Identification of Glu-D1 Alleles and Novel Marker-Trait Associations for Flour Quality and Grain Yield Traits under Heat-Stress Environments in Wheat Lines Derived from Diverse Accessions of Aegilops tauschii.

Heat stress during grain filling is considered one of the major abiotic factors influencing wheat grain yield and quality in arid and semi-arid regions. We studied the effect of heat stress on flour quality and grain yield at moderate and continuous heat stress under natural field conditions using 147 lines of wheat multiple synthetic derivatives (MSD) containing Aegilops tauschii introgressions. The study aimed to identify the marker-trait associations (MTAs) for the quality traits and grain yield under heat-stress conditions and identify stress-resilient germplasm-combining traits for good flour quality and grain yield. The MSD lines showed considerable genetic variation for quality traits and grain yield under heat-stress conditions; some lines performed better than the recurrent parent, Norin 61. We identified two MSD lines that consistently maintained relative performance (RP) values above 100% for grain yield and dough strength. We found the presence of three high-molecular-weight glutenin subunits (HMW-GSs) at the Glu-D1 locus derived from Ae. tauschii, which were associated with stable dough strength across the four environments used in this study. These HMW-GSs could be potentially useful in applications for future improvements of end-use quality traits targeting wheat under severe heat stress. A total of 19,155 high-quality SNP markers were used for the genome-wide association analysis and 251 MTAs were identified, most of them on the D genome, confirming the power of the MSD panel as a platform for mining and exploring the genes of Ae. tauschii. We identified the MTAs for dough strength under heat stress, which simultaneously control grain yield and relative performance for dough strength under heat-stress/optimum conditions. This study proved that Ae. tauschii is an inexhaustible resource for genetic mining, and the identified lines and pleiotropic MTAs reported in this study are considered a good resource for the development of resilient wheat cultivars that combine both good flour quality and grain yield under stress conditions using marker-assisted selection.

Transcatheter Closure of Atrial Septal Defects: Comparable Experience and Outcomes Between Developing and Developed Countries.

Atrial septal defect (ASD) is one of the most common congenital heart defects. Transcatheter device closure of ASDs is safe and effective with most of the reported data being described from developed countries. To evaluate the short and mid-term results and experience of device closure of ASDs at a tertiary center in a developing country and compare it to that from developed countries. Retrospective study based on data collection from all patients who have undergone transcatheter percutaneous device closure for ASD from January 2005 until December 2017 at the Children's Heart Center at the American University of Beirut, Medical Center, Lebanon. During the study period, a total of 254 cardiac catheterizations were performed for device closure of ASDs. The mean age of the patients was 18 ± 17.9 years with 37% being less than 6 years of age. Females were 54%. Defect size ranged from 7 to 37 mm and device size ranged from 8 to 40 mm. The procedure was executed with a success rate of 96%. Five patients had device embolization (2%); in one patient the device was snared and for the remainder the devices were removed surgically. None of the study patients had thrombus formation, neurological complications, bacterial endocarditis, or cardiac erosions. There was no mortality. Device closure of ASDs at our tertiary center in a developing country has an effective and safe profile with excellent results and low complications rates, which compare favorably to those reported from centers in developed countries.