Screening and quantification of an antiseptic alkylamide, spilanthol from in vitro cell and tissue cultures of Spilanthes acmella Murr.

The study revealed, for the first time, accumulation of spilanthol, an antiseptic alkylamide, in in vitro cultures of Spilanthes acmella Murr., a medicinal plant of immense commercial value. To achieve this, in vitro shoots were regenerated via direct organogenesis from leaf-disc explants of Spilanthes. Shoots were induced in the presence of N⁶-benzylaminopurine (BAP) alone or in combination with either α-naphthalene acetic acid (NAA) or Indole-3-acetic acid (IAA) in Murashige and Skoog medium. The best treatment for shoot regeneration was MS + BAP (5.0 μM) + IAA (5.0 μM), which promoted adventitious shoot proliferation in >82% cultures with an average of 5.3 shoots per explant. Regenerated shoots rooted spontaneously with a frequency of 100% on half strength MS medium (major salts reduced to half strength) containing 50 g l⁻¹ sucrose. The plantlets were acclimatized successfully with 90% survival rate. Additionally, ploidy stability of the regenerated plants was assessed by flow cytometry which showed that all investigated plants had the similar ploidy as that of the mother plant. For spilanthol identification, peaks eluted from HPLC were analyzed by mass spectrometry with its characteristic fragmentation pattern. For quantification studies, calibration curve was generated, which revealed a higher amount of spilanthol content (3294.36 ± 12.4 μg/g DW) in the leaves of in vitro plants compare to those of in vivo plants (2703.66 ± 9.6 μg/g DW of spilanthol). An efficient multiplication frequency, ploidy stability and enhanced spilanthol accumulation ensure the efficacy of the protocol developed for this industrially important medicinal plant.     

土壤中噻苯隆和敌草隆及其代谢物的残留量测定方法

[目的]为土壤中噻苯隆和敌草隆及其代谢物的残留分析建立一种简捷可行的方法。[方法]利用液相色谱法对供试土样中噻苯隆和敌草隆及其代谢物的残留量进行测定。[结果]噻苯隆及其代谢物的最大吸收波长为290nm左右,敌草隆及其代谢物的最大吸收波长为254nm。噻苯隆及其代谢物thidiazolylurea和敌草隆及其代谢物DCPU、DCPMU的线性回归方程分别为：y=0．5704x＋0．0723、Y=2．3635X＋0．2386、Y=0．5687X＋0．108、Y=0．5504x＋0．1163和Y=0．6107X＋0．3612;其最低检出浓度分别为0．04、0．08、0．05、0．04、0．03mg／kg;当添加浓度为其最低检出浓度时,平均加标回收率及其RSD分别为：86．78％和5．51％、95．13％和8．13％、89．04％和6．60％、84．10％和4．29％、92．05％和5．92％。[结论]该方法在定性和定量分析方面都能够满足土壤中噻苯隆和敌草隆及其代谢物的残留量测定分析要求。     

In vitro shoot regeneration from immature seeds of Epimedium alpinum induced by thidiazuron and CPPU

In vitro propagation of Epimedium alpinum L. was carried out using immature seed explants. The effects of various concentrations of thidiazuron (TDZ) and 1-(2-chloro-4-pyridyl)-3-phenylurea (CPPU), on the induction of organogenic callus, were evaluated. Organogenesis occurred most efficiently when explants were transiently exposed (48 h) to 20 μM CPPU or 80 μM TDZ followed by culture on hormone-free woody-plant medium (WPM). Organogenic callus consisting of white, compact clumps of tissue proliferated slowly on hormone-free WPM. To promote adventitious shoot induction, the effects of different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzyladenine (BA) were investigated. The highest per cent shoot regeneration, 66.7% of explants, and the maximum mean number of shoots, 2.6 per explant, were obtained on WPM containing 1.1 μM 2,4-D and 22 μM BA. Shoots were rooted on hormone-free WPM and well-developed plantlets were successfully transferred to soil.     

棉花应用脱叶催熟剂对后茬小麦生长及产量的影响

为探究麦后直播棉生产中应用脱叶催熟剂对后茬小麦出苗、苗期生长及产量的影响,在盆栽条件下,土壤添加不同浓度的'噻苯隆'后,测定小麦出苗及苗期生长指标;在田间条件下应用不同浓度的'噻苯隆'与'乙烯利'混用进行棉花脱叶催熟,并测定后茬小麦出苗率、苗期生长指标及产量等指标.结果表明,'噻苯隆'在土壤中的半衰期为6.9 d,土壤...     

