Medicago sativa RNA sequencing

Three types of samples were used: diploid and tetraploid samples deriving from a bilateral sexual polyploidization process (respectively, dBSP and tBSP), and tetraploid samples deriving from a unilateral sexual polyploidization (tUSP) process. BSP individuals derived from the M. sativa subsp. falcata mutant PG-F9 (2n = 2x = 16) able to produce 2n eggs (23,24) x the 2n pollen producer M. sativa subsp. coerulea genotype 12-P (2n = 2x = 16) (25). USP seeds were produced crossing the same 2n eggs producer used in the previous crossing (PG-F9 mutant) with a naturally tetraploid M. sativa subsp. sativa (variety Classe, 2n = 4x = 32) as pollen (n=2x) donor. For each sample, leaf tissues and reproductive tissues (male and female tissues) from flowers at four different developmental stages (i.e. flower bud, closed flower, open flower and pollinated flower) were sampled and used for RNA-seq analyses.