Agricultural Biotechnology

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All living organisms have the ability,to improve themselves through. natural means in order to adapt to,changing environmental conditions. However it takes hundreds of years,before any detectable improvement. is obtained Man then learned how,to domesticate and breed plants. in order to develop crops to his,own liking and needs using various.
means including biotechnology,Biotechnology is defined as. a set of tools that uses living,organisms or parts of organisms. to make or modify a product,improve plants trees or animals. or develop microorganisms,for specific uses Agricultural. biotechnology is the term used in,crop and livestock improvement.
through biotechnology tools This,monograph will focus only on. agricultural crop biotechnology,Biotechnology encompasses a. number of tools and elements of,conventional breeding techniques. bioinformatics microbiology,molecular genetics biochemistry. plant physiology and molecular,The biotechnology tools that.
are important for agricultural,biotechnology include. Conventional plant breeding,Tissue culture and,micropropagation. Molecular breeding or marker,assisted selection,Genetic engineering and GM. Molecular Diagnostic Tools,SandraMatic Thinkstockphotos com. Conventional Plant Breeding, Since the beginning of agriculture eight to ten thousand years ago.
farmers have been altering the genetic makeup of the crops they. grow Early farmers selected the best looking plants and seeds and. saved them to plant for the next year The selection for features such. as faster growth higher yields pest and disease resistance larger. seeds or sweeter fruits has dramatically changed domesticated plant. species compared to their wild relatives Plant breeding came into. being when man learned that crop plants could be artificially mated. or cross pollinated to be able to improve the characters of the. plant Desirable characteristics from different parent plants could be. combined in the offspring When the science of plant breeding was. further developed in the 20th century plant breeders understood. better how to select superior plants and breed them to create new. and improved varieties of different crops This has dramatically. increased the productivity and quality of the plants we grow for. food feed and fiber, Conventional plant breeding Figure 1 has been the method. used to develop new varieties of crops for hundreds. of years However conventional plant breeding can,no longer sustain the global demand with the. increasing population decline in agricultural,resources such as land and water and the. apparent plateauing of the yield curve of,the staple crops Thus new crop. improvement technologies should be,developed and utilized.
Figure 1 Conventional breeding entails sexual hybridization followed by. careful selection,Source Alfonso A 2007,Mutation breeding. The art of recognizing desirable traits and incorporating them into future. generations is very important in plant breeding Breeders inspect their fields and. travel long distances in search of individual plants that exhibit desirable traits. A few of these traits occasionally arise spontaneously through a process called. mutation but the natural rate of mutation is very slow and unreliable to produce. plants that breeders would like to see, In the late 1920s researchers discovered that they could greatly increase the. number of these variations or mutations by exposing plants to X rays and. mutation inducing chemicals Mutation breeding accelerated after World War. II when the techniques of the nuclear age became widely available Plants were. exposed to gamma rays protons neutrons alpha particles and beta particles to. see if these would induce useful mutations Chemicals such as sodium azide and. ethyl methanesulphonate were also used to cause mutations Mutation breeding. efforts continue around the world today In the 73 years of mutation breeding. 1939 2013 a total of 3 218 varieties obtained through mutation breeding have. been registered in the IAEA database Staple crops such as rice has registered 824. varieties barley 312 wheat 274 maize 96 common bean 57 tomato 20. potato 16 sugarcane 13 soybean 2 as well as other important crops that. were improved to possess agronomically desirable charateristics. Pure line and hybrid seed technology, The end result of plant breeding is either an open pollinated OP for corn or. inbred for rice varieties or an F1 first filial generation hybrid variety OP and. inbred varieties when maintained and properly selected and produced retain the. same characteristics when multiplied, Hybrid seeds are an improvement over OP and inbred seeds in terms of yield. resistance to pests and diseases and time to maturity. Hybrid seeds are developed by the hybridization or crossing of diversely related. parent lines Pure lines are offsprings of several cycles of repeated self pollination. that breed true or produce sexual offspring that closely resemble their parents. Pure line development involves firstly the selection of lines in the existing. germplasm which express the desired characteristics such as resistance to pest and. diseases early maturity yield and others These traits may not be present in only. one line thus selected lines are bred together by hand In self pollinated plants. flowers are emasculated by removing the anthers or the male part of the flower by. hand and are pollinated by pollen from another line The female parent is usually. the line that possesses the desired agronomic trait while the male parent is the. donor of the new trait F1 first filial generation offsprings are planted and selfed. as well as the F2 generation Breeders then select in the F3 and F4 generation. the lines which exhibit their desired agronomic characteristics and the added. trait Testing for resistances to pests and abiotic stresses are conducted also at. this time Lines with desired traits and are rated intermediate to resistant tolerant. to the pests and abiotic stresses are selected and selfed in two to three more. generations Lines which do not lose the new traits and are stable are termed pure. In hybrid seed technology two pure lines with complementing traits and are. derived from diversely related parents are bred together by hand F1 hybrids are. tested for hybrid vigor in all agronomic and yield parameters and compared to. both parents The resulting offsprings will usually perform more vigorously than. either parents, Since the technology has been developed it has brought.
