title: Induced mutations in cassava using somatic embryos and the identification of mutant plants with altered starch yield and composition.
abstract: A cyclic somatic embryogenic system was used to induce mutations in cassava variety PRC 60a in vitro. Globular-stage somatic embryos were selected as suitable experimental materials, and 50 Gy of gamma-rays was determined to be the optimal dose for inducing mutations. During subsequent field trials, more than 50% of the regenerated mutant lines varied morphologically from wild-type plants. Consequently, we used this approach to induce genetic variability for obtaining novel cassava cultivars. Among the different mutant lines obtained, lines S14 and S15 showed large morphological variations. In 10-month-old S14 and S15 mutant lines, storage root yield was reduced 17-fold and 60-fold, respectively, compared to wild-type plants, while the storage roots of S15 mutant plants also exhibited an almost 50% decrease in starch content and a significant reduction (30%) in amylose content. These two features were observed throughout the different developmental stages of the storage roots in S15 plants.
authors.affiliation: Department of Biological Sciences, 14 Science Drive 4, National University of Singapore, 117543, Singapore.
authors.forename: Roy
authors.initials: R
authors.lastname: Joseph
authors.forename: Hock-Hin
authors.initials: HH
authors.lastname: Yeoh
authors.forename: Chiang-Shiong
authors.initials: CS
authors.lastname: Loh
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000494:pharmacology; D000225:Adenine / Q000031:analogs & derivatives* / Q000494:pharmacology; D001593:Benzyl Compounds; D015536:Down-Regulation / Q000235:genetics; D005020:Ethyl Methanesulfonate / Q000494:pharmacology; D005720:Gamma Rays; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D005818:Genetic Engineering / Q000379:methods*; D014644:Genetic Variation / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D007211:Indoles / Q000494:pharmacology; D007701:Kinetin; D002365:Manihot / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D016296:Mutagenesis / Q000187:drug effects / Q000528:radiation effects; D009154:Mutation; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects; D011687:Purines; D012639:Seeds / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects; D013213:Starch / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*
chemical_list: D001593:Benzyl Compounds; D007211:Indoles; D011687:Purines; C014612:indolebutyric acid; D015084:2,4-Dichlorophenoxyacetic Acid; D013213:Starch; D005020:Ethyl Methanesulfonate; D000225:Adenine; C480551:benzylaminopurine; D007701:Kinetin