长沙地区龟甲竹高生长及光合特性研究

Young bamboo height growth and photosynthetic characteristics of Phyllostachys heterocycla in Changsha,Hunan

研究了湖南省森林植物园内龟甲竹的出笋规律、幼竹高生长规律以及光合特性。龟甲竹出笋和高生长规律的研究结果表明:龟甲竹发笋期分为明显的初期、盛期和末期3个时期,一般在3月中旬开始发笋,历期33天左右;2016年,园内龟甲竹共发笋48支,其中由于人为损伤和营养不良,5支退笋;龟甲竹幼竹在高生长过程中,呈现"慢—快—慢"的"S"型生长规律,符合Logistic方程;龟甲竹一天中总平均生长量为17.65cm,白天生长量更高。光合特性研究结果表明:龟甲竹净光合速率在12:00时达到最大值,呈"单峰型";其光响应与CO_2响应的结果表明龟甲竹利用弱光的能力较强,但CO_2同化能力弱,总体光合能力较弱;PAR、Gs、Tr、Ta和Ci是影响龟甲竹净光合速率日变化的主要生理因子,且影响效应逐渐减弱。

In this paper, the regularity of shooting, height-growth and photosynthetic characteristic of Phyllostachys heterocycla were studied in Hunan Forest Botanical Garden. The results of shooting and the regularity of young bamboo height-growth indicated that the shooting time was from mid-March to mid-April, which lasting about 33 days, and could be divided into three phases, including shooting initial phase, abundant phase and final phase. The total shooting number was 48, the total shoot degradation was 5, and the reason was artificial mechanical damage and short of nutrition.The height growth rate of young bamboo was slow, then was fast, and then was slow, and the logistic equation of height growth fitted with the height growth data. During the high growth period, the height growth at a day amounted to 17.65 cm, while the daytime height growth was higher than that in the night. The results of photosynthetic characteristic indicated that Phyllostachys heterocycla had a stronger ability to utilize the weak light, but its photosynthetic ability was weak. The abilities of C02 assimilation of toerocyc/a were weak and it had a narrow range for adapting to theC02 concentration. The daily change of net photosynthetic rate was a one-peak curve, and the peak value was at 12： 00.The correlation results pointed out main influence factors for Pn of Phyllostachys heterocycla and ranked the factors by the effects from the highest to the lowest as follow： PAR, Gs, Tr, Ta and Ci.