Selection for resistance to Fusarium wilt in red clover

Abstract

resistance to Fusarium wilt in red clover. Can. J. Plant Sci. 79: [351][352][353][354][355][356]. In Wisconsin, Fusarium oxysporum, Schlect., a pathogen causing vascular wilt, is the most prevalent fungal pathogen recovered from diseased red clover (Trifolium pratense L.) plants. This study was conducted to determine the mode of inheritance for red clover resistance to this pathogen and to develop resistant germplasm. Virulent isolates of this pathogen, collected from red clover plants at the Ashland Research Station, Ashland, Wisconsin, were used to screen three populations, the red clover cultivars Arlington and Marathon and the C11 germplasm, for resistant plants. Plants were inoculated with the pathogen and evaluated for reaction, using a disease-severity index (DSI) score from 1 to 5 (1 = no reaction, 5 = plant dead). Selected plants from each cycle were intercrossed to produce subsequent generations. After two and three cycles of selection, the developed populations were simultaneously evaluated for gain from selection. The gain from selection for resistance in these populations (cycle 0 minus cycle 2) ranged from 0.31 to 0.48, 0.12 to 0.75, and 0.13 to 0.83 DSI units, respectively, for Arlington, Marathon, and C11. Estimated narrow-sense heritabilities, based on cycle-1 and cycle-2 progeny, were, respectively, 0.20 and 0.37 for Arlington, 0.15 and 0.13 for Marathon, and 0.06 and 0.17 for C11. These results indicate that resistance is a quantitative trait controlled by many loci, each contributing some portion to overall resistance in the host. Fusarium oxysporum Schlecht., a ubiquitous fungal pathogen, is known for the vascular wilts it causes on a wide range of important agronomic and ornamental crops (Booth 1982). In Wisconsin, F. oxysporum is the most prevalent fungal pathogen recovered from diseased red clover (Trifolium pratense L.) plants (Kilpatrick et al. 1954;Velde 1980) and contributes to stand loss and reduced productivity. Isolates of this pathogen were identified in association with diseased red clover stands at the Ashland Research Station, Ashland, Wisconsin, and were determined to be virulent in a number of red clover populations (Venuto et al. 1995). Furthermore, this reaction was negatively associated with the level of persistence of respective red clover populations (Venuto et al. 1992).Efforts to incorporate genes for resistance into agronomically acceptable cultivars of red clover or develop new germplasm with these resistance genes have proven successful (Smith 1983

Chromosome-scale assembly of the highly heterozygous genome of red clover (Trifolium pratense L.), an allogamous forage crop species

“…The individual used in this study is HEN17-A07, a red clover plant selected from the US Dairy Forage Research Center (Madison, WI, USA) breeding program, representing elite North American red clover germplasm (Figure 1 ). This individual derived from 30 years of selection and breeding for red clover grazing tolerance, persistence, biomass yield, and Fusarium oxysporum Schlect resistance [ 16 , 17 ] . Source varieties and germplasm for HEN17-A07 include the red clover varieties “Dominion” [ 18 ] and “Redlangraze” (ABI Alfalfa Inc., now part of Land O’Lakes, Inc. Arden, MN, USA); and experimental populations C452, C11, and C827 out of the US Dairy Forage Research Center red clover breeding program.…”

A robust hydroponic‐based system for screening red clover (Trifolium pratense) for Fusarium avenaceum

“…Thus, identification of improved Fusarium resistance is an important aspect of red clover breeding programs. Previous Fusarium disease screening methods relied mainly on field evaluations or experiments in pots containing soil or peat‐sand potting compost conducted under greenhouse conditions (Coulman & Lambert, 1995; Skipp et al, 1986; Venuto et al, 1999; Yli‐Mattila et al, 2010). A common challenge in all these methods is to have an even disease pressure enabling comparisons between repeated experiments.…”

Effects of Post-Emergence Herbicides on in Vitro Growth of Fusarium Oxysporum Isolated From Red Clover Root Rot

“…Root rot, caused by infestations of certain Fusarium species and root borer, Hylastinus obscurus (Marsham) (Coleoptera: Scolytidae), are responsible for its short persistence not only locally but worldwide (Steiner and Alderman, 1999). Fusarium root rot is a common disease in red clover pastures in Chile as well as in other areas in the world (Ceballos et al, 2004(Ceballos et al, , 2006Steiner and Alderman, 1999), in which reduces productivity and persistence (Venuto et al, 1999). Fusarium oxysporum Schldt.…”

“…Fusarium oxysporum Schldt. is the most commonly studied and economically important Fusarium species (Ceballos et al, 2004;2006;Venuto et al, 1999).…”