烟草主茎生长动态模拟与异速生长关系分析

研究烟草主茎节距和茎围的生长动态及二者生长关系可为烟草合理株型塑造提供科学依据。以中烟100为试验材料，获取了团棵期到现蕾期烟株主茎节距和茎围的生长数据，通过Richards方程模拟不同部位节距、茎围的生长动态，采用标准化主轴回归估计方法分析节距和茎围之间的异速生长关系。结果表明：（1）所有部位主茎节距与茎围的Richards生长动态模拟均符合“S”型生长曲线（R²> 0.9），其中中部茎节距的Richards生长动态模拟模型为典型的“S”型曲线，且RMSE检验表明精度、准确度高；（2）不同部位主茎节距最大值大小顺序为上部>中部>下部，不同部位主茎茎围最大值大小顺序为下部>中部>上部；（3）标准化主轴回归估计表明不同部位主茎节距和茎围之间、不同时期主茎节距和茎围之间都呈极显著的异速生长关系（p<0.001），异速生长斜率上部>中部>下部，团棵期>旺长期>现蕾期。以上结果表明，Richards方程与标准化主轴回归估计可以准确模拟烟草主茎生长动态及生长关系，烟草主茎先以节距伸长为主，后以茎围增加为主，烟草主茎伸长的关键时期是团棵与旺长期，主茎加粗的关键时期是现蕾期。本研究结果将有利于建立合理株型，提高烟株抗倒伏性。

Dynamic Simulation and Allometric Relationship of Tobacco Stem Growth

Exploring the growth dynamics of pitch and circumference of tobacco stem and the growing relationship can provide a scientific basis for rational plant shape of tobacco. In this study, Zhongyan100 was selected to investigate the growth traits of pitch and circumference from the rosette stage to the flower-bud appearing stage. Richards growth dynamic model was used to simulate the growth dynamics of the pitch and circumference with different positions, and standardized major axis (SMA) method was used to analyze the allometric relationship between pitch and stem circumference. The results showed that:(1) the Richards growth dynamic model of the main stem pitch and circumference of all positions conforms to the "S" type growth curve (R²>0.9); among them, the Richards growth dynamic simulation of pitch at the middle leaf position is typical "S" type curve; and the RMSE test shows high precision and accuracy; (2) The order of maximum value of main stem pitch was upper > middle > lower, and the order of maximum value of main stem circumference was lower > middle > upper; (3) The standardized major axis method indicates showed that there is a significant allometric growth relationship between the pitch and circumference at different positions and different stages (p <0.001). The allometric slope was upper > middle > lower, and rosette stage > flourishing stage > flower-bud appearing stage. The above results showed that the Richards equation and standardized major axis could accurately simulate the tobacco main stem growth dynamic and growing relationship, verify the rule that the stem of tobacco is mainly pitch elongation at first, and then circumference thickening. Considering the tobacco plant type characteristics, the rosette stage and flourishing stage played a key role in stem elongation, while the flower-bud appearing stage played a key role in stem thickening. The results of this study will help to establish a reasonable plant type and improve the lodging resistance of tobacco plants