Compensatory growth and photosynthetic responses of Pharbitis purpurea seedlings to clipped cotyledon and second leaf

Institute of Grassland Science, Northeast Normal University, Changchun, 130024 China
Photosynthetica (Impact Factor: 1.41). 03/2011; 49(1):21-28. DOI: 10.1007/s11099-011-0004-4


Leaf tissue damaging to seedlings can limit their subsequent growth, and the effects may be more extensive. Compensatory photosynthesis
responses of the remnant cotyledon and primary leaf of Pharbitis purpurea to clipping and the effect of clipping on seedling growth were evaluated in a pot-cultivated experiment. Three treatments
were conducted in the experiment, which were clipped cotyledon (CC), clipped second leaf (CL), and control group (CG). The
area, thickness, mass, and longevity of the remaining cotyledon of CC exhibited over-compensatory growth. In contrast, seedlings
of CC had under-compensatory growth in seedling height, root length, seedling mass, and root to shoot ratio. However, the
traits of remnant cotyledon and seedling in CL treatment exhibited equal-compensatory growth. Net photosynthetic rate of the
cotyledon of CC was significantly higher than those of CL and CG treatments, and the diurnal changes in photosynthetic rates
showed significantly different patterns which were unimodal curve (CC) and bimodal curve (CL and CG), respectively. There
was no significant difference between CL and CG treatment. Net photosynthetic rate of the primary leaf of CL was significantly
higher than that of CG treatment. However, the photosynthetic rates of primary leaves of CL and CG treatments showed similar
photosynthetic patterns characterized by a bimodal curve. P. purpurea seedlings used a compensatory growth strategy in the remaining cotyledon or the primary leaf to resist leaf loss and minimize
any adverse effects.

Additional key wordsclipping–compensatory growth–photosynthesis–primary leaf–remnant cotyledon–seedling

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Available from: Hong-Xiang Zhang, Apr 03, 2015
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    • "Another possible explanation is that the mixture soil used had adequate nutrition for seedlings growth, and water was not limited as the pots were irrigated as required. Zheng et al. (2011) found that increased photosynthesis maintained or compensated plant growth after cotyledon removal. It is also possible that the compensatory capability of the remaining cotyledon makes an important contribution to seedling development at the deeper habitat in the soil. "
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