[Music] modern agriculture is on the brink of a new era one that represents a Quantum Leap into the 21st century although there will always be a need for conventional agricultural methods there's no doubt that the Green Revolution of a quarter century ago is rapidly giving way to today's Gene Revolution the Cornerstone of this new biotechnology is the propagation method known as tissue [Music] culture tissue culture is a relatively new laboratory science which encompasses a variety of procedures and techniques simply stated tissue culture is the method by which plant and animal cells and tissues are grown on a sterile media until recently most tissue culture studies were directed at Medical and Drug research but now scientists are broadening their perspectives to utilize tissue culture in nearly all phases of Agriculture with tremendous possibilities for example animal scientists use tissue culture to accomplish Embryo transfer and Bine embryo division forestry professionals are using tissue culture to significantly increase productivity of Douglas fur and Lali Pine plantations and to quickly propagate Superior specimens of slow growing trees in the food industry tissue culture provides a means by which protein Rich sweeteners are being developed for baked goods jams ice cream and candies to raise the nutritional value of these Foods aided by tissue culture plant Pathologists have created experimental bacteria that inhibit Frost formation on plant leaves soon strawberries and other tender crops will be able to sustain temporary periods of low temperatures without damage crop scientists have made spectacular advancements through tissue culture researchers are working on tomatoes that withstand herbicide sprays and thrive in salty soils corn hybrids capable of producing their own nitrogen fertilizer and super grains that tolerate extended drought currently tissue culture is more widely used in commercial horiculture than in any other area of Agriculture it was the Orchid industry more than 25 years ago that first used tissue culture on a large scale orchids are notoriously slow to reproduce and their seeds produce variable plants to compound the problem orchids are extremely susceptible to virus infections that are easily passed through conventional propagation methods however by surface sterilizing the virus-free shoot tips of orchids and propagating them by tissue culture Growers are assured that the resulting plants are free of pathogens and identical to the original plant nursery professionals are finding that tissue culture produces these genetically identical plants quickly economically and with less labor space and Main maintenance than is needed by traditional methods for example one grower uses tissue culture to produce 1,000 dayes each week on just 30 square ft of shelf space another grower using conventional propagation methods would need a half acre to produce the same number of dayes tissue culture techniques also enable Growers to produce vast numbers of plants when mother stock is in short supply as another example Dutch iris normally produce about five daughter bulbs per year under Optimum conditions but with tissue culture you could produce several hundred Dutch iris from a single bulb within 3 months the potential for Rapid mass production uction makes tissue culture particularly appealing in commercial horiculture an Oregon Nursery produces 5 million certified tree root stocks each year while a foliage plant nursery produces 100,000 Boston Ferns each month one of the largest tissue culture labs in California plans to produce more than 25 million plants annually because tissue cultured plants have a guaranteed health status it's possible to transport plants into countries forly inaccessible due to strict quarantine regulations this means we can look forward to Rapid worldwide introduction of new and improved plants in the not too distant future on the research level horticulturists are using tissue culture to create new plants from totally unrelated families they're also able to alter the number of chromosomes in Plants they can breed plants with improved form Vigor and productivity techniques such as Gene transfer that were once regarded as science fiction have become Reality by fusing into one cell the contents of two genetically different cells researchers hope to produce a blue rose a blue crystal anthemum and flower colors coordinated to the season changing Fashions another new technique is called embryo rescue plants that fail to produce viable seed can be tissue cultured by this method before the fertilized ovary or immature seed degrades embryo rescue is a valuable tool in the production of New Lies with mutagenesis scientists can induce mutation in an effort to develop plants resistant to disease cold toxins and herbicides tissue culture also enables long and shortterm germ plasm storage with this method the genetic material of old and rare plants can be preserved from Extinction in production a rododendron nursery uses germ plasm storage to hold its weekly output of over 1,000 plantlets until the proper planting season rounding out the newer tissue culture techniques in horiculture is encapsulation this involves the formation of embryos from single identical cells in the laboratory the artificial embryos are coated with a gel that may contain fertilizers herbicides pesticides growth regul ators and fungicides the resulting seeds produce identical plants giving uniform results at low cost potentially any living cell in the tissue of any plant can grow into a normal plant through tissue culture because such small pieces of plant tissue are used in tissue culture the procedure is often referred to as a type of micropropagation it's equally well known as inv vitro propagation a Latin term meaning in glass in the beginning all of the plants produced by tissue culture were grown in glass test tubes jars or Petri dishes but today modern Plastics are used as well the tissue obtained from the mother plant is called an eggs plant the resulting offspring are called clones because they're genetically identical to the parent we've seen that tissue culture is having an important impact in the field of Agriculture we've seen several important advantages of production with tissue culture these include improved propagation efficiency the development of pathogen-free planting stock and the cap ability of storing germ plasm for later use propagation by tissue culture also produces