Shoot development, chlorophyll, gas exchange and carbohydrates in lychee seedlings (Litchi chinensis)
Shoot development, chlorophyll, gas exchange and carbohydrates in lychee seedlings (Litchi chinensis)
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DOI：
10.1093/treephys/22.13.947
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发表时间：
2002-09-01
期刊：
影响因子：
4
通讯作者：
Lüdders, P
中科院分区：
文献类型：
--
作者：
Hieke, S;Menzel, CM;Lüdders, P
以荔枝（Litchi chinensis Sonn.）栽培品种“阿威”的幼苗生长在亚热带澳大利亚纳米比亚的加热温室中（27 ° S）。我们还研究了去枝和断根对叶片展开的影响。在恒定的温室条件下，新梢的生长表现出一个节律性的周期，在三个周期中，平均冲洗持续时间为20天，间隔时间为10天。芽和叶以S形模式扩展到约80分钟和500厘米（2），分别为每次冲洗。下部茎和根的淀粉含量随着幼叶的展开而降低，随着完全展开的叶变成深绿色而升高。叶绿素浓度和净CO2同化率在完全展开的深绿色叶中最高，去除50%的完全展开叶面积对嫩叶的展开影响不大，但去叶植株的总生物量仅为对照的60%。相比之下，在芽膨大前去除一半的根会使最终的叶面积减少80%。我们的结论是，幼芽有相对较低的光合速率，直到叶片完全展开和深绿色，并依赖于同化物从其他地方的植物。在叶片展开过程中，同化物向地上部的转运是以根系为代价的。
Shoot growth, chlorophyll concentrations, gas exchange and starch concentrations were studied in lychee (Litchi chinensis Sonn.) seedlings of cultivar "Wai Chee" grown in a heated greenhouse at Nambour in subtropical Australia (27degrees S). We also examined the effects of shoot defoliation and root pruning on leaf expansion. Shoot growth showed a rhythmic cycle under constant greenhouse conditions, with a mean duration of flushing of 20 days and an interval of 10 days over three cycles. Shoots and leaves expanded in a sigmoidal pattern to about 80 min and 500 cm(2), respectively, for each flush. Starch concentrations of the lower stem and roots decreased as the young red leaves expanded, and increased as the fully expanded leaves turned dark green. Chlorophyll concentrations and net CO2 assimilation rate were highest in the fully expanded dark green leaves.Removing 50% of the area of each fully expanded leaf had little effect on the expansion of younger leaves, but total biomass of defoliated plants was only 60% of that of controls. In contrast, removing half the roots just before bud swelling reduced final leaf area by 80%. We conclude that the young shoot has relatively low rates of photoassimilation until the leaves are fully expanded and dark green, and depends on assimilates from elsewhere in the plant. During leaf expansion, translocation of assimilates to the shoot occurred at the expense of the roots.