Unraveling the population structure of Diatraea saccharalis (Fabricius)
(Lepidoptera: Crambidae) in Argentina
Abstract
Diatraea saccharalis (Fabricius) is one of the major Lepidopteran pests
throughout the Western Hemisphere. In Argentina, it causes significant
losses mainly in sugarcane and corn. Previous studies determined the
existence of reproductive incompatibilities between populations from
Buenos Aires and Tucumán from different host plants; however, the
genetic base of this incompatibility is still unknown. The aim of this
study was to determine the existence of genetic structure of D.
saccharalis populations collected from different hosts and regions in
Argentina, comparing with those from Brazil, through COI and NGS. The
COI analyzes showed a haplotypic diversity of 0.8 and a Nucleotide
diversity of 0.0058. AMOVA revealed a greater variation within
populations than among them. The 17 haplotypes detected were linked in a
single parsimony network that did not reveal clusters clearly influenced
by geographic locations or the host plants from which populations were
collected. A total of 4.549 SNPs were obtained through NGS. Out of the
2,349 outlier loci, 84 showed similarities with known proteins
previously characterized. The coefficient of inbreeding showed that the
mating among the populations, although it is being random, presents the
same degree of selection. The FST values showed a high variation among
Argentina and Brazil populations; however, did not show a clearly
defined trend of the influence of the host and/or the distance. In the
DAPC, three different groups were formed, a group that includes the
samplings from Brazil and two groups from Argentina. Results indicated
the existence of genetic divergence in D. saccharalis populations.