Inducement, Growth And Photosynthetic Character Study On Polyploid Betula Platyphylla

This research is done on polyploidy Betula platyphylla from creation, identification, seed vigor, morphological character, physiological character, photosynthetic character, wood property, flowering and seeding, the expression of MADS-box gene famliy. It serves as reference of polyploid breeding of Betula platyphylla.In this experiment seeds of diploid Betula platyphylla were treated with 0.1% colchicines for 48 hours. With the help of flow cytometer, we found 99 tetraploid in 2004 and 11 tetraploid in 2009. Use tetraploid which had come into flower as female, all the progeny of hybridization between tetraploid and diploid was triploid.There were significant variations (P<0.05) in seedling height and leaf area between biennial tetraploid and biennial diploid. The height of tetraploid seedling was decreased 16.93% and the leaf area of tetraploid was increased 21.09% compared with diploid. Considering with seedling height, leaf area, C.D, WSP, chlorophyll, F12,F13,F10,F5,F19,F8,F1,F6 were excellent seedlings by membership function values from 11 tetraploid.There were significant variations (P<0.01) in leaf morphology and stomatic character between tetraploid and diploid which were five years old. The leaf length, leaf width and leaf area of tetraploid were increased 48.09%,47.61%,111.89% compared with diploid respectively. The stoma length, stoma width, guard cell length, guard cell width of tetraploid were increased 91.38%,69.42%,54.93%,21.20% compared with diploid respectively. There were significant variations (P<0.01) in net photosynthesis rate, LSP, LCP, CE between tetraploid and diploid which were five years old. The net photosynthesis rate, LSP, LCP, CE of tetraploid were increased 19.76%,9.41%,20.00%,25.19% compared with diploid respectively. There were significant variations (P<0.05,P<0.01) in the expression of MADS-box gene famliy between tetraploid and diploid which were five years old.There were significant variations (P<0.01) in germination rate and germination energy between seeds from different hybrid combination. The germination rate was between 3.33%～45.33% and the germination energy was between 2.00%～41.33%. The good germination rate and germination energy were Q65×F3, whose germination rate and germination energy were increased 53.14% and 58.17% compared with diploid respectively. There were significant variations (P<0.01) in seedling height, leaf area, net photosynthesis rate between annual triploid and annual diploid. The seedling height and leaf area of triploid were decreased 21.01% and 10.42%, the net photosynthesis rate of triploid was increased 23.86% compared with diploid. There were significant variations (P<0.05) in WSP and chlorophyll between annual triploid and annual diploid. The WSP and chlorophyll of triploid were decreased 44.76% and 6.71% compared with diploid respectively. Considering with seedling height, leaf area, C.D, WSP, chlorophyll, T28 was excellent seedlings by membership function values from 47 triploid. The membership function value of T28 was increased 2.55% compared with diploid.