锡林浩特多年生草本根部导管性状与植株生态策略的相关特征

干旱半干旱区植物的木质部输水系统对维持植物生长发育有重要作用。以中国干旱半干旱区的草本植物为研究对象，旨在探究草本物种根系导管解剖结构与植物生长之间的关系。用石蜡切片法，将在锡林浩特草原采集的草本物种的主根样品制作成切片，得到固定面积内导管解剖结构参量(导管数量、导管分数、平均导管面积、平均水力传导率和水力直径),然后用逐步回归法和Pearson相关分析各导管解剖性状与植物生长特征(年龄、生长速率和平均高度)之间的关系。结果发现(1)生长速率与导管数量(R=-0.494,P<0.01)和导管分数(R=-0.255,P<0.05)显著负相关，与平均导管面积(R=0.274,P<0.05)、平均水力传导率(R=0.263,P<0.05)和水力直径(R=0.245,P<0.05)显著正相关，表明生长快的草本具有大而少的导管，需要较高的水分传输能力，而生长慢的草本具有小而多的导管，水力安全性较高；(2)植株的高度与导管数量(R=-0.354,P<0.01)显著负相关，与平均导管面积(R=0.293,P<0.05)、平均水力传导率(R=0.289,P&l...

Vessel traits of main roots are linked to ecological strategies of the perennial herbs in Xilinhot of China

The hydraulic system plays an important role in supporting plant growth and development in arid and semiarid regions. In this study, we explored the relationship between vessel anatomical traits and growth characteristics of herbaceous species. We used paraffin sectioning method to make taproot sections, and acquired the characteristics of vessel anatomical structures (including number of vessels, vessel fraction, mean vessel area, mean hydraulic conductivity, and hydraulic diameter) in a fixed area. Pearson correlation and stepwise regression methods were used to analyze the relationship between vessel anatomical traits and plant growth characteristics (age, growth rate, and mean height). The results indicated that (1) the growth rate was significantly negatively correlated with vessel number (R=-0.494, P<0.01) and vessel fraction (R=-0.255, P<0.05), whilist, significantly positively correlated with mean vessel area (R=0.274, P<0.05), mean hydraulic conductivity (R=0.263, P<0.05), and hydraulic diameter (R=0.245, P<0.05), which may indicate that fast-growing herbs form larger and fewer vessels to increase the hydrualic efficiency, while slow-growing herbs form smaller and more vessels to increase hydraulic safety. (2) Mean height was significantly negatively correlated with vessel number (R=-0.354, P<0.01), whilist, significantly positively correlated with mean vessel area (R=0.293, P<0.05), mean hydraulic conductivity (R=0.289, P<0.05), and hydraulic diameter (R=0.278, P<0.05), which may suggest that in order to maintain the mechanical strength, high plants usually form few vessels to compensate for large vessels, while short plants form smaller and more vessels to increase hydraulic safety.