No abstract

No abstract

No abstract

No abstract

The eects of vernalization and photoperiod on¯owering time were studied in Stellaria media (L.) Vill., Stellaria neglecta Weihe and Stellaria pallida (Dumort.) Pire collected from various habitats in Kyoto, Japan. Short-and long-day treatments had little eect on¯owering in all strains of the three species. In two strains of S. media from riverside habitats and all strains of S. neglecta, the cohorts that were sown early in the autumn under natural conditions required a longer time to¯ower and had the ®rst¯ower at a higher node position than the cohorts that were sown later. When grown in the greenhouse (minimum temperature >10°C) these strains required a larger estimated thermal time than under natural conditions or did not produce¯ower buds at all, showing a requirement for vernalization. In comparison, most strains of S. media and all strains of S. pallida produced the ®rst¯ower at almost the same node position independent of sowing time, and showed no requirement for vernalization. The strains of S. media from vegetable ®elds required a smaller thermal time than those from ruderal or semi-natural habitats. This observation was also true even after the non-agrestal strains had been adequately vernalized.