Does Gibberellic Acid affect the germination of seeds?
INTRODUCTION
There are many factors that influence the germination of plant seeds. Adequate warmth and moisture seem to be essential prerequisites but many seeds fail to germinate even under optimal conditions. It has been noted that the gibberellin hormone can break dormancy in seeds, by removing inhibition effects of light (Chen and Chang, 1972). It has been suggested that growth of soil fungi that release gibberellins may be a trigger for seeds to germinate because the fungi will only grow extensively if there is persistent moisture in the soil. (Note: cactus seeds are often very slow to germinate and germination may be spread over many months. This can be rationalised as a response to the need not to germinate too soon after wetting because there may not be sufficient
…show more content…
soil moisture after light rain to enable seedlings to survive subsequent dry spells.) TASK - To test whether gibberellic acid (GA) affects the percent germination of your selected seeds. Work in groups of 3 or 4 You will be assigned two species of seeds, one from each category below: o CATEGORY 1 (slower germination): Echinocactus grusonii (Golden Ball) or poppy seed, and o CATEGORY 2 (quicker germination): radish or rocket salad Set up seed sample bags with differing concentrations of GA according to the method described below Record the number of seeds germinating over a three week period Share data between group members and ALL of the BioComms classes via spreadsheets on the portal Write an individual report on the effect of Gibberellic acid on germination of the seeds VARIABLES, CONSTANTS and CONTROL The independent variable is the concentration of gibberellic acid (GA) used to soak the seeds. The dependent variable is the number of seeds that germinate. Constants are any other factors that may affect germination, being held at some constant value over all trials. Examples are: Ambient temperature (if it cannot be held constant, all samples should be subject to the same temperature variations), Quantity of moisture, Available light. All samples should be subject to the same light conditions. Sowing density. Seeds/sq cm. The control is a standard against which other conditions are compared in a scientific experiment. In this case the control is the sample with zero concentration of gibberellic acid. HYPOTHESIS The Null Hypothesis (H0) is that gibberellic acid has NO effect on germination of seeds. That is why it is called the null hypothesis. You can write an Active Hypotheses (Ha) for each of your species based on your interpretation of any research that you have read.
e.g. Ha1 : Low levels of gibberellic acid ( 500 ppm) will
inhibit germination of Ferocactus seeds.
Ha2 : Germination of radish seeds will be increasingly inhibited as the concentration of GA is increased.
Method:
Label 20 snap-lock bags with your group members names.
Name 10 bags with one seed species and the remaining 10 bags with your other seed species.
For the first 10 seed-species bags, label 2 bags for each GA concentration: 0ppm, 125ppm, 250ppm, 500ppm, 1000ppm (this will give you 2 trials of germination, to increase the reliability of your results).
For the last 10 seed-species bags, label 2 bags for each GA concentration: 0ppm, 125ppm, 250ppm, 500ppm, 1000ppm (this will give you 2 trials of germination, to increase the reliability of your results).
Place a 11.5cm x 8cm piece of paper towel inside each bag.
Wet each paper towel with precisely 3 mL of GA solution appropriate to the label on the bag. The 0ppm bags will just get pure water (no GA solution
present). Spread 10 seeds (equally spaced, don’t overcrowd them) over the surface of the wet paper towel for each bag, paying attention that the correct seed is going into the correctly labeled bag. Seal the bags. Place all the bags, in an orderly fashion, on the table under the light in Studio 5/6. Return daily to check for germination.* Record the number of seeds germinated in each interval of time using the data table provided.** Close the bag and return it to the table after each day that you check on your results. * Seeds have germinated when the first little root emerges from the seed. This first root is called the radicle, and is usually white. It usually contrasts well with the dark seed coat but not the paper, so look carefully. ** Because you will not be able to record data over the weekend you will not know whether a seed germinated on Saturday or Sunday. How would this affect your graph of germination over time? You could differentiate by size of the radicle – larger would be Saturday’s germination, smaller would be Sunday’s. Is that a reliable or valid procedure?
This experiment was performed to test two hypotheses concerning the plant hormone gibberellic acid and a mutant rosette shaped phenotype of the plant Brassica rapa. This experiment was done in order to test the effects o gibberellic acid on plants and its effect on rosette shaped complexes. The two hypotheses in this experiment are as follows: Hypothesis number one states that Gibberellic acid allows for stem elongation in plants. Hypothesis number two. The rosette complex in the rosette phenotype plant contains less gibberellic acid naturally and therefore grows shorter.
Then, mark one cup with B, this is the control group. Next, poke two holes at the bottom of each cup for drainage. After this, fill both the A cup with two hundred and fifty milliliters of miracle grow soil. Then, fill the B cup, the control group, with two hundred and fifty milliliters of miracle grow soil. After both the A and the B cups are filled, the radish seeds must be placed in each cup. To do this, make two indents in the dirt of each cup about half an inch deep in which the seeds are to be placed. Next, plant two seedlings in both cups to insure one sprouts. Then cover both holes. After this, be sure to place both in direct
Then titrate with the sodium thiosulfate solution as in the standardization procedure, adding 6 drops of starch indicator near the end of the titration. Record the volume of thiosulfate solution used in the titration. Make a duplicate
3.) Divide your 30g of white substance into the 4 test tubes evenly. You should put 7.5g into each test tube along with the water.
