Reproduction

The image depicts the reproductive cycle explained. The blue boxes represent meiosis occuring and the pink boxes represent mitosis. The purple box towards the bottom of the image shows pollination and fertilization. Image courtesy of Wikimedia Commons.Silene latifolia is an angiosperm which means that it is a flowering plant. Reproduction of S. latifolia, as with most plants, follows the alternation of generations lifecycle. The alternation of generations alternates between a diploid sporophyte generation and a haploid gametophyte generation. Reproduction starts with a diploid sporophyte generation. The plant that is seen is the multicellular sporophyte.

Inside of the male flowers are anthers which contain microsporocytes. The microspores undergo meiosis which creates haploid spores. The microspore undergoes mitosis and becomes a pollen grain. The pollen grain is also known as the male gametophyte.

In the female flowers, meiosis occurs in the ovule and megaspores are produced. The megaspore divides by mitosis to become the female gametophyte. The pollen grain pollinates the female flower by landing on the stigma of the female. The sperm from the pollen grain fertilize the egg to form a zygote and the polar nuclei of the female gametophyte which is known as double fertilization. The zygote develops into an embryo which later grows into the sporophyte. When the sporophyte is fully mature, the life cycle begins again (Campbell, et al., 2008). To learn about another plant that has an alternation of generations life cycle, check out Linum marginale, wild flax!


 Seeds contained in fruit of S. latifolia plant. Image courtesy of Wikimedia Commons.Reproduction of Silene latifolia mainly occurs through seeds. Silene latifolia has extremely high reproductive rates because they can produce hundreds of seeds during one reproductive season. A single plant can produce about 50 capsules, each capsule containing an average of 500 seeds. These seeds are then dispersed (OARDC, n.d). Producing such high numbers of seeds is very advantageous to the survival strategies of this species. The high number of seeds allows for increased rate of reproduction and ensures that some offspring of the plant will survive.

Number 4 shows fruit and 5 shows the seed of White Campion. Image used courtesy of Wikimedia Commons.
Silene latifolia is unique compared to other angiosperms because it displays sexual dimorphism. Sexual dimorphism means that there is a difference between the male and females of the species. Male and female flowers are found on separate plants. The image on the right shows a female flower (number 3) and male flower (number 2). The female flowers are larger than male flowers, however male flowers have more flowers open at a time than female flowers do (Young, 2002). The flowers are open in the evening and stay open until midmorning which allows for pollination during the night and during the day as well. Most pollination occurs at night and is done by moths. To help increase chances of pollination, Silene latifolia has a strong scent to attract nocturnal pollinators (Dötterl, et. al,  2005). To learn more about moths that are nocturnal pollinators, check out the Hemaris thysby, the Hummingbird Clearwing moth. Besides nocturnal pollination, the flowers are open for a few hours during the day so bees and other insects are also minor contributors to pollination (Young, 2002).


Adaptation                          Interactions

References