crosses

Today I set up my first crosses in Arabidopsis thaliana. This is going to be a brief explanation of how to make crosses, but should provide enough information for anyone to perform an efficient cross between two parental lines. The first step is selecting an appropriately aged female. The proper age should be one primary bolt with no more than 3-4 flowers opened. Arabidopsis is an organism that self- pollinates, so one should be extremely careful to select flowers to emasculate that have not previously been pollinated. Emasculation should be performed with extreme caution. The goal here is to remove all male reproductive organs, namely, the anthers. After all anthers, sepals, and petals have been removed, the stigma, or female reproductive organ should stand-alone. After the flower has been emasculated, the plant should be set-aside for one day, until a crown has formed at the tip of the stigma. This morphological distinction represents a receptive stigma. This is the time that artificial pollination should take place. One should repeat pollination once a day for three consecutive days after the stigma has become receptive.