Efficient Micropropagation of Spilanthes acmella (L.) Murr.: A Threatened Medicinal Herb.

The present study describes an efficient and reproducible protocol for micropropagation of S. acmella. Shoot tips taken from 3 week-old aseptic seedlings were cultured on Murashige and Skoog (MS) semi-solid medium supplemented with different concentrations of TDZ. Among various concentrations, 0.25 μM TDZ was found to be optimum for shoot regeneration as it induced a maximum of 30.0 shoots per explant however with retarded growth (1.0 cm). Among different volumes of culture media, 15 ml liquid culture medium favored best response wherein a maximum of 80.2 shoots per explant with an average shoot length of 7.0 cm were induced after 6 week of subculturing. Successful in vitro rooting was induced on 2.5 μM NAA containing half-strength MS medium. Almost 96% rooted plants successfully transferred and acclimatized ex vitro under green house conditions. Morphological and physiological parameters compared with the in vivo-grown seedlings of the same age appeared to be ‘normal’ in respect to the fundamental characteristics examined.

Protocol for augmented shoot organogenesis in selected variety of soybean [Glycine max L. (Merr.)].

Development of a reproducible, versatile and efficient in vitro plant regeneration system is highly warranted for Indian soybean varieties for their mass multiplication in view of their commercial significance. Accordingly a protocol for direct shoot organogenesis in soybean variety JS 335 has been developed. Using cotyledonary node explants significant organogenic responses, mean shoot number and shoot length were observed when these were incubated on MS medium supplemented with 0.89 µM Benzyladenine (BA) and 5 μg/L triacontanol (TRIA) where in 9.3 ± 0.5 shoots were obtained. TRIA at 5 μg /L able to produce 6.8 ± 0.5 shoot buds in presence of 0.98 µM IBA and 0.89 µM BA. Highest mean shoot buds (14.0 ± 0.5 and 9.0 ± 0.5) and mean shoot length (4.6 ± 0.3 and 10.0 ± 0.7) were obtained when cotyledonary node and shoot tip explants were cultured on MS medium containing 0.14 µM gibberellic acid (GA3), 0.89 µM BA and 5 μg/L TRIA. Moreover, TRIA supported highest mean root number (6.3±0.5) and root length (21.5 ± 0.57 cm). Field survival of in vitro derived plants of TRIA treatment was 70% and the overall growth and seed yield was also significantly better than control plants. This protocol may be used for improving the in vitro regeneration of soybean variety JS 335 for transformation studies.

Organogênese a partir de segmentos foliares e internodais de videira cv. Merlot / Organogenesis from leaf segments and internodes of grapevine cv. Merlot

Objetivou-se, neste trabalho, estudar a indução da organogênese em segmentos foliares e internódios de videira cv. Merlot, utilizando diferentes tipos e concentrações de citocininas. O meio de cultura usado foi o MS com redução da metade dos sais e vitaminas, suplementado com 1 µM de ácido naftalenoacético (ANA). Os tratamentos consistiram das concentrações de 2,5; 5,0 ou 10 µM de 6-benzilaminopurina (BAP) ou 1-fenil-3-(1,2,3,-tiadiazol-5-il) uréia (TDZ). Foram avaliados o porcentual de formação de gemas, calos, oxidação e raízes, além do número de raízes e gemas. Aos 60 dias de cultivo in vitro foi observado que concentrações de 2,5-10 µM de BAP e TDZ permitem que segmentos foliares oxidem e não induzam à oxidação nos internódios. O nível de 5 µM de TDZ favore o maior porcentual de formação de gemas em internódios e segmentos foliares não apresentam capacidade para formar gemas nos níveis de 2,5-10 µM de BAP ou TDZ. O uso de BAP nas concentrações de 2,5 e 5 µM favorece altos porcentuais de enraizamento em internódios. O uso de TDZ no nível de 2,5 µM promove elevada taxa de formação de calos em internódios. Os internódios apresentaram maior capacidade organogênica do que os segmentos foliares.

The objective of this work was study the induction of organogenesis on leaf segments and internodes of grapevine cv. Merlot using different types and concentrations of cytokinins. MS half strength culture medium supplemented with 1 µM naftalenoacetic acid (NAA) was used. The treatments consisted of the concentrations of 2.5; 5.0 or 10 µM 6-benzilaminopurine (BAP) or thydiazuron (TDZ). The percentage of buds, callus, oxidation and roots as well as the number of roots and buds were evaluated. After 60 days of in vitro culture it was observed that the concentrations of 2.5-10 µM BAP or TDZ oxidize leaf segments and do not induce oxidation in the internodes. The level of 5 µM TDZ promote the largest formation of buds from internodes and leaf segments do not have capacity to form buds at the levels of 2,5-10 µM BAP or TDZ. The use of BAP at the concentrations of 2.5 and 5 µM promote high rooting percentage of internodes. TDZ at the level of 2.5 µM promotes high rate of callus formation in internodes. Internodes presented larger organogenic capacity than leaf segments.

Micropropagação de plântulas de erva-mate obtidas de embriões zigóticos / Micropropagation of holly plantlets obtained from zygotic embryos

O objetivo deste trabalho foi avaliar o potencial de micropropagação de erva-mate (Ilex paraguariensis Saint Hilaire) a partir de plântulas assépticas oriundas de embriões zigóticos imaturos. Ápices caulinares foram inoculados em meio base, formado por ¼ da concentração dos sais do meio MS, com diferentes doses de 6-benzilaminopurina (BAP). Ápices caulinares foram enraizados em meio base com diferentes doses de ácido indolbutírico (AIB) e avaliado o efeito do AIB do meio de enraizamento in vitro na aclimatização das plantas. O meio base com 8,88µM de BAP foi o mais efetivo para a multiplicação, promovendo o maior número e comprimento de brotações adventícias. Ápices caulinares enraizaram em 30 dias de cultivo em meio base, acrescido de 7,38µM de AIB. A dose de AIB utilizada no enraizamento in vitro interfere na aclimatização das plantas. A técnica de micropropagação descrita pode ser utilizada para a produção massal de plantas de erva-mate.

The aim of this research was to evaluate the micropropagation potential of holly (Ilex paraguariensis Saint Hilaire) aseptic plantlets derived from immature zygotic embryos. Shoot tip were inoculated in a quarter-strength MS basal medium with different doses of 6-benzylaminopurine (BAP) to induce multiple shoots. Shoot tips were inoculated in a basal medium with different doses of indol-butiric acid (IBA) for in vitro rooting and to test their effects in plantlet acclimatization. The addition of 8.88µM BAP to the basal medium increased the number of adventitious shoots and shoot height. Shoot tip rooted in basal medium with 7.38µM IBA in 30 days of culture. The IBA doses of the rooting medium affect plantlet acclimatization. The described micropropagation protocol might be used to produce a high number of holly plants.