Relation between Water Storage and Photoassimilate Accumulation of Neosinocalamus affinis with Phenology

Abstract

Reasonable management could produce the good growth of bamboo plants. There are few studies in bamboo that integrate phenology and ecophysiological traits; in this case, water relations, photosynthetic rates and carbohydrate content in different organs of Neosinocalamus affinis were determined. The moisture content was easily affected by the local precipitation and showed a similar trend in leaves and branches, with the highest values in July and August, but did not vary significantly between vegetative phenological stages in culms. The emergence and growth of shoots caused an apparent decrease in the moisture content of 1-year culms. NSC content showed a similar trend in culms and branches in classes of different ages and decreased progressively from March through November and then increased in the following months. Net photosynthetic rate and transpiration pull showed the highest values in July and then decreased constantly, which implied that a great deal of water was consumed for photoassimilate synthesis. The net photosynthetic rates of leaves were significantly affected by the water status of culms in the dry season, but correlated significantly only with the leaf water content in the wet season for the sufficient water supply. The transpiration pulls, water potential and sap flow rates revealed the water status of culms better than the water content of culms. The shoot germination and growth of N. affinis were more dependent on the photoassimilate accumulation in the early stage from May to July. There was no real dormancy period for N. affinis due to its apparent photoassimilate accumulation and water flow in January. This suggested that proper irrigation was essential during leaf and branch extension during the dry season.