Germination Ecology of Rhanterium epapposum Oliv.

Abstract

Problem statement: Rhanterium epapposum, locally called Arfaj is the national flower of Kuwait. The current situation of Rhanterium epapposum is quite critical in most areas of Kuwait. In fact it has completely disappeared from most parts of the country due to a combination of overgrazing, collecting for firewood and off road driving. Approach: Rhanterium epapposum is an excellent species for rangeland restoration and information on its germination ecology is meager. The considerable variations in germination between years lead us to study the variation in the size, mass and number of filled achenes in the capitulum. The variation in capitulum size, mass, number of achenes per capitulum and also the effect of dry heat (1-5 months), Moist chilling (1-5 months) and hydration dehydration cycles (1-5 cycles) on germination of the 6 different year collected Rhanterium epapposum (2002-2007) seeds were studied under laboratory condition. Results: The seed size, weight, the number of achenes per capitulum of Rhanterium epapposum varied considerably from one year to another. Climatic condition significantly decreased seed quality and germination when the precipitation is lower. Heat and moist stratification substantially improved the germination of 2003, 2004 and 2005 seeds. However hydration and dehydration treatment had very little effect on germination. Conclusion: It is concluded that results of germination tests differed depending on the presence of filled achenes in the capitulum. There was a strong correlation between the presence of filled achenes in capitulum and the precipitation during the growing season. This suggested that under natural condition precipitation plays key role in the formation of achenes in capitulum of the Rhanterium epapposum seeds.