Study on Tissue Culture of Leucophyta brownii ‘Canal Rocks Form’

[Objective] This study aimed to establish a tissue culture technology for Leucophyta brownii ‘Canal Rocks Form’. [Method] Leucophyta brownii ‘Canal Rocks Form’ stems with axillary buds were selected as explants in vitro to investigate the effects of different concentrations of 6-BA and NAA on proliferation culture and the effects of IBA, NAA and subculture cycle on rooting culture. [Result] The results showed that Leucophyta brownii ‘Canal Rocks Form’ plantlets need low concentrations of phytohormones and the rooting culture was significantly affected by the subculture cycle; the optimal medium for proliferation culture was MS＋0.5 mg/L 6-BA＋0.05 mg/L NAA＋30 g/L sucrose＋5.5 g/L agar, with a proliferation coefficient of 4.25; the plantlets with a subculture cycle of 28 d were the most suitable for rooting culture, with a rooting rate of 95.9% in 1/2 MS＋0.1 mg/L IBA＋0.05 mg/L NAA＋20 g/L sucrose＋5.5 g/L agar, and the average number and length of roots were 4.69 and 1.68 cm, respectively. [Conclusion] This study laid the foundation for establishing sterile culture system of Leucophyta brownii ‘Canal Rocks Form’.

Effects of in vitro subculture on the physiological characteristics of adventitious root formation in microshoots of Castanea mollissima cv.'yanshanhong'

Microshoots of Castanea mollissima cv.＇yanshanhong＇ in vitro acquired an enhanced rooting capability with increasing numbers of subculture.In this study,we investigated the effect of successive subculture on adventitious root formation in vitro by the determination of the endogenous hormone level and the enzyme activity.The levels of indoleacetic acid（IAA）,abscisic acid（ABA）,cytokinins（CTK） and gibberellic acid（GA3） were determined by high performance liquid chromatography（HPLC）,and the activities of indoleacetic acid oxidase（IAAO）,peroxidase oxidase（POD）,and polyphenol oxidase（PPO） were measured by ultraviolet-spectrophotometer assay after the induction of rooting at 2nd,4th,6th and 8th subculture.The relationships between physiological characteristics and subculture numbers or rooting rate were as follows：The levels of endogenous IAA in microshoots gradually increased,and endogenous levels of ABA,CTK and GA3 in microshoots decreased slightly after serial subcultures.The level of IAA was highly correlated with subculture numbers and rooting rates.The ratios of IAA/ABA and IAA/CTK both acutely raised with increasing rooting rate during successive subcultures and had high correlations with rooting rate.The activity of IAAO and POD are significantly negatively related with subculture numbers,and the activity of PPO increased after subcultures.

Study on Tissue Culture and Rapid Propagation of Lycium ruthenicum Murr.

[Objective] This study aimed to establish a tissue culture and rapid propagation system for Lycium ruthenicum Murr.[Method] Using tender stems of L.ruthenicum as explants,MS as basic culture medium,the effects of different factors on primary culture,subculture and rooting of L.ruthenicum plantlets were investigated.[Result] The most appropriate medium for primary culture of L.ruthenicum was MS ＋ ZT 0.2 mg/L ＋ IBA 0.01 mg/L,in which axillary buds grew well and were rarely vitrified with the germination rate of 88.73%.In addition,ZT exerted significantly better effects on subculture and proliferation of L.ruthenicum plantlets than 6-BA.The most appropriate medium for subculture and proliferation of L.ruthenicum plantlets was MS ＋ ZT 0.15 mg/L ＋ IBA 0.01 mg/L,in which L.ruthenicum plantlets grew rapidly and robustly without vitrification,and the proliferation multiple reached 5.83 times.The most appropriate medium for rooting of L.ruthenicum plantlets was MS ＋ IBA 1.0 mg/L,in which the rooting rate reached 100%.The most appropriate substrate for transplanting and hardening of L.ruthenicum plantlets was humus soil：perlite = 1：1,in which L.ruthenicum plantlets grew well with the survival rate of 92.37%.[Conclusion] This study provided theoretical basis for largescale production and popularization of L.ruthenicum.

桃儿七组织培养体系的建立及鬼臼毒素的检测

目的建立桃儿七组织培养体系及其鬼臼毒素的提取检测方法。方法以桃儿七成熟分离胚为材料,研究了不同浓度激素、活性炭(AC)对无菌苗诱导的影响;以桃儿七无菌苗切除后约2.0 cm的根茎为材料,考察不同浓度激素对根继代及生长发育的影响,并定期对继代根、叶(叶柄)及培养基进行鬼臼毒素的提取及HPLC法检测。结果分离胚在MS+2.0%蔗糖+0.4%琼脂+1.0 mg/mL GA3+1.0 g/L AC的培养基培养20 d后,无菌苗诱导率为92.0%,无菌苗生长发育良好;切除后约2 cm的根茎接种在MS+2.0%蔗糖+0.4%琼脂+1.0 g/LAC+1.0 mg/mLIBA继代40 d后,根长11.59 cm,植株生长发育良好;对继代根、叶(叶柄)及培养基进行鬼臼毒素的提取及HPLC法检测显示,鬼臼毒素量大小依次为根>培养基>叶(叶柄),50 d后分别为33.17、12.97、4.55μg/mL。结论本研究建立了桃儿七组织培养体系,证明了利用桃儿七根培养生产鬼臼毒素的可行性。