POSSIBLE INVOLVEMENT OF THE PHLOEM SEALING SYSTEM IN THE ACCEPTANCE OF A PLANT AS HOST BY AN APHID

Citation
Cm. Caillaud et Hm. Niemeyer, POSSIBLE INVOLVEMENT OF THE PHLOEM SEALING SYSTEM IN THE ACCEPTANCE OF A PLANT AS HOST BY AN APHID, Experientia, 52(9), 1996, pp. 927-931
Citations number
39
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Multidisciplinary Sciences
Journal title
ISSN journal
0014-4754
Volume
52
Issue
9
Year of publication
1996
Pages
927 - 931
Database
ISI
SICI code
0014-4754(1996)52:9<927:PIOTPS>2.0.ZU;2-J
Abstract
Possible reasons for the rejection of some lines of Triticum monococcu m (Tm44 and Tm46) by the aphid Sitobion avenae were explored. In all T . monococcum lines studied, whether unfavourable (non-host/resistant p lant) or favourable (host/susceptible plant), the concentrations of hy droxamic acids, a family of aphid-resistance factors in cereals, were significantly lower than the levels in the favourable host-plant Triti cum aestivum cv. Therefore, hydroxamic acids did not account for the h ost/non-host patterns observed. Phloem sap was collected by stylectomy from young seedlings of favourable and unfavourable plants. In non-ap hid-resistant genotypes, the success in stylectomy, the proportion of amputated stylets resulting in long (>1 min) exudations, the average d uration of exudation, and the final volume of sap exuded, were higher than in the aphid-resistant genotypes. It is concluded that aphid inte rference with the phloem sealing system of the plant is a likely mecha nism of rejection of T. monococcum lines Tm44 and Tm46 as hosts by S. avenae.