negatively regulates negative regulation of developmental process biological regulation haustorium mother cell formation regulation of haustorium mother cell formation negative regulation of haustorium mother cell formation Any process that stops, prevents, or reduces the frequency, rate or extent of symbiont haustorium mother cell formation. The host is defined as the larger of the organisms involved in a symbiotic interaction. biological_process negative regulation of haustorium mother cell formation on or near host Note that this term should not be used to annotate gene products of the host. It should only be used to annotate those gene products from the symbiont involved in this process. GO:0075195