Innovations in Tissue Culture Technology and the Impact on the CBD Industry

Tissue culture is the in-vitro aseptic culture of cells, tissues, organs or whole plant under controlled nutritional and environmental conditions often to produce the clones of plants. The resulting clones are a true-to-type of the selected genotype. Tissue culture (TC) can also be described as the cultivation of plant cells, tissues, or organs on specially formulated nutrient media.

Tissue culture is seen as an essential technology for developing countries for the production of disease-free, high-quality planting material and the rapid creation of many similar plants.

Micro-propagation is defined as a form of tissue culture, which inflates the amount of planting material for large scale planting to facilitate distribution. In this way, thousands of copies of a plant can be produced in a very short period of time, Micro-propagated plants are observed to establish more quickly, grow more vigorously and are taller, have a quicker and more regular production cycle, and produce higher yields than conventional propagules.

The controlled conditions provide the culture with a very conducive environment for multiplication and growth. These conditions include the proper supply of nutrients, pH medium, adequate temperature, and appropriate liquid and gaseous area.

Quantity:

Plant tissue culture technology has widely been used to produce large scale plant multiplication. Apart from their use as a tool of research, plant tissue culture techniques have in recent years, become of primary industrial importance in the area of plant propagation, disease elimination, plant improvement and production of secondary metabolites. Small pieces of tissue (called explants) can be used to produce hundreds and thousands of plants in a continuous process. A single explant can be multiplied into several thousand plants in a relatively short period and space under controlled conditions, irrespective of the season and weather on a year-round basis. Endangered, threatened, and rare species have successfully been grown and conserved by micropropagation because of the high coefficient of multiplication and small demands on several initial plants and space.

Quality:

Also, plant tissue culture is considered to be the most efficient technology for crop improvement by the production of somaclonal and gametoclonal variants. The micropropagation technology has a vast potential to produce plants of superior quality, isolation of useful options in well-adapted high yielding genotypes with better disease resistance and stress tolerance capacities. The specific type of callus cultures gives rise to clones that have inheritable characteristics different from those of parent plants due to the possibility of occurrence of somaclonal variability, which leads to the development of commercially critical improved varieties. Commercial production of plants through micropropagation techniques has several advantages over the traditional methods of propagation through seed, cuttings, grafting, and air-layering, etc. It is rapid propagation processes that can lead to the production of plants virus-free. Coryodalisyanhusuo, an important medicinal plant was propagated by somatic embryogenesis from tuber-derived callus to produce disease-free tubers. Meristem tip culture of banana plants devoid from a banana bunchy top virus (BBTV) and brome mosaic virus (BMV) were created. Higher yields have been obtained by culturing pathogen-free germplasm in vitro. An increase in yield up to 150% of virus-free potatoes was obtained in controlled conditions. The main objective of writing this chapter is to describe the tissue culture techniques, various developments, present, and future trends and its application in multiple fields.

History of the tissue culture:

The science of plant tissue culture takes its roots from the discovery of cells followed by propounding of cell theory. In 1838, Schleiden and Schwann proposed that the cell is the basic structural unit of all living organisms. They visualized that the cell is capable of autonomy and therefore, it should be possible for each cell if given an environment to regenerate into the whole plant. Based on this premise, in 1902, a German physiologist, Gottlieb Haberlandt for the first time attempted to culture isolated single palisade cells from leaves in knop’s salt solution enriched with sucrose. The cells remained alive for up to one month, increased in size, accumulated starch but failed to divide. Though he was unsuccessful but laid down the foundation of tissue culture technology for which he is regarded as the father of plant tissue culture.

Plant tissue culture is a straightforward technique, and many developing countries have already mastered it. Its application only requires a sterile workplace, nursery, and greenhouse, and trained human resources. Unfortunately, tissue culture is labor-intensive, time-consuming, and can be costly. Plants important to developing countries that have been grown in tissue culture are oil palm, plantain, pine, banana, date, eggplant, jojoba, pineapple, rubber tree, cassava, yam, sweet potato, and tomato. This application is the most commonly applied form of traditional biotechnology in Africa.

