Pammenter N W, Allison J C S
School of Life and Environmental Sciences, George Campbell Building, University of Natal, Durban 4041 South Africa.
J Exp Bot. 2002 Jan;53(366):123-9.
Two pot experiments and one field experiment were conducted on sugarcane to assess the effects of treatments expected to change total carbon assimilation on the partitioning of assimilate. In the first experiment pots of cultivars CP and N14 were arranged to simulate normal field spacing. At 5 months, plants were partially defoliated or left intact. In the subsequent four months, defoliation resulted in a small (not significant) decrease in total dry mass increment; it increased the proportional partitioning of assimilates to leaves in N14, whilst in CP it increased the proportional partitioning to stems. In both cultivars defoliation increased proportional allocation to non-structural dry matter, and thus sucrose, in the stem. In the second experiment pots of cv. CP were grown at normal spacing for 4 months, then left untreated, shaded, or placed further apart. During the subsequent four months shading decreased total dry matter increment, but increased proportional partitioning to the stems, and within stems to non-structural dry matter, and so sucrose. Widened spacing increased total assimilation, but decreased proportional allocation to stems; partitioning within the stems was not affected. In the field experiment plants of both cultivars were partially defoliated at 6 months, or left intact. Defoliation resulted in only a very small decrease in stem dry mass increment during the subsequent four months (leaves were not measured). Within the stem partial defoliation caused proportionally increased partitioning to non-structural dry matter, hence to sucrose. The results suggest that sucrose storage receives priority in the allocation of assimilate, rather than representing the accumulation of assimilate not required for vegetative growth.
进行了两项盆栽试验和一项田间试验，以评估预期改变总碳同化的处理对甘蔗同化物分配的影响。在第一个试验中，将CP和N14品种的盆栽按正常田间间距排列。5个月时，对植株进行部分去叶处理或保持完整。在随后的四个月中，去叶处理导致总干物质增量略有下降（不显著）；它增加了N14品种同化物向叶片的比例分配，而在CP品种中，它增加了向茎的比例分配。在两个品种中，去叶处理均增加了茎中向非结构性干物质（即蔗糖）的比例分配。在第二个试验中，CP品种的盆栽按正常间距种植4个月，然后不进行处理、遮荫或拉大间距。在随后的四个月中，遮荫降低了总干物质增量，但增加了向茎的比例分配，以及茎内非结构性干物质（即蔗糖）的比例分配。拉大间距增加了总同化量，但降低了向茎的比例分配；茎内的分配不受影响。在田间试验中，两个品种的植株在6个月时进行部分去叶处理或保持完整。去叶处理在随后的四个月中仅导致茎干物质增量非常小的下降（未测量叶片）。在茎内，部分去叶处理导致向非结构性干物质（因此向蔗糖）的比例分配增加。结果表明，蔗糖储存优先于同化物分配，而不是代表营养生长不需要的同化物积累。
