Field Spread of Soy bean Mosaic Virus Strains

콩모자익바이러스 계통의 포장전염

Isolates of soybean mosaic virus (SMV) strains classified based on virulence in silt resistant soybean cultivars caused the same reactions in soybean cultivars used as differentials as those obtained by sap inoculations to the same cultivars. Five species of aphids (Myzus persicae SULZ., Aphis craccivora KOCH, Aphis citricola VAN., Rhopalosiphum maidis FIT., End R. padi L.) were able to transmit each of SMV strains. However, R. maidis and R. padi were inefficient vectors for transmission of SMV strain G3. Spread if four SMV strains (G2, G3, G6, and G7) was monitored in the field from sapinoculated plants in a one meter row of Williams soybeans (source plants) to plants in an adjacent row of Williams 80cm away (test plants). Test plants wert downwind from the source plants. A complete block design was used. Spread of strain G6 was significantly greater than that of other three strains. Two hundred six aphids were collected from June 27, 1979 to August 2, 1979 in the same field. A. citricola was the mist prevalent, comprising $68\%$ of the total aphids. Yields of Williams inoculated with each strain were also compared. Yields were the least from plants inoculated with strain G2 following G6, G3, and G7 in that order.

콩모자익바이러스(SMV) 7계통의 진딧물 전염여부를 시험한 결과 SMV 7계통 전부가 전염되었으며 SMV의 진딧물 전염에 의한 대두판별품종의 반응도 침액접종에 의하여 SMV 계통을 분류하였을 때의 반응과 일치하였다. 공시한 5종의 진딧물중에서 복숭아혹진딧물, 아카시아진딧물, Aphis citricola는 SMV 7계통을 모두 잘 전명시키는 매개충이었으나 옥수수테두리진딧물과 기장테두리진딧물은 SMV계통 G3을 전염시키지 못하는 경우도 있었다. 포장에서 SMV 계통 G2, G3, G6 및 G7을 22.5m 이랑의 1m 내에 심겨진 콩 품종 Williams에 접종한 후 80cm 떨어진 이랑의 1m내 Williams의 발병율을 조사하였다. 공시한 SMV 4계통중 6G의 전염율이 가장 높았고 조사기간에 채집된 206 마리의 진딧물중 A. citricola가 $68\%$로서 우점종이었다. Williams의 수량은 G2로 접종하였을 때 가장 낮았다.