Summary
The lettuce cv. Valentine regularly produces non-heading off-type plants at the relatively high frequency of 4 × 10−3. They result from mutation to the dominant condition. A similar propensity has been reported twice before in lettuce; it is highly heritable.
The propensity to produce off-types was not present in the parents of Valentine so it must have arisen during the pedigree breeding programme. Closely related cultivars do not carry the character but it was subsequently transmitted to Dandie a new cultivar of which Valentine was one of the parents. Allelism tests to relate Valentine off-types to those in crisphead cultivars were not successful.
The elimination of off-types in breeding programmes is discussed. Contrary to the findings in day-neutral crisphead cultivars, mutant phenotypes in long-day butterhead cultivars have no selective advantage for seed production. Consequently, strict roguing ensures adequate varietal stability.
Similar content being viewed by others
Literature
Bohn, G.W.; Whitaker, T.W.: Recently introduced varieties of head lettuce and methods used in their development. Circ. U.S. Dep. Agric. 881, 27 (1951)
Bremer, A.H.; Grana, J.: Genetische Untersuchungen mit Salat. II Gartenbauwissenschaft. 9, 231–245 (1935)
Dixon, G.E.; Lewthwaite, J.J.: Lettuce. Rep. Natn. Veg. Res. Stn., 1971, 29 (1972)
Jagger, I.C.; Whitaker, T.W.; Uselman, J.J.; Owen, W.M.: The Imperial strains of lettuce. Circ. U.S. Dep. Agric., 596, 15 (1941)
Lindqvist, K.: Inheritance studies in lettuce. Hereditas, 46, 387–470 (1960)
Maxon Smith, J.W.: The production, pedigrees and performance of four new glasshouse lettuce varieties. Hort. Res., 12, 127–140 (1972)
Maxon Smith, J.W.: Lettuce. Rep. Glasshouse Crops Res. Inst. 1973, 37 (1974)
Pearson, O.H.: The nature of the rogue in 456 lettuce. Proc. Amer. Soc. Hort. Sci. 68, 270–278 (1956)
Pearson, O.H.: Unstable gene systems in vegetable crops and implications for selection. Proc. Symposium Horticultural Plant Breeding. Hort. Science 3 (4), 271–274 (1968)
Raleigh, G.; Minotti, P.L.: Lettuce production in muck soils. Extension Bull. Cornell University Agric. Exp. Stn., 1194, 16 (1967)
Rodenburg, C.M. (Ed.): Varieties of lettuce, An international monograph. Varietal Description No. 3, I.V.T. Wageningen. N.V. Uitgevers-Maatschappij W.E.J. Tjeenk Willink, Zwolle, Holland; pp. 228 (1960)
Thompson, R.C.; Ryder, E.J.: Description and pedigrees of nine varieties of lettuce. Tech. Bull. U.S. Dep. Agric. 1244, 19 (1961)
Watts, L.E.: Synonomy in lettuce varieties. Rep. Natn. Veg. Res. Stn. 1954, 16–36 (1955)
Welch, J.E.; Grogan, R.G.; Zink, F.W.; Kihara, G.M.; Kimble, K.A.: Calmar — a new lettuce variety resistant to downy mildew. Calif. Agric. 19, 8, 3–4 (1965)
Whitaker, T.W.; Bohn, G.W.; Welch, J.E.; Grogan, R.G.: History and development of head lettuce resistant to downy mildew. Proc. Amer. Soc. Hort. Sci. 72, 410–416 (1958)
Author information
Authors and Affiliations
Additional information
Communicated by R. Riley
Rights and permissions
About this article
Cite this article
Maxon Smith, J.W. Recurring off-types in lettuce: Their significance in plant breeding and seed production. Theoret. Appl. Genetics 50, 79–87 (1977). https://doi.org/10.1007/BF00277250
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00277250