Baker D, Newcomb W, Torrey J G
Can J Microbiol. 1980 Sep;26(9):1072-89. doi: 10.1139/m80-180.
The actinomycete, Frankia sp. EuI1, isolated from root nodules of Elaeagnus umbellata is an infective endophyte but which lacks the ability to form an effective nitrogen-fixing symbiosis with its host. This ineffective organism can be distinguished easily from other frankiae, in vitro, on the basis of size, morphology, and the elaboration of a diffusible pigment. Cross-inoculation studies indicated that the host range of this symbiont is narrow and probably restricted to the Elaeagnaceae. In all cases of nodulation the symbiosis never developed nitrogenase activity and the microsymbiont never produced endophytic vesicles within the infected host cells. Sporangia were produced in vivo and in vitro so the morphogenetic block is apparently restricted to vesicle formation.
从胡颓子根瘤中分离出的放线菌Frankia sp. EuI1是一种感染性内生菌，但缺乏与宿主形成有效固氮共生关系的能力。这种无效的菌株在体外很容易根据大小、形态以及可扩散色素的形成与其他Frankia菌株区分开来。交叉接种研究表明，这种共生体的宿主范围狭窄，可能仅限于胡颓子科。在所有结瘤情况下，共生关系从未产生过固氮酶活性，而且微共生体在受感染的宿主细胞内从未产生内生泡囊。体内和体外均产生了孢子囊，因此形态发生阻滞显然仅限于泡囊形成。
