Screening of weeds and rotation crops for their ability to host Fusarium oxysporum f. sp. zingiberi, the cause of Fusarium yellows of ginger

Andrea Matthews1

1University of Queensland

Abstract:

Ginger is an important local industry in Queensland producing about 9,850 tonnes of ginger rhizomes with an approximate gross value of $55 million as assessed in 2017-18 (Plant Health Australia). One of the most serious diseases of ginger is Fusarium yellows, caused by Fusarium oxysporum f. sp. zingiberi (Foz). This pathogen causes the ginger leaves to turn yellow, but more significantly, it causes the rhizomes to rot rendering them unmarketable. Ginger growers need to know if Foz can live in alternative hosts in the absence of the crop, as such knowledge has implications on weed management and crop rotation. For this purpose, in this study common weeds of ginger crops including ragweed, milk thistle, crowsfoot, nightshade and bluetop were collected from ginger fields and screened for the presence of F. oxysporum potentially including Foz. Roots, crowns, stems and leaves of the weeds were sampled and 250 isolates that were morphologically similar to Fusarium oxysporum were cultured. The DNA of these isolates was then screened for the presence of secreted in xylem (SIX) genes. Previous studies have shown that Foz carries SIX7, SIX9, SIX10 and SIX12, whereas non-pathogenic isolates of F. oxysporum obtained from ginger lacked these SIX genes. Our results showed that none of the isolates cultured from the weeds were found to have this SIX gene profile indicative of Foz. The next step will be to grow a range of weeds and rotation crops species of those commonly grown in ginger production systems, inoculate them with Foz and determine if Foz can colonise these plants and increase the inoculum potential. The results of this research could provide the Australian ginger industry with valuable information to help in the control of this serious ginger pathogen.


Biography:

My name is Andrea Matthews and I live in Brisbane, Queensland, Australia. I am very lucky to be studying at the University of Queensland, at St Lucia. This is where I completed my Bachelor’s degree in 1987. After graduation, I worked in the nursery industry and state and federal agricultural policy. I then had a career break to have a family and returned to study in 2014. My phd thesis is titled “Diversity of Fusarium oxysporum in ginger and the assessment of tissue cultured plants to infection”. I am studying part time. When I am not studying, I enjoy travelling and growing African violets.

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