind-pollinated plants (Smith, 1990), transport is possible. Corn is a monoecious plant with male and female flowers borne on separate parts of the pl...

Pollen is essential for seed production and serves as the primary means of gene flow in outcrossing species like switchgrass (Panicum virgatum L.). There is a lack of information on basic pollen biology in switchgrass. This study investigated pollen viability, pollen longevity, and pollen size using different materials, including the tetraploid cultivar Alamo, the octoploid cultivar Cave-in-Roc...

Habitat fragmentation, caused by the expansion of agriculture in natural areas, may be one of the strongest impacts humans have on the ecosystem. These changes can decrease the number of individuals in a population, leading to endogamy. In allogamous species, endogamy can have a negative effect on reproductive capacity. In this study, we analyzed the effects of forest fragmentation on micr...

The genus Brachiaria contains species that have great economic importance in the Brazilian agricultural sector, as they enable cattle ranching on acid and poor soils with species that are resistant to spittlebugs and form crop-livestock-forest integration systems. The genus mainly consists of tetraploid (2n = 4x = 36) and apomictic species such as B. decumbens and B. brizantha. Sexuality is fou...