Study On In Vitro Reproductive Ability And Tissue Culture Techniques Of Four Cultivars Of Catalpa Bungei

In order to promote and utilize superior germplasm resources,and solve the problem of sharp decline in seedling resources of Catalpa bungei in the market.The effects of optimal explant collecting time,basic medium type,induced seedling formation,proliferation,rooting culture and transplanting on Catalpa bungei ’Zhaoxia’、Catalpa bungei ’Yunduo’、Catalpa bungei ’Luoqiu 1’ and Catalpa bungei’Luqiu 1’ were studied by using its stem with axillary bud as explants.In addition,the plant regeneration abilities of the four varieties was also compared.Finally,tissue culture system was established for the four varieties of Catalpa bungei.The results showed that:1.The sterilization effect of Catalpa bungei ’Yunduo’ is better overall.After the stem segment was treated with 75%alcohol 30S,the best sterilization effect for ’Yunduo’ was 6 minutes with 0.1%mercuric chloride,and the success rate was 93.33%..The best sterilization effect was 8 minutes with 10%NaCIO for ’Luotuo 1’,with 0 pollution rate and 60.00%success rate2.Among the four varieties,’Luoqiu 1 ’,’Luqiu 1 ’ and ’Zhaoxia’ had stronger bud-inducing ability,and ’Yunduo Sorbus’ had the weakest ability to induce buds..Different varieties of Catalpa bungei have different requirements for the exogenous hormones used in the induction medium:The optimal induction medium for ’Luoqiu 1’ and ’Luqiu 1’ was MS+6-BA 1.0mg/L+IBA O.lmg/L,the induction rate was up to 100%;The optimal induction medium for ’Zhaoxia’ and ’Yunduo’ was MS+6-BA 2.0mg/L+IBA 0.1mg/L,the induction rate was 100%,81.82%,repectively.3.The same proliferation treatment had different proliferation effects on four varieties of Catalpa bungei.The bud proliferation ability was sorted as ’Luqiu 1’>’Luoqiu 1’>’Zhaoxia’>’Yunduo’.The optimal proliferation medium of ’Luqiu 1’ was DKW+6-BA 1.0mg/L+IBA 0.3mg/L,and the proliferation coefficient could reach 4.70;’Zhaoxia’ was DKW+6-BA 3.0 Mg/L+IBA 0.3mg/L,the proliferation coefficient can reach 5.49;’Yunduo’ and ’Luqiu 1’ was DKW+6-BA 1.5mg/L+IBA 0.3mg/L,and the proliferation coefficients were 3.38 and 5.68,respectively.4.The same concentration of NAA could better promote the rooting of four varieties of Catalpa bungei than IBA.’Zhaoxia’ had the strongest rooting ability,’Yunduo’ had the weakest rooting ability.The best rooting mediums of ’Luoqiu 1’ was WPM+NAA 0.4 mg/L and the rooting rate was 96.97%;’Zhaoxia’ was WPM+NAA 0.1 mg/L and the rooting rate was 97.50%;’Yunduo’ and ’Luqiu 1’ was WPM+NNAA 0.2mg/L and the rooting rate were 76.67%and 93.33%,respectively.