|Arias De Ares, Renee|
|Ray, Jeffery - Jeff|
Submitted to: The Journal of the Torrey Botanical Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/1/2015
Publication Date: 6/10/2015
Citation: Arias De Ares, R.S., Portilla, M., Ray, J.D., Blanco, C.A., Simpson, S.A., Scheffler, B.E. 2015. Ecology, Behavior and Bionomics: First Genotyping of Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) Progeny from Crosses between Bt-Resistant and Bt-Susceptible Populations, and 65-Locus Discrimination of Isofamilies. The Journal of Botanical Society. 4:18-29.
Interpretive Summary: Spodoptera frugiperda, also known as fall armyworm, is an insect pest that causes economic losses in multiple crops in America. This insect is frequently controlled by crops harboring a toxin of the bacterium Bacillus thuringiensis (Bt). In recent years, resistance to Bt toxin has been observed in some populations of fall armyworm raising concern that those populations could spread to other areas. In order to uniquely identify populations of this insect and potentially monitor migrations and possible crosses of resistant and susceptible populations we had developed and published 192 molecular markers (microsatellites or SSRs). In the current work, we did crosses of Bt-resistant and Bt-susceptible individuals, alternating the population origin of females and males. We genotyped the parents as well as the resistant and susceptible progeny of those crosses using the 192 markers previously developed. We report for the first time 24 markers that had alleles with some correlation to Bt resistance. We also report for the first time the presence of uniparental inheritance of alleles in this insect, showing 18 loci for which the progeny received either the paternal or the maternal alleles but not alleles from both parents as it would be expected.
Technical Abstract: Simple sequence repeat (SSR) markers from Spodoptera frugiperda (J. E. Smith) were analyzed in crosses of this species between Bacillus thuringiensis (Berliner) (Bacillales: Bacillaceae) (Bt) resistant and susceptible populations to determine a possible association between markers and Bt resistance. Crosses were made alternating male and female from Bt-susceptible and Bt-resistant populations. Oviposition, mortality and fecundity were evaluated for five pairs of each of the crosses. One pair of each cross, with their corresponding resistant and susceptible progeny (12 individuals per cross), were genotyped using 192 SSR markers. SSR results were analyzed using UPIC software to calculate heterozygosity of parents and progeny of each cross. Cluster analysis based on SSRs showed that the progeny of each cross was associated with the paternal and not the maternal genotypes. A total of 24 SSR markers had one or more alleles correlated (p = 0.002 to p = 0.099) with the Bt resistant phenotype. At 18 loci, either maternal or paternal alleles were absent in the progeny, and 55% of these loci matched with SSR markers related to Bt-resistance. This is the first report that shows association of multiple SSR markers with Bt resistant phenotypes, and the first evidence of uniparental inheritance at many loci in S. frugiperda.