Fertilization in Ugni molinae plants subjected to a domestication process increased insect biodiversity

Abstract

Plant domestication is a process in which plants increase their productive characteristics, such as size or number of seed according to the human needs. However, these improvements provoke changes on both insect community and biodiversity. Hence, plants with higher degree of domestication could be losing biodiversity in relation to their wild parents. Furthermore, studies have indicated that plants with a high level of fertilization are more susceptible to insect attacks. Currently, murtilla (Ugni molinae) is a native plant that has been domesticated near to 20 year ago. The objective of this research was evaluated how the fertilization on wild and cultivated U. molinae plants affects the insect biodiversity. We carried out a survey on wild plants collected one year ago from seven different locations of the Región de La Araucanía, and they were compared with their cultivated counterpart. Four groups of plants were established; 1) cultivated fertilized, 2) cultivated no fertilized, 3) wild fertilized and finally, 4) wild no fertilized. Fertilizer was applied and consisted of 80, 44, and 43g per plant of nitrogen, P2O5, and K2O, respectively. Survey was carried out each two months during one year. Insects were collected, and Margalef, Shannon and Simpson indexes were analyze for studying the effect of domestication in each system. Our results indicated that for cultivated plants, Margalef (2.88), Shannon (2.75) and Simpson (6.4) were higher in fertilized plants than control. Same results were obtained on wild plants (2.05, 2.12, 3.76). Finally, wild no fertilized plants presented lower biodiversity indexes (1.8, 1.9, 3.5) than cultivated plants (2.4, 2.3, 5). In conclusion, domestication effects and fertilization could be important factors for determining the insect biodiversity in murtilla. Keywords: Ugni molinae, Biodiversity, Margalef, Shannon, Simpson.