桉树无性系多区域联合测试的G×E分析及选优

G×E Analysis and Selection of Eucalyptus Clones by Multi-Region Combined Test

【目的】对广西、广东和海南的五个地点桉树无性系进行生长性状遗传多样性分析和基因型与环境互作评价,以筛选出优良无性系。【方法】基于3.5年生桉树无性系的树高、胸径、材积、保存率和蓄积量数据。首先联合五个地点数据对各性状进行单因素方差分析和多重比较。然后建立线性混合模型进行单地点和多地点方差分析,以无性系、无性系×重复(地点)为随机效应,得出各性状的方差分量以及各无性系的BLUP值,从而计算各性状的遗传参数值。最后综合AMMI模型与BLUP-GGE模型选择优良无性系及适生环境。【结果】1)该研究表明各生长性状中的不同亲本、无性系、地点之间存在显著差异(P<0.01)。不同亲本中,粗皮桉×韦塔桉的各性状表现较好,其年均材积和蓄积量可达到每株0.0690 m^(3)、26.6 m^(3)·hm^(-2)a^(-1);不同无性系中,EC245为较为优良的无性系,材积和年均蓄积量可达每株0.0909 m^(3)、118.46 m^(3)·hm^(-2)a^(-1),但保存率(77.8%)相对较低;不同地点中,雷州地区的无性系生长表现最好,平均材积和保存率分别为每株0.0836 m^(3)、85.5%,海口地区生长表现最差,平均材积和保存率分别为每株0.0238 m^(3)、55.5%。2)多地点联合的方差分析及遗传参数表明,无性系各性状与环境互作达到显著水平(P<0.01),同时各性状的重复力介于0.7174~0.8695之间。不同性状的效应量中,树高的环境效应量(43.2%)、互作效应量(17.0%)远大于其他性状,胸径的环境效应量(26.5%)、互作效应量(8.8%)最低,说明树高易受到环境的影响,而胸径却较稳定;不同地点中,树高重复力介于0.6539~0.9018,胸径重复力介于0.6791~0.9301,材积重复力较高介于0.6808~0.9360,蓄积量重复力介于0.4811~0.9250,说明材积适合作为目标性状进行选优。3)基因型与环境互作分析表明基于材积性状的AMMI与BLUP-GGE双标图结果略有不同。两模型一致得出雷州为理想环境以及EC245为高材积无性系,其次是EC234、CM1509。AMMI模型得出稳定性较高的是EC244、EC228和EC238,最低的是EC245,并且筛选出EC245为高材积、低稳定的无性系;但是BLUP-GGE模型得出稳定性较高的是EC244、EC232和EC224,最低的是EC238,并且筛选出EC245为高材积、中等稳定的无性系。【结论】综合评价EC245为高材积、稳定性中等的无性系,且其在各个地点都有较好的生长表现。

【Objective】The aim of this study was to screen out superior clones of Eucalyptus from five locations in Guangxi,Guangdong and Hainan by analyzing the genetic diversity of growth traits and evaluating the interaction between genotype and environment.【Method】The data of tree height,DBH and volume,preserving rate and forest stock of 3.5-year-old Eucalyptus clones was collected,The single factor analysis of variance and multiple comparison were conducted for each trait with the collected data from the five locations.Then,a linear mixed model was established for single-location and multi-locations analysis of variance.The variance components of each trait and the BLUP values of each clone were obtained by taking clones and clones×repeats(locations)as random effects,so as to calculate the genetic parameters of each trait.Finally,AMMI model and BLUP-GGE model were integrated to select elite clones and suitable environment.【Result】1)This study showed that there were significant differences in each growth trait among different parents,clones and locations(P<0.01).Among the different parents,the traits of E.pellita×E.wetarensis were relatively better,and its volume and annual average forest stock were 0.0690 m^(3) per plant and 26.6 m^(3)·hm^(-2) a^(-1),respectively.Among the different clones,EC245 was the best,and the volume and annual average forest stock were 0.0909 m^(3) per plant and 118.46 m^(3)·hm^(-2) a^(-1),respectively,but the preserving rate(77.8%)was relatively lower.Among the different locations,the clones in Leizhou area had the best growth performance with the average volume and preserving rate of 0.0836 m^(3) per plant and 85.5%,respectively,while those in Haikou area had the worst growth performance with the average volume and preserving rate of 0.0238 m^(3) per plant and 55.5%,respectively.2)The analysis of variance with data from multiple locations and genetic parameters showed that the interaction between each trait and the environment reached a significant level(P<0.01),and the repeatability of each trait ranged from 0.7174 to 0.8695.Among the effect sizes of different traits,the environmental effect size(43.2%)and interaction effect size(17.0%)of tree height were much greater than those of other traits,and the environmental effect size(26.5%)and interaction effect size(8.8%)of DBH were the lowest,indicating that tree height was susceptible to environmental effects,while DBH was relatively stable.In different locations,tree height repeatability ranged from 0.6539 to 0.9018,DBH repeatability ranged from 0.6791 to 0.9301,volume repeatability ranged from 0.6808 to 0.9360,and annual average forest stock repeatability ranged from 0.4811 to 0.9250,indicating that volume was suitable as the target trait in selection.3)The interaction analysis between genotype and environment showed that the result of AMMI and BLUP-GGE biplots based on volume traits were slightly different.Both models agreed that Leizhou was the ideal environment and EC245 was the high volume clone,followed by EC234 and CM1509.AMMI model showed that EC244,EC228 and EC238 had the higher stability,and EC245 was the lowest,and EC245 was screened as the clones with high volume and low stability.However,the BLUP-GGE model showed that EC244,EC232 and EC224 had higher stability,and EC238 was the lowest,and EC245 was screened as a high volume and medium stability clone.【Conclusion】According to the comprehensive evaluation,EC245 was a clone with high volume and medium stability,and it has good growth performance in all locations.