Health status evaluation of certified wheat seed of Semnan province against seed-borne pathogen T. laevis in order to issue national wheatseed standard

Seed is an important input in sustainable agriculture. Pests and diseases damage estimated for themost important eight crops grown in the world is about ٣٠٠-٤٠٠ billion USA each year and aconsiderable proportion of these losses are due to seedborne infections. Keeping in mind theimportance of seeds and their role in transmission and scattering of threatening seedbornepathogens, seed health test is unavoidable. For this purpose in the year ١٣٩٢, ٨٢ seed samples ofcommercial varieties Arg, Pishtaz, Alvand and Kavir from wheat certified category were collectedand based on International Seed Testing Association protocol, washing test by weighing ١٠٠ gramof seed, adding ١٠٠ CC distilled water and ١or ٢ drops of T٢٠, shook and centrifugation wascarried out. Then after, adding known amount of distilled water to sediment,١٠ μL of suspensionfor observation and counting of spores if present was transferred under light microscope. Thenumber of spores per seed counted as ٣.٣. Result reveals that as compare to result obtained in year١٣٨٩, (٤.٣number of spore /seed), there is ٢٤.٣% reduction in contamination by spores of T. laevis.Reduction of number of spore pre seed indicates selected management strategies were satisfactoryand continuity of selection of healthy fields, field inspection, seed treatment with chemical poisonsand etc is compulsory.

کلیدواژه ها:

certified ، seed ، spore ، standard ، test