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Durum wheat (Triticum turgidum L. subsp. durum) production in North America in recent years has been seriously threatened by epidemics of Fusarium head blight (FHB), caused mainly by Fusarium graminearum Schwabe [teleomorph Gibberella zeae (Schw.) Petch]. Deployment of FHB-resistant cultivars has been considered the most effective and cost-efficient strategy to combat this disease; however, progress in developing FHB-resistant durum wheat cultivars has been hindered by a lack of effective sources of resistance. The objective of this study is to identify tetraploid wheat germplasm that could be used to enhance FHB resistance in durum wheat. We evaluated FHB reactions in 376 accessions of five cultivated subspecies of T. turgidum, including Persian wheat [T. turgidum subsp, carthlicum (Nevski) A. Love and D. Love], cultivated emmer wheat [T. turgidum subsp, dicoccum (Schrank ex Schubler) Thell.], Polish wheat [T. turgidum subsp, polonicum (L.) Thell.], Oriental wheat [T. turgidum subsp. turanicum (Jakubz.) A. Love and D. Love], and Poulard wheat (T. turgidum L. subsp, turgidum). We used point inoculation to evaluate resistance to the spread of infection over three greenhouse seasons and used the grain inoculum method of inoculation to evaluate putatively resistant accessions in two field locations. Preliminary evaluation data showed that 16 T. turgidum subsp, carthlicum and 4 T. turgidum subsp, dicoccum accessions consistently exhibited resistance or moderate resistance to FHB. These accessions likely carry genetic resistance to FHB and could be used directly in breeding programs to enhance FHB resistance in durum wheat.

Fusarium head blight (FHB), caused mainly by Fusarium graminearum Schwabe, is a serious disease of wheat (Triticum spp.) worldwide. Host resistance has proven the most effective method of controlling FHB in common wheat (T. aestivum L., 2n = 6x = 42, genomes AABBDD). Progress in breeding for FHB resistance in durum wheat (T. turgidum L. ssp. durum, 2n = 4x = 28, genomes AABB), however, has been limited by a lack of resistance sources. Fortunately, durum wheat has a large number of tetraploid relatives, which represent a gene pool for improvement of FHB resistance in durum. The objective of this study was to search for sources of FHB resistance in wild emmer wheat [T. turgidum L. ssp. dicoccoides (Korn. ex Asch. & Graebner) Thell., 2n = 4x = 28, genomes AABB] (TDIC). We evaluated 416 accessions of wild emmer wheat for reaction to FHB using the point inoculation method in a greenhouse environment. Accessions exhibiting a low FHB disease rating in preliminary evaluations were retested in fully replicated experiments. Among the 416 accessions tested, there was wide variation in response to FHB, ranging from highly resistant to highly susceptible. Several accessions showed minimal disease development across two or more seasons and represent potential new sources to enhance resistance of durum wheat to FHB.

Fusarium head blight (FHB), caused mainly by Fusarium graminearum Schwabe, is a destructive disease of wheat (Triticum spp.) in humid growth conditions throughout the world. Genetic resistance of the host plant is considered the most effective and sustainable method of defense against FHB; however, only limited sources of resistance are available in wheat. Relatives of wheat have proven to be an invaluable gene pool for wheat improvement. The objective of this study was to explore relatives of wheat for FHB resistance. We evaluated 293 lines derived from the crosses of wheat with its relatives for resistance to spread of FHB infection over two greenhouse seasons. Of these 293 derivatives, 66 were susceptible, 153 appeared moderately resistant, and 74 lines exhibited a level of resistance comparable with T. aestivum L. 'Sumai 3', the most widely used source of resistance to FHB. Alien species involved in development of these derivatives include T. tauschii (Coss.) Schmal., Roegneria kamoji C. Koch, R. ciliaris (Trin.) Nevski, Leymus racemosus Lam., Thinopyrum ponticum (Podp.) Barkworth & D.R. Dewey, Th. elongatum (Host) D.R. Dewey, Th. junceum (L.) Love, Th. intermedium (Host) Barkworth & D.R. Dewey, Dasypyrum villosa L., Secale cereale L., and oat (Avena sativa L.). The wheat-alien species derivatives identified as resistant to FHB include wheat-alien species amphiploids, synthetic hexaploid wheat lines, and wheat-alien species substitution and translocation lines. These derivatives could serve as novel sources to enhance resistance of wheat to FHB. Abbreviations: FHB, Fusarium head blight., FUSARIUM HEAD BLIGHT is a serious threat to wheat production throughout the world (Schroeder and Christensen, 1963; Bai and Shaner, 1994; McMullen et al., 1997; Stack, 2003). In North America, [...]

