外源激素、芽苗数及大小对文心兰试管苗增殖的影响

Effects of Hormones Shoot Length and Number on Oncidium Shoot Propagation

分别进行了外源激素、芽苗数和芽苗大小对文心兰试管苗增殖影响的试验研究。结果表明:2类细胞分裂素6-BA(6-苄基腺嘌呤)和Ad(腺嘌呤硫酸盐)对文心兰试管苗增殖的作用差异较大。与0.2mg/L的生长素a-NAA(a-萘乙酸)配合使用,6-BA质量浓度在2.0￣4.0mg/L的培养基较适合文心兰试管苗的增殖,最大增殖系数可达7.27,苗生长健壮,叶色鲜绿,适合进一步生根移栽;Ad在1.0￣6.0mg/L的范围内增殖系数较小,苗生长缓慢、矮小,但有形成丛生苗的倾向;以2.0mg/L的6-BA和1.0mg/L的Ad组合使用,易形成丛生芽苗且苗体相对较小,增殖系数也较高;接种单株小苗较大苗易形成丛生芽苗;接种2株连体小芽苗,全部能形成丛生芽苗,增殖系数可达10.07,适合于进一步增殖使用。MS培养基添加2.0mg/L6-BA,1.0mg/LAd及0.2mg/La-NAA,在特定的培养条件下,接种2￣4株长1.5￣2.5cm连体芽苗,可建立高效的文心兰试管苗丛生芽增殖体系。

The experiments on effects of hormones, shoot length and inoculated shoot numbers on oncidium shoot propagation were conducted. The results showed that the effects of two kinds of Cytokinin. 6-BA and Ad. on Oncidium shoot propagation in vitro culture were quite different. The concentrations of 6-BA between 2.0-4.0 mg/L weresuitable for Oncidium shoot propagation and the highest coefficient of propagation reached 7.27. The shoots grew stronger than others and had brighl green leaves. Therefore. these shouts were suitable for rooting and transplanting. Howevcr. Cytokinin Ad was not suitable for Oncidium shoot propagation. The shoots grew slowly and were short and small, but tended to form clusters. The smaller shoots were easier to from clusters than the bigger ones. All of the linked small shoots could form clusters and their coefficient of propagation reached as high as 10.07. Those new induced clustered shoots could be used for the next propagation. The best medium for oncidium shoot propagation was MS ＋ 2.0 mg/L 6-BA-1.0mg/L＋1.2 mg/L a-NAA ＋ 30g/L sucrose ＋ 4.0g/L;agar. The oncidium shoot propagated rapidly in this medium under special in vitro cultural conditions. The highly cfficient oncidium shoot propagation system was thus established.