The Nobel Prize-winning scientist who co-discovered the structure of DNA 60 years ago has said Ireland cannot be a success in science unless it knows as much as other nations.

Dr James Watson, 86, said the investment made in research in Ireland over the past 40 years is beginning to pay off and there are some very good scientists in the country.

He was asked about comments he made last month in San Diego, where he referred to ignorance being the curse of the Irish.

Dr Watson said what he meant was that historically Irish people lacked knowledge.

He said that he was not implying that Irish people were stupid.

Ireland just has to be good at technology, he said, and that takes a long time and requires a serious university system.

He said it is very important to make science appealing to young people.

Dr Watson, who is now engaged in cancer research, said he is convinced genetics will not lead to the discovery of a cure for cancer, but chemistry will.

On the level of investment in cancer research, he said he does not believe that too much is being spent on it.

Dr Watson also said he did not think the future of cancer research is dependent on a big burst of investment in the area.

He said what is really limiting the search for a cure for cancer is ideas and intelligent people.

Dr Watson was in Dublin to unveil a new sculpture in the Botanic Gardens in Dublin marking the 60th anniversary since the discovery of the double helix structure of DNA.