Development, characterization and use of genomic SSR markers for assessment of genetic diversity in some Saudi date palm ( Phoenix dactylifera L.) cultivars

Background: The present study was undertaken towards the development of SSR markers and assessing genetic relationships among 32 date palm ( Phoenix dactylifera L.) representing common cultivars grown in different geographical regions in Saudi Arabia. Results: Ninety-three novel simple sequence repeat markers were developed and screened for their ability to detect polymorphism in date palm. Around 71% of genomic SSRs were dinucleotide, 25% tri, 3% tetra and 1% penta nucleotide motives. Twenty-two primers generated a total of 91 alleles with a mean of 4.14 alleles per locus and 100% polymorphism percentage. A 0.595 average polymorphic information content and 0.662 primer discrimination power values were recorded. The expected and observed heterozygosities were 0.676 and 0.763 respectively. Pair-wise similarity values ranged from 0.06 to 0.89 and the overall cultivars averaged 0.41. The UPGMA cluster analysis recovered by principal coordinate analysis illustrated that cultivars tend to group according to their class of maturity, region of cultivation, and fruit color. Analysis of molecular variations (AMOVA) revealed that genetic variation among and within cultivars were 27% and 73%, respectively according to geographical distribution of cultivars. Conclusions: The developed microsatellite markers are additional values to date palm characterization tools that can be used by researchers in population genetics, cultivar identification as well as genetic resource exploration and management. The tested cultivars exhibited a significant amount of genetic diversity and could be suitable for successful breeding program. Genomic sequences generated from this study are available at the National Center for Biotechnology Information (NCBI), Sequence Read Archive (Accession numbers. LIBGSS_039019).

Comparison of Complications and Efficacy of NIPPV and Nasal CPAP in Preterm Infants With RDS

Background: Respiratory distress syndrome (RDS) is one of the most common diseases in neonates admitted to NICU. For this important cause of morbidity and mortality in preterm neonates, several treatment methods have been used. To date, non-invasive methods are preferred due to fewer complications. Objectives: Herein, two non-invasive methods of ventilation support are compared: NCPAP vs. NIPPV. Patients and Methods: This is a randomized clinical trial. Premature neonates with less than 34 weeks gestation, suffering from RDS entered the study, including 151 newborns admitted to Vali-Asr NICU during 2012-2013. Most of these patients received surfactant as early rescue via INSURE method and then randomly divided into two NCPAP (73 neonates) and NIPPV (78 neonates) groups. Both early and late complications are compared including extubation failure, hospital length of stay, GI perforation, apnea, intraventricular hemorrhage (IVH) and mortality rate. Results: The need for re-intubation was 6% in NIPPV vs. 17.6% in NCPAP group, which was statistically significant (P = 0.031). The length of hospital stay was 23.92 ± 13.5 vs. 32.61 ± 21.07 days in NIPPV and NCPAP groups, respectively (P = 0.002). Chronic lung disease (CLD) was reported to be 4% in NCPAP and 0% in NIPPV groups (P = 0.035). The most common complication occurred in both groups was traumatization of nasal skin and mucosa, all of which fully recovered. Gastrointestinal perforation was not reported in either group. Conclusions: This study reveals the hospital length of stay, re-intubation and BPD rates are significantly declined in neonates receiving NIPPV as the treatment for RDS.