Role of Plant Tissue Culture in Crop Improvement

Tobacco plant is one of the many agricultural crops that benefit from tissue culture.

In the agricultural world, there are over 150 plant species propagated exclusively, with many cultivars that portray various attributes. These attributes where obtained through genetic selection by cross pollination and cross breeding. These crop plants are reaching their limit of improvement, and that is where tissue culture comes into play. Tissue culture is a biotechnology that can produce new genetic variability, create healthy, virus-free material, rescue embryos that would otherwise abort and help to preserve strains of genetic material for generations to come.

Create Genetic Variability

There are many benefits to tissue culture, but one of the most important reasons for propagating plants this way is to introduce new genetic material into desirable lines of crops. During natural pollination, there are several steps that can take place to prevent the blending of two genes. In vitro fertilization and protoplast fusion can overcome these barriers to hybridization. Hybrid plants often exhibit new attributes that may be desirable in crop improvement, including disease resistance, drought tolerance, heavy flowering, early and larger yields and so forth. It is through this production of new genetic material that we gain improved cultivars.

Improve Plant Health

There are over 60 viruses and micoplasms that can infect strawberry plants, which necessitates replacing mother plants yearly. Tissue culture propagation can create virus-free planting material to plant breeders in large quantities economically. Plants that are grown from virus-free material produce larger amounts of food for longer periods of time. According to a 1995 article in the World Journal of Microbiology and Biotechnology, in China, virus-free potatoes grown from tissue culture in vitro resulted in 150 percent higher yields. Eradication of pathogens is a huge advancement in crop improvement.

Embyro Rescue

Thanks to embryo rescue technology, breeding new varieties of irises was shortened.

The most common reason for post-zygotic (after fertilization) failure is the abortion of the embryo due to poor endosperm development. Embryo rescue has eliminated this major barrier to hybridization and helped to reduce problems such as low seed set, poor germination and seed dormancy. For example, iris generally takes two to three years to complete a breeding cycle, but with embryo rescue techniques, that time is shortened to a few months. Many other crops benefit from this technology, including roses, orchids, cotton, barley, tomato, rice and many others.

Germplasm Preservation

Another major contributor to crop improvement is the ability to preserve germplasm. Germplasm is an alternative to seed banks and field banks of clonally propagated crops. The germplasm is stored in a low temperature in vitro, which virtually suspends the growth of the plant. Storage of germplasm helps to assure access and safe transportation of virus-free material. Germplasm preservation helps to manage all the physical outputs that tissue culture produces.

References

• Foundation for Biotechnology Awareness and Education; Applications of Biotechnology in Horticulture; Sukhada Mohandas
• World Journal of Microbiology and Biotechnology; Crop Improvement through Tissue Culture; D.C.W. Brown and T.A. Thorpe; 1995