Do genes affects plant????

Yes, the first research on genetics was carried out on plants. A lot of the information gathered about plant genes has been used to work out what human genes are like (it is difficult to carry out genetics experiments on humans without breaking moral codes). Work is also carried out on animals but it all started with plants.

Yes they do, you should research Gregor Mendel and his research on genetics using plants. Here is the Wiki page on him http://en.wikipedia.org/wiki/Gregor_Mendel