Fast Plants® Seeds: Which Genetic Stock Do I Use?
Mendelian genetics can seem abstract to students. Bring your genetics lessons to life using a model organism!
Wisconsin Fast Plants® are ideal model organisms for the study of genetic inheritance. Its short life span allows students to perform crosses and trace traits through multiple generations. Alternatively, seed sets are available with seed from both parent populations, and from the F1 and F2 cross populations.
Purple stem trait
Several traits are available for study. Anthocyanin is a pigment found throughout the plant kingdom. It is thought to play a role in protecting plants from the sun. A mutation in the genome of some Wisconsin Fast Plants® disables the production of anthocyanin. This mutation is recessive, so only individuals that are homozygous and have 2 copies of the mutation will be non-purple. Expression levels of the purple trait are influenced by environmental conditions, including light exposure, so any hint of purple indicates the presence of the anthocyanin gene.
When plants homozygous for the anthocyanin gene are bred to plants homozygous for the mutation, the F1 generation will exhibit the anthocyanin trait 100% of the time. If you cross that F1 generation back to itself, you can expect a ratio of 3 purple plants to 1 non-purple plant.
Seeds are available from all 4 populations, so students don’t need to wait to view the crosses. All 4 populations can be grown up and scored in around 72 hours. Plants can be germinated in soil or in a Petri dish. Choose handy seed disks, or get everything you need for a full class in our Wisconsin Fast Plants® 72-Hour Monohybrid Genetics Kit.
Yellow-green leaf mutation
You can also use the yellow-green leaf mutation to study Mendelian inheritance. When a plant is homozygous for this recessive mutation, it produces lower levels of chlorophyll than plants with a normal copy of the gene. Because this trait is easiest to observe in plants that are around 7 days old, petri dish germination is not recommended for this variety.
Because both the purple stem and yellow-green leaf genes can affect leaf color, we recommend that this variety be used by instructors who are familiar with Wisconsin Fast Plants®. The 2 genes allow students to track the inheritance of multiple, independently assorted alleles through multiple generations, while at the same time observing how multiple genes can affect plant appearance. By measuring the growth rates and seed production of the 2 variants, students can observe how reduced chlorophyll concentrations affect the structure and function of plants. They can also make predictions about how natural selection might impact the numbers of each allele in a population.
Rosette-dwarf variety
Another trait that can be used to demonstrate Mendelian inheritance is the rosette trait. In a rosette plant, the gene that produces gibberellic acid is not functional. Without gibberellic acid, hormone pathways are interrupted and growth between nodes is inhibited. If the plants are treated with gibberellic acid, they will grow to normal size. This makes these plants perfect for examining hormone mediated mechanisms.
In our F1 rosette-dwarf seed packs, non-rosette, non-purple stem plants have been crossed with rosette form, purple stemmed plants. Using these genetic stocks, students can observe dihybrid inheritance patterns of 2 independent phenotypes. These phenotypes can be observed in 72-hour seedlings, but are easier to view the longer they are allowed to grow. Our Wisconsin Fast Plants® 72-Hour Dihybrid Genetics Kit contains all the materials you need to grow the plants in petri dishes.
No matter which genetic stock you choose, Carolina has resources to support your lessons.
For more information on how to grow Fast Plants®, check out the care guide.
And don’t miss the free NGSS activity Wisconsin Fast Plants® Monohybrid Crosses Inquiry.
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