phytophthora root and crown rot of soybean is known as a destructive disease of soy-bean both through out the world and in iran. physiologic races of phytophthora soja were determined in this research and also a fast, accurate and simple method for inoculation of soybean to test race specific resistance. during the years　2001-4, infected soybean plants at different growth stages were collected ...

sunflower downy mildew, caused by plasmopara halstedii, is one of the most important diseases of this crop in west-azarbaijan, urmia. it causes economic yield losses during favorable environmental conditions. the pathogen is a polycyclic one, and it is likely that physiological changes occur in its population and subsequent appearance of new physiological races. hence, identification of the exi...

Turesson (14, 15, 16) demonstrated that species occurring in a wide range of climates are composed of genetically distinct races, and developed the concept that such races are products of natural selection. This concept is fundamental to an understanding oi mechanisms underlying natural selection and evolution of higher plants. Extensive later experiments bv other wvorkers on the response and s...

Costa VP, De-Oliveira FR. Physiological variables to predict performance in cross-country mountain bike races. JEPonline 2008;11(6):14-24. Mountain bike (MTB) is a recent sport derived from cycling with little information about the athletes and races. The aim of this study was to identify the morph-physiological characteristics in Elite MTB athletes and the physiological variables associated in...

How generalist parasites with wide host ranges can evolve is a central question in parasite evolution. Albugo candida is an obligate biotrophic parasite that consists of many physiological races that each specialize on distinct Brassicaceae host species. By analyzing genome sequence assemblies of five isolates, we show they represent three races that are genetically diverged by ∼1%. Despite thi...

Eighteen hosts were inoculated with each of four races of Heterodera glycines. A discriminant function analysis of the reactions of these races to these hosts demonstrated that these races could be separated but not consistently. Then 33 H. glycines populations collected from 13 states and five obtained from Japan were tested on differential hosts. The number of variants discriminated within th...

The host preferences of populations of Meloidogyne naasi from England, California, Illinois, Kentucky and Kansas were compared. Among 22 plant species tested, most were hosts for isolates of all five populations; crabgrass was added to the list of known hosts. Differential reactions of isolates on creeping bentgrass, curly dock, sorghum, and common chickweed demonstrated the existence of at lea...

BACKGROUND AND AIMS Orobanche minor is a root-holoparasitic angiosperm that attacks a wide range of host species, including a number of commonly cultivated crops. The extent to which genetic divergence among natural populations of O. minor is influenced by host specificity has not been determined previously. Here, the host specificity of natural populations of O. minor is quantified for the fir...