Studies On Embryogenesis And Polyploid Induction Of Populus Deltoides Hybrids

Populus deltoides hybrids with significant heterosis were widely used in construction of industrial timber and ecological shelter forest.In order to provide evidence for the cross-breeding,parafin section method was used to observe the embryogenesis ofⅠ-69×S3804.Choosing the hybrids from the cross of Populus deltoids with Populus simonii,we dealt with the polylpoid induction through dispensing growing points and co-culture.We look forward to provide an effective way to breeding new poplar and analysing traits stomatal.Flow cytometry(FCM) analysis of DNA content were used in the identification of polyploid poplar.Pollen tubes begin to emerge through the grain 0.5h after pollination.The type of embryo development is Epilobium.The successful fertilization process proved that the hybridization was practicable.Two tetraploid samples were treated by 0.5%colchicines.After colchicine treatment on the growing points of 338 plants,we found that the extent of poisoning effect was deeply related to the colchicine concentration.Terminal bud mortality was 71.43%by 0.5%colchicines.At the same time,rates of polyploid induction were related to the concentration of colchicines.The best concentration of ??hicines was 0.5%.Establishment of tissue culture system was one of the preconditions for the co-culture.The result of tissue culture showed that the most appropriate medium for buds propagation was MS+6-BA0.5mg/L+TDZ0.002 mg/L+ sucrose 30g/L+ gelose 7g/L.The most appropriate medium for rooting induction and sound seedling of bulblets is 1/2MS+ sucrose 30g/L+ gelose 7g/L.The buds induction,browning,and root-related are related to the concentration of colchicines,light,and explants.No tetraploid plant was identified finally.