H^m—毒素在玉米大、小斑病菌相互关系中的作用

The Effect of Hm—toxin on the Interaction Between Exserohulum Turcieum and Helminthosporium Maydis

玉米小斑病菌(Helminthosporium maydis)所产生的致病毒素(Hmtoxin)能抑制玉米大斑病菌(Exserohilum turcicum)的生长和降低产孢量。在PDA培养基上、当小斑菌存在时,也象Hm—毒素一样,使大斑菌的生长受到抑制,而且凡是有利于小斑菌产生毒素的培养条件都能使小斑菌对大斑菌的抑制作用更加强烈。在幼苗上,Hm—毒素象小斑菌一样使大斑病的病斑少而小。据此,本文进一步明确了在小斑病常发区大斑病一般不易流行,从而大大减轻了在小斑病常发区防治大斑病的压力。

Hm-toxin produced by Helminthosporium maydis could inhibit the growth and sporulation of Exserohilum turcicum.H.maydix like its toxin could also inhibit the growth and sporulation of Exserohilum turcicum. H.maydis like its toxin could also inhibit the growth of E.turcicum on PDA plate, and had a stronger inhibition of the latter when the conditions were advantageous to the Hm-toxin production.In vivo, Hm-toxin like its pathogen could reduce lesion size and lesion numbers of E.turcicum. It was concluded that epidemic of E.turcicum not easy in the epidemic area of H.maydis so that the pressure to control E.turcicum could be reduced in the epidemic area of H.maydis.