Influence of germination date on survival and fecundity in wild lettuce Lactuca serriola [seed, seedlings, germination peaks, mortality, plant density, fertility, England, UK]
1981
Marks, M. (Calabar Univ. (Nigeria). Dept. of Biological Sciences) | Prince, S.
Lactuca serriola L. seedlings emerge throughout the year with germination peaks in early winter and late spring. These peaks are followed closely by high levels of mortality which together produce an almost constant plant density. Plants from seeds which germinate in the winter months produce more seeds than those which germinate in spring and summer and this is considered to be associated with the duration of the rosette stage. However, the increased fecundity of the former is partially annulled by their higher mortality. It is concluded that the winter-germinated plants are the main seed producers while those which germinate in spring and summer may act as insurance against complete loss of the more fecund individuals.
显示更多 [+] 显示较少 [-]