Sandalwood: basic biology, tissue culture, and genetic transformation

Abstract

Sustainable resource preservation of Santalum species that yield commercially important forest products is needed. This review provides an understanding of their basic biology, propagation, hemi-parasitic nature, reproductive biology, and biotechnology. Many species of the genus Santalum (Santalaceae) have been exploited unremittingly for centuries, resulting in the extinction of one and the threatened status of three other species. This reduction in biodiversity of sandalwood has resulted from the commercial exploitation of its oil-rich fragrant heartwood. In a bid to conserve the remaining germplasm, biotechnology provides a feasible, and effective, means of propagating members of this genus. This review provides a detailed understanding of the biological mechanisms underlying the success or failure of traditional propagation, including a synopsis of the process of hemi-parasitism in S. album, and of the suitability of host plants to sustain the growth of seedlings and plants under forestry production. For the mass production of economically important metabolites, and to improve uniformity of essential oils, the use of clonal material of similar genetic background for cultivation is important. This review summarizes traditional methods of sandalwood production with complementary and more advanced in vitro technologies to provide a basis for researchers, conservationists and industry to implement sustainable programs of research and development for this revered genus.

Building a Genetic Manipulation Tool Box for Orchid Biology: Identification of Constitutive Promoters and Application of CRISPR/Cas9 in the Orchid, Dendrobium officinale

“…Compared with other Orchidaceae species, the sequenced and annotated genome of D. officinale (Yan et al, 2015; Zhang G.Q. et al, 2016), and the well-established transformation systems of the Dendrobioum genus (Teixeira da Silva et al, 2016) make it an ideal genetic manipulation model for the Orchidaceae family.…”

Date palm ( Phoenix dactylifera L.) biotechnology: a mini-review

“…In a bid to establish a production system for the Pakistani date palm market based on micropropagation, this mini-review focuses on the key aspects of date palm tissue culture focusing on selected studies to exemplify core concepts and tissue culture steps and is not meant to be an exhaustive description of the date palm literature. A successful tissue culture procedure involves the selection of a suitable explant, an effective disinfection procedure, and in vitro protocols that will result in the desired outcome such as plantlet production, which can be particularly difficult for tree species (Teixeira da Silva et al, 2016a). Applied biotechnologies such as genetic transformation require a well-established tissue culture protocol.…”

Sandalwood spike disease: a brief synthesis

“…and Indian sandalwood plantations throughout the Indian subcontinent and the Pacific (Teixeira da Silva et al 2016), greater research into the causal agents, methods of transmission, molecular mechanisms underlying infectivity and methods to control or eradicate SSD would be beneficial. Research into SSD has stagnated in recent years, restricted to a very limited number of laboratories, primarily in India.…”

“…Therefore, sustainable cultivation methods are required for the large-scale propagation and production of disease-free S. album plants. This can be successfully achieved using biotechnological approaches such as tissue culture (Teixeira da Silva et al 2016). The survival and growth of seedlings, or of tissuecultured plantlets at the ex vitro stage, even those with an established root system, can be a difficult task due the hemiparasitic nature of S. album, which requires one or more specific hosts (Teixeira da Silva et al 2016).…”

“…This can be successfully achieved using biotechnological approaches such as tissue culture (Teixeira da Silva et al 2016). The survival and growth of seedlings, or of tissuecultured plantlets at the ex vitro stage, even those with an established root system, can be a difficult task due the hemiparasitic nature of S. album, which requires one or more specific hosts (Teixeira da Silva et al 2016). There is evidence that S. album is susceptible to various insect pests (Sundararaj, Muthukrishnan 2011) and to sandalwood spike disease (SSD) (Arun Kumar, Joshi 2012;Kumar 2014).…”