Crisis de los Polinizadores - TvAgro por Juan Gonzalo Angel

Twitter @juangangel Bees are disappearing. The problem of pollinators worldwide is of great concern to humans, since without the work of these animals, life on the planet as we know it could disappear. Pollination is the process of transferring pollen from the stamens to the stigma, or receptive part, of flowers in angiosperms, where it germinates and fertilizes the flower's ovules, enabling the production of seeds and fruits.123 Pollen can be transported by different agents called pollination vectors. Pollination vectors can be both biotic, such as birds, insects (mainly bees), bats, etc., and abiotic, such as water or wind. There are a wide variety of biotic vectors, including Hymenoptera (bumblebees, bees, and wasps), Lepidoptera (butterflies and moths), and Diptera (flies), as well as hummingbirds, some bats, and, in rare cases, some mice or monkeys. Some flowers can be pollinated by many vectors, in which case they are called generalist pollinator flowers; or, conversely, they can only be pollinated by one genus or species because the morphology of both the flower and the pollinator have been adapted over the course of evolution, in which case the flowers are called specialists. Pollination specialization benefits both the plant and the pollinator, making the pollinator highly efficient, as the insect will safely fly to another flower of the same species and deposit the pollen on that flower's stigma. Among orchids, it is common to find a high degree of specialization in interactions with pollinators (see Xanthopan morganii praedicta). Pollen transport can be carried out by physical agents such as wind (anemophilous plants), water (hydrophilous plants),4​ or an animal pollinator (zoophilous plants).5​ The physical and phenological characteristics of anemophilous, hydrophilous, and zoophilous flowers, as well as those of their pollen, are often markedly different. Zoophilous plants must attract the attention of their vectors with attractive colors and scents, as well as reward them with food or shelter. Different types of pollinators require different types of attractants, thus zoophilous flowers have evolved and diversified into a wide variety of types, which can be grouped into floral syndromes. The visual beauty characteristically associated with flowers is the effect of their coevolution with insects or other animal pollinators. In cases where pollination occurs as a result of plant-animal relationships, these relationships are predominantly mutualistic, that is, relationships in which both participants benefit. Unlike obligatory (strictly symbiotic) relationships that exist in nature, most pollination relationships are facultative or optional and very flexible: the disappearance of a pollinator or plant does not necessarily lead to the extinction of the other participant in the interaction, as each has alternatives (other food sources in the case of the animal, or other pollinator species in the case of the plant). However, there are some extremely interesting cases of symbiotic relationships between a pollinator and a plant species, such as the fig wasp and the yucca moth. The oldest fossils demonstrating pollination are spermatophyte plants from the Late Carboniferous. Some gymnosperms from the Triassic period already show signs of biotic pollination, that is, by animals, in that the fossilized grains have some of the characteristics of pollen grains carried by pollinators today. Furthermore, the gut contents, mouthparts, and wing structure of certain beetles and flies suggest that they must have acted as pollinators. The first floral pollination syndromes emerged at this time. The association between beetles and angiosperms in the Early Cretaceous led to evolutionary radiations of both in the Late Cretaceous. The evolution of nectaries, or nectar-producing organs, marks the beginning of a mutualism between hymenopteran insects and angiosperms. Source: https://es.wikipedia.org/wiki/Poliniz... Juan Gonzalo Angel Restrepo www.tvagro.tv