生根粉浓度和环剥宽度对银杏高空压条生根的影响

Effects of rooting powder concentration and girdling width on shoot rooting during Ginkgo biloba air layering

为研究ABT 1号生根粉和压条环剥宽度对银杏高空压条生根和育苗成活率的影响,以扬州大学银杏资源圃内20年生银杏的枝条为试材,采用双因子试验,设定环剥宽度和ABT 1号生根粉浓度2个控制因子,环剥宽度设置7、12、18 mm 3个不同梯度,ABT 1号生根粉浓度设置0、500、1 000、1 500 mg/L 4个水平。结果表明:银杏枝条生根率随ABT 1号生根粉浓度的升高呈先上升后下降趋势,最佳浓度为1 000 mg/L。3种不同环剥宽度中,12 mm环剥宽度的愈伤组织产生率较高,可达90%以上,生根率也最高,达50%。但银杏枝条生根非常缓慢,高空压条需要在母株上生长3个月之久才能形成根系,移栽5个月后压条开始展叶,根系也进一步生长。此外,在母株上已形成根系的压条移栽成活率极高,达到100%,而形成愈伤组织的枝条移栽成活率较低,为56.67%,且植株的生长势较弱,根系形成也较弱。

In order to study effects of ABT No.1 rooting powder and girdling width on rooting and seedling survival rate of G. biloba air layering, using 20-year-old branches in G. biloba at the ginkgo resources nursery of Yangzhou University as materials, a two-factor test was carried out, and the two control factors were girdling width and concentration of ABT No.1 rooting powder. Girdle width was set three gradients of 7, 12, 18 mm, and concentration of ABT No.1 rooting powder was set four levels of 0, 500, 1 000, 1 500 mg/L. The results showed that rooting rate was increased firstly and then decreased with increase of concentration of ABT No.1 rooting powder, and the optimal concentration was 1 000 mg/L. Among the three girdling widths, 12 mm girdling width treatment had the highest callus formation rate and rooting rate, and they were over 90% and 50%, respectively. But branch rooting in G. biloba was very slow, it need grow in mother plant for 3 months before root systemt formating, and leaves in transplanted shoot began to expand after 5 months and root system growed further. In addition, survival rate of transplanted branches forming root system in mother plant was extremely high, reaching 100%. Transplanted branches that only formed calli had lower survival rate, which was 56.67%, but growth potential of plants and formated root system was weaker.