ABSTRACT

Seed potato (Solanum tuberosum L.) physiological age (PA; defined as the developmental stage of a potato seed) and genotype are known to influence potato yield and final tuber yield distribution. We investigated the impacts of PA of two contrasting cultivars (‘Bondi’ and ‘Fraser’) on growth and development of individual canopy organs and their linkage with the source–sink process that regulates final tuber yield distribution. Differences in tuber yield distribution were associated with key morphological and phenological changes in the potato canopy. The beginning of the tuber growth phase was marked by a change in phyllochron across cultivars. PA influenced individual leaf expansion rate and time of flowering, which impacted the final tuber yield distribution. Time of flowering, or, number of leaves produced prior to first flower appearance, reflected the PA and could be used to indicate potential ‘sink strength' or sink limitations (associated with tuber yield distribution) later in the tuber growing phase. The results suggest crop source limitations might arise in indeterminate main potato cultivars that rely on physiologically older leaves (or early emerged large leaves) for green leaf area at the end of the tuber growing phase, which may shift the yield distribution towards smaller tuber grades.

摘要

种薯（Solanum tuberosum）L.) 生理年龄（PA；定义为马铃薯种子的发育阶段）和基因型已知会影响马铃薯产量和最终块茎产量分布。我们研究了两个对比品种（'Bondi' 和 'Fraser'）的 PA 对单个冠层器官生长和发育的影响，以及它们与调节最终块茎产量分布的源汇过程的联系。块茎产量分布的差异与马铃薯冠层的关键形态和物候变化有关。块茎生长阶段的开始以不同品种的叶轮时间变化为标志。PA影响个体叶片膨胀率和开花时间，从而影响最终块茎产量分布。开花时间，或在第一朵花出现之前产生的叶子数量，反映了 PA，可用于指示块茎生长后期的潜在“汇强度”或汇限制（与块茎产量分布相关）。结果表明，作物来源限制可能出现在不确定的主要马铃薯品种中，这些品种在块茎生长阶段结束时依赖生理上较老的叶子（或早期出现的大叶子）来获得绿叶面积，这可能会使产量分布转向较小的块茎等级。