Pathogenicity tests verifying the behavior of Septoria tritici isolates should be considered as a priority in the selection of resistant wheat materials to this pathogen, since the aggressiveness of each isolate can vary significantly, causing problems in the evaluation and selection of resistant genotypes. The objective of this work was to determine whether physiologic specialization exists am...

The bird cherry-oat aphid Rhopalosiphum padi (L.) transmits the nonpersistent Potato virus Y (PVY) to seed potatoes. Planting a nonvirus host plant around the main crop can reduce PVY incidence, because aphids tend to land in high numbers at the edge of a field and the crop border acts as a virus sink. This study determined R. padi landing and settling preferences and reproductive rates on thre...

et al., 1981) and timothy (Phleum pratense L.; Braverman, 1966; Nielson and Dickson, 1958). In addition, Genetic resistance to stem rust (caused by Puccinia graminis several cultivars of perennial ryegrass (Lolium perenne Pers.:Pers. subsp. graminicola Z. Urban) could reduce the need for fungicides to control the disease in tall fescue [Lolium arundinaceum L.) with reduced susceptibility to ste...

Fourteen cultivars included in the University of Arkansas Soybean Variety Testing Program were selected for evaluation based on their tolerance to Roundup herbicide (Roundup Ready® or Conventional) and their ability to include or exclude chloride (Table 1). Trials conducted at the Cotton Branch Experiment Station (CBES) near Marianna, Ark., and the Rice Research Extension Center (RREC) near, St...

The world-wide capacity of genebanks for ex situ conservation of crop genetic resources has increased greatly since the 1970s, improving the access of crop breeders to landraces and wild and weedy relatives. But utilization of genebank resources has not kept pace. The set of popular cultivars in major crops is typically rather small, and their ancestry encompasses only a fraction of the genetic...

The purpose of the present investigation was to study the effects of Ca 2+ on water relation of two wheat cultivars (Akbar and Kanchan) under salt stress. The two wheat cultivars were grown in pots with 0 and 150 mM NaCl salinity. Calcium was applied in the form of gypsum in 0.12, 0.24 and 0.36g pot -1 (that is 20, 40 and 60 kg ha -1 ) respectively. Salinity decreased RWC, WRC, exudation rate a...

Changes in quantity and quality of corn crop stover can have a large impact on soil conservation and soil carbon (C) sequestration over large areas. The aim of this study was to evaluate changes in production, concentration and amount of C and nitrogen (N) in corn stover fractions due to cultivar development. Two field experiments were conducted in the city of Rolândia (Paraná State, Brazil) us...

Drought is the most significant constraint for crop production in arid and semi-arid regions. In order to assess drought tolerance in fifteen rapeseed (Brassica napus) cultivars using yield-based drought tolerance indices, two experiments were conducted at the research station of College of Agriculture, Shiraz University, Shiraz, Iran during 2009-2010 growing season. The cultivars were...

TaGS5 genes were cloned from bread wheat and were physically mapped on 3AS and 3DS. Sequencing results revealed that a SNP was found in the sixth exon of TaGS5-A1 gene. The SNP resulted in amino acid change from alanine to serine at the 303 bp position of TaGS5-A1. These two alleles were designated as TaGS5-A1a (alanine at the 303 bp position) and TaGS5-A1b genes (serine at the 303-bp position)...