Genetic distance between nests and population genetic diversity of Nasutitermes nigriceps and N. corniger (Isoptera: Termitidae) in Guatemala using AFLP markers

Termites, distributed mainly in tropical regions, are eusocial insects that live in highly organized and integrated colonies. It is considered that eusociality is favored by high intracolony relatedness, since inclusive fitness is increased. It has been argued that in the case of termites, high genetic relatedness within the colony is achieved by alternating cycles of inbreeding and outbreeding within the population, where a pair of reproductives that are unrelated but a product of intense inbreeding, produces highly related offspring. However, population inbreeding, intercolony genetic relationships, and the hierarchical structure of termite populations have been under studied. In this study, we used the amplified fragment length polymorphism (AFLP) technique to analyze population genetic diversity and genetic distance between termite nests of Nasutitermes nigriceps and between nests of N. corniger in Guatemala to clarify the degree of genetic relatedness among different colonies within a termite population. Genetic distance was analyzed at both long- and short-distance-scales. Genetic diversity was determined within termite populations and genetic distance was estimated between colony nests. A Mantel test was applied to the values of geographic and genetic distances. For N. nigriceps a total of 181 AFLP fragments were obtained from the three primer combinations resulting in 26 (14%) polymorphic bands. For N. corniger a total of 199 AFLP fragments were obtained from the three primer combinations resulting in 39 (19%) polymorphic bands. At both distance scales, a clear correlation was not found between geographic and genetic distances. These low values of genetic diversity suggest that a genetic bottle neck could have occurred in the termite populations. The weak relationship between genetic and geographic distances could be the result of the low genetic diversity within the termite populations, or the result of sampling a non-substructured population.