White clover cryptic virus-1 in New Zealand and eastern Australia

The distribution and abundance of cryptic viruses (Partitiviridae) in natural and agricultural systems have received little attention. White clover cryptic virus-1 (WCCV-1) was detected infecting white clover plants and seed growing in New Zealand, but was not detected in field collections and in only two of 114 seedlings grown from seed collected in eastern Australia using enzyme-linked immunosorbent assay and RT-PCR. WCCV-1 was detected at high incidences (14–48%) in the cultivars Huia, Kopu II and Tahora and at low incidences (0–7%) in Aran, Haifa, Ladino, Siral and Sustain white clovers. WCCV-1 remained viable in seed stored for 50 years. The results are compared with another group of obligate seed-transmitted pasture microbes: the fungal endophytes of perennial grasses.