Effect Of Magnetic Field And Exogenous Hormones On Rooting Of Softwood Cuttings Of Catalpa Bungei

Catalpa bungei is a very important timber tree and a famous garden tree species in China.There are problems such as low seed germination rate need to be improved for this specis.Simple and efficient cutting propagation techniques are important for maintaining the good traits of the female parent and breeding new varieties.In this study,the three-year old seedlings were used as a material to study the rooting copacity,nutrient substance and root morphology of Catalpa bungei softwood cuttings under various exogenous hormone and high voltage magnetic field treatments.The result showed:(1)When cuttings were treated with NAA 500 mg/L and IB A 1000 mg/L,the total root length,total root surface area,total root volume,and root biomass were the highest,which were 78.7 cm,19.79cm2,0.57ccm3,and 69.69mg,respectively.The addition of high-voltage magnetic field could significantly increase the rooting rate of adventitious roots of Catalpa bungei tender branches cuttings(56.63%),increasing the total root length(55.32cm),increasing the total root surface area(13.93cm2)and the total volume(0.33cm3).(2)NAA 500mg/L and IBA1000mg/L mixed hormone treatment with high voltage magnetic field can affect the rooting index of cuttings of tender branches.The occurrence rate of adventitious roots(60.68%)is 22%higher than the control treatment.The total root length,total root surface area,and total root volume were 82.85 cm,20.77cm2,and 0.63cm3,respectively,which were 3.15,2.81,and 3.5 times the control treatment.This treatment has the best integrated rooting effect,and the optimal comprehensive performance of root development.(3)Nutrients are required during the rooting.therefore,the soluble sugar,soluble protein,total nitrogen and the mass ratio of C to N in cuttings will change with the rooting process.(4)The treatment of NAA 500 mg/L mixed IBA 1000 mg/L under magnetic field congdition could increase the mass ratio of C to N,adventitious root number,average root length,rooting index,total root length,total root surface area,total root volume,root biomass,these indicators were the highest among the seven treatments.The content of nutrients in cuttings of Catalpa bungei tender branches was increased,which was more conducive to increase the rooting rate of twigs.The best combination treatments for tender branche rooting were NAA 500 mg/L mixed with IBA 1000 mg/L under a high voltage magnetic field treatment...