Genetic Variability and Resistance to Orobanche in Oriental Nicotiana tabacum L.

Broomrape as an obligate parasite that threatens tobacco production (Nicotiana tabacum L.), has destructive effects on its characteristics. The reduction in yield caused by this parasite is so great that sometimes farmers are forced to leave their fields due to the severity of the infection. Since the stages of contamination and pathogenicity mainly occur underground, and the major damage of the parasite to host plants produce before the diagnosis of contamination, the development of effective controlling strategies is a great challenge in front of scientists. Unfortunately, no control method (agricultural, chemical, mechanical, etc.) has been effective so far. The lack of effective agro-chemical controlling methods makes the need more obvious for biotechnological methods. Host resistance as an integrated pest management method is a multifaceted process that can occur at several stages of the parasite's life cycle; before attaching to the host during root penetration, or after attaching to the phloem. In recent years, various breeding activities have been started to develop “Orobanche-resistant” genotypes. In this paper, the conducted research activities on the genetic variability and resistance of tobacco to broomrape have been reviewed. The results determine the importance and also the path to achieving “Orobanche-resistant” varieties.