Search results for "Hybrid seed"
showing 2 items of 2 documents
Molecular parameters involved in bee-plant relationships: a biological and chemical approach
1987
Abstract Honeybee-plant relationships are based on a conditioning process in which olfactory (plant aroma) and gustatory cues (mainly nectars) are closely linked, leading to a selective foraging behaviour. Among crops dependent upon entomophilous cross-pollination, the sunflower has recently undergone extensive expansion due to hybrid variety selection. Sunflower hybrid seed production is strictly dependent upon pollinating insects, mainly the honeybees, but foragers may have preferences among the parental lines, leading to a lack of pollen carriage and consequently to a decrease of hybrid seed yield. In order to define the role of plant chemicals (aromas, nectars) involved in the pollinati…
The effectiveness of pre- and post-zygotic barriers in avoiding hybridization between two snapdragons (Antirrhinum L.: Plantaginaceae)
2014
Reproductive barriers play an important role in the maintenance of species boundaries. However, to date, few studies have provided a detailed analysis of reproductive isolation barriers between species or examined their importance in maintaining species identity. This is the first detailed study into pre- and post-zygotic reproductive isolation barriers in Antirrhinum, based on a mixed population with two species that rarely co-occur. The study revealed that pollinator constancy and preference and poor hybrid seed viability were the most important reproductive isolating mechanisms. Reproductive isolation was practically complete by both pre- and post-zygotic barriers. Average pre-zygotic is…