Love is Spore



I suspect that by now most of you will have purchased your very own tree fern and are falling madly in love with it.  Of course, if you’re a university student like I am, you will know that money doesn’t grow on tree ferns. If you want to collect spores and grow your own for free, then you need to understand the life cycle of a tree fern.

A. Mature Sporophyte producing spores from its Sporangia B. Mature Gametophyte C. Young Sporophyte
https://www.flickr.com/photos/internetarchivebookimages/20219695479/
viewed on 15/3/2018

Before we get into the juicy details of tree fern reproduction, there are some terms we need to understand.  A sperm and an egg are called "haploids" because they each contain only one set of unpaired chromosome. Once the two merge to become a zygote, it is called a diploid; it contains two sets of chromosomes (Campbell et al., 2008).  The terms “haploid" and "diploid” are important, so take a moment to let their roots establish. 

A young Sporophyte
https://commons.wikimedia.org/wiki/File:Onoclea_sensibilis_4_crop.jpg viewed on 15/3/2018
Tree ferns have “Alternative Generations” meaning they have a haploid generation and a diploid generation. If we start at fertilisation, we start in the diploid part. The diploid zygote develops into the frond part of the tree fern, this is called a sporophyte  (Large & Braggins, 2004). The Mature sporophyte is what you are familiar with when you think of a tree fern. Eventually, underneath the fronds of a mature plant (A mature sporophyte), sacks called Sporangia will develop (Large & Braggins, 2004). The sporangium is where cell division or “Meiosis” takes place and it is at this point that we begin the haploid part of the life cycle.

A young Gametophyte
https://commons.wikimedia.org/wiki/File:Fern_young_gametophyte.jpg
viewed on 15/3/2018
When the sporangium dries out, the haploid spores will be released into the environment. The spore, once grounded, will develop into a young Gametophyte (Jones & Clemesha, 1989). A Gametophyte looks nothing like the tree ferns you are used to, and is very small. When it matures, it will have both male and female parts. The male part is an antheridium that contains sperm, and the female part is Archegonium that contain eggs. Here, you will realise, we have returned back to the start of our life cycle, Fertilisation. 

Now that you know how tree ferns reproduce,
you best believe that you have no excuse.
Pack a sandwich, some snacks and a bottle of juice.
Go find a tree fern, put this knowledge to use!
Reference List
Tree Fern Sporangia
https://commons.wikimedia.org/wiki/File:Tree_Fern_Spores.jpg
viewed on 15/3/2018
Campbell, N & Reece J, & Meyers, N & Urry, L & Cain, M & Wasserman. S & Minorsky, P & Jackson, R 2008, BIOLOGY (8th Edition Australian Version), Pearson Education Australia Pty Ltd, Sydney

 Jones, D.L. & Clemesha, S.C.C 1989, Australian Ferns and Fern Allies, The Currawong Press, 2 Aquatic Drive Frenchs Forest NSW 2086

 Large, M.F. & Braggins, J.E. 2004, Tree ferns, CSIRO Publishing, Collingwood, Victoria.

Comments

  1. Tasmin16 March 2018 at 00:32

    An interesting post about the fern’s life cycle. I was wondering if there is any particular difference in how tree ferns reproduce and how other ground-dwelling ferns reproduce?

    ReplyDelete
  2. Saint Dale18 March 2018 at 19:38

    Hi Tasmin. The reproductive methods by which tree ferns reproduce is no different to that of the ground fern. Interestingly, The trunk does not even offer any advantage in spore dispersal over ground ferns apparently.

    Thanks for the thought provoking question.
    Dale Perkins

    ReplyDelete

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