Comparative Research On Seedling Traits Of Differeng Clones Of Triploid In Arid Area Of North-Western China

Tissue culture of the new clones of Populus tomentosa Carr. was studied. The clonal test of 16 clones and 6 clones which were obtained by tissue culture were established respectively in both areas of Wuwei city and Pingliang city of Gansu province. Completely random block design was applied in these experiments. And seedling quantitative traits of the new clones were studied.Results indicated the optimal medium of bud differentiation of subculture of new clones of P. tomentosa Carr. is MS+BA0.3mg/L+NAA0.1mg/L+sugar30g/L+agar5g/L;Rooting medium of the new clones is 1/2MS+IAAl.0mg/L+sugar15g/L+agar5g/L. The difference of the new clones in bud differentiation, rooting, growth in bottle and survival rate of transplantation was significant.The determination result of seedling quantitative traits of the new clones in field of one annual growth period indicated: there were signicant diffenences among different clones and different sites, aslo existed significant interaction between both clone and site. In one annual growth period, the growth process of tree height and diameter of breast height of the new clones P. tomentosa Carr. existed significant differences in different clones, and both tree height and diameter of breast height had the second growth phenomenon, but the two had obvious difference in beginning time and sustaining time of the second growth.The quantitative traits in field had significant difference in the different new clones of P. tomentosa Carr. Among the 12 quantitative traits of the new clones of P. tomentosa Carr. in Zhazigou experimental site, the difference of foliage was the biggest and the clone No.1-'401', clone No.3-'83-1'etc. presented obvious superiority; the bad one with the least quantitative trait was triploid P. tomentosa Carr. such as the clone No.7-'423'and the clone No.15-'463, all of which showed that triploid P. tomentosa Carr. came from doubling female gamete presented diversity on quantitative traits. So it is necessary to select it strictly.Through variance analysis, selected three fine new clones of Populus tomentosa Carr. were clone No.1-'401',clone No.3-'84-1'and clone No.11-'227-1'.