influence of wsmv infection on biochemical changes in two bread wheat cultivars and in their f2 populations

wheat streak mosaic virus (wsmv) causes extensive economic damage to wheat (triticum aestivum l.) in many regions of the world. the present study was conducted to find out if the variations in biochemical changes in reaction to wsmv infection in f2 generation of either potentially resistant (adl-cross) or susceptible (marvdasht) cultivars are genetically inherited. a factorial experiment was employed with two factors of: genotypes (adl-cross, marvdasht, reistant f2s and susceptible f2s), and inoculation (either infected or non infected) at shiraz university, iran during 2007-2009. leaves of seedlings were harvested at different time intervals for total protein, total phenolic compounds and peroxidase activity analysis. results indicated that virus infection caused stress in all genotypes. total protein reduction in the inoculated resistant adl-cross and in its f2s was not significant whereas it was significant in the inoculated susceptible marvdasht and its susceptible f2s. viral infection reduced peroxidase activity in the susceptible marvdasht cultivar and in its susceptible f2s whereas in adl-cross and in its resistant f2s the activity was increased. it is speculated that peroxidase enzyme may affect synthesis of compounds effective in resistance to wheat streak mosaic virus. the trend in the increase in phenolic compounds indicated that their formation and accumulation is faster in the resistant genotypes as compared with the susceptible ones. it appears that the extent of total protein, total phenolic compounds as well as peroxidase activity changes in response to wsmv are inherited by the next generations and these biochemical changes in a genotype could be adopted as selective factors in the preliminary experimental stages of selection for tolerance to the virus.