2.2 Molecular Screening
Molecular studies were conducted at the State Key Laboratory of
Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy
of Sciences, Beijing, China, using the 20 mg silica gel-dried leaves
collected from six Oryza types from Sri Lanka. Preliminary
screening of 150 pairs of simple sequence repeat (SSR) loci across
representative individuals sampled from different populations revealed
that 33 SSRs produced clear and reproducible products. These 33 SSR
primer pairs were designed based on cultivated rice sequences from the
RiceGenes Database (https://gramene.org), and used to assess the genetic
variation of DWWC in this study. The 33 loci were dispersed in all 12
chromosomes in the rice genome, with the polymorphism varying widely
among loci. Detailed information on the primer pairs is given in Table
S4. Primers were synthesized by ABI DNA Analyzer (Applied Biosystems,
Foster City, CA, USA), with the forward primers labelled with blue
(FAM), yellow (TAMAR), and green (HEX) fluorophores.