Induced mutations in cassava using somatic embryos and the identification of mutant plants with altered starch yield and composition

• Published in: Plant cell reports 2004-08, Vol.23 (1-2), p.91-98
• Main Authors: Joseph, R, Yeoh, H.H, Loh, C.S
• Format: Article
• Language: English
• Subjects: 2,4-Dichlorophenoxyacetic Acid - pharmacology; Adenine - analogs & derivatives; Adenine - pharmacology; Benzyl Compounds; Biological and medical sciences; biosynthesis; Biotechnology; carbohydrate composition; Cassava; Cultivars; Developmental stages; Down-Regulation - genetics; Embryos; Ethyl Methanesulfonate - pharmacology; Eukaryotic cell cultures; Fundamental and applied biological sciences. Psychology; gamma radiation; Gamma Rays; Gene Expression Regulation, Plant - drug effects; Gene Expression Regulation, Plant - genetics; Gene Expression Regulation, Plant - radiation effects; Genetic Engineering - methods; Genetic Variation - drug effects; Genetic Variation - genetics; Genetic Variation - radiation effects; in vitro regeneration; Indoles - pharmacology; Kinetin; Manihot - genetics; Manihot - growth & development; Manihot - metabolism; Manihot esculenta; Methods. Procedures. Technologies; micropropagation; Miscellaneous; Mutagenesis - drug effects; Mutagenesis - radiation effects; Mutants; Mutation; Plant cells and fungal cells; plant morphology; Plant Roots - growth & development; Plant Roots - metabolism; Plant Roots - radiation effects; Purines; Roots; Seeds - growth & development; Seeds - metabolism; Seeds - radiation effects; somatic embryogenesis; somatic embryos; Starch; Starch - biosynthesis; Starch - chemistry; Starch - genetics
• ISSN: 0721-7714; 1432-203X
• DOI: 10.1007/s00299-004-0798-7

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.