EVALUATION OF SCAB RESISTANCE QUANTITATIVE TRAIT LOCI (QTL) EFFECTS ON WHEAT

Fusarium Head Blight (FHB) of wheat (Triticum aestivum), caused by Fusarium graminearum, is a disease that periodically strikes the mid-Atlantic region of the USA. Breeding for resistant wheat cultivar is an effective method of disease control. McCormick, a genotype adapted to the mid-Atlantic region, was used in a backcross program with the Chinese cultivar Ning7840. Eight Near-Isogenic Lines (NIL) were developed by marker-assisted backcrossing. Three FHB resistance QTL on chromosomes 3BS, 2DL, and 5A were introgressed from non-adapted Ning7840 into the elite soft red winter wheat McCormick. The objective of this study was to evaluate the effects of QTL singly and in combination on FHB resistance. The 3BS+2DL NIL showed higher resistance and lower deoxynivalenol content than other NIL in both field and greenhouse studies. This suggests that the 3BS+2DL NIL can be used in the mid-Atlantic region to breed for improved FHB resistance

Massive and Red Objects predicted by a semianalytical model of galaxy formation

We study whether hierarchical galaxy formation in a concordance $\Lambda$CDM universe can produce enough massive and red galaxies compared to the observations. We implement a semi-analytical model in which the central black holes gain their mass during major mergers of galaxies and the energy feedback from active galaxy nuclei (AGN) suppresses the gas cooling in their host halos. The energy feedback from AGN acts effectively only in massive galaxies when supermassive black holes have been formed in the central bulges. Compared with previous models without black hole formation, our model predicts more massive and luminous galaxies at high redshift, agreeing with the observations of K20 up to $z\sim 3$. Also the predicted stellar mass density from massive galaxies agrees with the observations of GDDS. Because of the energy feedback from AGN, the formation of new stars is stopped in massive galaxies with the termination of gas cooling and these galaxies soon become red with color $R-K>$5 (Vega magnitude), comparable to the Extremely Red Objects (EROs) observed at redshift $z\sim$1-2. Still the predicted number density of very EROs is lower than observed at $z\sim 2$, and it may be related to inadequate descriptions of dust extinction, star formation history and AGN feedback in those luminous galaxies.Comment: Accepted for Publication in ApJ, added reference

Probing the CP-even Higgs Sector via H3→H2H1H_3\to H_2H_1 in the Natural NMSSM

After the discovery of a Standard Model (SM) like Higgs boson, naturalness strongly favors the next to the Minimal Supersymmetric SM (NMSSM). In this letter, we point out that the most natural NMSSM predicts the following CP-even Higgs $H_i$ sector: (A) $H_2$ is the SM-like Higgs boson with mass pushed-upward by a lighter $H_1$ with mass overwhelmingly within $[m_{H_2}/2,m_{H_2}]$; (B) $m_{H_3}\simeq 2\mu/\sin2\beta\gtrsim300$ GeV; (C) $H_3$ has a significant coupling to top quarks and can decay to $H_1H_2$ with a large branching ratio. Using jet substructure we show that all the three Higgs bosons can be discovered via $gg\to H_3 \to H_1H_2\to b\bar b \ell\nu jj$ at the 14 TeV LHC. Especially, the LEP-LHC scenario with $H_1\simeq98$ GeV has a very good discovery potential.Comment: 5 pages, 2 figures. Some typos corrected and reference adde