ADDIS ABABA UNIVERSITYSCHOOL OF GRADUATE STUDIESPlant Biology and Biodiversity ManagementProgramme UnitCrop DiversityName. ZewdeAchisoID. No.GSR/0865/05June,2013
Outline Introduction Crop Diversity and their Role in sustaining Food securityDiversity in major and minor crops in EthiopiaConservation Strategies to Maintain Crop DiversityWhy Diversity of Crop Matters?Types of conservation In-situ conservationEx-situ conservationBenefits and Challenges of in-situ and ex-situ conservationValue of conserving crop diversity
IntroductionLife is all around us. From the microbes in our gut, the insectscrawling in our garden soil , the garden and wild variety ofplants to the largest mammal on earth -the blue whales.In other words, Biodiversity is the variability among livingorganisms from all sources, including terrestrial, marine,and other aquatic ecosystems and the ecologicalcomplexes of which they are part: This includes diversity within species, between speciesand ecosystems.It is both essential for our existence and intrinsically valuable inits own right.Because it provides the fundamental building blocksfor goods and services a healthy environment provides
Agro-biodiversity is subpart of biodiversity thatincludes all the components of biological diversity ofrelevance to food and agriculture, andCrop diversity refers to the biological diversity foundin crops used for food and agriculture.It is sometimes referred to as `plant geneticresources for food and agriculture.This diversified crops and other plant species helpour ecosystem function; Basically to fix nitrogen, sequester carbon dioxideand stabilize soils,Directly or indirectly providing us with medicines,building materials, lubricants, resins, waxes,perfumes, dyes, fibers and, of course, food.Cont---
cont--- Diversity of crop both in landraces and in their wildrelatives provide important resources for Food security, Environmental sustainability andEconomic stability.Generally crops have values, like social, cultural,economic, and ecological and based on this valueswe will try to focus on the following pointsWhat crop diversity is, Diversity in major and minor crops,The role of crop diversity,Conservation strategies to maintain their diversity,Their benefits and challenges andValue of conserving crop diversity
Crop diversity embraces the great variety within andbetween crops and their wild relatives.These varieties evolved over thousands of years in adynamic interaction between nature and farmers’ carefulselection and breedingAbout 7,000 plant species have been used for humanconsumption, but only four crops (wheat, maize, rice and potato) provideone-half of the total world food production andOnly 15 crops contribute two-thirds of the world population Crop Diversity and their Role in sustaining Food securitywheat maize rice potato
Diversity in major and minor crops inEthiopiaEthiopia is one of the richest genetic resource centers inthe world.This is principally attributed to the diversefarming systems, socio-economics, cultures and agro-ecologies.Crop plants such asCoffee (Coffea arabica),Safflower (Carthamus tinctorius),Tef (Eragrostis tef),Noug (Guizotia abyssinica), Anchote (Coccinia abyssinica),Enset (Ensete ventricosum), are known to haveoriginated in Ethiopia.
The four of the world’s widely grown food cropswheat, barley, sorghum and peas;The three world’s most important industrial crops linseed, castor and cotton;The most important cash crop (coffee) in the world; The number of food crops of regional and local importance Tef, Noug, Ethiopian mustard, Enset, Fingermillet, Cowpea, Lentil, andNumber of forage species of world importanceClovers, Medics, OatsGenerally Ethiopia is center of major and minor crops originand diversificationWhy Diversity of Crop Matters? Diversity is necessary to furnish new genes for crop improvementcont---
Conservation is crucial because the extent of diversityshows declining by the advancement of geneticallyuniform improved cultivars.The two forms of diversity are diversity among crops andwithin cropWider diversity is needed to meetHuman nutritional needsDependence on too few varieties is Dangerous because disease orPests can spread rapidly in genetically uniform cropBlack rot on carrot (left), nematode injury to carrots (middle),carrot weevil injury (right)
Most widely accepted scientific methods of biodiversityconservations are:(I)In situ methods & (ii) Ex situ methodsConservation Strategies to Maintain CropDiversity
Benefits and Challenges of in-situ and ex-situ conservationBoth conservation methods have their own benefits anddrawbacksThe merits of in situ conservation includesAvoidance of storage problems associated With field gene banks and Recalcitrant seeds, Allowance of evolution and Enhancement to continue through exposure to pest and Diseases and other environmental factors,Indirect benefits, like ecosystem support and the likeBut ex-situ conservation has advantages ofRescue of threatened germplasm, Requires limited space and, conserves adequaterepresentativeEase of accessibility and exchange of germplasm,Ease for documentation, no exposure to pests, disease andother hazards and more cost effectiveHowever, both methods have their own drawbacks
Value of conserving crop diversityAttaching the value of crop diversity is a complex task,But describing the kinds of benefits associated with theseresources is easierThe simplest benefit arises from the direct use of crop diversityProducing food and fiber orEvolving new varieties of crops andLivestock.Benefits of crop varieties can be measured inIncreased output,Higher quality, andBetter resistance to pests, diseases, stressCrop genetic resources are the basis from which all cropproduction stems andHaving large amount single crop can not satisfy the necessity ofhuman being ( see the above figure)But habitat loss, the dominance of scientific breed over farmer-developed varieties, and genetic uniformity are all threats tocontinued diversity
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