Wubs A M, Ma Y, Heuvelink E, Marcelis L F M
Horticultural Supply Chains, Department Plant Sciences, Wageningen University, PO Box 630, 6700 AP Wageningen, The Netherlands.
Ann Bot. 2009 Oct;104(5):957-64. doi: 10.1093/aob/mcp181. Epub 2009 Jul 30.
Fruit set in indeterminate plant species largely depends on the balance between source and sink strength. Plants of these species show fluctuations in fruit set during the growing season. It was tested whether differences in fruit sink strength among the cultivars explained the differences in fruit-set patterns.
Capsicum was chosen as a model plant. Six cultivars with differences in fruit set, fruit size and plant growth were evaluated in a greenhouse experiment. Fruit-set patterns, generative and vegetative sink strength, source strength and the source : sink ratio at fruit set were determined. Sink strength was quantified as potential growth rate. Fruit set was related to total fruit sink strength and the source : sink ratio. The effect of differences observed in above-mentioned parameters on fruit-set patterns was examined using a simple simulation model.
Sink strengths of individual fruits differed greatly among cultivars. Week-to-week fruit set in large-fruited cultivars fluctuated due to large fluctuations in total fruit sink strength, but in small-fruited cultivars, total fruit sink strength and fruit set were relatively constant. Large variations in week-to-week fruit set were correlated with a low fruit-set percentage. The source : sink threshold for fruit set was higher in large-fruited cultivars. Simulations showed that within the range of parameter values found in the experiment, fruit sink strength and source : sink threshold for fruit set had the largest impact on fruit set: an increase in these parameters decreased the average percentage fruit set and increased variation in weekly fruit set. Both were needed to explain the fruit-set patterns observed. The differences observed in the other parameters (e.g. source strength) had a lower effect on fruit set.
Both individual fruit sink strength and the source : sink threshold for fruit set were needed to explain the differences observed between fruit-set patterns of the six cultivars.
无限生长型植物的坐果情况在很大程度上取决于源库强度之间的平衡。这些植物品种在生长季节的坐果情况会出现波动。本研究旨在验证品种间果实库强度的差异是否能够解释坐果模式的差异。
选用辣椒作为模式植物。在温室试验中对六个坐果、果实大小和植株生长存在差异的品种进行评估。测定坐果模式、生殖和营养库强度、源强度以及坐果时的源库比。库强度以潜在生长速率进行量化。坐果与总果实库强度和源库比相关。使用一个简单的模拟模型研究上述参数差异对坐果模式的影响。
不同品种间单个果实的库强度差异很大。大果品种每周的坐果情况因总果实库强度的大幅波动而波动，但小果品种的总果实库强度和坐果情况相对稳定。每周坐果的大幅变化与低坐果率相关。大果品种坐果的源库阈值更高。模拟结果表明，在实验中发现的参数值范围内，果实库强度和坐果的源库阈值对坐果的影响最大：这些参数的增加会降低平均坐果率并增加每周坐果的变异性。两者都需要用来解释观察到的坐果模式。在其他参数（如源强度）中观察到的差异对坐果的影响较小。
需要单个果实库强度和坐果的源库阈值两者来解释六个品种坐果模式之间观察到的差异。
