library_construction_protocol: RNA extraction was conducted via Tri reagent method (Plant RNA reagent Invitrogen, USA), followed by purification using Plant/Fungi Total RNA Purification Kit (Norgen Biotek Corp., Canada) and on column DNAse treatment (Qiagen, Germany). Six pair-end (100bp) bar-coded cDNA libraries were prepared for multiplex sequencing on the Illumina HiSeq 2500 sequencer (Technion Genome Center, Haifa, Israel) using the TruSeq RNA sample preparation kit ver. 2 (Illumina, San Diego, CA), according to manufacturer's standard protocols. Bulk segregant RNA-seq