Atlantic Giant (AG), the world largest pumpkin, was bred through continuously crosses and strict selections from the small fruit ancestor. To understand the change caused by the artificial cross and selection in the recent 100 years, differences of morphology, anatomy and physiology between two cultivars with distinct fruit size in Cucurbita maxima, AG and Hubbard were investigated. Comparing with Hubbard, AG owns more fruit cell number and larger fruit cell volume at harvest stage, accompanied by larger leaves, higher net photosynthetic rate, lower leaf total sugar concentration, higher leaf stachyose level, larger peduncle vascular cross area and higher phloem sap sugar concentration. Further theoretical calculation indicates that AG needs more leaves and longer translocation time per day to support its huge fruit growth. In addition, considerable glucose and stachyose were found in the phloem sap and sarcocarp of AG respectively, suggesting different loading and unloading mechanisms are involved in the giant pumpkin growth. These results provide useful cues for improving cultivation and breeding techniques of giant pumpkins.

大西洋巨人 (AG) 是世界上最大的南瓜，它是通过不断杂交和从小果实祖先的严格选择中培育出来的。了解近100年来人工杂交和选择引起的变化，两个不同大小的葫芦品种在形态、解剖和生理方面的差异, AG 和 Hubbard 进行了调查。与哈伯德相比，AG在收获期拥有更多的果实细胞数和更大的果实细胞体积，伴随着更大的叶片，更高的净光合速率，更低的叶片总糖浓度，更高的叶片水苏糖水平，更大的花梗维管横截面积和更高的韧皮部汁液糖专注。进一步的理论计算表明，AG 每天需要更多的叶子和更长的易位时间来支持其巨大的果实生长。此外，在AG的韧皮部汁液和肉果皮中分别发现了大量的葡萄糖和水苏糖，表明巨型南瓜的生长涉及不同的加载和卸载机制。这些结果为改进巨型南瓜的栽培和育种技术提供了有用的线索。