Pollen and Seed-Transmitted Viruses and Viroids

Abstract

Virus transmission through seed and pollen has been reviewed or summarized in various reports (3, 5, 10, 23, 24, 34, 37, 63, 78, 81, 99, 102-105, 117, 120, 121, 125, 142, 147, 148). Some of these reviews include viruses with general lists of seedbome pathogens (3, 5,121), while others focus on specialized groups of viruses such as those transmitted by nematodes (99, 117) or those that affect specific crops (78). Eleven reviews provide comprehensive lists of viruses and viroids that are transmitted through seed and pollen (Table 1). Although many reviews focus on the interaction between viruses and seed, aspects of virus-pollen interactions are also examined (10, 103, 142). At least four reviews concentrate on virus interactions with pollen (34, 81, 104, 105). Given the recent interest in both pollen and seed transmission, and the fact that several workers were examining these areas shortly after the tum of the century (49, 134), the first cited review (147) of seed transmission of viruses was, surprisingly, only published in 1951. Between 1951 and 1988, however, there were at least 22 reviews on the subject; nine of these were published between 1981 and 1988. The appearance of 22 reviews on seed and pollen transmission within 37 years probably speaks as much for overall interest in the subject as for advancements being made in the field at the time. Nevertheless, the number of viruses listed as seedor pollen-