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http://education-portal.com/academy/lesson/asexual-plant-reproductionvegetative-propagation-and-bulbs.html In the asexual reproduction, the offspring are genetically identical to the parent. It only requires –and only allows for- one parent. Not all plants make attractive flowers in order to reproduce. Some plants will not make seeds and pollen either. These plants have other ways to create new offspring. We will look at a few key methods of vegetative propagation. You may know that plants produce seeds and pollen in order to create new plants. However, this form of reproduction is not the only way to create new plants. For plants that do not make seeds, there are many options for making new offspring. We will look at a few of these forms of reproduction. But first, let's understand some general aspects of asexual plant reproduction. Asexual reproduction occurs when offspring are genetically identical to the parent. Asexual reproduction only requires - and only allows for - one parent. Most of the time we think of two parents -a male and a female- making an offspring, however, asexual reproduction only uses one parent. In plants, asexual reproduction can occur by spores or by vegetative propagation. Many plants form spores during their biological life cycle in a process called sporogenesis which takes place in the sporophyte, as you remember in ferns and mosses life cycle. Vegetative propagation, like many things, has its advantages and disadvantages. It is beneficial for plants that are well suited for their environment and when the environment is stable. Remember that asexual reproduction results in genetically identical organisms, so these organisms must be well adapted to their environment in order to survive. Because asexual reproduction doesn't allow for evolution and adaptations to occur as frequently as sexual reproduction, vegetative propagation is not advantageous for plants that live in changing environments. In unstable environments, plants that are identical to each other may all die out at once. However, if plants are genetically different, which is a result of sexual reproduction, some plants may survive in an unstable environment. For example, if we have a specific type of plant that grows very well in hot, humid environments, all of the plants may die out if there is a change in the climate. If the temperature or humidity change, the plants that produce asexually are all the same and therefore, they will all die out because they are not adapted to the new climate. However, a plant that produces sexually will have some diversity in the individual plants and some may survive this change in temperature or humidity. We also see this in plants that are affected by diseases - those plants that are genetically identical are more likely to die out than those plants that are genetically diverse. Bulbs Now that we have explored what vegetative propagation is, as well as some benefits and downsides, let's now look at a few forms of asexual reproduction in plants. We will first look at how bulbs result in vegetative propagation. Generally, you may think of bulbs that you plant in the fall in order to get flowers, such as daffodils or tulips, in the spring. Bulbs are underground buds that have fleshy leaves extending from them. Bulbs are food storage units for future developing plants. Bulbs contain several buds near the node, which is where leaves are produced. These new buds can eventually develop into new plants. If you plant one bulb, you may find that years later you have several plants coming from that one bulb. If you want, you can separate these new bulbs and plant more flowers. Because this one plant produces new offspring that are genetically identical, bulbs are a form of vegetative propagation. Tubers Tubers are somewhat similar to bulbs. Tubers, such as potatoes, are enlarged, fleshy underground stems. While potatoes do not always reproduce by using tubers, if you've ever left a potato for too long, you know that new potato plants can develop from the tuber. These new stems start on the eyes of the potato and, if you plant a potato with new growth from the eyes, a potato plant will develop. We can see the stems starting to develop on the eyes of the potato here. You can even see that leaves have started to develop. Rhizomes and Stolons Let's next look at two ways stems can be involved in vegetative reproduction. First, Rhizomes are horizontal underground stems. These horizontal stems will grow and then develop a new vertical stem at certain critical points. Rhizomes are responsible for the growth of many grasses, sedges and weeds. The rhizomes grow out from the original plant and invade the nearby soil. They then make new flowering stalks. Even though we think of grasses and weeds most often with this type of vegetative propagation, this method of asexual reproduction can even be seen in irises. Irises can reproduce sexually through pollen and seeds but sometimes will use rhizomes to reproduce as well. This is why you may see a patch of irises growing close together - they are all sharing the same root system. The second type of stem growth we will look at uses stolons, which are horizontal aboveground stems. These horizontal stems grow along the ground and may develop adventitious roots along with new flowering plant stems. The most common example of stolons can be found in strawberries. Strawberries have runners, which are really stolons that grow along the ground and continue to develop new flowering stems and roots. Again, this form of vegetative propagation can explain why you will see a large number of strawberry plants in the same area - they are all connected by the stolons.