title: Effect of seedling age and water depth on morphological and physiological aspects of transplanted rice under high temperature.
abstract: To study the effect of high temperature, rice seedlings 20, 30, 40 and 50 d were kept at 5, 10, 15 and 20 cm water depth in a water pool. Meteorological findings indicated that water temperature varied up to 10 cm but became stable below this depth. Deep water inflicted higher tiller mortality, minimal increase in dry weight of aerial parts and leaf area, decrease in root length, and decrease in root dry weight especially at 20 cm water depth and produced an unbalanced T/R ratio (top versus root dry weight). However, deep water tended to increase plant length. These parameters, however, excel in shallow water. Older seedlings, with the exception of root dry weight, could not perform well compared to young seedlings in all physiological and morphological aspects. The study revealed that seedlings, particularly young ones, stand well in shallow water and can cope with high temperature.
authors.affiliation: Agricultural Research Institute, Dera Ismail Khan, NWFP, Pakistan.
authors.forename: Abdul Aziz
authors.initials: AA
authors.lastname: Khakwani
authors.forename: Masaaki
authors.initials: M
authors.lastname: Shiraishi
authors.forename: Muhammad
authors.initials: M
authors.lastname: Zubair
authors.forename: Mohammad Safdar
authors.initials: MS
authors.lastname: Baloch
authors.forename: Khalid
authors.initials: K
authors.lastname: Naveed
authors.forename: Inayatullah
authors.initials: I
authors.lastname: Awan
mesh_terms: D003890:Desiccation; D009929:Organ Size; D012275:Oryza / Q000033:anatomy & histology* / Q000166:cytology / Q000254:growth & development / Q000502:physiology*; D035261:Plant Components, Aerial / Q000033:anatomy & histology / Q000254:growth & development; D018515:Plant Leaves / Q000033:anatomy & histology / Q000254:growth & development; D018517:Plant Roots / Q000033:anatomy & histology / Q000254:growth & development; D036226:Seedlings / Q000166:cytology / Q000254:growth & development*; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000032:analysis*
chemical_list: D014867:Water