Plant Propagation

Course Schedule - Week 7

Last week we discussed the foundational principles of the clonal propagation of plants - including the fundamental role "ontogenetic juvenilty" plays in the ease with which plants can be "cloned."

Today we will focus on the influence of "phytohormones" (especially auxins and cytokinins) on the formation of adventitious roots, buds and shoots in stem, leaf and root cuttings, as well as the sequence of events leading to the formation of these organs.

From a practical perspective we will also discuss the critical importance of "stock plant" management, the treatment of cuttings, and manipulation of the propagation system environment in the successful clonal propagation of plants. It will be emphasized that should you fail to focus sufficiently on any one of these three inputs, the application of a growth regulator (typically auxin) will not result in success.

We'll end the class with a quiz (Quiz #8) covering content from Chapter 10 and related videos and readings (note that this content is found in Chapter 9 of the 7th and 8th editions of the assigned textbook).

Today's discussion may cover most of the information you were hoping to take away from this entire class; the nuts and bolts of propagating plants by cuttings!

We'll discuss the many different kinds of stem cuttings and when best to use them depending upon the objective of your propagation effort, the condition of the stock plant, the time of year, etc. We'll also discuss the practical applications of leaf and root cuttings.

We'll then turn our attention to process of propagation by cuttings - from the collection and transportation of cuttings, to their treatment with rooting compounds, to their management while forming adventitious organs (roots, buds and/or stems) in the propagation environment be it a humidity chamber, greenhouse bench, outdoor rooting bed, etc.

I'm hopeful that by the end of this class session you will be well-prepared to provide a thorough analysis of the Clonal Propagation by Cuttings (Lab #1) results you're observing (whether good, or not so good). I'm also hopeful that based on our discussions, the readings, and your experience with this lab exercise that you'll be well-prepared to propagate a wide range of plants by cuttings far into the future.

We'll end the class with a quiz (Quiz #9), and I'll return Monday's ungraded quiz (Quiz #8). You'll have until midnight this Friday evening, February 28, to email your score (between 0 and 10 as always) to me, using the Quiz 8 grading rubric and review video at this link.

If all goes according to plan, we will make observations, collect data and terminate the seed dormancy exercise that we initiated on February 15th.

We will then spend rest of this session discussing strategies for creating lab reports that both accurately portray your results, can be used as examples of your analytical and writing skills, and possibly most importantly can be be shared with others that are interested in propagating plants.

Come to this session prepared to write!

For more information on this lab session including treatment rubrics and video instructions, click on this link, Lab Session #6 - Lab Report Preparation.

I will also return Wednesday's ungraded Quiz #9. As always, you'll find a grading rubric and review video for this quiz here. Please email me your score (between 0 and 10 points) no later than midnight this coming Sunday, March 1.