title: In vitro screening of potato against water-stress mediated through sorbitol and polyethylene glycol.
abstract: With the objective to develop a practical and effective method of screening potato for drought tolerance, shoot and root growth in microtuber-derived plantlets was studied in vitro in three genotypes with known root mass production under field conditions. Different levels of water-stress were induced using five concentrations of either sorbitol or polyethylene glycol (PEG) in MS medium. Water potential of various media ranged from -0.80 MPa to -2.05 MPa. Water-stress in culture adversely affected plantlet growth, and genotypes differed for their responses. Genotype IWA-1 was less affected than IWA-3 and IWA-5. At the same level of water potential, sorbitol had lower adverse effect than PEG; the latter being sticky. Genotype x sorbitol and genotype x PEG interactions were significant. At 0.2 M sorbitol and 0.003 M PEG, IWA-1 had significantly more roots with higher total root length, root volume, as well as root-dry weight than those of IWA-3 and IWA-5, whereas the latter two genotypes were at par for all these characters. This pattern was similar to the reported pattern of these genotypes for root-dry weight under field conditions. It is concluded that in vitro screening of potato under specific and limited water-stress conditions may provide a system for effectively differentiating the genotypes for their expected root mass production under field conditions.
authors.affiliation: Crop Science Laboratory, Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589 Japan. jai_gopal54@yahoo.co.in
authors.forename: Jai
authors.initials: J
authors.lastname: Gopal
authors.forename: Kazuto
authors.initials: K
authors.lastname: Iwama
mesh_terms: D003890:Desiccation; D005838:Genotype; D018517:Plant Roots / Q000254:growth & development; D011092:Polyethylene Glycols / Q000494:pharmacology*; D011198:Solanum tuberosum / Q000187:drug effects* / Q000378:metabolism*; D013012:Sorbitol / Q000494:pharmacology*
chemical_list: D011092:Polyethylene Glycols; D013012:Sorbitol