2. Materials and methods
2.1. Plant materials
2.1.1. Genotypes
Four pineapple cultivars with different levels of susceptibil-
ity to IB were selected for this study: 1) Very susceptible: 'Trad
Sri Thong' (TST), 2) Moderately IB-tolerant: 'Savee' (SV) and 'Pat-
tavia' (PTV), and 3) Resistant: 'MD2'. The TST and SV belong
to the 'Queen' group of pineapple. These plants were grown in
Trat (12 ◦ 11 35.3 N 102 ◦ 26 58.5 E) and Chumphon (10 ◦ 14 19.4 N
99 ◦ 02 20.1 E) provinces, Thailand, respectively. The PTV and MD2
belong to the 'Smooth Cayenne' group of pineapple and were grown
in Rayong (12 ◦ 55 21.8 N 101 ◦ 15 08.7 E) province, Thailand.