Characteristics of Indigenous Rhizobium to Korean Soils III. Symbiotic Dynamics of Bradyrhizobium japonicum YCK Strains According to Their Competitive Conditions for Nodulation

우리나라 토착근류균(土着根瘤菌)의 제(諸) 특성(特性) 연구(硏究) III. 수종(數種) Bradyrhizobium japonicum YCK 균주(菌株)의 경합여부(競合與否)에 따른 공생효과 변이(變異)

The symbiotic dynamics of Bradyrhiwbium japonicum YCK strains indigenous to Korean soils were investigated accordingly to their competitive conditions for nodulation. For this experiment the single strain inoculants of YCK strains and the mixed inoculants of one YCK strain and one USDA strain were applied to Korean Jangbaekkong and American Clark soybeans at mollisol soils(Torroxic Haplustoll, pH 6.8). The results were summarized as follows : 1. The symbiotic effectiveness of B. japonicum YCK strains was increased on the average of nitrogen accumulation by mixing with USDA strains, especially with strain USDA 110. 2. The effectiveness of each mixed inoculant was affected by soybean cultivar. 3. YCK strains occupied on the average of 83 and 86 % of the nodules against strain USDA 110 on Jangbaekkong and Clark soybeans, respectitvely. 4. The most effective strain among three YCK strains was strain YCK 213 as a single inoculant and was strain YCK 141 as a mixed inoculant with USDA strains. 5. The mixed inoculants of YCK strains and strain USDA 123 showed antagonism for nodulation.

우리나라 토양에서 분리(分離)된 수종(數種) YCK균주(菌株)의 경합여건(競合與件)에 따른 공중실소고정(空中室素固定) 즉 공생효과(共生效果) 변화양상을 조사코자, 우리나라 장백(長白)콩과 미국(美國)의 Clark콩에 대하여 YCK균주(菌株)를 단독(單獨) 및 USDA균주(菌株)와 혼합접종(混合接種)한 결과는 다음과 같았다. 1. YCK균주(菌株)들은 단독접종시(單獨接種時) 보다 USDA균주(菌株) 특히 USDA 110균주(菌株)와 혼합접종(混合接種)했을 때 공생효과(共生效果)의 증가 경향을 보였다. 2. YCK균주(菌株)와 USDA균주(菌株)의 혼합접종(混合接種) 조합별(組合別) 공생효과(共生效果) 경향은 대두품종에 따라 상이하였다. 3. YCK균주(菌株)들은 근류형성경함력(根瘤形成競含力)에 있어서 USDA110균주(菌株)보다 우수하였으나 USDA 127균주(菌株)보다는 저조하였다. 4. 공시(供試)된 YCK균주중(菌株中) 우리나라 장백(長白)콩에서 공생효과(共生效果)가 우수하였던 것은 단독접종시(單獨接種時) YCK 213, YCK균주(菌株)와 혼합접종시(混合接種時)는 YCK 141균주(菌株)였다 5. YCK균주(菌株)들는 USDA 123균주(菌株)와 혼합접종(混合接種)했을 때 근류형성상(根瘤形成上)의 길항작용(拮抗作用)을 보였다.