AOBPreview originally published online on January 17, 2005
Annals of Botany 2005 95(4):685-693; doi:10.1093/aob/mci070
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Annals of Botany 95/4 © Annals of Botany Company 2005; all rights reserved
Partitioning of 13C-photosynthate from Spur Leaves during Fruit Growth of Three Japanese Pear (Pyrus pyrifolia) Cultivars Differing in Maturation Date
1 The United Graduate School of Agricultural Sciences, Tottori University, Tottori, 680-8533, Japan, 2 Laboratory of Horticultural Science, Faculty of Agriculture, Tottori University, Tottori, 680-8533, Japan and 3 Department of Plant Science, College of Agriculture and Biology, Shanghai Jiaotong University, Shanghai, 201101, China
* For correspondence. E-mail tanabe{at}muses.tottori-u.ac.jp
Received: 21 September 2004 Returned for revision: 11 November 2004 Accepted: 29 November 2004 Published electronically: 17 January 2005
• Background and Aims In fruit crops, fruit size at harvest is an important aspect of quality. With Japanese pears (Pyrus pyrifolia), later maturing cultivars usually have larger fruits than earlier maturing cultivars. It is considered that the supply of photosynthate during fruit development is a critical determinant of size. To assess the interaction of assimilate supply and early/late maturity of cultivars and its effect on final fruit size, the pattern of carbon assimilate partitioning from spur leaves (source) to fruit and other organs (sinks) during fruit growth was investigated using three genotypes differing in maturation date.
• Methods Partitioning of photosynthate from spur leaves during fruit growth was investigated by exposure of spurs to 13CO2 and measurement of the change in 13C abundance in dry matter with time. Leaf number and leaf area per spur, fresh fruit weight, cell number and cell size of the mesocarp were measured and used to model the development of the spur leaf and fruit.
• Key Results Compared with the earlier-maturing cultivars ‘Shinsui’ and ‘Kousui’, the larger-fruited, later-maturing cultivar ‘Shinsetsu’ had a greater total leaf area per spur, greater source strength (source weight x source specific activity), with more 13C assimilated per spur and allocated to fruit, smaller loss of 13C in respiration and export over the season, and longer duration of cell division and enlargement. Histology shows that cultivar differences in final fruit size were mainly attributable to the number of cells in the mesocarp.
• Conclusions Assimilate availability during the period of cell division was crucial for early fruit growth and closely correlated with final fruit size. Early fruit growth of the earlier-maturing cultivars, but not the later-maturing ones, was severely restrained by assimilate supply rather than by sink limitation.
Key words: 13C labelling, fruit growth, sink strength, spur leaves, pear, Pyrus pyrifolia Nakai
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  P. A. Nortes, M. M. Gonzalez-Real, G. Egea, and A. Baille Seasonal effects of deficit irrigation on leaf photosynthetic traits of fruiting and non-fruiting shoots in almond trees Tree Physiol, March 1, 2009; 29(3): 375 - 388. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. ZHANG, K. TANABE, S. WANG, F. TAMURA, A. YOSHIDA, and K. MATSUMOTO The Impact of Cell Division and Cell Enlargement on the Evolution of Fruit Size in Pyrus pyrifolia Ann. Bot., September 1, 2006; 98(3): 537 - 543. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Zhang, K. Tanabe, F. Tamura, K. Matsumoto, and A. Yoshida 13C-photosynthate accumulation in Japanese pear fruit during the period of rapid fruit growth is limited by the sink strength of fruit rather than by the transport capacity of the pedicel J. Exp. Bot., October 1, 2005; 56(420): 2713 - 2719. [Abstract] [Full Text] [PDF]
|
|