Cross Pollination In Biology

SCHOOL OF MOLECULAR AND LIFE SCIENCES

LESAILANE M

201505020

BOTANY ASSIGNMENT 1

28/JULY/2017

INTRODUCTION

Plants have evolved mechanisms to avoid self-pollination which brings about inbreeding, cross pollination is encouraged. It is of crucial importance that not only does a plant grow to its maturity stage, but also that it should produce fertile offspring and ensure that it maintains genetic continuity of the plant population. Plants are immobile organisms, so they need pollinating vectors to help them transfer pollen from the anthers to the stigma of different flowers, in order to ensure cross-pollination.

Animal pollinators are of a huge importance in the production of various flowering plants. Interspecific pollen transfer

They have evolved through the years and have adapted to pollination syndromes in order to ensure successful fertilization by attracting pollinators that have the ability to pollinate them. Their pollinating agents are mostly vertebrates such as mammals, birds, reptiles, amphibians, and fish. Insects can also be pollinating agents, with bees being one of the most economically beneficial agents.

Every pollinator has its own unique morphological, behavioral and floral preferences, this result in each one having different directions on floral phenotype. When a flower has evolved be pollinated by different pollinators (polyphilic flowers), less effective pollinators can waste pollen which would be distributed better by the main pollinator. This less effective pollinator will be regarded as a parasite caused by conditions and not a mutualistic in the community of more effective pollinators since its presence in the community of effective pollinators will reduce plant fitness.

Hummingbirds and bats have different morphological characteristics, activity patterns and modes of locating flowers. These differences such as being active during the night or day can introduce adaptive changes in the appearance of the plant.Pollinating agents are color discriminatory and can only see within a given range on the electromagnetic

The Aphelandra acanthus shrub from the cloud forest of Ecuadore (Wasshuasen, 1975), suggested that this species has adapted to pollination by both bats and hummingbirds. Its flowers had narrow, tubular corolla bases similar to those of other flower species similar to hummingbird pollinated plants, yet the distal portion flares into a wide opening like those of some bat pollinated flowers. The flower color was bright yellow to pale cream which suited both the hummingbird and bats respectively.

Flowers of Aphelandra acanthus present a mix of characteristics representative of different pollination syndromes. Flower Anthesis cannot be classified as either nocturnal or diurnal. Rather, flowers open throughout the day and night and last for several