marker-assisted selection in wheat - ictsd

Chapter 2 – An assessment of the use of molecular markers in developing countries 23Apart from Australia, no countries inthe Southwest Pacific region report the useof molecular markers.In the Near and Middle East one report(CR Jordan, 2003) refers to molecularcharacterization and genetic distancestudies in indigenous goats, while another(CR Egypt, 2003) notes that molecularstudies of buffalo, sheep and goats hadrecently been initiated with the aid ofregional and international organizations.Survey on the use of molecularmarkers in genetic distancestudies in livestockMore specific and detailed information onthe use of molecular markers in AnGRresearch was obtained from a questionnairestudy launched in 2003. One hundredand thirty-two questionnaires were sentout via e-mail to research teams that hadbeen involved in genetic distance studiesduring the past ten years. The researcherswere identified through a literature searchand enquiry via several Internet discussiongroups. The points covered in thesurvey were: number of breeds and samplesizes; number and type of markers used;additional breed information such as phenotypictraits or geographic spread; andthe mathematical and statistical methodschosen for measuring genetic distance. Thestudy also aimed to verify the degree offamiliarity and acceptance of measurementof domestic animal diversity (MoDAD) recommendations,which had been proposedas standards for genetic diversity studiesby the International Society for AnimalGenetics (ISAG) and FAO about ten yearsearlier (FAO, 1998a; b). Compliance withthe recommendations was seen as importantas it would enable the compilationof results from different genetic distancestudies.Table 7Number of countries where samples werecollected for AnGR genetic distance studiesFAO regionNumber of countriesAfrica 13Asia and the Pacific 19Europe 37Latin America and the Caribbean 10Near East 9North America 2Total 93Information on 87 genetic distance studieswas obtained from 57 researchers. Thestudies covered breeds from 13 mammalianand avian species and investigated samplesfrom 93 countries; the largest number ofcountries was in Europe, followed by thosein Asia and the Pacific (Table 7). Most ofthe studies focused on ruminants. The sizeof the projects varied between one and120 breeds originating from up to 33 countries.However, a large number of nationalprojects focused on breeds within a specificcountry or region. There were also a fewlarge international projects involving cattleand goats (Table 8). A smaller number ofpig and chicken projects were implemented.No feedback was received regarding breedsof llamas, ducks, turkeys or geese.With regard to compliance with the recommendationsof the FAO/ISAG advisorygroup, 95 percent of all projects aimed tofulfil the minimum requirement of sampling25 animals per breed. Although microsatellitemarkers were used in 90 percent of thestudies, in only 23 percent were all markerstaken from the recommended marker list.In about 57 percent of studies some recommendedmicrosatellites were used. Thedegree of acceptance of the recommendationswas highest in pigs and lowest inchickens. More detailed information on theresults is given by Baumung, Simianer andHoffmann (2004) and FAO (2004).