The Journal of Heredity 1984:75(6):426-430
© 1984 The American Genetic Association 75:426-430
research-article |
Variation in lettuce plants regenerated from protoplasts
Applied Genetics Laboratory, Agrigenetics Corporation 3375 Mitchell Lane, Boulder, CO 80301
Department of Plant Pathology, University of California Davis, CA 95616
Abstract
The variation demonstrated by regeneratIng 119 lettuce plants from mesophyll protoplasts of a single variety is described. Twenty regenerated plants had severely reduced fertility. Cytological analysis revealed that, for twelve of these, the reduced fertility probably is due to tetraploidly. Seed arising from self-pollinated, regenerated plants were significantly more variable in size than controls. Plants derived from these seed were examined for somaclonal variation, which occurred in two distinct patterns. Seedlings from 10 protoplast-derived clones segregated for mutant phenotypes in approximately 3:1 ratios suggesting single-gene recessive mutations. One additional clone family segregated for a mutant phenotype at maturity. Seedlings from two other clones were 100 percent variant. No obvious variation was seen in the remaining 58 clonal families that were subjected to field trials. One potentially useful variant was identified that appeared to have increased seedling vigor. The Implications of these findings with respect to the nature and usefulness of somaclonal variation are discussed.