SEED DORMANCY IN LETTUCE: INFLUENCE OF TEMPERATURE ON INDUCTION AND EXPRESSION OF SEED DORMANCY AND STUDIES ON THE INHERITANCE

A.H. Eenink
Seed dormancy causes large problems for lettuce growing. Limited information was available of environmental influences on a) the induction of seed dormancy during seed formation and b) the expression of dormancy after imbibition.

It appeared that certain temperatures, such as e.g. a constant temperature of 20°C, induced a clear distinction for degree of dormancy between lettuce cultivars (cvs Magiola and Portato dormant and cvs Deci-Minor and Valore non-dormant). This distinction was optimal at e.g. 23°C during imbibition.

Diallel crosses were carried out between the above four lettuce cultivars to study the inheritance of dormancy.

F1 seeds from crosses between dormant x non dormant cultivars showed a large variation for dormancy compared to the variation of the homozygous parents. The germination time - counted from the beginning of imbibition - was usually intermediate between the dormant and the non-dormant parent. About 40–60% of the F2 seeds from the above crosses germinated within 6–8 days. In F2's from crosses between dormant cultivars (Portato x Magiola) no rapidly germinating seeds were found while in F2's from crosses between non-dormant cultivars (Deci-Minor x Valore) no accumulation of genes for dormancy was found. Comparison of the degree of dormancy of F2 seeds and corresponding F3 progenies from crosses between dormant and non-dormant cultivars showed that h2-narrow was rather large (0.4–0.5) which enables a succesful selection for non-dormant genotypes.

On the basis of the behaviour of the F1, F2 and F3 seeds it is not unlikely that the dormant cultivars (Magiola and Portato) and the non-dormant cultivars (Deci-Minor and Valore) differ for one major gene for dormancy maybe accompagnied by modifier genes.

Eenink, A.H. (1981). SEED DORMANCY IN LETTUCE: INFLUENCE OF TEMPERATURE ON INDUCTION AND EXPRESSION OF SEED DORMANCY AND STUDIES ON THE INHERITANCE. Acta Hortic. 111, 41-46
DOI: 10.17660/ActaHortic.1981.111.4
https://doi.org/10.17660/ActaHortic.1981.111.4

Acta Horticulturae