ABSTRACT
Objective: To optimize the culture methods and conditions for the rapid propagation of Lycium ruthenicum in vitro, explore effective proliferation methods, and screen suitable plant regeneration pathways, so as to establish an artificial high-efficiency breeding technology system. Methods: Stem segments with one or two nodes of aseptic seedlings were used as materials. MS, modified MS1 and modified MS2 were used as basic media. The effects of different plant hormones and their concentrations on callus induction, axillary bud germination, basal stem adventitious cluster bud induction and plant regeneration were studied by single factor, complete combination and L9(34) orthogonal experiments. Results: A large number of callus were induced in MS + NAA 1.0 mg/L + 6-BA 0.1 mg/L medium, but the ability of redifferentiation was weak, and the highest multiplication coefficient was only 4.36 after 35 d of culture; While in MS + NAA 0.1 mg/L + 6-BA 0.05 mg/L + KT 0.5 mg/L medium, with axillary buds starting to germinate, the node of stem segment contacted with culture medium began to swell and appeared adventitious bud points, which sprouted basal stem cluster budswith the incidence rate of 100%: And the highest multiplication coefficient could up to 42.84 after 45 d of culture. The suitable medium (MS1 + NAA 1.0 mg/L) for rooting of test-tube seedlings was modified. After 40 d of culture, the rooting rate reached 98.9%; And the survival rate of transplanted tube seedlings after refining was over 90%. Conclusion: In this study, the basal stem cluster buds were used as a new way for proliferation, and an efficient propagation system of L. barbarum in vitro was successfully established, which not only greatly improved the yield and quality of test-tube seedlings, but also provided another idea for the rapid propagation of other Lycium plants in vitro.
ABSTRACT
Objective: To set up a callus induction system for Amomum villosum by tissue culture. Method: The rhizome buds of A. villosum and stem segments,root tip segments of sterile A. villosum plantles were used as explants and cultured in MS media with different concentrations of 6-BA,NAA and 2,4-D (the pH of each medi is about 5.8). A callus induction system was established to explore the effect of different explants and different medium on callus induction for A. villosum. Result:The findings showed that the rhizome buds and sterile plantlet stems and root tip segments of three different explants can be successfully induced into calli. The most suitable medium for callus induction from rhizome buds and sterile plantlet stems was MS with 6-BA (1.5 mg·L-1),2,4-D (1.0 mg·L-1) and NAA (0.5 mg·L-1) with the highest induction rates of 15% and 60% respectively. MS medium combined with 6-BA (2.0 mg·L-1),2,4-D (1.0 mg·L-1) and NAA (1.0 mg·L-1) was the most suitable proposal for inducing the callus from sterile root tip segments with the highest induction rate of 76%. Conclusion:Under certain culture conditions,rhizome buds,stem or root tip segments of sterile plantlet can be effectively induced into callus. The callus induction system of A. villosum is preliminarily established, and root tip segments of sterile plantlet are the optimal explant.
ABSTRACT
ABSTRACT: The objective of this study was to develop an in vitro protocol for the micropropagation of Pluchea sagittalis (Lam.) Cabrera. Plants were regenerated in vitro from stem segments. The procedure employed includes: 1) surface sterilization of shoots by immersion in 70% ethanol for 10 s followed by 1.0% NaOCl for 10 min, and subsequent immersion in 0.05% HgCl2 for 3 min and two washes with sterile distilled water; 2) induction of root and shoot by culture on hormone-free Murashige and Skoog medium (MS); 3) acclimatization of 60 day-old-plantlets in soil under ex vitro conditions. Minimum contamination was observed for apical shoot explants (10%). However, independently of the explant position in the stem, all explants regenerated new shoots. Various successive cultivations from stem explants every 60 days during more than 1 year have been shown to be a suitable method to propagate P. sagittalis in vitro. Low salt concentration (25% of the normal concentration) in the medium promoted greater growth of plantlets because the plants had a higher number of roots and longer roots in such an environment. Our protocol for the micropropagation of P. sagittalis can be accomplished as a two-step procedure within a short period of time (two months) before transplanting.
RESUMO: O Objetivo deste estudo foi desenvolver um protocolo para a micropropagação in vitro da Pluchea sagittalis (Lam.) Cabrera. Plantas foram regeneradas in vitro a partir de segmentos de ramo. O procedimento empregado incluiu: 1) esterilização da superfície de ramos pela imersão em etanol 70% por 10 s seguida pela de NaOCl 1.0% por 10 min e, subsequentemente, em HgCl2 0.05% por 3 min e duas lavagens em água destilada e esterilizada; 2) indução de raízes e parte aérea pelo cultivo em meio Murashige & Skoog (MS) isento de hormônio; 3) aclimatização de plantas com 60 dias de idade em solo sob condições ex vitro. Contaminação mínima foi observada em explantes caulinares do ápice (10%). Entretanto, independentemente da posição do segmento no caule, todos explantes regeneraram novos ramos. Vários cultivos sucessivos a cada 60 dias durante mais de um ano tem mostrado ser um método adequado para a propagação in vitro de P. sagittalis. A baixa concentração de sais no meio (25% da concentração normal) promoveu maior crescimento das plântulas devido às mesmas apresentarem maior número e comprimento de raízes. O protocolo para a micropropagação da P. sagittalis pode ser executado em procedimento de duas etapas dentro de um período de tempo curto (dois meses) antes do transplantio.