Plant Genetics

In this article researchers estimated the genetic increase of grain yields of the carioca type (beige with brown stripes) of the common beans after 8 cycles of recurrent selection. They wanted to know if they kept selecting the genes they wanted if they could increase the grain yield in the bean plant. When conducting this experiment the researchers of The Federal University of Lavras (UFLA) did not have a clear hypothesis. They had an idea of what the outcome might be but they never created a hypothesis. They used past studies of different crops such as, wheat, rice, oats, and soybeans to estimate what might happen when they preformed the study with beans.
The researchers started out this experiment by using 10 different genetic bean lines that were created in 1990.They crossed the different genetic lines creating a F1 generation. They then double-crossed them creating F2 generation. They took 150 seeds from the F2 generation to perform this experiment. They planted the seeds in plots that consisted of two 4m rows with 15 seeds per meter. They took the highest yield producing plants and crossed them to create a F3 generation. They continued to repeat this until they had reached the F9 generation. By doing this they were selecting the plants that had the gene for producing a higher yield. Once those plants were cross breed with each other eventually most of the offspring from the parent plant would contain the same high yield gene. They also preformed this experiment in several locations at three different times of the year when beans grow the best, February, July and November. The F9 generation of the recurrent selection process is the eighth selection cycle that the researchers were looking for. Researchers found that recurrent selection is an effective way to increase grain yields in future generation. This is what the researchers thought would happen. They didn’t have a clear hypothesis but they suggested what they thought might happen with reference to previous studies.
I found this article very interesting. Plant genetics has always caught my eye. The thing I liked the most about this article is that I can take what the article says and apply it to something more practical. For example instead of trying to increase grain yields we could breed the beans to be resistant to a certain disease. You would use the same type of procedure but instead of selecting the plants with the gene for higher crop yield you would select the gene for being resistant to the disease. I find it very interesting that people can control the outcome of how a plant will look or any special features it may have just by picking what genes each plant has that you cross. I learned that there is a lot more to plant genetics then just cross breeding for the best genes. It may take years for the trait you are looking for to appear and many different cross breeding cycles for that plant to produce offspring with the same traits. Recurrent selection is also used to improve several other traits in plants such as plant architecture, and pathogen resistance.


Olivia Callahan