The interaction between stored organic matters in crowns and leaf cytokinin induced by roots was determined to investigate the compensatory growth of Italian ryegrass (Lolium multiflorum. Lam). The experiment comprised five treatments: (a) clipping once with 5 cm crown height, (b) clipping once with 2 cm crown height, (c) clipping twice with 5 cm crown height, (d) clipping twice with 2 cm crown height and (e) no clipping. Results showed that low crowns and single clipping promoted regrowth and the sum total of all previously clipping and final harvest of Italian ryegrass. Super compensatory growth and compensatory growth, which were assessed based in total biomasses, respectively, occurred in Italian ryegrasses with high crowns and single defoliation and those with high crowns only. Increased leaf net photosynthetic rates in Italian ryegrasses with high crown were promoted by stored organic matter in crown and leaf cytokinin in the first and later 7‐day regrowth periods, respectively. Compared with single clipping, frequent clipping decreased the stored organic matter in roots; causing decreases in leaf cytokinin concentration and photosynthetic rate. The delivery rate of cytokinin from the roots to the leaves determined the leaf cytokinin concentration in Italian ryegrass during the regrowth period. Thus, organic matters from crowns and leaf cytokinin induced by roots played a combined effect on aboveground compensatory growth in the Italian ryegrasses.

中文翻译：

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基于储存的有机物和细胞分裂素的联合效应，冠高对意大利黑麦草代偿性生长的影响

确定冠层中所存储的有机物质与根部诱导的叶细胞分裂素之间的相互作用，以研究意大利黑麦草（黑麦草）的补偿性生长。我是）。该实验包括五种处理方法：（a）剪一次冠高5厘米，（b）剪一次冠高2厘米，（c）剪两次，冠高5厘米，（d）剪两次，冠高2厘米，以及（e）不剪裁。结果表明，低冠和单修剪促进了意大利黑麦草的再生长以及所有先前修剪和最终收获的总和。分别基于总生物量评估的超补偿生长和代偿生长分别发生在高冠和单落叶和仅高冠的意大利黑麦草中。在冠龄和叶细胞分裂素在头一个和以后的7天再生期中分别储存有机质，可以促进冠状高黑麦草中叶片净光合速率的提高。与单剪裁相比 频繁的修剪减少了根中储存的有机物；导致叶片细胞分裂素浓度和光合速率降低。细胞分裂素从根部到叶片的输送速率决定了再生期意大利黑麦草中叶片细胞分裂素的浓度。因此，根部诱导的冠和叶细胞分裂素中的有机物对意大利黑麦草的地上代偿性生长起综合作用。