Comparative Electron Microscopy of Chenopodium quinoa Leaves Infected with Apple Chlorotic Leaf Spot, Apple Stem Grooving, or Citrus Tatter Leaf Virus

grooving virus (ASGV)2), and citrus tatter leaf virus (CTLV)3,4) range 600•`750nm in length, but resemble closteroviruses5) in morphology. Closteroviruses cause phloem necrosis and their particles are found to be confined to the phloem cells associated with vesicles containing nucleic acid-like fibrils6). However, little information is available in cytopathology of ACLSV-, ASGV-, or CTLV-infected tissues. Small projections containing masses of elongated particles have so far been observed in cytoplasm of chlorotic areas in the sections of ACLSV-infected Chenopodium quinoa7). CTLV particles were reported to be found only in phloem cells of the infected C. quinoa leaves4). To elucidate the relationship between the three viruses and closteroviruses, electron microscopy on C. quinoa tissues infected with ACLSV, ASGV, or CTLV was conducted. Viruses and plants. ACLSV P-205, ASGV P-209, originally isolated from apple infected with top-working disease8), and CTLV Li-234) from lily were used. C. quinoa plants mechanically inoculated with either of the viruses and the healthy controls were incubated in a