Effects Of Different Treatments On The Hardwood Cuttings Propagation Technique Of Catalpa Bungei

Catalpa bungei is a precious native trees and excellent timber species, with good prospects for development. Catalpa bungei has the characteristics of self-sterility, and the progress of asexual reproduction technology such as shoots cutting is slow, as a result, it is unable to meet the practical needs. It is necessary to explore the hardwood propagation of Catalpa bungei deeply, and lay the foundation for large-scale propagation of catalpa bungei.Cutting of Catalpa bungei is widely used in clonal breeding afforestation method, which has the advantages of low cost of breeding, short of breeding time, fast, simple of operation and higher propagation coefficient comparing with other breeding technology. In addition to the research from the traditional methods, the article attempts to explore the negative pressure irrigation.Using different hormone concentrations, scratches, inversion and negative pressure washing handling hardwood cuttings of Catalpa bungei, the conditions of callus formation and germination is observed. The results as follows:(1)IAA 1000 mg/L + NAA 500 mg/L + no scratch + flat, under the process that show the obvious and largest effect on callus. It ensures that germination percentage of 25% and greatly promote the formation of callus at the lower end of the cuttings, then advantageous to rooting.(2)IAA 500 mg/L + NAA 500 mg/L + inversion + scratch, under the condition of germination rate can be as high as 70.73%, and on the performance of individual cuttings can reach 100%, namely all buds were germinated on cuttings.(3)Hardwood cuttings is treated by negative pressure washing with MS nutrient solution,as which significantly improve the germination of cuttings, and also significantly promoted the callus of incision of cuttings. The longer the negative pressure washing, the higher safranin solution in the spike and also a better effect, but it show a growth trend of deceleration.