Table 1 shows averages of each replicate for each series of seeds relating to mortality rate/germination rate, budding rate, and mean plant weight (total, with buds, and without buds).
Every student in a lab section planted eight seeds, two in each cell in a quad, to make sure that we had at least one plant for each week for 4 weeks. After planting the seeds we put the plants on a water mat tray to make
Tacitus is considered by many to be the greatest Roman historians to ever live. Clearly his knowledge and skills are fully demonstrated in his writings Agricola and Germania. Tacitus captures his readers attention witnessing different ethnic groups and there various customs from each other. Agricola focusses on Tacitus father in-law Julius Agricola. Because of Agricola Tacitus saw ethnography on the many people of the ancient Britain. In Germania Tacitus writes about the different Germanic groups of the time. Tacitus in both of his writings portrays the cultures, traditions, and establishments of many different ethnic groups. Cornelius Tacitus was born 56 AD in southern Gaul which is now modern Providence. In 75 AD he moved to Rome and became an orator. A year later he married the daughter of the consul Cn. Julius Agricola. Tacitus is best known writings included Agricola (97-98), Germania (98), The Histories (110), and The Annals. Harold Mattingly (1884-1964) translated Agricola and Germania. J.B. Rivers published his translation, with introduction, and commentary of Germania in 1999. How does reading Tacitus’s Agricola and Germania help provide a better understanding to classical Rome? Through Tacitus’s writings we can pick out important parts of
· Wear the lab coat all the time in case the acid spills on you.
To make the test fair I will use the same amount of water and the leaf
Although bitterness between the divided community surely had a major part in the rising tensions, another theory proposes that the village’s grain may have been tainted and had something to do with the erratic behaviors going on in Salem. The hysterical behaviors of the girls during the trials was most likely more a result of environmental factors than witchcraft. Salem Village, like many other communities, harvested wild rye. After harvesting the grain, it was then stored in barns and sometimes kept months before it was used. Ergot is a fungus that under the conditions the grain was kept, could have potentially infected the rye. Rye is susceptible to ergot poisoning, also known as ergotism. “Convulsive ergotism is characterized by a number
Janick. J. (2011). Center for New Crops & Plant Products - Department of Horticulture and
After distributing the seeds, place two or three fertilizer pellets into each quadrant, followed by another layer of dirt. Finish by watering quadrants. After 2-3 weeks, count the parent generation number of trichomes and record. Then, choose 25% of the hairiest plants out of the P1 population and replant their seeds following the same directions earlier on. When plants are grown, follow the same steps and count trichomes and record. Compare both sets of P1 data to F1 data to determine if evolution took
Plant defences are those mechanisms employed by plants in response to herbivory and parasitism. According to Hanley et al. (2007), “the tissues of virtually all terrestrial, freshwater, and marine plants have qualities that to some degree reduce herbivory, including low nitrogen concentration, low moisture content, toxins or digestibility-reducing compounds”. The type of chemical defence may be species specific (Scott 2008). The defences that plants possess may be in the form of chemical production or in the form of physical defences such as thorns or spikes and even through reinforced, rigid leaves. “The compounds that are produced in response to herbivory can either have a direct effect on the attacker itself (e.g. toxins or digestibility reducers), or serve as indirect defenses by attracting the natural enemies of the herbivores” (Bezemer & van Dam 2005). This essay will focus on chemical plant defences and in particular the effects of terpenes, phenolics, nitrogen-based defences as well as allelopathy in plants.
Weigh out two 0.100 g. samples of the product and put each into a test
Pod size ranges from 15-30 mm in length, 7-14 mm in thickness, and 2-15 mm in width. Depending on the basal and apical zones as well as the dorsal and ventral regions, pod shape varies from rhomboid, oblong to ovate. The number of seeds per pod ranges from 1-2, with the maximum being three. The seeds are ramhead or owl's-head shaped, and the surface may be smooth or wrinkled. The length of the seed ranges from 4-12 mm and its width from 4-8 mm. The seed mass varies from 0.10 to 0.75 g per seed. The seeds of kabuli type are large (100 seed mass >25 g), round or ram head, and cream colored. The plant is medium to tall in height, with large leaflets and white flowers, and contains no anthocyanin, whereas the seeds of the desi type are small and angular in shape. The seed color varies from cream, black, brown, yellow to green. There are 2-3 ovules per pod but on an average 1-2 seeds per pod are produced. Chickpea seeds germinate at an optimum temperature (28-33°C) and moisture level in about 5-6 days. Germination begins with absorption of moisture and swelling of the seed. The radicle emerges first followed by the plumule.