养分添加对美丽箬竹鞭段育苗成竹生长的影响

Effects of nutrient addition on the growth of Indocalamus decorus rhizome segments

为探究养分添加时间和添加量对埋鞭育苗鞭段质量的影响及其与出笋成竹、新竹质量、形态塑性的关系,以美丽箬竹1年生鞭段为试验材料,分别设置两个养分添加时间(育苗前15和30 d)及4个养分添加量[高量(45 g·盆^(-1),HA)、中量(30 g·盆^(-1),MA)、低量(15 g·盆^(-1),LA)和对照(0 g·盆^(-1),CK)]的埋鞭育苗试验,测定了美丽箬竹埋鞭育苗的新竹质量、叶片形态塑性及生物量积累与分配特征。随着养分添加时间的延长,LA和MA处理的美丽箬竹新竹高度、数量及萌发率略有降低,而HA处理则相反,新竹叶、根生物量比例及叶片形态塑性总体上呈逐渐降低的变化趋势,秆生物量比例则相反;育苗前15 d,MA处理的新竹秆、叶、根、总生物量及叶片叶绿素a、叶绿素a+b含量均显著高于育苗前30 d的。随着养分添加量的增加,美丽箬竹新竹质量和叶片形态塑性总体上均呈先升高后降低的变化趋势,MA处理的生物量积累效率显著提高,且叶生物量分配比例明显升高。育苗前的养分添加会影响美丽箬竹鞭段质量进而对其侧芽萌发、新竹生长及其形态建成产生明显作用。育苗前15 d,MA处理可显著提高美丽箬竹鞭段质量并促进新竹萌发生长,增强叶片形态塑性,提高生物量积累效率,是美丽箬竹鞭段育苗适宜的养分添加方式。

To determine the effect of nutrient addition time and amount on the quality of the rhizome and its promotion on the quality and morphological plasticity of young bamboo,a breeding seedling experiment with two nutrient addition times(15 and 30 days before breeding seedlings)and four nutrient addition amounts(high amount(45 g·pot^(-1),HA),medium amount(30 g·pot^(-1),MA),low amount(15 g·pot^(-1),LA),and control(0 g·pot^(-1),CK))for first⁃year rhizomes of Indocalamus decorus was conducted.The growth,leaf morphological plasticity,biomass accumulation,and allocation of young bamboo were determined.As the nutrient addition time increased,the height,mass,and germination rates of young bamboo treated with low and medium nutrient addition amounts decreased overall.In contrast,the young bamboo under the high nutrient addition amount increased.The leaf and root biomass proportions of young bamboo and leaf morphological plasticity decreased gradually while the culm biomass proportion increased.Furthermore,the culm,leaf,root,total biomass,and leaf chlorophyll a and a+b contents of young bamboo receiving the medium amount of nutrients 15 d before breeding seedlings were significantly higher than those when nutrients were applied 30 d before breeding.As the nutrient addition amount increased,the seedling quality and leaf morphological plasticity of young bamboo first increased and then decreased.Moreover,biomass accumulation in young bamboo treated with a medium amount of nutrients was much higher than that in young bamboo under the other treatments,and the leaf biomass proportion increased significantly.These results indicate that nutrient addition before seedling breeding greatly influenced germination,growth,leaf functional plasticity,and biomass.In addition,the medium amount of nutrient addition(30 g·pot^(-1))15 d before seedling breeding promoted the quality of rhizome segments and increased the germination,growth,leaf morphological plasticity,and biomass accumulation of young bamboo;thus,it was the most suitable form of nutrient addition for breeding seedlings of I.decorus from rhizome segments.