03164nam a2200349 a 450000100080000000500110000800800410001910000260006024500680008626000400015430000100019450000240020452023320022865000100256065000240257065000290259465000100262365000140263365000120264765000090265965000250266865300110269365300110270465300080271565300110272365300180273465300120275265300090276465300120277365300210278565300080280614443572006-06-01       1989    bl uuuu  m   00u1 u    #d1 aFRANCA NETO, J. de B.  aPathological and physiological studies of soybean seed quality.  a[S.l.]: University of Floridac1989  a121p.  aPh.D. Dissertation.  aPathological and physiological qualities of soybean [Glycine max (L.) Merrill] seeds were studied. In a survey of the quality of commercial soybean seeds produced in Florida in 1986, mechanical damage was the most detrimental factor affecting seed quality, followed by weathering and stink bug damage. Due to climatic conditions, seed produced in the eastern region of the Florida panhandle had lower levels of infection by several fungi. Apparently this region is more suitable for production of soybean seed. Phomopsis spp. were the fungi most frequently associated with soybean seeds (up to 77% incidence). Seed infection was mainly restricted to the seedcoat. Rolled paper toweling was not the best substrate to evaluate germination of soybean seed infected with high incidence of Phomopsis spp. Emergence in sand, which simulates emergence in soil, provide a more representative estimate of viability. The tetrazolium test provided similar results to the emergence-in-sand test. Seed infection by Colletotrichum truncatum (Schw.) Andrus and Moore was mainly restricted to the seedcoat, but 15% of the seed samples had up to 10% embryo infection. Although C. truncatum infected fewer seeds than Phomopsis spp., it caused more damping-off. Emergence in sand provided better estimates of viability for seeds infected by C. truncatum than the standard germination test. Cercospora kikuchii (Matsu. and Tomoyasu) Gardner was almost exclusively restricted to the seedcoat. An antagonistic effect between C. kikuchii and Phomopsis spp. was observed. No detrimental effects of seed infection by C. kikuchii were observed on germination, emergence, and vigor of soybean seeds. The tetrazolium test can be used for estimating germination and vigor of soybean seeds. The test also diagnoses the causes that contribute to lower seed quality, such as mechanical, weathering, and stink bug damages. The tetrazolium test will enable seed producers to identify and correct the causes that affect soybean seed quality. The test is not influenced by the presence of fungi infecting soybean seed. Therefore, this technique can help the researcher visualize and understand some processes of seed deterioration. When combined with bio-assays, the test allows the researcher to separate fungal deterioration from other sources of deterioration.  afungi  aCercospora Kikuchii  aColletotrichum Truncatum  aFungo  aQualidade  aSemente  aSoja  aTeste de Tetrazólio  aEfeito  aEffect  aEUA  aFungus  aPhomopsis spp  aQuality  aSeed  aSoybean  aTetrazolium test  aUSA