杂交桉家系在冷凉区优势评价与遗传分析

Study on heterosis estimation and genetic analysis of Eucalyptus hybrids in cold area

【目的】为粤北及华南等种植冷凉区选育桉树速生和耐寒品系。【方法】利用方差分析和BLUP法估算广东连山5年生97个桉树人工控制授粉家系、15个母本自由授粉家系和2个无性系试验林生长、干形、耐寒和保存率性状的杂种优势、育种值及配合力。【结果】各性状在家系、家系与区组交互效应间均存在极显著差异。以单株蓄积为指标筛选优良杂交组合,参试家系中有3个家系(101、14和74号)的单株蓄积高于最优自由授粉家系103号均值0.191 4 m^3,超过对照DH 3229的控制授粉家系有17个,所有控制授粉家系中超过对照无性系(115号)的优良单株有288株;大于参试总体均值的40个控制授粉交家系,其平均单株蓄积的超亲优势达25.78%,而相对对照无性系的超标优势仅达4.18%;育种值与表型值大小的变化趋势基本一致,育种值超过0.02的控制授粉家系有13个,仍然还是101、14和74号家系。【结论】通过亲本一般配合力分析认为,RT04赤桉、邓恩桉2号、U64尾叶桉3个母本,以及KX10巨桉、2B边沁桉、D17邓恩桉、KX5巨桉和DX19巨桉5个父本是今后杂交育种的优选亲本;特殊配合力排名前3的邓赤(邓恩桉×赤桉)、尾尾细(尾叶桉×(尾叶桉×细叶桉))和尾蓝(尾叶桉×蓝桉)杂交桉,其特殊配合力效应值均大于0.05,相对效应值超50%,适合将其中的优良单株无性系化并扩繁利用。

【Objective】Select Eucalytpus hybrids that are adapted to north of Guangdong Province and other cool areas in southern China.【Method】Using ANOVA and BLUP to estimate the heterosis,breeding values,SCA（specific combining ability） and GCA（general combining ability） of various traits.We assessed 97 controled-pollination families,15open-pollination families and two clones from the Lianshan Forest Farm of Guangdong,China.【Result】There were significant differences in growth traits among tested families.The SV（average single-tree volume） values of the controledpollination families including of No.101,14 and 74 exceeded the highest 0.191 4 m3 value of No.103 open-pollination family,and the SV values of 17 controled-pollination families,288 trees exceeded the SV value of DH3229 control clone in the trials.There were 40 controled-pollination families that exceeded the overall average SV value in trial,and their SV value had 25.78% heterosis more than average value of 15 parents,4.18% heterosis more than the same of clones＇.The breeding value of 13 controled-pollination hybrids,including No.101,14 and 74,reached 0.02,and their phenotype values exhibited the same trend.【Conclusion】According to the GCA and SCA values analyzed,three females RT04（E.camaldulensis）,D2（E.dunnii）,and U64（E.urophylla）,and five males KX10（E.grandis）,2B（E.benthamii）,D17（E.dunnii）,KX5（E.grandis） and DX19（E.grandis） could be used as elite parents for future breeding programs,and the superior families,including E.dunnii × camaldulensis,E.urophylla×（E.urophylla×tereticornis）,and E.urophylla ×globulus,could be used as cloning materials,owing to their high SCA values（0.05） and 50% relative effect SCAs.