2.1 | Sampling
Two sampling campaigns were conducted in Cuba in 2011 and in 2013 in
three different locations (Villa Clara, Ciego de Avila and Matanzas)
located between 20 and 300 km apart using the same paired population
sampling design (Figure 1, Table 1). Infected banana leaves were
collected in a banana plantation pair in each location except in Ciego
de Avila, where two pairs were sampled in 2013. The same varieties were
collected in all pairs; one plot was planted with a susceptible variety
(Macho ¾ belonging to the banana AAB genomic group and the plantain
subgroup) and the other with a resistant variety (the tetraploid FHIA 18
belonging to the banana AAAB genomic group). More than 1 000 strains
were isolated representing 14 populations with a number of isolates per
population ranging between 38 and 135. The six populations sampled in
2011 had already been analyzed to investigate local adaptation to banana
quantitative resistance and the underlying genetic basis in P.
fijiensis (Dumartinet
et al., 2019; Carlier et al., 2021b). To further describe adaptive
architecture, in this study, we added eight more populations sampled in
2013 in the same locations. Banana plantations are frequently replanted
and different plantation pairs were collected in the two first locations
in 2011 and in 2013. In Matanzas, the same plantations were sampled but
they were replanted between 2011 and 2013. The data obtained from
samples collected in the two years were then considered as spatial
replicates but not as time series.