Translation:The subject of the lecture is the equality between men and women.
Aŭ "viroj kaj feminoj" (both have their own root, so that's equal).
Aŭ "homiĉoj, kaj hominoj" (if you really want to make it come from the same root, and still have symmetry, you can use -iĉ- for masculine, and -in- for feminine. Even though it is not grammatically correct according to the standard rules of Esperanto grammar, languages change, and a lot of people choose to use -iĉ- nowadays, and make the root words neutral (or epicene) ).
My native language doesn't have any articles, so I have again hard time to understand them. One of the rules for the definite article in E-o is, that one should use it when the substantive represents "individuo, kiu reprezentas iun aron". For instance
La hundo estas la plej fidela de la bestoj.
The first "la" tells, that this is a general dog. The second "la", that it is "the most", and the third defines the group.
So shouldn't it in this case be "la viroj" and "la virinoj", since they represent the general ones and not specific ones?
(If you ask me, you should ditch the article all together and use demonstrative pronouns when necessary.)