plants that are the exact replicates of the mother stock now let's turn our attention to a laboratory's basic layout and the equipment used in propagating plants by tissue culture tissue culture Labs vary in size and sophistication however all Labs share several basic features whether large or small it's most important that aseptic working conditions are provided that is the laboratory must be free of bacteria fungi and other microorganisms all working surfaces tools and equipment are regularly sterilized and kept free of contamination that would hinder plant growth typically a tissue culture lab consists of three workspaces a preparation area a transfer room and a growth room the preparation area is the scientist's kitchen where plants equipment and the sterile nutrient media are ready for culturing look around and you'll find the basic tools and equipment used in the preparation area a refrigerator to store the chemicals a Precision scale for accurate measuring of ingredients a hot plate for heating media a pH meter to measure the alkalinity or acidity of the nutrient media and an autoclave to sterilize tools and glassware an autoclave is a pressurized steam sterilizer commonly used in commercial labs to save money some smaller Labs often use a pressure cooker for sterilizing tools and glassware through a restricted passage which minimizes the entry of airborn microorganisms we find the transfer room this is where the cultures are started divided trimmed and moved from one container to another in this room laminar airflow hoods called transfer Chambers continuously circulate clean air to remove dust particles and to provide a sterile working environment a dissecting microscope may be used to Aid in the accurate division of the cultures finally the cultures are moved to the growth room extensive shelving uniform fluorescent lighting regulated temperatures and filters to remove air born contaminants ensure rapid and Healthy Growth of the cultures adjacent to the laboratory an office provides easy access to records vitally important to the business of tissue culture and usually a greenhouse or a shade house is conveniently located so that newly cultured plantlets can be established in plugs or tubes and hardened off for shipping or sale the lab setup allows for the smooth flow of people cultures media and glassware from one area to another most critical is the movement of media from the preparation area to the transfer room and onto the growth room and then to the greenhouse or shade house needless contamination of the cultures and media can be prevented if the lab is entered through a hallway series of doors or the office to minimize infestation by Airborne microorganisms now that you're acquainted with the basic layout and equipment used in a tissue culture laboratory let's take a brief look at the four stages of the tissue culture process initiation proliferation pre-transplant and establishment in stage one the culture is initiated eggplants taken from the mother stock are cut disinfected and moved to a transfer chamber for insertion onto sterile nutrient media the tubes are capped and placed in the growth Room for 2 to 3 weeks when cultures reach sufficient size they enter stage two the proliferation stage at this time the plantlets are removed from the tubes and placed in larger containers with a scalpel each plantlet is divided into small sections and replanted onto a multiplication media then the containers are once again returned to the growth room for multiplication here the cultures remain for many months during which time the plants increase in number two to three times every 3 to 4 weeks they must be divided and transferred to Fresh media regularly during stage two after the last divisions are taken the pre-transplant stage Begins the goal of stage three is to harden the plants for conditions outside the laboratory this is done by using a nutrient media designed to stop multiplication and in some cases initiate Roots at this stage the intensity of light striking the plants is increased until stage three the plants haven't manufactured their own food through photosynthesis instead the nutrient media has been providing necessary carbon and energy for growth after approximately 3 weeks in stage three the plants enter the fourth and final stage of tissue Culture The Establishment stage in this final stage the plants are transplanted into growing media and exposed to Greenhouse conditions similar to Conventional vegetative propagation but with higher humidity and reduced light intensity than is found in a typical Greenhouse this adjustment stage May last 1 to 6 weeks we've just seen the four stages of tissue culture in the initiation stage eggplants are taken from the mother's stock and established on a sterile nutrient media in the proliferation stage the plantlets multiply and are divided and placed in a larger container in the pre-transplant stage the plants are hardened off for conditions outside the laboratory and in the establishment stage the plants are transplanted and established in a greenhouse or Nursery environment on the one hand tissue culture offers many advantages over traditional plant propagation space labor and maintenance needs are dramatically lessened and vast quantities of pathogen-free plants can be produced in a relatively short period of time with limited mother stock the procedure isn't affected by the changing seasons because work is done on the cellular level not with the whole organism tissue culture offers a time-saving alternative to Conventional cross breeding programs and makes combinations of totally unrelated plants possible it's also an efficient means by which genetic material can be stored for future study but there are stumbling blocks to preventing the more widespread use of tissue culture it's evident that startup costs for a facility and Equipment can be substantial also skilled labor is needed to ensure profitable results plants produced by tissue culture are initially quite small and must be given time to acclimate to conditions outside the lab any mistake in any stage of the procedure can cause contamination or genetic aberration ruining the crop if you were to pull commercial tissue culture Labs worldwide You' discover that these agricultural pioneers and anticipate a promising future tissue culture offers an efficient and economical solution to some of the major challenges facing all areas of agriculture in the 21st [Music] century [Music]