江津凡　丁次平　张凌云　胡兴宜

摘要 通过对江汉平原23年生落羽杉15个家系子代测定林的胸径、树高和材积进行调查和分析，结果表明：不同家系间的胸径、树高和材积差异极显著，胸径、树高和材积性状家系遗传力均在44%以上，各性状受到中等强度的遗传控制，其中胸径家系遗传力最大为53.53%;利用育种值评分法和性状表现水平分析法从15個参试家系中选出5个优良家系，用2种方法选出的家系完全一致，胸径、树高和材积平均遗传增益分别为2.04%、0.88%和4.29%，平均现实增益分别为3.81%、2.00%和8.54%，并在优良及家系的基础上再选出优良单株13株，其平均胸径、树高和材积分别为32.35 cm、20.38 m和0.806 1 m3。所选出的优良家系和优良单株生长优势明显，可作为优良遗传材料进行保存和利用。

关键词 落羽杉;子代测定林;优良家系;优良单株;江汉平原

中图分类号 S722文献标识码 A文章编号 0517-6611（2020）11-0124-03

doi：10.3969/j.issn.0517-6611.2020.11.037

Abstract Progeny test was conducted on diameter at breast height（DBH），tree height，stem volume of 15 families of 23 years old Taxodium distichum in Jianghan Plain.The result showed there were significant differences among families on DHB， tree height and stem volume.The family heritability of DHB， tree height and volume were above 44% and DHB was up to 53.53%， the growth characters were mainly controlled by genetic factors.5 excellent families were selected according to grading of breeding value and performance level of phenotypic traits，the two methods selected five identical families，their average genetic gains were 2.04%，0.88% and 4.29%，and the real gains were 3.81%，2.0% and 8.54%.The average tree height，DHB and volume of 13 excellent plus trees were 32.35 cm，20.38 m and 0.806 1 m3.The selected eccellent families and plus trees had obvious growth advantage and should be preserved as excellent genetic materials.

Key words Taxodium distichum;Progeny test forest;Excellent family;Excellent plus trees;Jianghan Plain

落羽杉原产于北美洲东南部，20世纪20年代引种至我国，现以长江中下游地区栽培较多。该树种适应性强，耐水、耐污染能力强，且病虫害少，生长快，适合作为用材、防护及庭院观赏树种，也是营建抑螺防病林的优良树种[1-3]。目前国内利用落羽杉的优良特性，围绕良种选育和杂交育种开展了系列研究，并研发了生长特性更加优良的中山杉等优良新品种[4]，已在各地开展引种造林试验和推广[5-7]。长期以来，江汉平原湖区造林绿化以杨树为主，随着杨树纯林面积过大和胁地效应突显，出现了林农矛盾日益突出和生态系统功能脆弱等问题，农民种植杨树积极性逐渐降低，因此，增加造林树种选择多样性迫在眉睫。……