Progeny Test At Nursery Stage For Several Mating Combinations And Salt Tolerance Evaluation Of Aspen Hybridization Clones

Eighteen species and hybrids in populous were selected as parents, and hybrid seeds were obtained through the cutting cross technology, and develop a hybrid population. Analyzed the number and growth, branch, leaf traits of the seeds and hybrid seedlings, and processed hybrid seedlings with different concentration of salt solution, then observe the growth and the change of various physiological indicators of the hybrid seedlings under different salt concentration. The major research conclusions were summarized as follows:(1)By testing the pollen viability of four kinds of populus pollen stored under different temperature, it can be concluded that both in the room temperature storage, low temperature cold storage, frozen storage or cryogenic storage, populus pollen viability was reduced with the extension of time, and the fastest is for room temperature storage. Low temperature storage can prolong the life of poplar pollen. The 4 kinds of poplar pollen stored under- 80 ℃ ultra-low temperature for long-term storage after a year have viability, but also can be pollinated and developed to normal seeds.(2)Infructescence length, number of seeds per infructescence, thousand seed weight and germination rate of seeds and other characters of various cross combinations all have a wide range of variation. And infructescence length and thousand seed weight are largely affected by female parent, so there is an obvious phenomenon of female parent prepotency. Section Leuce was easier to get seeds than Tacamahaca and its seed germination rate of seeds was higher than Tacamahaca. The combination taking(P. tomentosa×P.bolleana) ×P.canescensas male paren have large number of seeds and have reached significant level.So(P. tomentosa×P.bolleana) ×P.canescens is the cross combination parent of high crossability.(3)The analysis of seedlings growth, branch, leaf traits of cross combinations shows that hybrid combinations and combination between individuals exist a wide range of variation, and the shape of the differences between all reached significant level. The hybrid combinations heritability seedling height, ground diameter, branch number, leaf length, leaf width, petiole characters were all above 0.86. And only branched angle and branch roughness are 0.66 and 0.77 and greater than 0.5, so they also have the high heritability. The individual heritability of seedling height, ground diameter are 0.26 and 0.27, were greater than 0.2, belongs to the strong genetic control, so selecting superior cross combinations and plus seedlings according to growth characters could be considerable.(4)According to the result of main component analysis, the ten cross combinations are divided into eight groups. The first group including(P. alba×P. glandulosa)×P. bolleana×(P. tomentosa×P.bolleana)×P.canescens, P.tomentosa ‘25-2’ ×(P. tomentosa×P.bolleana) ×P.canescens, P.tomentosa ‘25-1’ ×(P. tomentosa×P.bolleana) ×P.canescens, P.alba ? P.gnaludotas ‘1’ ×P.abla ? P.glandulosa, P.alba ? P.gnaludotas ‘1’ ×(P. tomentosa×P.bolleana) ×P.canescens, P.alba ?P.gnaludotas ‘2’ ×(P. tomentosa×P.bolleana) ×P.canescens,(P. tomentosa×P.bolleana) ×P.canescens×P.alba ? P.gnaludotas‘3’ has high value of growth, leaf, branch trait.. The second group including P.alba ? P.gnaludotas ‘1’ ×P.alba ? P.gnaludotas‘3’, P.alba ? P.gnaludotas‘2’ ×P.abla ? P.glandulosa has low value of growth, leaf, branch trait. The third group including((P. alba×P. glandulosa)×P. tomentosa) ×(P.abla?P.glandulosa) has high value of growth trait but low value of branch and leaf trait.(5)According to the analysis of two year hybrid seedlings, forty three hybrid seedlings were selected as superiors, selection rate of super seedlings is between 3.70 percent and 10.81 percent.(6)Through seedlings set different levels of salt stress on 10 kinds of poplar seedlings and measuring its growth and physiological indexes of changes regularly,compared with P.tomentosa ‘LM50’,P. tomentosa cl. ’0057’,P.bolleanaLauche,(P. tomentosa×P. bolleana)×P. canescens were selected as the most tolerant varieties,the P. tomentosa cl. ’0085’, P. tomentosa cl. ’3-5-3’, P. tomentosa cl. ’3-5-3’ the more salt-tolerant varieties,P. tomentosa cl. ’1418’, P. tomentosa cl. ’1008’,(P.tomentosa×P.bolleana)×P.tomentosa Carr.var. the not tolerant varieties.