Developmental Dynamics and Early Growth Vigour in Rice. I. Relationship Between Development Rate (1/Phyllochron) and Growth

摘要: Achieving early vigour, that is, rapid dry matter accumulation, is a priority in rice crop improvement, but this trait complex and not well understood genetically physiologically. This study tested the hypothesis development rate (DR) contributes to vigour. Two diversity panels were phenotyped during vegetative stage for traits constituting vigour (shoot weight, SDW; relative growth rate, RGR) or contributing (tillering, leaf size, DR). The first panel comprised 169 genotypes from all major genetic groups of Oryza sativa was under irrigated upland conditions field (Philippines, Exp1). second with 190 representing tropical japonica group pots greenhouse (Montpellier, France, Exp2). Results pot experiment pointed out DR, tillering size positively correlated RGR SDW, although contribution small. DR both negatively size. vs. correlation conserved subsets similar tillering, suggesting an effect on independent other traits. promising, still underexploited requiring further physiological characterization.