Seed Germination in Plantago asiatica L. as Affected by Environmental Factors during Seed Development

Abstract

Seeds ofPlantago asiaticawere collected from population growing in a certain site at the end of each month from July to November. The sampling seeds matured within the month when they were harvested, because all of the seeds matured in the preceding month had been previously taken off. When germination rates were determined a week after the begining of incubation, all lots of the seeds, regardless of the harverting month, maintained a high level of germination at 25°C under illumination.Incubating at 20°C under illumination or 25°C in darkness, the seeds harvested in autumn showed higher percentage of germination than the ones in summer.
The parental plants were exposed to four controlled environmental conditions, long day (LD : 16 hr photoperiod) -high temperature (HT : day/night temperature of 30/20°C), short day (SD: 8 hr photoperiod) -low temperature (LT : day/night temperature of 20/10°C), LD-LT and SD-ITT, during seed development and maturation. Despite of fructification under various environments, all lots of the seeds held a high level of germination at 25°C under illumination. Except the seeds matured in SD-LT, the germination of seeds incubated at 20°C under illumination or 25°C in darkness for a week resulted in low level or complete failure. The seeds matured in SD-LT were similar in germinative response to incubative conditions to the ones harvested in autumn. Autumn is naturally lower in temperature and shorter in day length than summer.
The day length and temperature to which the parental plant of plantain was exposed during development and maturation of seed effect to the following germination.