The reproductive assurance hypothesis states that self-incompatible female plants must produce twice the number of seeds relative to their self-compatible hermaphroditic counterparts to persist in gynodioecious populations. This is a viable life-history strategy, provided that pollination rates are sufficiently high. However, reduced pollination rates in alpine plants are likely due to climate ...

California valley oak is threatened by landscape alteration and failing recruitment in remnant stands. Its reproductive ecology is a key element of the seedling recruitment process. We first examine the mating system, to determine the extent of inbreeding in a population at Sedgwick Reserve, in Santa Barbara County. We then quantify variation in germination success and acorn size, evaluating th...

The reproductive assurance hypothesis states that self-incompatible female plants must produce twice the number of seeds relative to their self-compatible hermaphroditic counterparts to persist in gynodioecious populations. This is a viable life-history strategy, provided that pollination rates are sufficiently high. However, reduced pollination rates in alpine plants are likely due to climate ...

Selenium (Se) is an essential micronutrient for many organisms, but is also a toxin and environmental pollutant at elevated levels. Due to its chemical similarity to sulphur, most plants readily take up and assimilate Se. Se accumulators such as Brassica juncea can accumulate Se between 0.01% and 0.1% of dry weight (DW), and Se hyperaccumulators such as Stanleya pinnata (Brassicaeae) contain be...

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...

Bee-collected pollen (bee pollen) is reported as a health food with a vast range of nutritional and therapeutic effects. Biochemical and hematological parameters in blood of rainbow trout treated to various concentrations of pollen (0.5, 2.5, 5, 10, 20 and 30 ppm) for 96 h were determined. The levels of total protein, creatinine, chloride and sodium in fish which exposed to different concentrat...

the developmental period, prey consumption of different nymph instars, survival, reproduction and longevity of orius albidipennis were studied on three different diets including the two-spotted spider mite, tetranychus urticae plus corn pollen; two-spotted spider mite; and eggs of sitotroga cerealella plus corn pollen under laboratory conditions. leaves of pelargonium hortom served as ovipositi...