Kawamura Koji, Takeda Hiroshi
Kansai Research Center, Forestry and Forest Products Research Institute, Nagaikyutaro 68, Momoyama, Fushimi, Kyoto 612-0855, Japan.
New Phytol. 2006;171(1):69-80. doi: 10.1111/j.1469-8137.2006.01737.x.
Size-related variation in the cost and probability of flowering among shoots within a crown of Vaccinium hirtum was investigated to clarify patterns and regulation of flowering at the shoot-module level, below the level of the individual. The apices of previous-year shoots differentiated into current-year shoots vegetatively (vegetative branches) or became reproductive by developing inflorescences (reproductive branches). Length growth and fate of current-year shoots were determined, and the future potential for reproduction was estimated using a matrix model of shoot dynamics. Reproductive branches had fewer current-year shoots and shorter total shoot lengths and thus had a reduced potential for reproduction compared with vegetative branches, indicating the cost of flowering at the shoot level. This cost of flowering was higher in longer shoots. The probability of the initiation of flowering in a shoot increased with increasing shoot length in shorter shoots, reached a maximum in medium-sized shoots, and decreased in longer shoots. The size-related changes in the probability of flowering at the shoot level can be largely explained by the size-dependent changes in shoot-level resource availability and cost of flowering.
为了阐明在个体水平以下的枝条模块水平上开花的模式和调控，研究了矮越桔树冠内枝条间开花成本和开花概率与大小的关系。前一年枝条的顶端通过营养生长分化为当年枝条（营养枝），或通过发育花序而成为生殖枝（生殖枝）。测定了当年枝条的长度生长和命运，并使用枝条动态矩阵模型估计了未来的繁殖潜力。与营养枝相比，生殖枝的当年枝条较少，总枝条长度较短，因此繁殖潜力较低，这表明了枝条水平上开花的成本。这种开花成本在较长的枝条中更高。在较短的枝条中，枝条开花起始的概率随着枝条长度的增加而增加，在中等大小的枝条中达到最大值，而在较长的枝条中则下降。枝条水平上开花概率与大小相关的变化在很大程度上可以由枝条水平上资源可用性和开花成本随大小的变化来解释。
