濒危植物长叶竹柏种苗质量分级标准及光合特性研究

Study on Seedling Quality Grading Standards and Photosynthetic Characteristics of the Endangered Plant,Nageia fleuryi

关键词:  长叶竹柏  质量分级  聚类分析  光合特性  光合-光响应曲线

Key words:  Nageia fleuryi  quality grading  cluster analysis  photosynthetic characteristics  photosynthetic-light response curve

摘要:

探究濒危植物长叶竹柏(Nageia fleuryi)种苗的分级标准及光合生理特性，可为其引种栽培和优质苗木繁育提供参考。本研究以1年生长叶竹柏为研究对象，运用主成分分析、K-均值聚类分析确定其种苗质量分级标准,并采用Li-6800XT便携式光合测定仪对其光合特性进行测定。结果表明，长叶竹柏种苗共划分为两个等级，其质量分级标准如下：Ⅰ级种苗株高>17.00 cm,地径>4.01 cm,冠幅>16.33 mm,叶片数>21.00；Ⅱ级种苗株高11.00-17.00 cm,地径3.44-4.01 cm,冠幅8.04-16.33 mm,叶片数7.00-21.00。Ⅲ级种苗因各指标未达到Ⅱ级种苗的最低标准，故未列入质量分级标准中。光合-光响应曲线结果显示，Ⅰ级种苗与Ⅲ级种苗的暗呼吸速率(R_d)、最大光合速率(P_max)、表观量子效率(AQY)均存在显著性差异(P＜0.05)；Ⅰ、Ⅱ、Ⅲ级种苗的光饱和点(LSP)具有显著性差异(P＜0.05)，而光补偿点(LCP)均无显著性差异(P＞0.05)。本研究结果可为濒危植物长叶竹柏的引种栽培和优质种苗繁育提供科学依据。

Abstract:

To explore the grading standards and photosynthetic physiological characteristics of endangered plant Nageia fleuryi seedlings can provide valuable reference for its introduction,cultivation,and propagation of high-quality seedlings. In this study,one-year-old seedlings of the endangered species N.fleuryi was used as the research object. The principal component analysis and K-means cluster analysis were used to identify the seedling quality grading standards,and the photosynthetic characteristics were measured by Li-6800XT portable photosynthesis system. The results showed that the seedlings of N.fleuryi were divided into two grades,and their quality grading standards were as follows: the plant height,ground diameter,crown width and leaf number of grade Ⅰ seedlings was >17.00 cm,>4.01 cm,>16.33 mm and >21.00,respectively. The plant height,ground diameter,crown width and leaf number of grade Ⅱ seedlings was 11.00-17.00 cm,3.44-4.01 cm,8.04-16.33 mm and 7.00-21.00,respectively. Because the indexes of grade Ⅲ seedlings did not reach the minimum standard of grade Ⅱ seedlings,they were not in the quality grading standard. The results of photosynthetic-light response curve showed that there were significant differences in dark respiration rate (R_d),maximum photosynthetic rate (P_max) and Apparent Quantum Yield (AQY) between grade Ⅰ seedlings and grade Ⅲ seedlings (P<0.05). The Light Saturation Point (LSP) of grade Ⅰ,Ⅱ and Ⅲ seedlings were significant differences (P<0.05),while the Light Compensation Point (LCP) was not significant differences (P>0.05).The results of this study can provide a scientific basis for the introduction,cultivation and high-quality seedling propagation of the endangered plant N.fleuryi.