Glara Yazdanparast told her father's trial: "I know that 100 per cent there was absolutely no relationship. It's an excuse."
The former university student was questioned over her father, Ahmad, becoming concerned and angry about a relationship between her mother and another Iranian man and replied: "There was no relationship and he knew that."
She said there had been long-standing problems in her parents' marriage and said: "As long as I can remember he used to always argue with my mum."
Miss Yazdanparast, 21, from Stirling, who has a twin sister, Gloria, and a younger brother, said that both her parents were from Iran.
Her mother, Ahdieh, worked as a hairdresser at a salon near her former husband's takeaway in Stirling's Maxwell Place and ran a bed and breakfast establishment. The couple separated in 2010 and Miss Yazdanparast said she was aware of her father making threats to her mother, including pouring acid on her face.
Electrical contractor Harvey Robertson told the court Yazdanparast, who he knew as Chico, had told him: "I wish she was dead. If this was back in Iran she would be dead now."
Yazdanparast, 61, has denied murdering his former wife at the Venus Hair and Beauty Salon on October 12 last year. It is alleged that he assaulted her and poured petrol or a similar flammable substance over her head and body, ignited it and set fire to her and that she was so severely injured she died later that day in hospital.
Yazdanparast has lodged a special defence in his trial at the High Court in Edinburgh that he was acting in self-defence.
The trial before Lady Wise continues.