长沙地区3种优良观赏竹发笋及幼竹高生长规律

为给长沙地区观赏竹的引种培育和科学经营管理提供参考,研究了湖南省森林植物园中黄秆乌哺鸡竹、花秆早竹和花毛竹这3种竹的出笋、退笋及幼竹高生长规律。结果表明:黄秆乌哺鸡竹发笋期在4月初,花秆早竹和花毛竹在3月中下旬,历期均为20~25 d,明显分为初期、盛期和末期3个阶段;同一竹种不同发笋时期的发笋数间存在显著性差异(P0.05),其中黄秆乌哺鸡竹、花秆早竹和花毛竹的平均每株母株发笋数分别为1.09、1.85和1.16株;造成3种观赏竹退笋的原因有很多,其中在初期萌发笋退笋原因主要是人为机械损伤,盛期萌发笋退笋原因为机械损伤和营养缺乏等,而末期萌发笋的退笋原因主要是营养供应不足;3种观赏竹3个不同时期萌发笋幼竹高生长过程均呈"S"型生长曲线,符合"慢-快-慢"生长规律,相应的Logistic方程均较好地拟合了各个时期萌发笋幼竹的平均高生长过程;在幼竹高生长历期和株高方面,3种观赏竹初期和盛期萌发笋均优于末期,留笋养竹时选择初期和盛期萌发笋为宜;3种观赏竹幼竹昼夜生长均呈现一定节律,且夜间增长量均高于白天增长量。

Shoot development and growth of three varieties of young bamboos of ornamental bamboo in Changsha

In order to provide some references for introduction, cultivation and scientific management of ornamental bamboos, shoot development, shoot degradation and height growth of young bamboos inP. vivax,P. praecox andP. hetercycla were studied in Hunan Forest Botanical Garden. The results indicated that the shooting period of P. vivaxwas in early April, and the shooting periods of P. praecox andP. hetercyclaboth were in middle and late March. Shooting periods of all of the three bamboos last about 20-25 days, and the shooting periods could be divided into three phases, including initial phase, abundant phase and ifnal phase. Shooting number had signiifcant differences (P<0.05) among three phases for one variety of bamboo, and mean shooting number per one mother bamboo inP. vivax,P. praecox andP. hetercycla was 1.09, 1.85 and 1.16 respectively. There were many reasons for bamboo shoot degradation. The main reason was artiifcial mechanical damage at initial phases, the ones were artiifcial mechanical damage and short of nutrition at abundant phase, and the one was short of nutrition at ifnal phase. The three varieties of young bamboo germinating at initial, abundant and ifnal phases had“S” type of height growth curves, which exhibited a tendency of“slow-fast-slow”, and the logistic equations of height growth respectively iftted with their height growth process. Height growth process and height of the young bamboos germinating at initial and abundant phases were better than those germinating at ifnal phase, so the bamboo shoots germinating at initial and abundant phases were suitable for retaining. Height growth of the three varieties of ornamental bamboos showed relatively day-night regularity, and height increments at night were higher than that in the day.