滇西南旱冬瓜优树及种源选择研究

Superior Tree and Provenances Selection of Alnus nepalensis in Southwest Yunnan

在滇西南5个州(市)采用五株优势木对比法开展旱冬瓜优树选择,以旱冬瓜初选优树为材料,运用统计学相关性分析方法对优树选择的相关因子进行分析,结合数量化回归方法得出的方程,开展优树选择标准的研究,采用多点试验的方法开展旱冬瓜种源/家系选择。结果表明,(1)在滇西南的普洱、西双版纳、临沧、德宏和保山5个州(市)的15个县采用对比木法选出144株旱冬瓜初选优树;(2)相关性分析显示,旱冬瓜胸径、树高是衡量旱冬瓜优树的重要因子,旱冬瓜树高、胸径、材积、冠幅、枝下高、分枝角度、林分郁闭度、树皮厚度8个性状间存在着多重线性关系,且以材积与其他性状间的相关性最为紧密,数量化回归方法建立的树高和枝下高组成的材积生长量回归模型为Y=0.055X1+0.021X2+0.01X3-1.406(Y=材积;X1=胸径;X2=树高;X3=枝下高),以材积实测值与理论值间的差值H作为划分优树等级的主要依据;(3)在德宏州瑞丽市、保山市龙陵县、普洱市镇沅县开展多点种源/家系试验,选择出优良旱冬瓜种源4个,优良家系40个。其中优良种源为西盟、瑞丽、昌宁、龙陵种源;(4)对滇西南地区的旱冬瓜种源进行区划,可划分为滇南(江城、思茅、宁洱、景洪、孟连)和滇西(瑞丽、龙陵、陇川、保山、昌宁、潞西、腾冲、西盟)2个大的种源区。

Superior tree selection of Alnus nepalensis were conducted in five prefectures and cities of southwest Yunnan using the five dominant tree comparison method. Taking the superior trees from preliminary selection as the materials, the correlation factors in superior tree selection were analyzed, and the superior selection standard was developed by combining with the quantitative regression method. The superior provenances and families of south- west Yunnan were therefore selected out through multi-site experiments. Results of the following four aspects were obtained. 1 ） Totally one hundred and forty-four preliminary selected superior trees were selected out from 15 coun- ties respectively belonging to Pu＇ er, Xishuangbanna, Lincang, Dehong and Baoshan in southwest Yunnan. 2） The correlation analysis implied that DBH and height were two important factors evaluating the superior trees of Alnus nepalensis. There was multiple co-linear relation between height, DBH, volume, crown width, height under branch, branch angle, crown density and bark thickness, volume was the parameter with the closest relationship with other parameters. The regression model of volume growth increment established with height, under branch height and DBH was Y = 0. 055X1 ＋ 0. 021X2 ＋ 0. 01 X3 - 1. 406, the difference H value between the measured value and the theoretical value was the main basis for iments conducted at Ruili city, Longling ranking the superior trees. 3 ） Through mulit-site planting expercounty and Zhenyuan county, four superior provenances and 40 superior families were selected out, four superior provenances were Ximeng, Ruili, Changning and Longling respectively. 4） As far as provenance regionalization was concerned, the Alnus nepalensis in southwest Yunnan could be divided into south Yunnan （ Jiangcheng, Simao, Ning＇ er, Jinghong and Menglian） and west Yunnan （ Ruili, Longling Longchuan, Baoshan, Changning, Luxi, Tengchong and Ximeng） respectively.