Study On Softwood Cutting Techniques Of Catalpa Bungei And Its Rooting Mechanism

Based on Catalpa bungei softwood for cutting materials, Catalpa bungei softwood cutting technology was researched and discussed. The dynamic changes of cuttings'nutrients, enzymatic defense system and endogenous hormone in Yuanjichangguo Catalpa and Jinsi Catalpa, were analyzed. The inhibiting root matters were also detected with biometric technology. The rooting mechanism of Catalpa bungei was explored and the reason of rooting difficulties were discussed at last.Zi Catalpa and gray Catalpa had the best rooting capacity. The rooting capacity of Nanyang Catalpa, Yuanjichangguo Catalpa and Yu Catalpa-1, were also better than other fives varieties (types).The rooting capacity was greatly affected by hormones, softwood position and cutting period. Cutting in mid-June with taper shoots can get better rooting capacity and if the tender shoots were dealt with IBA 1000- NAA500mg/kg proportion, the result would be better too. The data of orthogonal test can conclude that:The optimal combination for Yuanjichangguo Catalpa is using 1500mg/kg ABT6 Powder for dealing with softwood, which was about 10~12cm long and 0.3~0.6cm rough, about 30 seconds. The optimal combination for Jinsi Catalpa is using 2000mg/kg ABT6 Powder for dealing with softwood about 2 minutes,compared to Yuanjichangguo Catalpa. The optimal combination for Guangye Catalpa is different from Yuanjichangguo Catalpa at using 2000mg/kg ABT1 Powder. And Yu Catalpa-1 is using 1500mg/kg IBA.The dynamic changes of cutting nutritional substances, endogenous hormones and enzymatic defense system were related to the rooting processes closely. The trend of these mainly physiological indicators will be changed at those important periods of rooting processes.The content and distribution of nutrients of Yuanjichangguo Catalpa, was more reasonable than Jinsi Catalpa. Yuanjichangguo Catalpa's endogenous hormones regulated the inter environment and make it more suitable for rooting. And enzymatic defense system of Yuanjichangguo Catalpa is good at defending the environment stress. And the use of ABT1 can make good improvement at some aspect. The biometric for Jinsi Catalpa extracts indicated that there were some inhibitory substances in cuttings.Based on the research of softwood cuttage technology, the analysis for dynamic changes of nutrients, enzymatic defense system and endogenous hormone in cuttings, and the biometric for inhibitory substances, it was concluded that: the integrated effect of nutrient, enzymatic defense system and endogenous hormone make Catalpa bungei hard to root. The rooting difficulty of Catalpa bungei was lies in nutrient supply weak, different hormones regulation unsuitable and enzymatic defense system not perfect enough. The presence of rooting inhibitory substances also is one of the important reasons.