Identifying Rare FHB-Resistant Segregants in Intransigent Backcross and F\u3csub\u3e2\u3c/sub\u3e Winter Wheat Populations

Fusarium head blight (FHB), caused mainly by Fusarium graminearum Schwabe [telomorph: Gibberella zeae Schwein.(Petch)] in the US, is one of the most destructive diseases of wheat (Triticum aestivum L. and T. durum L.). Infected grain is usually contaminated with deoxynivalenol (DON), a serious mycotoxin. The challenge in FHB resistance breeding is combining resistance with superior agronomic and quality characteristics. Exotic QTL are widely used to improve FHB resistance. Success depends on the genetic background into which the QTL are introgressed, whether through backcrossing or forward crossing; QTL expression is impossible to predict. In this study four high-yielding soft red winter wheat breeding lines with little or no scab resistance were each crossed to a donor parent (VA01W-476) with resistance alleles at two QTL: Fhb1 (chromosome 3BS) and QFhs.nau-2DL (chromosome 2DL) to generate backcross and F2 progeny. F2 individuals were genotyped and assigned to 4 groups according to presence/ absence of resistance alleles at one or both QTL. The effectiveness of these QTL in reducing FHB rating, incidence, index, severity, Fusarium-damaged kernels (FDK) and DON, in F2-derived lines was assessed over 2 years. Fhb1 showed an average reduction in DON of 17.5%, and conferred significant resistance in 3 of 4 populations. QFhs.nau-2DL reduced DON 6.7% on average and conferred significant resistance in 2 of 4 populations. The combination of Fhb1 and QFhs.nau-2DL resistance reduced DON 25.5% across all populations. Double resistant lines had significantly reduced DON compared to double susceptible lines in 3 populations. Backcross derived progeny were planted in replicated yield trials (2011 and 2012) and in a scab nursery in 2012. Several top yielding lines performed well in the scab nursery, with acceptable DON concentrations, even though the average effect of either QTL in this population was not significant. Population selection is often viewed as an “all or nothing” process: if the average resistance level is insufficient, the population is discarded. These results indicate that it may be possible to find rare segregants which combine scab resistance, superior agronomic performance and acceptable quality even in populations in which the average effect of the QTL is muted or negligible

The First Korean Case of Beare-Stevenson Syndrome with a Tyr375Cys Mutation in the Fibroblast Growth Factor Receptor 2 Gene

Here we report the first case of a Korean infant with a cloverleaf-shaped craniosynostosis, in which the diagnosis of Beare-Stevenson syndrome was suspected upon observation of the typical morphological features. This infant exhibited craniofacial anomalies, ocular proptosis, cutis gyrata, acanthosis nigricans, prominent umbilical stump, furrowed palms and soles, hypospadia, and sacral skin tag coupled with dermal sinus tract. Brain magnetic resonance imaging revealed that the patient also had non-communicating hydrocephalus with Chiari malformation. This is the 8th report of Beare-Stevenson syndrome in the literature, which was confirmed by the detection of a Tyr375Cys mutation in the fibroblast growth factor receptor 2 (FGFR2) gene

Allelic Variations in Phenology Genes of Eastern U.S. Soft Winter and Korean Winter Wheat and Their Associations with Heading Date

Wheat heading time is genetically controlled by phenology genes including vernalization (Vrn), photoperiod (Ppd) and earliness per se (Eps) genes. Characterization of the existing genetic variation in the phenology genes of wheat would provide breeding programs with valuable genetic resources necessary for the development of wheat varieties well-adapted to the local environment and early-maturing traits suitable for double-cropping system. One hundred forty-nine eastern U.S. soft winter (ESW) and 32 Korean winter (KW) wheat genotypes were characterized using molecular markers for Vrn, Ppd, Eps and reduced-height (Rht) genes, and phenotyped for heading date (HD) in the eastern U.S. region. The Ppd-D1 and Rht-D1 genes exhibited the highest genetic diversity in ESW and KW wheat, respectively. The genetic variations for HD of ESW wheat were largely contributed by Ppd-B1, Ppd-D1 and Vrn-D3 genes. The Rht-D1 gene largely contributed to the genetic variation for HD of KW wheat. KW wheat headed on average 14 days earlier than ESW wheat in each crop year, largely due to the presence of the one-copy vrn-A1 allele in the former. The development of early-maturing ESW wheat varieties could be achieved by selecting for the one-copy vrn-A1 and vrn-D3a alleles in combination with Ppd-B1a and Ppd-D1a photoperiod insensitive alleles

Calcium Hydroxide Inactivates Lipoteichoic Acid from Enterococcus faecalis through Deacylation of the Lipid Moiety

Introduction: Lipoteichoic acid (LTA) is a major virulence factor of Enterococcus faecal is that is closely associated with refractory apical periodontitis. Recently, we have shown that calcium hydroxide, a commonly used intracanal medicament, abrogated the ability of LTA to stimulate the production of tumor necrosis factor alpha in a murine macrophage line, RAW 264.7. Because calcium hydroxide could potentially modify the glycolipid moiety of LTA, we examined if calcium hydroxide inactivates LTA through deacylation of the LTA. Methods: LTA was prepared from E. faecalis by organic solvent extraction followed by chromatography with the hydrophobic-interaction column and the ion-exchange column. RAW 264.7 cells were stimulated with intact LTA or calcium hydroxide treated LTA for 24 hours, and the productions of nitric oxide (NO) and chemokines interferon-gamma induced protein (IP-10) and macrophage inflammatory protein-1 alpha (MIP-1 alpha) were determined. The glycolipid structure of LTA was analyzed using matrix-assisted laser desorption ionization-time of flight mass spectrometry and thin layer chromatography (TLC). Results: The production of NO, IP-1, and MIP-1 alpha was augmented in LTA-stimulated cells, whereas no such effect was observed upon stimulation with calcium hydroxide pretreated LTA. Mass spectrometry showed that intact glycolipids of LTA yielded distinct mass peaks at 930 to 1,070 mass over charge (m/z) units, corresponding to dihexosyl-diacylglycerol consisting of two acyl chains with chain lengths of C(16) to C(22) and with one or two unsaturated double bonds. However, those peaks were not observed in the mass spectra of the calcium hydroxide-treated LTA. Furthermore, free fatty acids released from the calcium hydroxide-treated LTA were detected using TLC. Conclusion: We suggest that calcium hydroxide attenuates the inflammatory activity of E. faecal is LTA through deacylation of the LTA. (J Endod 2011;37:191-196)Supported by grants from Korea Research Foundation funded by the Korean Government (KRF-2008-314-E00223), from the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2010-0029116), and from a Science Research Center grant to the Bone Metabolism Research Center (20100001746) funded by the Korean Ministry of Education, Science and Technology, Republic of Korea.