Technology Of Intersectional Crossing Between Sect. Aigeiros And Sect.Leuce

Poplar are important afforestion species in many countries of the world , which are also important resource of tree species for ecology construction in China. For a long time tree breeders of the world have made much effort in poplar crossing,and a great of achievements have been gained. Because there is a natural incompatible barriers between Sect.Aigeiros and Sect.Leuce, and it was highly difficulty in getting their hybrids . 57×新(P.deltoides CL '57'×P.bolleana), ShannLin-3, P.hoperensis and P.bolleana as materials,this paper studied the effect of different crossing combinations,suffocating and brushing stigma with hexane as well as treating pollen with freezing-thaw and tryphine on obtaining hybrids. In the same time growth-testing and resistance-testing of hybrid seedlings were carried. Serveral excellent clones were selected. The results are as follows: 1. There was obvious compatibility difference among while Sect.Aigeiros and Sect. Leuce as female parent respectively,more hybrid seeds were gotten with Sect.Aigeiros. The fomer thousand-seed weight was bigger than that of the later . 2. To treat pollen with freezing-thaw and tryphine,no hybrid seeds obtained,and indicating that the two ways did not have obvious effect on crossing between Sect.Aigeiros and Sect .Leuce . 3. Although suffocating as well as brushing stigma with hexane had obvious effect on getting hybrid seeds, it was different results among parent combination. Hybrid seedling were gained by suffocating stigma with hexane and brushing stigma with hexane in combination of P. deltoides CL '57'×P .bolleana, and the former was better than the later. For combination of P. hoperensis×ShannLin-3, brushing stigma with hexane was more suitable. 4. To identify hybrid with morphlogy characteristics and POD isozyme, the results showed that the hybrid has not only parents chracteristics, also new genetic characters. So the hybrids have genetic variation. 5. Seedlings testing of hybrid clones growth character showed that several clones such as P.deltoides CL '57'×P.bolleana 11,2,10, and P.hoperensis×ShannLin-3-5,-1,-2,10 are good in growth performances . 6. Resistance studies of the hybrids showed that the ability of P. deltoides CL '57'×P.bolleana2 of Marsson-ninabronnea resistance was poor, the others were good. P.deltoides CL '57'×P.bolleana 11,10, and P.hoperensis×ShannLin-3-5,-2 have a better drought-resistance. Ability of cold-resistance with conductivity of the branch in low temperature, the results showed that P.deltoides CL '57'×P.bolleana 11,10, and P.hoperensis×ShannLin-3-5,-2 have a stranger resistance ability for low temperature. 7. By comprehensive assessment hybrid clones's growth and resistance, the excellent clones include P.deltoides CL '57'×P.bolleana 11,10, and P.hoperensis×ShannLin-3-5,-2, and they need to be studied continuously.