A Handbook of Rice Seedborne Fungi TW Mew and P ... - IRRI books

Detection frequency (%)120100East AsiaEuropeLatin AmericaSouth AsiaSoutheast AsiaSub-Saharan Africa806040200Detection level (%)353025201510501990 1991 1992 1993 1994 1995 1996 1997YearFig. 34. Detection frequency (a) and level (b) of Sarocladium oryzae from imported untreated seeds, 1990-97.seed surface, rarely becoming aerial. Conidiophoresare very short with conidia collected in aslime drop that are globose and shiny (Fig. 35a-c).c. Location on seedS. oryzae is mostly observed on the entire seed(about 46%) and on the lemma and/or palea(about 31%) (Fig. 36).Microscopic charactera. Mycelia—white, sparsely branched, septate (Fig.35d).b. Conidiophores—slightly thicker than the vegetativehyphae, simple, or branched either once ortwice; terminal branches tapering at the tip (Fig.35e).c. Conidia—hyaline, smooth, single-celled, cylindricalwith rounded ends; straight, sometimes slightlycurved, formed singly (Fig. 35f). Measurements:2.07–8.74 µ × 1.15–3.68 µ (PDA); 4.14–8.28 µ ×1.38–3.68 µ (PSA); and 4.14–7.13 µ ×1.38–3.91 µ(MEA).Colony characters on culture media (Fig. 37)Colonies on PDA at ART (28–30 °C) are restricted ingrowth and attain a 4.33-cm diam in 15 d. They areazonated, plane, velvety with even margins, and pale36