Hybrid rice farmers and seed growers can now quickly assess seed purity with the addition of a new trait in Mestiso 20 (M20), a public hybrid rice variety.
To assess seed purity as early as seedling stage, PhilRice researchers have introduced purple coloration on the leaf sheaths of the male parents of M20 while keeping the other traits intact. As hybrids are generated through outcrossing of two different rice lines, they are prone to contamination as female parents may be pollinated by males of other lines than their intended partners.
Hybrid rice specialist Mel Anthony Talavera explains that maintaining seed purity is crucial to attaining the maximum potential of any variety.
“Without use of sophisticated tools, the purple coloration inherited by M20 will make it easier to assess seed purity through visual observation of the seedlings. If the leaf sheath is not purple, then it’s an off-type,” Talavera said.
Compared with grow-out testing that usually lasts for a season, initial purity of the seeds may be gauged in just a few days since the purple coloration starts to appear in as early as seedling stage, becomes more pronounced during vegetative stage, and fades as the plant matures.
Bred by PhilRice and UP Los Baños, M20 yields 6.4-11.7t/ha, matures in 111 days after sowing, and is moderately resistant to bacterial leaf blight, yellow stem borer, green leafhopper, and brown planthopper. Purple coloration is also being introduced to other public hybrids like Mestiso 19.