The apical bud as a novel explant for high-frequency in vitro plantlet regeneration of Perilla frutescens L. Britton

Abstract

In this study, we established an in vitro regeneration system to maximize the recovery of leafy perilla (Perilla frutescens L. Britton) plantlets as part of developing a molecular biotechnology-based metabolic engineering program for this crop plant. Hypocotyl segments including the apical buds were used as explants for the direct production of shoots without an interim callus phase. The number of shoots produced from the apical buds peaked within 3-4 weeks, and the shoots were subsequently cultured on Murashige and Skoog (MS) media supplemented with 2 mg l -1 benzylaminopurine (BA). Spontaneous rhizogenesis was observed after 7-10 days of culture on MS media without hormonal additives. The rooted shoots developed into normal plants in soil after hardening on distilled water for 3-4 days. The average plantlet regeneration frequency was higher for the apical buds (64.33%) than for the top (15.66%), middle (4%), and basal (1.33%) segments of the hypocotyls. This regeneration system demonstrates a capacity for high-frequency plantlet recovery and thus should be considered for use in the genetic manipulation of leafy perilla.

Methods of asepsis for in vitro establishment and germination of Eucalyptus grandis

“…The process for the establishment of Eucalyptus in vitro using seeds has been laborious mainly due to the size of them and the method of processing that generate a mixture with high amount of inert materials, which may be responsible for the simultaneous inoculation of bacteria and fungi, and in turn delay in the establishment of seed culture medium in vitro. In vitro tissue culture is important to offer high rates of multiplication from segments of tissue, however it is also an efficient tool for obtaining large numbers of individuals free of contaminating sources (Dutra et al, 2009;Hossain et al, 2010;Hung and Trueman, 2010;Silva et al, 2010;Silva et al, 2011). Since the seeds of Eucalyptus are subjected to intense exchange of germplasm, methods of seed cultivation in vitro offer alternatives to mitigate these problems, limiting the spread of pests and diseases such as rust.…”

Aspectos morfofisiológicos na clonagem de Eucalyptus benthamii

“…Considerando o estabelecimento in vitro de segmentos nodais de E. benthamii, os valores foram semelhantes aos reportados na literatura BRONDANI et al, 2011;PENCHEL, 2007), os quais podem ser considerados elevados e adequados para a micropropagação de Eucalyptus Em termos de controle morfogênico na fase de multiplicação de gemas (axilares ou adventícias), os reguladores mais usados em variadas combinações referem-se a auxinas e citocininas (DAVEY; ANTHONY, 2010; GEORGE; HALL; HOSSAIN;KIM;LEE, 2010;PAPP;PLATH;2011 ARYA et al, 2009;BISHT et al, 1999;BRONDANI et al, 2011;JOSHI et al, 2003;RAMAMURTHY, 2000). O ajuste das curvas de superfície de resposta também foi eficiente para auxiliar na estimativa dos pontos próximos ao ótimo das combinações dos reguladores de crescimento (platô), apresentando coeficientes de determinação adequados para explicar o comportamento dos clones em relação as combinações de reguladores de crescimento.…”