几种丛生竹愈伤组织诱导与防褐变技术研究

利用小佛肚竹、凤尾竹和孝顺竹幼竹的茎尖和带节茎段研究了愈伤组织诱导和控制褐变的方法.试验结果表明:在3种生长调节剂(2,4-D、KT、IBA)的组合中,以2,4-D(2～3 mg·L-1)效果最好,愈伤组织的诱导率最高,大部分外植体都能诱导出愈伤组织,生长良好;2,4-D 2 mg·L-1 KT0.5 mg·L-1能使部分茎段诱导出愈伤组织,而茎尖诱导的愈伤组织水渍化,易褐变;KT 4 mg·L-1能使个别茎段有愈伤组织产生,但易褐化;KT 4 mg·L-1 IBA0.5 mg·L-1能诱导出愈伤组织,但生长缓慢.添加抗氧化剂控制愈伤组织褐变的效果要优于吸附剂,其防褐化能力:抗坏血酸(5 mg·L-1)＞半胱氨酸(100 mg·L-1)＞PVP(1 g·L-1)＞活性炭(1 g·L-1).在培养基中加入抗坏血酸(5 mg·L-1),使小佛肚竹、凤尾竹、孝顺竹的茎尖和茎段的褐变率分别比对照下降了51.3%、43.3%、36.8%和62.7%、42.7%、30.8%.外植体在无菌水或半胱氨酸(100 mg·L-1)溶液中浸泡2～4 h也有利于控制褐化.暗培养有利于愈伤组织生长,对控制褐化也有一定作用.

Study on Callus Induction and Brown Stain Prevention Techniques of Some Sympodial Bamboo Species

The stem tops and stems with node of young bamboo of Bambusa ventricosa,B. multiplex cv. Fernleaf and B. multiplex were used to study the callus induction and brown stain control. The results showed that among three regulator combinations(2,4-D KT and IBA) ,2,4-D(2-3 mg·L^-1)treatment was the best with the highest callus induction rate,most of the explants induced callus and grew well. 2,4-D(2 mg·L^-1) + KT(0. 5 mg·L^-1) treatment could induce callus from stem parts while the callus induced from the stem top was water-soaked and easy to be brown stained. KT(4 mg·L^-1) treatment could induce callus on some stems but was easy to be brown stained. KT(4 mg·L^-1) + IBA(0. 5 mg·L^-1) treatment could induce callus but they grew very slowly. The effect of adding anti-oxidant was better than adding adsorbent in controlling brown stain of callus. The ability of brown stain control is in the order of ascorbic acid(5 mg·L^-1) > cyste-ine(100 mg·L^-1) > activated carbon(1 g·L^-1) . By adding ascorbic acid(5 mg·L^-1) in culture media,the brown stain rates of stem top and middle part of Bambusa ventricosa, B. multiplex, var. nana and B. multiplex reduced by 51. 3% , 43. 3% ,36. 8% and 62. 7% ,42. 7% ,30. 8% respectively compared with that of the control. Soaking explants in non-bacteria water or cysteine(100 mg·L^-1)for 2 to 4 hours would benefit controlling the brown stain. Culturing in dark would benefit the growth of callus and control of brown stain.