Genomic regions involved in the control of 1,000-kernel weight in wild relative-derived populations of durum wheat

Terminal drought is one of the most common and devastating climatic stress factors affecting durum wheat (Triticum durum Desf.) production worldwide. The wild relatives of this crop are deemed a vast potential source of useful alleles to adapt to this stress. A nested association mapping (NAM) panel was generated using as a recurrent parent the Moroccan variety 'Nachit' derived from Triticum dicoccoides and known for its large grain size. This was recombined to three top-performing lines derived from T. dicoccoides, T. araraticum, and Aegilops speltoides, for a total of 426 inbred progenies. This NAM was evaluated across eight environments (Syria, Lebanon, and Morocco) experiencing different degrees of terminal moisture stress over two crop seasons. Our results showed that drought stress caused on average 41% loss in yield and that 1,000-kernel weight (TKW) was the most important trait for adaptation to it. Genotyping with the 25K TraitGenetics array resulted in a consensus map of 1,678 polymorphic SNPs, spanning 1,723 cM aligned to the reference 'Svevo' genome assembly. Kinship distinguished the progenies in three clades matching the parent of origin. A total of 18 stable quantitative trait loci (QTLs) were identified as controlling various traits but independent from flowering time. The most significant genomic regions were named Q.ICD.NAM-04, Q.ICD.NAM-14, and Q.ICD.NAM-16. Allelic investigation in a second germplasm panel confirmed that carrying the positive allele at all three loci produced an average TKW advantage of 25.6% when field-tested under drought conditions. The underlying SNPs were converted to Kompetitive Allele-Specific PCR (KASP) markers and successfully validated in a third germplasm set, where they explained up to 19% of phenotypic variation for TKW under moisture stress. These findings confirm the identification of critical loci for drought adaptation derived from wild relatives that can now be readily exploited via molecular breeding.

Detection of blaoxa genes and identification of biofilm-producing capacity of Acinetobacter baumannii in a tertiary teaching hospital, Klaten, Indonesia

INTRODUCTION

Acinetobacter baumannii (A. baumannii) is commonly found as an agent of nosocomial infections and demonstrates a high antibiotic resistance due to its carbapenemase production. The objectives of this study were to explore the antibiotic resistance pattern, the presence of OXAs genes and the biofilm-producing capacity of A. baumannii isolated from clinical specimens.

METHODS

Antibiotics susceptibility testing, detection of OXAs genes and the biofilm-producing capacity were performed using the Kirby Bauer method, polymerase chain reaction (PCR) and adherence quantitative assays, respectively.

RESULTS

A total of 80 A. baumannii isolates were mainly obtained from sputum and most of them were resistant to antibiotics. All A. baumannii carried bla_OXA-51 gene, yet no bla_OXA-24 and bla_OXA-58 genes were detected. Fourteen (82.4%) of the 17 meropenem resistant isolates carried bla_OXA-23 gene, but it was not found in meropenem sensitive isolates. In addition, sixty (75.0%) of 80 isolates were biofilm producers with 2 (2.5%), 16 (20.0%), and 42 (52.5%) isolates were identified as strong, moderate and weak biofilm producers, respectively.

CONCLUSION

Most of A. baumannii isolates had a high level of antibiotic resistance and had a capacity to produce biofilm.

Evolution of Physiologic Races and Virulence of Puccinia striiformis on Wheat in Syria and Lebanon

Virulence-avirulence phenotypes of Puccinia striiformis isolates collected in Lebanon and Syria were determined on seedlings of the wheat-yellow rust differential genotypes. We found 25 and 11 physiologic races over 6 years (1994 to 1999) in Syria and Lebanon, respectively. The composition of physiologic races found in Syria and Lebanon differed greatly between 1994 and 1999. Races identified in 1999, such as 230E150 and 230E134, have wider spectra of virulence on resistant genotypes than races collected in 1994. In Lebanon, three races were found in 1994 compared with six races in 1999. Yellow rust differential genotypes were used in a trap nursery to monitor yellow rust populations under natural conditions. Races identified from cultivars in the trap nursery in Syria and Lebanon, and from land race cultivars in Iraq, were recovered among the races identified from farm fields. Yellow rust samples were collected from Yemen, and none of the races identified from Yemen samples were identical to those in Syria and Lebanon. Virulence frequencies in the yellow rust population on the differential genotypes tested in the trap nurseries were above 70% for some resistance genes. Yellow rust populations in Syria and Lebanon have diverse virulence phenotypes. P. striiformis populations appear to be changing over, and this would be an important consideration for wheat breeding programs in the region.

A new predictive modality of cranial bone thickness

The objective of this study was to evaluate A-mode ultrasound in the assessment of cranial bone thickness utilizing an in vivo animal model. A prospective study was performed that identified four standardized calvarial points in 10 Landrace porcine skulls. The individual points were scanned with an A-mode ultrasonic transducer to obtain bone thickness measurements. The same points were measured subsequently using digital calipers for objective comparison. The accuracy of each of the measurement modalities was evaluated for inter- and intrarater reliability. The association between ultrasonic and caliper measurements was evaluated using Student's t-test, Pearson's correlation coefficient, and linear regression models to assess the effect of confounding variables. The mean difference between the ultrasonic and the caliper values was 0.31 +/- 0.22 mm (standard deviation). The statistical analyses employed strongly supported the predictive value of ultrasound as a function of the true calvarial thickness (p < 0.05, r > 0.88, R2 = 0.89). The results suggest that ultrasound is an accurate reflection of cranial bone thickness in an in vivo animal skull model. The development of a portable, noninvasive ultrasonic device can have substantial clinical implications for craniomaxillofacial surgery.