An experiment was conducted to find the consequence of the allelopathic compounds of Encelia Farinosa ( brickle shrub ) on desert native annuals and non-native seed sprouting. The experiment was set up by seting native wild flower seeds in six Petri dishes and boodle seeds in six different dishes. To three of each dish incorporating the different seeds. H2O was added as a control. To the three other dishes. a prepared toffee shrub tea ( filtered land toffee shrub foliages and H2O ) was added. After a week’s clip. the figure of germinated seeds in each dish was counted.
The consequences showed that the allelopathic compound in brickle shrub did hold a important consequence on both the boodle seeds and the native wild flowers when compared to their several controls. However. the consequences showed no important difference between the two agencies of the native seeds with brickle shrub tea and the boodle with brickle bush tea. This led to the rejection of our hypothesis and credence of the nothing hypothesis which stated that no important difference existed between the two agencies. Introduction In the natural universe. workss are in changeless strain of development and competition.
Through the evolutionary procedure. workss have developed many ways to assist get by with assorted environmental emphasiss. Some workss overcome environmental strain by turning taller or deeper to pull out as many resources as possible. Others resort to Numberss and seek to overpower their marauders and rivals by population size. However. perchance the most interesting method many workss take is the usage of chemicals to kill or suppress marauding herbivores and viing workss. Plants that resort to this method of defence are known as allelopathic and the chemicals used by these workss are called secondary metabolites.
Nowhere is the battle for resources more critical than in the desert. The usage of secondary metabolites in desert workss is believed to be one of the most common defence mechanisms in the desert community. Among these allelopathic desert workss is Encelia Farinosa or more normally known as brickle shrub ( Tesky 1993 ) . The effects of the secondary metabolites used by brickle shrub have been studied by ecologists for many old ages.
Due to limited exposure. many believe the effectivity of desert allelopathic compounds on on-native species would be great because the evolutionary procedure would non prefer the development of a defence against the secondary metabolites ( Fritzke 2003 ) . However. other research has shown brickle shrub to be extremely damaging and effectual against assorted desert annuals ( wild flowers ) . It is believed that desert annuals are under dual the emphasis due to the fact that they merely survive for a really short season. non leting development to prefer the development of defence against the toxicity of brickle shrub. and besides are in ferocious conflict with the specialisation of the brickle bush’s secondary metabolites ( Kunze et al. 994 ) .
In this experiment. a squad of research workers set out to happen the effectivity of brickle shrub in the hurt of seed sprouting of native desert annuals ( wild flowers ) and non-native species. It is believed that native one-year seeds treated with the secondary metabolites from brickle shrub will demo a greater difference in seed sprouting than non-native seeds besides treated with the secondary metabolites. We predict that the native seeds will shoot significantly less than the non-native seeds. Materials and Methods
To get down the experiment. our squad obtained several brickle shrub foliages ( about 30 gms deserving ) . The foliages were so land in a howitzer for a period of two proceedingss. Fifteen gm of the land leaves were weighed out so transferred into a big glass container. Once in the containers. 150ml of H2O was added to each of the containers. Then the water/leaf cocktail was allowed to sit for a period of 24 hours. After the twenty-four hours of soaking. the mixture was filtered through a paper towel into a different glass container. as to take all the crushed foliages. go forthing merely the liquid.
Once the foliage extract mixture was complete. twelve Petri dishes were obtained. A piece of six-inch filter paper was placed at the underside of each dish. Each dish was so labeled as follows ; dishes one through three were labeled “water control lettuce” . dishes four through six were labeled “brittle shrub lettuce” . dishes seven through nine were labeled “water control desert flowers” . and dishes ten through 12s were labeled “brittle shrub desert flowers” . Then. 25 boodle seeds were placed in dishes one through six and twenty five desert wild flower seeds were placed in seven through 12.
In the dishes labeled “water control lettuce” and “water control desert flowers” . a measuring cup was used to add 12 milliliter of apparent H2O to the seeds. In the dishes labeled “brittle shrub lettuce” and “brittle shrub desert flowers” . 12ml of the liquid solution obtained from the brickle shrub tea was added. The 12 dishes were so covered and allowed to sit for a hebdomad. The desert wild flower consisted of flowers native to the Arizona desert that appear on an one-year base.
An of import note is that the two different types of seeds were exposed to the Sun harmonizing to what was considered ample sum of clip. For case. the boodle seeds called for partial Sun. Therefore the seeds were exposed to the Sun for portion of the twenty-four hours. so shade for the remainder. The desert wild flowers called for complete Sun. They were left out in the Sun at all times. After a one hebdomad clip period. the dishes were opened and the figure of germinated seeds within each of the dishes were counted and documented.