Local environment (temperature and relative humidity) affects reproductive biology in Pyrostegia venusta (Bignoniaceae) growing at Agra and Mysore. At Agra, the species flowers profusely during December to March, but fails to bear fruits. At Mysore, on the other hand it flowers during November to February and produces well developed fruits with winged seeds. This species, growing at two places,...

Abstract. Avocado pollen was germinated in vitro without recourse to germination on the style. The technique employed involved inclusion of pollen grains in liquid medium of 15% sucrose and minerals and application of 1 or 2 drops on 1% agar plus 15% sucrose and minerals. No germination was obtained on agar plus sucrose without placement of pollen in liquid first. Of the cultivars tested, 'Etti...

There is minimal information about the effect of heavy metals such as lead and copper on pollen grains and pollen tubes of fruit trees. Fruit set of these plants are affected by different environmental, biological, physical and chemical factors. If one of these factors be abnormal, pollination, fertilization and fruit set and orchard yield will decrease. In polluted cities, this phenomenon is a...

28 Research on threats to pollination service in agro-ecosystems has focused primarily on 29 the negative impacts of land use change and agricultural practices, such as insecticide use, on 30 pollinator populations. Insecticide use could also affect the pollination process, through non31 lethal impacts on pollinator attraction and post-pollination processes such as pollen viability or 32 pollen...

Despite much effort, a robust protocol for in vitro germination of Arabidopsis thaliana pollen has been elusive. Here we show that controlled temperatures, a largely disregarded factor in previous studies, and a simple optimized medium, solidified or liquid, yielded pollen germination rates above 80% and pollen tube lengths of hundreds of microns, with both Columbia and Landsberg erecta (Ler) e...

this study was conducted to determine the best pollinizer for five selected pecan cultivars in southwest of iran at safiabad agricultural research center in 2014-2015. the cultivars included: 'gratex', '10j', 'wichita 6j', 'graking', 'choctaw' as pollinated cultivars (♀) and 'gratex', 'peruque', 'comanche 4m', &apos...

Pollen quantity, viability and germination of four genotypes of Rosa dumalis and R. villosa were investigated. The number of anthers per flower were 90.3 in genotype 4 (Rosa villosa) and 116.4 in genotype 1 (Rosa dumalis). Genotype 1 showed the highest pollen viability on the basis of both TTC and IKI tests. Most of the rose species are diploid but there are several species with higher ploidy l...

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...

The influence of ethylene and CO(2) on pollen germination and tube growth was investigated employing ventilated culture systems. Ethylene had no effect on pollen germinability or tube growth. Germinating pollen did not produce a detectable amount of ethylene (less than 0.1 nl/g.hr). Supplementing the cultures with CO(2) caused a marked increase in germination and tube growth. The half-maximal r...

Speciation involves the formation of reproductive isolating mechanisms such as a difference in pollinators, incompatibility between pollen tubes and stylar tissue, hybrid seed abortion, or poor growth of hybrid seedlings. We studied reproductive isolating mechanisms in naturally sympatric populations of Penstemon spectabilis Thurber and Penstemon centranthifolius (Benth.) Benth. where F1 hybrid...