Root herbivory in vitro: Interactions between roots and aphids grown in aseptic coculture

An in vitro coculture system has been established to study interactions bet ween roots and aphids. Eight aphid species (Aph is spiraecola P.. Trama rar a M..Macrosiphum euphorbiae S., Rhopalosiphum padi L..Sitobion avenue F.. R hopalosiphum maidis F.,Metopolophium dirhodum W., and Pemphigus populivenae F.) were reared on air species of hairy root cultures Carthamus tinctorius L. cr N10, Tagetes patula L.. Trichosanthes cucumerina L. var an,anguina, Hyoscyamus muticus L., Nicotiana tabacum L., and Beta vulgaris L. subsp. vu lgaris. All species of aphids survived on root cultures for at least 2 d. T hree cocultures have been maintained aseptically for periods ranging from 2 mo. to over 2 yr. The coculture of R. padi on C. tinctorius ev N10 (N10-Rp ) was used to study morphological and biochemical responses of root under a phid herbivory. Aphid herbivory caused browning of cultures, reduced root v egetative growth, and increased production of polyacetylenes in C. tinctori us cv N10 roots. Our results suggest that this coculture system may improve our understanding of interactions between aphids and plant roots.