The battle between plants and pollinators

  A plant called pineapple lily is abundant in southern Africa. Its flower is green and has a strange smell, so it cannot attract the attention of insects and birds during pollen transmission. So how does pineapple lily transmit pollen? When photographing the pineapple lily, the researchers found small mammalian rock mice around it. It turns out that the scent of pineapple lily when it blooms contains methylthiopropionaldehyde. This chemical substance has a strong onion and meaty smell, which can attract rock squirrels to lick nectar, so rock squirrels become the pollinator of pineapple lilies. .
  plant breeding depends on the success of pollen transfer. Except for a few plants that can self-pollinate, most plants need the help of pollinators to achieve pollination. As early as more than 100 million years ago, there was a phenomenon of vector pollination. In the amber unearthed in northern Spain recently, there are solidified female thrips insects with hundreds of pollen grains on their bodies. Thrips have ring-shaped hairs on their body, and this body structure helps them collect pollen. According to the researcher, thrips may be one of the earliest pollinators in the history of geology. Since then, the relationship between plants and pollinators has gradually strengthened, resulting in the prosperity of flowering plants in the plant kingdom.
  Plants have formed a variety of pollinators in the process of evolution. Among them, wind and insects are the two most common transmission vectors.
  Oak, poplar, birch and hazel in woody plants, rice, carex and wheat in herbaceous plants all use wind to transport pollen. Their pollen grains are generally small and dry, with a smooth surface, simple quilts, easy to be transported by wind, and easy to spread over long distances.
  Plants that are pollinated by insects have large flower shapes, beautiful perianth colors, and often have a fragrant smell and sweet nectar. Pollen grains are sticky and easy to adhere to insects. Common insect vectors include bees, butterflies and moths.
  In addition, aquatic plants such as Ceratophyllum, Lyceum, Hydrilla, and Vallisneria use flowing water as pollinators; some small mammals and birds are also pollinators, such as the rock rat mentioned at the beginning of the article. It pollinates pineapple lilies. The green jade vines in the tropical rain forests of the Philippines are mainly pollinated by bats. An Australian opossum pollinates longan plants. There are about 2,000 species of birds that pollinate plants, such as myna, thrush, crow and hummingbird.
  in the study of links between plants and pollinators, the scientists were surprised to find that, in its calm exterior, plants have evolved a variety of clever means to attract pollinators, some strategies for both sides is mutually beneficial reciprocal.
  In order to better attract insects, the flowers of general plants are bright in color and fragrant. However, it is difficult to attract pollinating insects for a long time only by color and smell. Therefore, most insect-pollinated flowers provide certain rewards to insects in some form. Some plants secrete sweet pollen and nectar to attract diners; some provide odorous substances as information materials for insect communication; some provide insects with some resin and other nesting materials.
  Various insects pollinate different kinds of plants. There are a very small number of insects that specifically pollinate a certain kind of flower and rely on it to reproduce offspring. Yucca and yucca moths are typical of this mutual symbiosis. Every time after sunset, the flowers of yucca slowly open, emitting a strange fragrance, attracting yucca moths to pollinate it. The yucca moth lays its eggs in the yucca flower house, which is conceived and raised by the yucca. When the seeds of the yucca mature, the larvae of the yucca moth are also mature, they bite through the fruit wall, spin silk down to the ground, and then cocoon in the soil to form a pupae. When the yucca blooms in the coming year, it will break out of the cocoon and fly to the yucca ovary to pollinate and give birth.
  The reciprocal symbiosis between the banyan tree and the pollinating banyan bee is even closer, and it has developed to a one-to-one co-evolution, that is, only one kind of banyan tree allows only one kind of banyan bee to pollinate. There have been many adaptive specializations in the morphology and structure of the two: the length of the banyan style and the ovipositor of the banyan tree are matched; the maturity of the banyan tree is highly consistent with the emergence period of the adult banyan wasp; the evolution of the tentacles of the banyan wasp The curved hook can quickly pry open the bracts of the banyan fruit, and the shovel-shaped head is easier to enter the bracts of the banyan fruit.
  Camouflage and deception
  mutually beneficial relationship between plants and pollinating animals in the ecosystem is very common. However, many plants use various deception methods to lure insects to achieve pollination.
  For example, the petals of Cymbidium orchids have dark spots, which give pollinators a false impression of nectar. However, there is no nectar in the Cymbidium. The poor little bee does not know whether it is true or not. He digs into the Cymbidium to find honey to eat. As a result, he can only pollinate the Cymbidium for free.
  There is a kind of king butterfly orchid in Ecuador that has neither fragrance nor sweet juice. Insects are reluctant to approach king butterfly orchids. King butterfly orchids like to grow near the sting honeycomb. The sting bee has a strong sense of territory and does not allow other insects to invade its territory. The color of the stamens and lips of King Phalaenopsis resembles insects, swaying in the breeze, like insects whirling. When the sting bee saw it, it bit and stung it, instead spreading pollen for the king butterfly orchid.
  Rafflesia is a fleshy parasitic herb. The whole plant has no leaves, stems, and roots. It only blooms one flower in its lifetime. It emits a rotten smell like rotting fish during flowering. Many odorous flies are deceived by the smell of flowers, thinking that they have found suitable prey. They will soon find themselves fooled when they enter the flowers, and then fly away, unknowingly pollinating the Rafflesia flower.
  Trap and murder
  Some plants are taken to set traps ways to trick insect pollination for themselves. There is an enlarged sac at the base of the flower of Aristolochia grandiflora, and the stamens grow in the sac. The weird smell and petal spots of the giant flower Aristolochia can lure insects that shuttle through the flowers into the sac. Because the inner wall is covered with inverted hairs, insects lose their freedom once they enter the sac. When the stamens are mature, the anthers burst and emit pollen. At this time, the hairs on the inner wall of the flower shrink and become soft. When the insects escape, they will be covered with pollen, so that the insects will fly to another flower that has just opened. , Spread the pollen to the stigma.
  Compared with the giant flower Aristolochia, the South African water lily is much more cruel. It not only imprisons pollinators, but also achieves the purpose of pollination by “murdering” pollinators. The stamens of South African water lilies mature first when they bloom, and the densely packed stamens in the center of the flower exude a sweet smell attracting visitors such as hoverflies, bees and beetles to enjoy a pollen feast. When the water lily pistil matures, the previous stamen has no pollen, and there is a pool of sap around the center of the flower, with a flat and round stigma hidden at the bottom of the pool. When a visitor with stamen pollen on his body comes to collect pollen again, the visitor will sink into the liquid and drown quickly. The stamen pollen on his body will fall off and deposit on the stigma of the water lily to complete the pollination.
  This inexhaustible relationship between plants and pollinators has made each other, and also constructed a rich and colorful nature.