Abstract
Plants undergo two very different types of reproduction – asexual reproduction and sexual reproduction. As plant life on Earth is extremely diverse, it follows that the methods of sexual reproduction among plants would also be quite diverse. Plants employ various techniques to accomplish this sexual reproduction based on their environment and what technique will improve their fitness. The boxelder maple uses wind to disperse the male seeds into the environment to find and fertilize a female plant (Greene & Johnson, 1995). Another plant, a mistletoe, utilizes a marsupial animal to disperse its seeds (Garcia, Rodriguez-Cabal, & Amico, 2009). These two separate but equally effective techniques are used to continually increase the fitness and therefore the survival of the species.
The boxelder maple, Acer negundo, has a widespread habitat throughout most of the United States (Greene & Johnson, 1995). The seed of the maple is known as a samara, a winged “helicopter” that is readily recognizable. This particular study examined how far the wind-dispersed seeds could travel, and the results indicated a seed could effectively travel up to one kilometer, or about 0.6 miles from the parent plant (Greene & Johnson, 1995).
The method of wind dispersal to send out seeds to fertilize female plants is a common technique for some plants. The boxelder maple has a fairly large distribution geographically. If it were not possible for the seeds to travel far, the population size would likely diminish as more trees would grow closer to each other, resulting in competition. However, the employment of wind dispersal allows the maple to spread out and increase the likelihood of survival and therefore the overall fitness of the species.
In South American rain forests exists a small marsupial known as Dromiciops gliroides, or the Monito del Monte (Garcia et al., 2009). This marsupial is responsible for the dispersal of the seeds of a mistletoe, Tristerix corymbosus. The mistletoe produces a sticky substance that coats the seed and allows the seed to stick to an animal that brushes against it. The seed is thus transported away from the parent plant to be dropped off in a new location (Garcia et al., 2009).
The mistletoe is a small plant in the heart of a thick rain forest. This makes it very unlikely for the seeds to be dispersed by any abiotic factors, like wind or water dispersal. Therefore, the mistletoe has adopted a strategy to disperse the seeds via passing animals. A healthy and fit plant is one that can successfully reproduce given its environment, and the mistletoe has adopted a special way to overcome the obstacles and disperse.
Conclusion
Both asexual reproduction and sexual reproduction in plants have their own particular advantages. However, sexual reproduction provides variety in the genes, the driving factor behind evolution. It takes genetic material from two parent plants and makes a genetically different offspring. There are many ways that the male sperm is spread to various plants and locations. The boxelder maple and the mistletoe use two very different techniques with the same end goal of successfully dispersing and continuing the survivorship and fitness of the species.
References
Greene, D. F., & Johnson, E. A. (1995). Long distance wind dispersal of tree seeds. Canadian Journal of Botany, 73(7), 1036-1045.
Garcia, D., Rodriguez-Cabal, M. A., & Amico, G. C. (2009). Seed dispersal by a frugivorous marsupial shapes the spatial scale of a mistletoe population. Journal of Ecology, 97(2), 217-229.