正交设计在花椰菜不育系丛生芽诱导培养中的应用

为给“瓯雪60天”制种中核不育系母本9901A组培快繁提供依据,以9901A花球表面花枝为外植体,采用正交设计方法对培养基中TDZ、BA、NAA、2,4-D 4种激素浓度配比进行筛选。结果表明：MS＋6-BA0.5mg/L＋NAA0.001mg/L芽诱导率最大,为94%,但每外植体平均诱导芽数为1.1个;MS＋TDZ0.1mg/L＋NAA0.001mg/L每外植体平均诱导芽数最大,为10个,但芽诱导率为50%。TDZ和NAA浓度适中促进外植体平均芽数的诱导,过高则抑制外植体平均芽数的诱导;2,4-D 和6-BA总体表现为随浓度增加而抑制外植体平均芽数的诱导。     

桑树叶片愈伤组织的诱导及不定芽分化影响因素的研究

通过正交试验,探讨了植物生长调节剂噻二唑苯基脲(Th id iazuron,TDZ)、α-萘乙酸(NAA)、桑品种、叶龄、叶位等5种因素对桑树叶片愈伤组织诱导的影响。筛选出了桑树叶片愈伤组织诱导的最佳条件为:21 d苗龄的陕305组培苗叶片,培养基MS+1.0 mg/L TDZ+0.2 mg/L NAA。在此条件下,陕305愈伤组织诱导率可达93.9%。对得到的陕305叶片愈伤组织进行了不定芽分化诱导,结果表明,最佳分化培养基为MS+3.0 mg/L 6-BA+0.1 mg/L IAA+2%果糖,愈伤组织不定芽分化率高达100%。     

Establishment of high frequency shoot regeneration system in Himalayan poplar (Populus ciliata Wall. ex Royle) from petiole explants using Thidiazuron cytokinin as plant growth regulator

Populus species are important resources for industry and in scientific study on biological and agricul-tural systems. Our objective was to enhance the frequency of plant regeneration in Himalayan popla...     

Feathering of ‘Doyenné du Comice’ pear in the nursery using repeat sprays of benzyladenine and gibberellins

This work sets out to examine the effectiveness of a number of cytokinins or products with cytokinin-like activity, with and without additional sprays of gibberellins or leaf plucking, on the production of feathers (sylleptic shoots) on trees of the European pear cultivar ‘Comice’ in a fruit tree nursery. It covers the results from three successive years experimentation.     

大树杜鹃组织培养技术研究

选用大树杜鹃试管苗的带芽茎段进行离体培养，通过正交试验设计并结合方差分析、多重比较从中选出了大树杜鹃组织培养的最佳培养基配方，建立起了大树杜鹃离体培养体系。结果表明：TDZ是适合大树杜鹃离体培养的细胞分裂素，带芽茎段增殖培养基为WPM＋TDZ0．40mg／L＋IBA0.05mg／L；壮苗培养为WPM＋TDZ0～0．10mg／L＋IBA0.40mg／L＋AC0.20％或者TDZ0.10～0.20mg／L＋NAA0．20mg／L＋AC0.20～0．40％；生根培养：WPM＋糖15g/L＋IBA1．50mg／L＋NAA1．50mg／L＋AC0．20％。     

Effect of Defoliants Application on Physiological Characters of Cotton Leaf without Defoliants

[Objective]The aim of this study is to elucidate the physiological mechanism of cotton leaf without defoliant response to thidiazuron (TDZ). [Method] A pot experiment was conducted to study the effect of defoliants on the photosynthesis, chlorophyll fluorescence, antioxidant enzyme activity, and endogenous hormone contents of cotton leaf without defoliant at 1 d, 3 d, 6 d and 10 d after the application of TDZ. Cultivar CCRI-50 was used for this experiment. [Result] TDZ rapidly induced cotton leaf abscission, however, no abscission was detected to the cotton leaf without defoliants. The net photosynthetic rate (P_n) of cotton leaf without defoliants was reduced by 1 d, 3 d and 6 d after TDZ applied, but rise to the control treated with water level by 10 d. TDZ also caused a significant decline in the maximum photochemical efficiency of photosystem II (F_v/F_m), the quantum yield of electron transport (Φ_PSII), the electron transport rate (R_et) and the photochemical quenching coefficient (q_P), but an increase in the non-photochemical quenching coefficient (qNP). However, with the same changes as P_n, the chlorophyll fluorescence characters got to the control by 10 d. TDZ application significantly increased the superoxide dismutase activity, did not affect the peroxidase activity, decease the malondialdehyde content. Abscisic acid contents in the cotton leaf without defoliant were lower than control by 3 d and 6 d after the applied of TDZ, but have the same level with control at 10 d, and the auxin had a little changes compared with control during the whole period of experimental time. [Conclusion] TDZ application significantly affect the photosynthesis, chlorophyll fluorescence, antioxidant enzyme activity, and endogenous hormone contents of cotton leaf without defoliant. When the leaf with defoliant drop off, the physiological characters of cotton leaf without of defoliants recovered to control level, and no abscission were detected.