`Belzer' (Reg. no. CV-868, PI 603286), spring durum wheat (Triticum turgidum L. var. durum Desf.) was developed by the North Dakota Agricultural Experiment Station in cooperation with USDA-ARS and officially [...]

'Glenn' (Reg. no. CV-974, PI 639273), is a hard red spring wheat (Triticum aestivum L.) developed at North Dakota State University (NDSU) and released by the North Dakota Agricultural Experiment [...]

ND 652 (Reg. no. GP-783, PI 639177) is a hard red spring wheat (Triticum aestivum L.) developed at North Dakota State University (NDSU), Fargo, ND, USA. ND 652 was released [...]

ND 744 (Reg. no. GP-778, PI 634936) is a hard red spring wheat (Triticum aestivum L.) developed at North Dakota State University (NDSU), Fargo, ND, USA. ND 744 was released [...]

ND2710 (Reg. no. GP-771, PI 633976), a Fusarium head blight (FHB) {caused by Fusarium graminearum Schwabe [teleomorph Gibberella zeae (Schwein.) Petch]} resistant spring wheat (Triticum aestivum L.) was developed at [...]

'Steele-ND' (Reg. no. CV-965, PI 634981) is a hard red spring wheat (Triticum aestivum L.) cultivar developed at North Dakota State University (NDSU) and released by the North Dakota Agricultural [...]

Fusarium head blight, more commonly known as scab, is a fungal disease of small-grain crops that causes yield loss and poor grain quality. The extensive damage caused by Fusarium head [...]

Fusarium head blight (FHB) caused by Fusarium graminearum is one of the most destructive diseases of durum (Triticum turgidum sp. dururn) and common wheat (T aestivum). Promising sources of FHB resistance have been identified among common (hexaploid) wheats, but the same is not true for durum (tetraploid) wheats. A previous study indicated that chromosome 7A from T. turgidum sp. dicoccoides accession P1478742 contributed significant levels of resistance to FHB. The objectives of this research were to develop a genetic linkage map of chromosome 7A in a population of 118 recombinant inbred lines derived from a cross between the dururn cv. Langdon (LDN) and a disomic LDN-T turgidum sp. dicoccoides P1478742 chromosome 7A substitution line [LDN-DIC 7A(742)], and identify a putative FHB resistance quantitative trait locus (QTL) on chromosome 7A derived from LDN-DIC 7A(742). The population was evaluated for type 11 FHB resistance in three greenhouse environments. Interval regression analysis indicated that a single QTL designated Qfhs.fcu-7AL explained 19% of the phenotypic variation and spanned an interval of 39.6 cM. Comparisons between the genetic map and a previously constructed physical map of chromosome 7A indicated that Qfhs.fcu-7AL is located in the proximal region of the long arm. This is only the second FHB QTL to be identified in a tetraploid source, and it may be useful to combine it with the QTL Qfhs.ndsu-3AS in order to develop durum wheat germ plasm and cultivars with higher levels of FHB resistance. [ABSTRACT FROM AUTHOR]

During the past decade Fusarium head blight (FHB) caused by Fusarium graminearum Schwabe has resulted in severe grain yield and quality losses of wheat (Triticum aestivum L.) in the Northern Great Plains of the U.S. Given the complexity of breeding for FHB resistance, molecular markers associated with this trait will be valuable in accelerating efforts to breed resistant cultivars. The objective of this study was to identify molecular markers linked to quantitative trait loci (QTL) for FHB resistance in wheat using a set of lines obtained by several cycles of crossing to North Dakota adapted genotypes, which derived their resistance from cv. Sumai 3. Microsatellite markers spanning the wheat genome were used to screen parents and derived lines. Polymorphisms for parental alleles were compared to disease scores for Type II resistance. The probability of linkage between markers and introgressed resistance genes was calculated using a binomial probability formula based on the assumption that a molecular marker at a specific distance from the introgressed gene, in a near-isogenic line (NIL), will carry the donor-parent allele as a function of the distance between marker and gene and the number of backcrosses/selfs performed in deriving the NIL. Microsatellite loci Xgwm533 and Xgwm274 were significantly associated with QTL for FHB resistance. [ABSTRACT FROM AUTHOR]