The possibilities and challenges of in vitro methods for plant conservation

Abstract

Seed-based methods are generally the most efficient for propagating and storing plant germplasm, but these methods are not always adequate, and some species can benefit from in vitro methods for conservation. For species that produce few or no seeds in the wild, plants may be propagated in vitro, and in vitro shoot tips can provide material for cryostorage when seeds are not available or are recalcitrant. In vitro propagated plants may also serve as subjects for research, without depleting the genetic resources of the species. Clonal plants can be used to test out suitable habitat and can be used for basic research on endangered species, without disturbing the wild population. Despite the effectiveness of widely used techniques, however, there are still species that resist initiation into culture or that may be difficult to root or acclimatise. Similarly, tissue cryopreservation methods may be restrained by cost, particularly in maintaining multiple genotypes of many species. Maintaining such genotypes in vitro is also costly and runs the risk of loss or change over time. Examples of the successful use of in vitro methods will illustrate the variety of applications of these techniques, but costs and specific challenges will also be discussed to help define areas where further research is needed to realise the potential of in vitro methods as a tool for conservation.

Micropropagation of the Narrow Endemic Hladnikia pastinacifolia (Apiaceae)

“…Root development with an intermediary callus indicated that at that roots and shoots were not well connected with vascular tissue and that plants are insuffi ciently supplied with nutrients (George 1993). Successful rooting in other members of the Apiaceae family was also achieved with 1-5 μM IBA (Tavares et al 2010a, Das et al 2008, Jana and Shekhawat 2011, Coste et al 2012, Jaheduzzaman et al 2012, and with higher concentrations of IBA (Hossain et al 2000, Sharma and Wakhlu 2001, Banerjee et al 1999, Tavares et al 2009-2010, with NAA or IAA (Karuppusamy et al 2007, Jaheduzzaman et al 2012) and only rarely without growth regulators (Makunga et al 2003).…”

“…The other is connected with problematic seed germination established in the Apiaceae family (Hendrawati et al 2012, Baskin andBaskin 2014). For such exceptional botanical rarities, it is nowadays usual to apply, besides the conventional propagation methods, in vitro propagation methods, which provide an important opportunity for the propagation and preservation of endemic, rare and/or endangered plant species in general (Fay 1992, Rao 2004, Pence 2010, 2011, Cruz-Cruz et al 2013.…”

Conservación de plantas regeneradas in vitro y análisis de la variación somaclonal de Cinchona officinalis, Linneo

“…Esto puede estar provocando erosión genética (Rivera et al 2008) y disminución de las poblaciones naturales, haciendo que las que las especies se conviertan en vulnerables o amenazadas (Holobiuc et al 2009;Krishnan et al 2011), peligrando la permanencia en su hábitat natural. La conservación de las especies vegetales requiere de un enfoque integrado y complementario de las estrategias de conservación in situ y ex situ (Holobiuc et al 2009;Pence 2010). La conservación in situ, por sí sola puede no ser suficiente para mantener especies que se encuentran amenazadas (Sarasan 2010;) y no siempre son aplicables o adecuadas para muchas especies debido a su naturaleza o estado de amenaza (Pence 2010).…”

“…La conservación de las especies vegetales requiere de un enfoque integrado y complementario de las estrategias de conservación in situ y ex situ (Holobiuc et al 2009;Pence 2010). La conservación in situ, por sí sola puede no ser suficiente para mantener especies que se encuentran amenazadas (Sarasan 2010;) y no siempre son aplicables o adecuadas para muchas especies debido a su naturaleza o estado de amenaza (Pence 2010). La conservación in situ requiere de grandes espacios naturales, mano de obra e implica la participación e interacción de varias disciplinas como la ecología, el manejo de recursos naturales, la genética, entre otras (Radhamani & Sivaraj 2013).…”

In vitro propagation of Homalomena aromatica Schott., an endangered aromatic medicinal herb of Northeast India

“…As conventional propagation method through rhizome axillary buds is time consuming and provides a limited number of propagules, it is necessary to promote rapid production of H. aromatica through tissue culture techniques for its commercial availability and conservation. Tissue culture has been an effective technique to propagate endangered medicinal plants (Pence 2010). Despite the increasing commercial demand for H. aromatica, there are no reports for in vitro propagation of this plant.…”