-Weed management is a primary concern in direct seeded rice (DSR) cropping because weed growth becomes a major constraint on crop yield. A two year field study was set up to evaluate the effect of various weed control measures on crop growth, grain yield and grain quality of DSR. The experiment involved five different weed control measures: hand weeding, hoeing, inter-row tine cultivation, inter-row spike hoeing and herbicide treatment (Nominee 100 SC). The extent of weed control (compared to a non-weeded control) ranged from 50-95%. The highest crop yield was obtained using hand weeding. Hand weeding, tine cultivation and herbicide treatment raised the number of fertile rice tillers formed per unit area and the thousand grain weight. Tine cultivation provided an effective and economical level of weed control in the DSR crop.Keywords: herbicides, direct seeded rice, grain yield, tine cultivator. Palavras-chave: herbicidas, arroz em plantio direto, rendimento de grãos, cultivo com forcado. RESUMO

Background Armillaria species are plant pathogens, but a few Armillaria species can establish a symbiotic relationship with Gastrodia elata, a rootless and leafless orchid, that is used as a Chinese herbal medicine. Armillaria is a nutrient source for the growth of G. elata. However, there are few reports on the molecular mechanism of symbiosis between Armillaria species and G. elata. The genome sequencing and analysis of Armillaria symbiotic with G. elata would provide genomic information for further studying the molecular mechanism of symbiosis. Results The de novo genome assembly was performed with the PacBio Sequel platform and Illumina NovaSeq PE150 for the A. gallica Jzi34 strain, which was symbiotic with G. elata. Its genome assembly contained ~ 79.9 Mbp and consisted of 60 contigs with an N50 of 2,535,910 bp. There were only 4.1% repetitive sequences in the genome assembly. Functional annotation analysis revealed a total of 16,280 protein coding genes. Compared with the other five genomes of Armillaria, the carbohydrate enzyme gene family of the genome was significantly contracted, while it had the largest set of glycosyl transferase (GT) genes. It also had an expansion of auxiliary activity enzymes AA3-2 gene subfamily and cytochrome P450 genes. The synteny analysis result of P450 genes reveals that the evolutionary relationship of P450 proteins between A. gallica Jzi34 and other four Armillaria was complex. Conclusions These characteristics may be beneficial for establishing a symbiotic relationship with G. elata. These results explore the characteristics of A. gallica Jzi34 from a genomic perspective and provide an important genomic resource for further detailed study of Armillaria. This will help to further study the symbiotic mechanism between A. gallica and G. elata.

No abstract

Foot and mouth disease (FMD) is highly contagious viral infection of cloven footed animals caused by Aphthovirus of family picornaviridae. Genome of virus is single stranded positive sense RNA. Experiment was conducted to optimize multiplex PCR (mPCR) for rapid detection of circulating serotypes of FMD virus in Pakistan. The serotype-specific primers were selected from VP1 region of FMDV genome responsible for antigenic diversity of the virus. After RNA extraction cDNA was synthesized followed by PCR reaction with serotype specific primers. In multiplex PCR (mPCR) serotype specific primers amplified products of 386, 232 and 240 base pair (bp) for A, O and Asia1 serotypes of FMDV respectively at 56.5 0 C annealing temperature. Sensitivity of multiplex PCR was tested at different concentrations (1.5 μl, 2 μl and 3 μl) of template DNA. It was found to be highly sensitive at 3 μl concentration of template DNA. On 20 suspected FMD clinical samples, mPCR showed that it belongs to Asia1 serotypes. The test was found to be very specific for FMDV and exhibited no cross reactivity with peste de petits ruminants virus (PPRV). Multiplex PCR have shown 100% sensitivity on field samples. The test is sensitive and specific and can be used for serotyping of FMDV.All copyrights reserved to Nexus® academic publishers

No abstract