tremendous impact in major crops including rice corn wheat. cotton and other crops including many vegetables In the. USA corn yield from 1866 to 1936 was only 26 bu acre. Adoption of hybrid corn has increased corn yield by 0 8 bu. ac yr from 1947 1955 With improved genetics availability. of N fertilizer chemical pesticide and mechanization corn. grain yield has constantly increased by 1 9 bushels acre. year to become 115 bushels in 1990 s to an expected. increase of 159 bu acre in 2012 However with the Great. Drought in the US in 2012 grain yield was only 123 4 bu. acre In 2013 an increase of 50 bu acre of corn yield was. Hybrid rice technology helped China to increase production from. 140 million tons in 1978 to 188 million tons in 1990 Since then hybrid rice has. helped increase rice production which yields 1 35 to 2 tons hectare more than the. ordinary rice and hence an average yield of 7 2 to 7 5 tons hectare Hybrid rice. production area is expected to increase by more than 6 million hectares in 2012. In September 2012 Yuan Long pin the farther of hybrid rice has completed the. development of super rice DH2525 that sets a new record of hybrid rice yield at. 926 6 kg mu, During the 6th Hybrid Rice Symposium in India in September 2012 Indian. government and scientists realized the country s need to increase hectarage of. hybrid rice from 2 to 5 million hectares to be able to increase rice yield by 1 5 to. 2 million tonnes of rice every year and feed the teeming millions in the next 15 to. 20 years India has 59 hybrid rice varieties released form the public 31 varieties. and private 28 varieties institutions, With the proven impact of hybrid seed technology new tools for hybrid breeding. were discovered and utilized for self pollinating crops including cytoplasmic male. sterility cms Cytoplasmic male sterility is a condition where the plant is unable. to produce functional pollen and would rely on other pollen source to produce. seeds This greatly facilitates large scale hybrid seed production by passing hand. pollination, Current hybrid seed technology uses three lines in order to produce the hybrid. seed a the A line which contains a defective mitochondrial genome in the. cytoplasm and a suppressed restorer gene b the B line which is genetically similar. to the A line but contains a normal cytoplasm and a suppressed restorer gene and. c the restorer line a distinctly unrelated line which contains normal cytoplasm and. an active restorer gene dominant, The two line hybrid system another hybrid seed technology relies on temperature. and geographic location affecting the nuclear genome of the plant manifested. as male sterile Hybrid seed technology assures hybrid vigor in the progenies but. discovery and development of cms lines requires a lot of work and time. Figure 2 Pure line inbred line development,Hybridization.
Parent A X Parent B,Repeated self,pollination and,selection F3. Pure Stable,Source Alfonso A 2007,Conventional plant breeding. resulting in open pollinated,varieties or hybrid varieties. has had a tremendous impact,on agricultural productivity. over the last decades While,an extremely important tool.
conventional plant breeding,also has its limitations First. breeding can only be done,between two plants that can. sexually mate with each other,This limits the new traits. that can be added to those, that already exist in that species Second when plants are crossed many traits. are transferred along with the trait of interest including traits with undesirable. effects on yield potential Agricultural biotechnology is an option for breeders to. overcome these problems, Alfonso A 2007 Rice Biotechnology Presentation during PhilRice R D March 13 15 2007.
China sets new record in hybrid rice 19 September 2012 http www chinadaily com cn. business 2011 09 19 content 13735947 htm, Eckart N A 2006 Cytoplasmic male sterility and fertility restoration The Plant Cell 18 515. Food and Agriculture Organization 2002 Crop Biotechnology A working paper for. administrators and policy makers in sub Saharan Africa. Historical corn Grain Yields for Indiana and the US 2012 http www agry purdue edu ext. corn news timeless YieldTrends html, History of Plant Breeding http www colostate edu programs lifesciences TransgenicCrops. history html, Hybrid rice to be grown in 5 million hectares Ayyappan 11 Sept 2012 http www thehindu. com news states andhra pradesh hybrid rice to be grown in 5 million hectares. ayyappan article3882644 ece, Hybrid varieties and saving seed http aggie horticulture tamu edu plantanswers. vegetables seed html, International Atomic Energy Agency http www infocris iaea org MVD and click first on.
introduction and then on FAO IAEA Mutant Variety Database. International Rice Research Institute http www irri org. Kunz K ed 2002 East West Seeds 1982 2002 Vegetable Breeding for Market Development. Bangkok Thailand October 2002, Q A with the Father of Hybrid Rice 19 July 2012 http irri org index php option com. k2 view item id 12236 qa with the father of hybrid rice lang en. Schnable P S and R P Wise 1998 The molecular basis of cytoplasmic male sterility and. fertility restoration Trends in Plant Science 3 175 180. USDA Crop Production 213 Summary 2014 usda01 library cornell edu usda current. cropProdSu CropProdSu 01 10 2014 pdf, Yuan L P 2002 The second generation of hybrid rice in China Proceedings of the 20th. Session of the International Rice Commission Bangkok Thailand 23 26 July 20http www. fao org docrep 006 y4751e y4751e0f htm, Photos Page 1 nanoqfu Thinkstockphotos com amnarj2006 Thinkstockphotos com. Page 5 angorius Thinkstockphotos com,Page 7 joloei Thinkstockphotos com. Tissue Culture and Micropropagation, Plants usually reproduce through sexual means they have flowers.
and seeds to create the next generation Egg cells in the flowers are. fertilized by pollen from the stamens male part of the flower of the. same plant self pollination or another plant cross Each of these. sexual cells contains genetic material in the form of DNA During. sexual reproduction DNA from both parents is combined creating. offsprings similar to the parents in self pollinated crops or in new. and unpredictable ways creating unique organisms in cross pollinated. crops Some plants and trees on the other hand need several years. before they flower and set seeds making plant improvement difficult. Plant scientists have developed the science and art of tissue culture to. assist breeders in this task, Tissue culture is the cultivation of plant cells tissues or organs on. specially formulated nutrient media Under the right conditions an. entire plant can be regenerated from a single cell. Plant tissue culture is a technique that has been,around for more than 30 years There are several. A Lot More than Just GM Crops Agricultural Biotechnology 2 All living organisms have the ability to improve themselves through natural means in order to adapt to changing environmental conditions However it takes hundreds of years before any detectable improvement is obtained Man then learned how to domesticate and breed plants in order to develop crops to his own liking and needs using

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