The effect of monochromatic light on sclerotial formation of Rhizoctonia solani Kuhn (AG-1,IA) (Department of Agriculture)

Rhizoctonia solani Kuhnの菌核形成に及ぼす4種類の単色光及び近紫外光の影響を検討した。菌糸の伸長はC-14株の近紫外光区以外の区ではほとんど影響は見られなかった。一方, 菌核数はC-324株の近紫外光区で僅かに減少したが他の区では増加し, 特にC-324株でその傾向は著しかった。1シャーレ当たりに形成された菌核の総重量は両菌株とも近紫外線照射により増加し, 特にC-14株では60%増加した。菌核の成熟に伴う着色化はすべての照射区で抑制されたがこれはメラニン化を触媒するTyrosinaseの活性の低下と一致した。Effects of four coloured and near-ultraviolet lights irradiation on sclerotial morphogenesis of two isolates of Rhizoctonia solani were examined. The hyphal linear growth of the isolates was not obviously affected by every light without in C-14 isolate by near-UV. On the other hand, the number of sclerotia was slightly decreased in C-324 isolate by near-UV while increased by other light in C-14 in particular. The total weight formed in a Petri dish was increased in two isolates by near-UV, especially about 60% in C-14. The pigmentation of sclerotia during maturation was inhibited by every light, which well agreed with the decrease of tyrosinase activity catalyzes melanization