香椿半同胞家系在川中丘陵区生长变异及早期选择

Growth variation and early selection of Toona sinensis half-sib families in the hilly area of central Sichuan Province

【目的】选择出适宜于川中丘陵区的香椿优良家系,为速生珍贵用材树种造林提供良种。【方法】以来自4个省8个地区的44个香椿优树半同胞家系为研究对象,以蓬溪本地种源为对照,采用随机区组设计,在四川省蓬溪县开展造林对比试验,通过对不同家系4年生胸径、树高和单株材积的生长变异进行分析比较,开展了优良家系的早期选择。【结果】香椿家系胸径、树高和单株材积与种源所在地的纬度、经度和海拔呈不同程度的负相关,与年均气温和年均降水量均呈极显著的正相关,与无霜期呈显著的正相关,选择比区验点纬度低、海拔低、经度小、年均气温高、降水量大、无霜期长的种源开展良种选育,对香椿家系选育有利。44个家系及对照4年生香椿的平均胸径、树高、单株材积分别为7.14 cm、7.54 m、0.0178 m^(3),变异系数分别为21.97%、18.26%和52.71%,遗传力均在0.60以上,不同家系间均有极显著差异。以4年生香椿单株材积为主,胸径和树高为辅,选择出福安112号、乐至10号、蓬溪9号、筠连66号4个优良家系,入选率为8.89%,胸径、树高、单株材积平均值分别为8.54 cm、8.84 m和0.0279 m^(3),选择差分别为1.4 cm、1.3 m和0.01 m^(3),遗传增益分别为44.41%、26.25%和113.62%。随着树龄的增大,4个优良家系胸径之间的差异变小,树高之间的差异变大。【结论】选择出的4个早期优良家系遗传增益高,入选率低,选择差大,生长优势显著,年均胸径2.13 cm,年均树高2.21 m,将成为川中丘陵区香椿良种选育的重要种质资源。

【Objective】In this study,the superior families of Toona sinensis suitable for the hilly area of central Sichuan were selected to provide a good variety for afforestation of fast-growing precious timber species.【Method】44 half-sib families of superior trees of Toona sinensis from 8 regions in 4 provinces were selected as the research object,with the local samples from Pengxi provenance as the control.A randomized block design was adopted to carry out comparative afforestation experiment in Pengxi County,Sichuan Province.The early selection of superior families was carried out by comparing the variation of DBH,height and volume of individual plant of different families.【Result】The results showed that DBH,tree height and individual volume of Toona sinensis families were negatively correlated with latitude,longitude and altitude of provenance,and were significantly positively correlated with annual average temperature and precipitation,and were significantly positively correlated with the frost-free period.Selection of provenances with low latitude,low altitude,small longitude,high annual temperature,strong precipitation and long frost-free period is beneficial to the breeding of Toona sinensis families.The average DBH,tree height and individual volume of the 4-year-old trees of 44 families and the control were 7.14 cm,7.54 m and 0.0178 m^(3),respectively.The coefficients of variation were 21.97%,18.26%and 52.71%,respectively.The heritability was above 0.60,and there were extremely significant differences among different families.4 superior families including Fuan 112,Lezhi 10,Pengxi 9 and Junlian 66,were selected by taking the volume of 4-year-old trees as the main factor,DBH and tree height as the supplementary factors.The selection rate was 8.89%.The average values of DBH,tree height and individual volume were 8.54 cm,8.84 m and 0.0279 m^(3),respectively.The selection differences were 1.4 cm,1.3 m and 0.01 m^(3),respectively.The genetic gains were 44.41%,26.25%and 113.62%,respectively.With the increase of tree age,the difference of DBH among the 4 superior families became slightly smaller,and the difference of tree height became slightly larger.【Conclusion】The 4 early superior families selected in this study have high genetic gains,low selection rates,large selection differences,and significant growth advantages,with an average annual DBH of 2.13 cm and an average annual tree height of 2.21 m,which will become important germplasm resources for breeding of improved varieties of Toona sinensis in hilly area of central Sichuan.