Plant Reproduction Lab

Introduction Plant reproduction is a fascinating part of biology. Plants, specifically angiosperms, have unique ways of reproducing. Angiosperms use pollen vectors such as insects, mammals, birds, wind, and even water to deliver their pollen grains to stigmas. The plant of study for this experiment was Mimulus guttatus, also known as the monkeyflower. This plant produces yellow flowers that are bilaterally symmetrical and have five petals. Interestingly, their petals are fused together and contain the anthers and stigma, the reproductive parts of the plant. This morphology makes this species cosexual, so each individual flower contains both male and female parts. Since M. guttatus is hermaphroditic, it is considered herkogamous, which …show more content…
Pollen viability with use of Alexander Stain for germinated, self-pollinated pollen had an average of 2 grains and non-germinated had an average of 49 grains. Outcrossed, germinated pollen had an average of 0 grains and non-germinated had an average of 18 grains. T-tests were performed for germinated and non-terminated and were both not statistically significant (p = 0.16 and p = 0.13, respectively). For the germinated total pollen grains of In vitro pollen viability within Brewbaker-Kwack medium had averages of: 5% = 14 grains, 10% = 16 grains, 15% = 50 grains, and 20% = 104 grains (Figure 1). Germinated pollen grains had averages of: 5% = 0 grains, 10% = 3 grains, 15% = 5 grains, and 20% = 14 grains (Figure 2). A t-test was performed for the 15% and 20% conditions and was not statistically significant (p = 0.09). Indirect pollen viability with use of FDA had an average of 26% of pollen was viable out of total pollen grains. Self-pollinated styles collected after 24 hours showed presence of pollen and pollen tubes germinating. One outcrossed style collected after 24 hours showed presence of pollen germinating and the other style was lost. It was not clear if pollen tubes were germinating in the outcrossed style. One self-pollinated style collected after 72 hours showed the presence of pollen germinating and the other …show more content…
Pollen viability was determined in a few ways. The use of Alexander Stain to stain the pollen grains on the stigma showed that there was some germination on the self-pollinated flowers and no germination on the outcross flowers. This was interesting data because these results should have been opposite, since outcross-pollination is usually favored. Increasing the sample size by pollinating more flowers and collecting more stigmas might increase the likelihood of this being observed. Viable pollen was also observed in vitro by using the Brewbaker-Kwack medium protocol. Inducing germination of pollen grains showed that they were viable, especially in the higher sucrose concentrations (Figure 2). Lastly, pollen viability was observed with the use of FDA. The average of 26% of viable pollen could have been more reliable with increasing the sample size. Individual reports of pollen grains said to be viable were variable and not consistent. Examining styles for pollen tube growth had some qualitative results that may support an outcross pollination was favored. The 72-hour self-pollinated style had a lot of callose, suggesting that the plant was trying to “block” the self-pollen grains from growing further into the style. One of the 72-hour outcross styles had clear evidence that pollen tubes were growing. This may suggest that the plant