Uses of TC technology in Asia

Tissue culture has been refined to suit the needs of orchid species and hybrids known to grow well in Southeast Asia. Judging from the experience of Thailand, Singapore, and Malaysia, the ornamental and cut flower trade is a substantial source of foreign exchange and additional income for small growers.

In Thailand, tissue culture is used to reproduce slow-growing and environment-sensitive orchids. Thailand is the leader in tissue culture in Southeast Asia, producing 50 million plantlets a year. Most of these are orchids, which have helped the country become the biggest exporter of whole and cut orchids in the world.

Propagation by shoot culture technique has been developed for the mass proliferation of banana. In the Philippines, this is used as a control approach to viral diseases in banana such as banana bunchy top virus (BBTV) and banana bract mosaic virus (BBrMV), which are commonly spread through propagative materials.

Hemp cultivators turn to tissue culture to increase propagation levels, preserve genetics
Hemp cultivators have long relied on cloning as a way to propagate plant inventory and preserve their genetics. Still, the practice of taking a rooted cutting from a mother plant may be giving way to a new method of maintaining a plant’s genetics: tissue culture.

Plant tissue culture is a collection of techniques harnessed to maintain or grow plant cells, tissues or organs under sterile conditions in culture media, a vibrant blend of ingredients that promote plant-cell growth.

These ingredients can include macro-nutrients, micro-nutrients, vitamins, agar and activated charcoal, and they can be blended in-house or found in commercial blends such as Murashige and Skoog. The process is widely used to produce plant clones utilizing a method known as micropropagation.

“These techniques are done in Big Ag, the food industry. We’re just adapting what’s already out there,” said Hope-Jones, CEO of Emergent Cannabis Sciences, a cannabis consulting firm in Phoenix specializing in tissue culture.

Tissue culture advantages

The advantages of tissue culture versus cloning are stark, horticulture experts say, including:

• Significantly more efficient and prolific plant production, enabling growers to save money and increase revenue
• The ability to better preserve cannabis genetics
• More vigorous plants than those that come from clones

Tissue culture also lends itself to multiple business models. A small number of cannabis cultivation companies have adopted tissue culture as a way to increase plant counts. In contrast, ambitious entrepreneurs have started nurseries to supply hemp farmers small and large.
It can also be used by small growers to preserve genetics or for proof-of-concept efforts that show how strains can be replicated through tissue culture.

But setting up a tissue-culture shop requires expertise, time and capital – tens or hundreds of thousands of dollars, depending on the size of your business, your goals and where you get your equipment and labor.

If done correctly, an investment in tissue culture can take you to grow to a new level. Mostly anyone who has the desire, the willingness and some funds to designate this can do it. Who should do it? That depends on what their goals are.

There is also less genetic variation in plants grown from tissue culture than plants clipped from mother plants.

Adaptable for multiple companies

Another advantage of a tissue-culture operation is that it requires less space than clones do. Grant Guelich, a cannabis consultant for Vancouver, British Columbia-based Weekend Unlimited, estimated that outfitting a tissue-culture space costs about 75% more than an area needed to produce an equivalent number of clones; the tissue-culture area, however, will be roughly 10% the size of the space necessary for clones.

For example, making 2 million clones yearly with traditional methods would require a 30,000-square-foot space; with tissue cultures, it only requires 2,000-3,000 square feet, Guelich estimated.

Large Canadian marijuana cultivators such as Canopy Growth, Hydropothecary, and AgMedica Bioscience are setting up tissue-culture operations to produce at least some of their plants.

They also see it as a way to outproduce the competition in a national marketplace. Others like Front Range Biosciences in Lafayette, Colorado, have harnessed tissue culture to start nurseries that provide cannabis plants to farmers.

Under its model, Front Range breeds high-CBD strains and then uses tissue culture to micro propagate those strains to produce young plants that are sold to farmers.

On the production side, tissue culture is a tool to produce cleaner, healthier, more efficient plants. Tissue culture can also be useful to growers or others who may not want to scale but would use the procedure to preserve their plant genetics.