This Ancient Plant Will Not Compete Against Siblings

In a low resource situation, the roots of Cycas micronesica refrain from competing with close relatives, according to research from the University of Guam published in Tropical Conservation Science. C. micronesica is an endangered cycad species that hails from several western Pacific Micronesian islands. The global population of cycad plants is facing increasing threats, yet many of the roughly 340 species have never been the subject of ecology or horticulture experimental work. Authors Drs. Thomas Marler, Nirmala Dongol, and Gil Cruz used an established experimental approach that forced two plants to compete within a fixed volume of rooting substrate. By using the seedlings from a single mother tree as the focal plants, then altering the closeness of the relationship of the competing seedlings, the behavior of the focal plant’s roots was carefully observed. Under these conditions, the identity of the competing plant determined the behavior of the focal plant. “The results revealed that one plant can recognize when an adjacent plant is a close relative, and when an adjacent plant is not a relative,” said Cruz. This ability of roots to recognize kin has been proven for many plant species, but the team’s interest in the subject is founded in the fact that contemporary cycads are derived from an ancient plant lineage. They contend that inclusion of more cycad species in this line of research may help validate if the root behavior is an ancient plant trait. The results also revealed a decline in competitive behaviors when a close relative was the adjacent plant, and an increase in competitive behaviors when a non-relative was the adjacent plant. “The results provide compelling evidence that this insular cycad species exhibits cooperative behaviors when closely-related individuals are forced to compete for soil resources,” said Marler. Read more from Asian Scientist Magazine at: http://www.asianscientist.com/2016/08/in-the-lab/cycad-plants-roots-recognize-kin/