Spongospora subterranea f. sp. subterranea (Sss) is an obligate parasite that can only multiply within the living tissues of a host plant. Greenhouse experiments were carried out to determine the host status of Sss in some crops and weeds commonly found in southern African fields. These experiments used both qPCR and light microscope examination to study the development of Sss in the roots of weeds and crops grown in inoculated Merz solution. Zoosporangia and sporosori were observed microscopically in weed species Acanthospermum hispidum, Ageratum conyzoides, Bidens pilosa, Cleome monophylla, Datura stramonium, Euphorbia heterophylla, Oxalis latifolia, Physalis angulata, Setaria pumila and Tagetes minuta, whilst Ipomea plebia, Setaria verticillata and Galinsoga parviflora were non-hosts of Sss. Root galls were only observed on D. stramonium roots. The crops Allium cepa, Solanum lycopersicum, Zea mays, Avena sativa and Triticum aestivum were both zoosporangial and sporosorial hosts, whilst Phaseolus vulgaris and Brassica juncea were sporosorial hosts only. This study has added three new families to the hosts of Sss, namely Oxalidaceae, Euphorbiaceae and Cappardaceae. Two zoosporangial hosts were identified, namely Avena strigosa and Glycine max. These crops would be ideal to be included as trap crops in rotations with potatoes. The highest quantity of Sss DNA in weed species was recorded in the roots of P. angulata, N. physalodes and A. conyzoides, whilst in cultivated crops the highest quantity of Sss DNA was recorded in Brassica juncea followed by Avena strigosa. The study has shown the importance of weeds and some crops used in rotation with potatoes as alternative hosts of Sss and their potential to increase Sss inoculum level in the soil.

海绵地下孢子虫f。sp。地下（Sss）是专性寄生虫，只能在寄主植物的活组织内繁殖。进行了温室实验，以确定南部非洲田间常见的一些农作物和杂草中Sss的寄主状态。这些实验使用qPCR和光学显微镜检查来研究在接种了Merz溶液的杂草和农作物的根中Sss的发育。显微镜下观察到了杂草物种Acanthospermum hispidum，Ageratum conyzoides，Bidens pilosa，Cleome monophylla，Datura stramonium，Euphorbia heterophylla，Oxalis latifolia，Angularata Angulata，Setaria pumila和印加孔雀草，而Ipomea plebia，倒刺狗尾草和牛膝菊是SSS的非主机。根gall仅在D. stramonium根上观察到。作物葱属，番茄，玉米，燕麦和小麦都是寄主和孢子体寄主，而菜豆和芥菜则仅是孢子体寄主。这项研究为Sss的寄主增加了三个新科，即草Ox科，大戟科和卡帕科。确定了两个动物孢子宿主，即Avena strigosa和甘氨酸最高 这些农作物很理想，可以作为诱集农作物与马铃薯一起轮作。杂草物种中，Sss DNA的量最高，发生在红角菜，N。physalodes和A. conyzoides的根中，而在耕作作物中，芥菜中Sss DNA的量最高，其次是Avena strigosa。该研究表明杂草和一些轮作的作物与马铃薯一起作为Sss的替代寄主的重要性，以及它们增加土壤中Sss接种物水平的潜力。