The floral traits of bisexual flowers may evolve in response to selection on both male and female functions, but the relative importance of selection associated with each of these two aspects is poorly resolved. Sexually dimorphic traits in plants with unisexual flowers may reflect gender-specific selection, providing opportunities for gaining an increased understanding of the evolution of spec...

the present experiment was carried out to assess the general combining ability (gca) and specific combining ability (sca) of six important commercial cultivars of gossypium hirsutum l. of venezuela, viz., ‘deltapine 16’, ‘tamcot-sp-21’, ‘cabuyare’, ‘stoneville’, ‘ospino’ and ‘acala 90-1’ and their 15 f1 hybrids, respectively. the data were analyzed using griffing’s model i method ii. significan...

Flowers need insects for their pollination and insects rely on the nectar and the pollen as a food resource. But instead of visiting all flowers, the insects limit their visits to a small number. This paper presents a simulation of the behavior of the insects which results in a specialized perception of blossom colors and fragrances by the insects. A coevolution can be observed only based on si...

Silene alba, a perennial, dioecious plant, produces flowers that open in the evening and can remain open and receptive to pollination for up to 5 d, though in hot and dry conditions the flowers will wilt during the day only to reopen night after night. In the field, it is visited by two different kinds of pollinators with differential success: moths visit the flowers at night, and their movemen...

As first described by Aristotle, honey bee (Apis mellifera) workers show a strong tendency to visit flowers of only one type during a foraging trip. It is known that workers rapidly learn a flower colour when rewarded with artificial nectar (sucrose solution). However, some previous studies report that the degree of constancy after training is unaffected by reward quantity and quality when bees...