Architectural Differences between Hybrid Potato Plants Grown from True Seeds and Seedling Tubers Do Not Influence Leaf Photosynthetic Traits
摘要
Plants grown from different propagules can develop different architectures that influence their functioning. Hybrid potato (Solanum tuberosum) plants grown from true seeds and seedling tubers differ in architectural development, particularly in spatiotemporal distribution of leaves, generating variations in leaf age across leaf positions and origins (main stem or branch). This may affect nitrogen distribution and leaf photosynthesis. The increasing use of true seeds in potato breeding and propagation requires a better understanding on to what extent these differences influence leaf photosynthesis and plant productivity. A greenhouse experiment was conducted, using potato plants of the same genotype grown solitarily, from true seeds and seedling tubers. Key leaf photosynthetic and physiological traits were compared between propagule types across different leaf positions, origins, and developmental stages. No significant differences were found between propagule types in leaf traits, including light-saturated net CO2 assimilation rate (Asat), dark respiration rate (Rd) and specific leaf nitrogen (SLN), and their changes across leaves over time. The decline in Asat with leaf age corresponded with the decrease in SLN and stomatal conductance (gsw), regardless of leaf position, origin or propagule type. We conclude that under identical environmental conditions, architectural differences between true-seed-grown and seedling-tuber-grown plants of the same genotype do not influence leaf photosynthetic traits. Leaf age is the main determinant of leaf photosynthetic properties in potato plants grown solitarily. This relationship can be used to estimate whole-plant photosynthesis yet requires accurate estimation of leaf appearance. Different architectural design may be needed for different propagule types for improved crop-level productivity.