Breeding of Hibiscus sabdariffa L.: evaluation of resistance to Fusarium oxysporum Schlecht. Emend. Snyd. and Hans in two varieties

Abstract

Various diseases such as Fusarium wilt adversely affect the growth of roselle (Hibiscus sabdariffa L.) plant in various parts of the world. Two varieties (sabdariffa, altissima) of this species were inoculated in vitro and under nursery conditons. Non inoculated plants of each variety were used as control plants. The damages caused by the fungal attacks on the growth of plants was measured by their negative impact on the morphological traits such as length, width and fresh weight of leaves. According to the level of this negative impact on in vitro grown plantlets, sabdariffa plantlets were considered as more resistant to Fusarium oxysporum than altissima ones. In nursery, compared to their respective control, the values of the morphological traits of the inoculated plants increased in sabdariffa variety and decreased in altissima one. The inoculated in vitro plantlets of the sabdariffa variety had higher phenol content than those of altissima variety. In nursery, the variations of the total phenol content were negative for the sabdariffa variety and positive for altissima. Negative and highly significant correlations were observed between the resistance traits and the total phenolic content. F. oxysporum had no significant effect on photosynthesis of the plants of sabdariffa or altissima varieties.