Sector 4 of tetrad a9
DNA were extracted using a Plant Genomic DNA extraction kit (Tiangen, China) following the manufacturers protocol. DNA concentration and quality were evaluated with a Qubit.2.0 fluorometer (Invitrogen, USA), 1% agarose gel electrophoresis, and a N60 UV-vis spectrophotometer (Implen, Germany). Genomic DNA was then sequenced on an Illumina platform as 150 bp paired-end reads.