Tagosodes orizicolus is one of the main plagues of rice in tropical America causing two types of damages, the direct one, feeding and oviposition effect, and an indirect one, by the transmission of the "Rice hoja blanca virus". During 2006-2007 we carried out research under greenhouse conditions at Fundaci6n Danac, Venezuela, in order to determine the mechanisms of antixenosis, antibiosis and t...

Determining the most Tolerant Genotypes of Hashemi Rice Mutant (M3) in Response to Drought Stress using Physiological Growth Indices and Enzymatic Changes

Genetic divergence is an efficient tool for the selection of parents used in hybridization programme. In the present study, fifty three rice genotypes consisting of high yielding rice varieties/ cultures and IRRI germplasm lines were raised at Rice Research Station, Tirur during Sornavari, 2009 to identify diverse genotypes. They were evaluated for eight yield and yield attributing characters u...

Continuous cropping of rice (Oryza sativa L.) and wheat (Triticum aestivum L.) deplete soil fertility and crop productivity. One strategy to increase crop productivity under rice-wheat system is balanced application of crop nutrients. Field experiment was conducted to assess the impact of phosphorus (0, 40, 80, 120 kg P ha(-1)) and zinc (0, 5, 10, 15 kg Zn ha(-1)) on the productivity of rice ge...

In order to study the genetic diversity in rice (Oryza sativa L.), 29 genotypes consisting land races, pure and improved lines were evaluated using simple sequence repeat (SSR) markers. A total of 30 SSR primers were used to amplify some part of rice genome in germplasms, the PIC values ranged from 0.07 (RM 340) to 0.71 (RM 7426) with an average of 0.45. The results showed a total number of 106...

A total of 448 samples in five natural populations of wild rice (Oryza rufipogon) were collected in Cambodia. They were examined using 12 SSR and two chloroplast markers to evaluate the degree of variation among populations and the genetic structure within populations. In the two annual populations, the number of plants with homozygous alleles at all 12 SSR loci were high (66.3% and 79.5%), sug...

Expression profiling is one of the most important tools for dissecting biological functions of genes and the upregulation or downregulation of gene expression is sufficient for recreating phenotypic differences. Expression divergence of genes significantly contributes to phenotypic variations. However, little is known on the molecular basis of expression divergence and evolution among rice geno...

The use of genetic resources for rice has been suggested as the most relevant alternative to raise the productivity levels achieved by modern cultivars (Brondani et al. 2003). However, before using these resources, it is fundamental to compile in depth knowledge on the existing genetic variability in these accessions to identify genotypes that could ultimately contribute effectively to genetic ...

Bacterial leaf blight (BLB) of rice is a very destructive disease worldwide and is caused by Xanthomonas oryzae pv. oryzae (Xoo). The aim of the present study was to examine if the Xoo virulence pathotypes obtained using phenotypic pathotyping could be confirmed using molecular approach. After screening of 60 Operon primers with genomic DNA of two Xoo isolates (virulent pathotype, Vr, and mildl...