Genesys provides data primarily through the `fetch_accessions` function. Data download using **genesysr** is equivalent to downloading data from www.genesys-pgr.org, with the advantage that **genesysr** ensures reproducibility.
Filters to query Genesys are:
- `fetch_accessions(filters = list(taxonomy.genus = c('Musa')))` - Retrieve all accession data for genus *Musa*
- `fetch_accessions(list(institute.code = c('BEL084')))` - Retrieve all accession data for the Musa International Transit Center, Bioversity International
- `fetch_accessions(list(institute.code = c('BEL084','COL003')))` - Retrieve all accession data for the Musa International Transit Center, Bioversity International (BEL084) and the International Center for Tropical Agriculture (COL003)
And also by using [Multi-Crop Passport Descriptors (MCPD)](https://www.genesys-pgr.org/doc/0/basics#mcpd) definitions:
- `fetch_accessions(mcpd_filter(ORIGCTY = c("DEU", "SVN")))` - Retrieve data by country of origin (MCPD)
# Selecting columns for data download
Genesys fetches all accession data by data. One can reduce the amount of data fetched by selecting only the columns of interest:
- `fetch_accessions(list(taxonomy.genus = c('Musa')), selector = function(x) {list(id = x$id, acceNumb = x$acceNumb, instCode = x$institute$code)`- Fetch only **id**, **acceNumb** and **instCode** for *Musa* data.
# Processing fetched data
Fetched data is provided as a deeply nested list. To flatten such list, we recommend the following procedure:
```r
require(tidyverse)
musa.flatten <- lapply(musa$content, unlist) #looks good