title: Adventitious root primordia formation and development in stem nodes of 'Georgia Jet' sweetpotato, Ipomoea batatas.
abstract: •
  
  
  OBJECTIVE
  Yield in sweetpotato is determined by the number of storage roots produced per plant. Storage roots develop from adventitious roots (ARs) present in stem cuttings that serve as propagation material. Data on the origin of sweetpotato ARs and the effect of nodal position on AR establishment and further development are limited.•
  
  
  METHODS
  We anatomically described root primordium initiation using stem sections and measured number of root primordia formed at different nodal positions using light microscopy and correlated nodal positions with AR number and length 14 d after planting (DAP).•
  
  
  RESULTS
  Primordia for ARs initiate at the junction of the stem pith ray and the cambium, on both sides of the leaf gap, and they are well developed before emerging from the stem. The number of ARs that develop from isolated stem nodes 14 DAP corresponded to the number of AR primordia detected inside the stem. The total length of established roots at nodes 9-13 from the apex is about 2-fold longer than at nodes 5-8.•
  
  
  CONCLUSIONS
  Nodal position (age) has a significant effect on the developmental status and number of root primordia inside the stem, determining the number and length of ARs that have developed by 14 DAP. Adventitious roots originating from nodes 9-13 possess similar AR systems and develop better than those originating from younger nodes 3-8. The mechanism regulating AR initiation in nodes is discussed. This system can serve for studying the effect of environmental conditions on AR initiation, development, and capacity to form storage roots.
authors.affiliation: Institute of Plant Sciences, The Volcani Center, Agricultural Research Organization, Bet Dagan 50250 Israel College of Landscape Architecture of Sichuan Agricultural University, Chengdu, Sichuan 611100, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
authors.affiliation: Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel Aviv 69978 Israel.
authors.forename: Roni
authors.initials: R
authors.lastname: Aloni
authors.affiliation: LSU AgCenter Sweet Potato Research Station, Chase, Louisiana 71324 USA.
authors.forename: Arthur
authors.initials: A
authors.lastname: Villordon
authors.affiliation: LSU AgCenter School of Plant, Environmental, and Soil Sciences, 137 J.C. Miller Hall, Baton Rouge, Louisiana 70803-2120 USA.
authors.forename: Don
authors.initials: D
authors.lastname: Labonte
authors.affiliation: Savyon Diagnostics, Habosem Street 3, Ashdod 7761003, Israel.
authors.forename: Yanir
authors.initials: Y
authors.lastname: Kfir
authors.affiliation: Institute of Plant Sciences, The Volcani Center, Agricultural Research Organization, Bet Dagan 50250 Israel.
authors.forename: Hanita
authors.initials: H
authors.lastname: Zemach
authors.affiliation: Faculty of Agricultural, Food and Enviromental Sciences, Hebrew University of Jerusalem, Rehovot, Israel.
authors.forename: Amnon
authors.initials: A
authors.lastname: Schwartz
authors.affiliation: Institute of Plant Sciences, The Volcani Center, Agricultural Research Organization, Bet Dagan 50250 Israel.
authors.forename: Leviah
authors.initials: L
authors.lastname: Althan
authors.affiliation: Institute of Plant Sciences, The Volcani Center, Agricultural Research Organization, Bet Dagan 50250 Israel.
authors.forename: Nurit
authors.initials: N
authors.lastname: Firon
mesh_terms: D027723:Ipomoea batatas / Q000033:anatomy & histology / Q000254:growth & development*; D018515:Plant Leaves / Q000033:anatomy & histology / Q000254:growth & development; D018517:Plant Roots / Q000033:anatomy & histology / Q000254:growth & development*; D018547:Plant Stems / Q000033:anatomy & histology / Q000254:growth & development*
keywords: Convolvulaceae; Ipomoea batatas; adventitious root; adventitious root primordia; nodal position; storage roots; sweetpotato