Histopathology of Seed-Borne Infections - Applied Research Center ...

50 Histopathology of Seed-Borne InfectionsBPBACEDFGFIGURE 3.1 SEM photomicrographs of surface and micropyle of seeds of soybean cultivars.A, cultivar Williams seed coat surface with micropores. B to D, cultivar Sooty. B, Seed coatsurface without pores. C, D, Seed coat surface showing areas without and with blooms,respectively. E, Cultivar Williams seed coat surface showing areas with and without deposits.F, G, Micropyle, open-type cultivar Williams and closed-type cultivar Laredo, respectively.(Abbreviation: p, pore.) (A, B, F, G, From Kulik, M.M. and Yaklich, R.W. 1991. Crop Sci.31: 108–113; C to E, From Yaklich, R.W., Vigil, E.L., and Wergin, W.P. 1986. Crop Sci. 26:616–624. With permission.)3.2.5 MICROPYLEThe size and position of the micropyle are usually given in seed descriptions and,usually, in dry seeds the micropyle is described as occluded. SEM micrographs haveindicated significant differences in measurements of the micropyle in seeds ofdifferent cultivars of soybean (Kulik and Yaklich, 1991). Kuklik and Yaklich dividethe micropyle into two broad types: open (Figure 3.1F) and closed (Figure 3.1G).The average opening of the open micropyle is 0.44 mm 2 and the average openingof the closed micropyle is 0.18 mm 2 . In soybean cultivars, the open type of micropyle