Multi-location Evaluation Of Hybrid Populus×euramericana And Its Response To Light Duration

Poplar(Populus spp.)is one of the important timber species in China.It has the characteristics of fast growth,wide distribution,and easy reproduction.Populus×euramericana is an important cultivar for poplar production in our country.The growth of poplars is mainly affected by genetics and environment,and the regionalization test is an effective research method for the G×E effect.However,the impact of the environment on poplars in the early growth stage is comprehensive.The light duration,temperature,and precipitation have different effects on different Populus×euramericana genotypes.Regarding the influence of the duration of the light,it has been ignored for a long time.In this study,12 genotypes of the three-year-old Populus×euramericana were tested in multiple locations(Zhucheng,Yuncheng,Ningyang,Shishou,Heishan,and Luannan)and the light duration of 4 genotypes(11h,12 h,13h,14 h And15h)based on experiment,using quantitative genetics and statistical theory as the method.The main results are as follows:(1)The variation of DBH of Populus×euramericana in the early growth stage is greater than that of tree height,and the growth traits vary greatly in Northeast and Central China.The growth traits of the three-year hybrid Populus×euramericana are significantly affected by genotype,environment and G×E effect.The fit of the model data in GGE Biplot is above 80%,and the results are reliable.The selected genotypes are No.5,No.7,No.3,No.4 and No.9.No.7 has the highest yield and stable yield,No.5 is the high-yield type,and No.4 is higher than the average yield and has good high and stable yield.No.3 and No.4 are suitable for planting in Heishan and Zhucheng areas;No.5 is suitable for planting in Ningyang and Shishou areas;No.7 is suitable for planting in Luannan and Yuncheng areas.The 4 genotype trees with different high and stable yields had different responses to light duration,temperature and precipitation,and light duration had a significant effect on growth.(2)Under different light duration treatments,the number of nodes,seedling height,ground diameter,leaf morphology,SPAD value,original light energy conversion efficiency,potential photochemical activity,leaf water content,leaf dry weight,root biomass,stem biomass,leaf biomass and root crown ratio of 4 genotype showed significant difference.The extension of light time has a significant positive effect on the growth of each genotype.It shows that the date of capping is delayed or not capped,the leaf morphology changes to obtain more effective light,the seedling biomass increases,photosynthetic physiological activities is further enhanced,and the biomass is preferentially Of the 4 genotypes allocated to the ground,G2 is the most sensitive to light duration,followed by G10,G7 only performs better under 14 h light duration,and G11 performs the worst among all treatments.G2,G7 and N146 are breeding materials with hybridization potential.