Designed and validated novel allele-specific primer to differentiate Kernel Row Number (KRN) in tropical field corn.

BACKGROUND: Kernel row number (KRN) is an important yield component trait with a direct impact on the productivity of maize. The variability in KRN is influenced by the inflorescence meristem size, which is determined by the CLAVATA-WUSCHEL pathway. A CLAVATA receptor-like protein, encoded by the FASCIATED EAR2 (fea2gene), enhances the growth of inflorescence meristem and is thus involved in the determination of KRN. The amplicon sequencing-based method was employed to dissect the allelic variation of the fea2 gene in tropical field corn. METHODOLOGY/PRINCIPAL FINDING: Amplicon-based sequencing of AI 535 (Low KRN) and AI 536 (High KRN) was undertaken for the gene fea 2 gene that codes for KRN in maize. Upon multiple sequence alignment of both sequences, A to T transversion at the 1311 position was noticed between Low KRN and High KRN genotypes resulting in different allelic forms of a fea2 gene in tropical maize. An allele-specific primer 1311 fea2.1 was designed and validated that can differentiate High and Low KRN genotypes. CONCLUSION/SIGNIFICANCE: Maize has high variability for KRN and is exemplified by the wide values ranging from 8-26 KRN in the maize germpalsm. The sequence-based approach of SNP detection through the use of a specific primer facilitated the detection of variation present in the target trait. This makes it possible to capture these variations in the early generation. In the study, the PCR-based differentiation method described for the identification of desirable high KRN genotypes would augment the breeding programs for improving the productivity of field corn.

Endoscopic pancreatic necrosectomy: why scuff when you can flush the muck - make it an easy row to hoe.

BACKGROUND AND AIMS: Endoscopic ultrasound (EUS) guided drainage of symptomatic pancreatic walled-off necrosis (WON) followed by fully covered self-expanding metal stent (FCSEMS) placement offers several advantages such as higher technical success rate and the option of necrosectomy. The aim of this study was to evaluate the safety and efficacy of EUS guided drainage of patients with WON by using FCSEMS and intracavitary lavage with a solution containing hydrogen peroxide and adopting a step-up approach. METHODS: A prospective open label study was carried out at a single tertiary care center between January 2014 and January 2016. Patients with symptomatic WON who underwent EUS guided drainage followed by FCSEMS placement were included. Primary end points were complete drainage with improvement in symptoms or major adverse events. Secondary end points were minor adverse events related to the procedures. RESULTS: A total of 64 patients (mean age 36 years; 52 males) were included. Technical success was achieved in 100 % of patients and clinical success was achieved in 90.6 %. Complete drainage was achieved with FCSEMS alone in 18 (28.1 %), FCSEMS with necrosectomy using lavage in 40 (62.5 %), FCSEMS with percutaneous drainage (PCD) in 5 (7.8 %), and 1 (1.6 %) patient required salvage surgery. The major adverse event was life threatening bleeding in 3 (4.7 %) patients. Minor adverse events were non-life threatening bleeding in 2 (3.1 %) patients and stent migration in 3 (4.7 %) patients. CONCLUSION: EUS guided WON drainage with FCSEMS followed by necrosectomy with lavage using a solution containing hydrogen peroxide as a step-up approach is a minimally invasive and effective method with a high technical and clinical success rate. Patients with solid debris > 40 % need aggressive management.

Diverse role of fast growing rhizobia in growth promotion and enhancement of psoralen content in Psoralea corylifolia L.

BACKGROUND: Psoralea corylifolia (Bakuchi), a weed, which possesses a highly potent and medicinally important compound psoralen. P. corylifolia has been widely exploited since ages for its biological potential. MATERIALS AND METHODS: Fifteen root nodulating bacteria as pure culture collection (PCC) were isolated from P. corylifolia in India. Further, these strains were evaluated for their effect on the psoralen content in P. corylifolia. High performance liquid chromatography (HPLC) method was used for the estimation of psoralen in P. corylifolia seed extracts. The effectiveness of these rhizobial strains was assessed on the basis of screening of various plant growth promoting attributes. RESULTS: The 16S ribosomal RNA sequencing analysis revealed the identity of two most effective rhizobial isolates PCC2 and PCC7 as Rhizobium leguminosarum and Sinorhizobium meliloti, respectively. The R. leguminosarum PCC2 (JN546144) and Ensifer meliloti PCC7 (JN546145) strains showed solubilization of insoluble inorganic phosphate, secreted indole acetic acid (IAA), produced siderophore, showed ACC deaminase activity, and were positive for nodulation and nitrogen fixing genes. Seeds of P. corylifolia were bacterized with combination of R. leguminosarum PCC2 and Ensifer meliloti PCC7 along with their individual application that resulted in enhancement of various early vegetative and late reproduction parameters of plants in two consecutive field trials in the year 2009 and 2010. The psoralen content in the seeds of P. corylifolia was observed to be increased in the field trials where the combination of rhizobial strains PCC2 and PCC7 was used (2.79%) compared to control (1.91%). CONCLUSION: These findings indicate that rhizobial strains PCC2 and PCC7 showing good plant growth promoting attributes can be effective for increasing the psoralen content in the seeds of P. corylifolia to a certain level.