We have no nucleotide sequencing data for a set of population, except for genotype and allele frequency . Is it possible to infer the type of selection based on such data?
Yes you can. Without using the sequencing data you can use your genotypic and allele frequency data to analyze the population you considered . However, if you are able to sequence your samples, you can make a better interpretation...(single nucleotide popolymorphism etc.) I dont know the purpose of your study to make better explanation...
Classically, folks would look for evidence of selection knowing just phenotypic data. Yes, of course you can use allele frequencies and genotypes. I'd suggest you read some intro to population genetics textbook chapters and talk with folks in your lab.
Yes, you can absolutely use genotype and allele frequency data to infer selection. Please go through any population genetics textbook to get a better idea. Please feel free to get in touch if you need any further help. All the best.