TILLERING RESPONSES OF LOLIUM-MULTIFLORUM PLANTS TO CHANGES OF RED FAR-RED RATIO TYPICAL OF SPARSE CANOPIES
TILLERING RESPONSES OF LOLIUM-MULTIFLORUM PLANTS TO CHANGES OF RED FAR-RED RATIO TYPICAL OF SPARSE CANOPIES
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DOI：
10.1093/jxb/38.9.1432
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发表时间：
1987-09-01
影响因子：
6.9
通讯作者：
DEREGIBUS, VA
中科院分区：
文献类型：
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作者：
CASAL, JJ;SANCHEZ, RA;DEREGIBUS, VA
多花Lolium multiflorum植株分别生长在具有等效PAR但R/FR比值在0.46 ~ 2.36之间的不同辐射源的生长室内，或在整个光周期内补充一系列小FR通量的阳光下。在这两种试验中都发现分蘖减少，R/FR比低于典型光照值的小下降。在此范围内，分蘖的平方根转换率和立地灌浆率与光敏色素光平衡的估计值呈线性相关，在高分蘖率的条件下，坡度非常陡。在芽根部添加低通量红光，使暴露于低R/FR比下植株的分蘖提高到高R/FR比下植株的分蘖水平，尽管植株的其余部分接受了低通量红光比。此外，辐照中R/FR比较低的植物基部会减少分蘖，表明这可能是一个感知位点。这些结果表明，疏林冠层对不同遮荫程度的R/FR变化具有较高的敏感性。这表明，通过监测这些变化，何乐莲植物能够感知到生长冠层即将发生竞争的预期信号。
Plants of Lolium multiflorum were grown either in growth rooms under radiation sources providing equivalent PAR but different R/FR ratios between 0.46 and 2.36, or under sunlight supplemented with a series of small fluence rates of FR throughout the photoperiod. In both kinds of experiments a reduction of tillering was found along with small depressions of R/FR ratio below the values typical of sunlight. In this range both the square-root-transformed rate of tillering and the site-filling rate were linearly related to the estimated phytochrome photo-equilibria and the slope was very steep under conditions that allowed high tillering rates. The addition of low fluence rates of red light at the base of the shoots raised tillering of plants exposed to low R/FR ratios to the level of plants grown under high R/FR ratios in spite of the ratios received by the rest of the plant. Moreover, irradiation of plant bases with intermediate low R/FR ratios reduced tillering indicating that this would be one site of perception. These results show a high sensitivity to changes of R/FR ratio typical of different degrees of shade in sparse canopies. This suggests that by monitoring these changes Lolium multiflorum plants would be able to perceive in anticipated signal of impending competition in growing canopies.