A STUDY ON THE EVALUATION OF WATERLOGGING TOLERANCE OF DIFFERENT DACTYLIS GLOMERATA L. GERMPLASM RESOURCES AND THE DIFFERENCE IN ROOT MICROSTRUCTURE UNDER WATERLOGGING STRESS

In order to characterize the physiological mechanisms of waterlogging tolerance of Dactylis glomerata L. and to help rationally select waterlogging-tolerant species to alleviate the waterlogging damage to agricultural production, effects of waterlogging on the growth, morphological indexes, physiological changes and root microstructure of Dactylis glomerata L. were studied. A total of 20 varieties (lines) of Dactylis glomerata L. from different areas were flooded treatment for 0 day and 28 days, respectively. Morphological indexes and physiological indexes of 20 Dactylis glomerata L. resources were evaluated under waterlogging stress comprehensively. In addition, paraffin section technology was used for observing the microstructure changes on root of 6 types of Dactylis glomerata L. under waterlogging stress for 0 day, 14 days and 28 days respectively. Our results demonstrated that the orders of 20 Dactylis glomerata L. resources by ability of waterlogging tolerance were Dianbei' Cambria' > Aldebaran' > Athos' > Donata' > Sparta'> PI 231482' >Endurance' > PI 598418' > 02-114' > PI 311388' > 01472' > PG28' > Glorus Sweden' = PI593995'> Smithii PI 441032' = PI594994' > Geneal Belgnaio' > PG49' > Amba'. What's more, with the extension of waterlogging stress time, the number/size of vessel and the diameter of vascular cylinder were significantly (P<0.05) reduced. Cells ruptured and structure collapsed were found in the root microstructure of PI 594994', Geneal Belgnaio', PG 49' while structurallycomplete of root in Dianbei', Cambria', Aldebaran' for under waterlogging stress 28 days. Therefore, they could be used as the key selection accessions and studied on their genes of waterlogging tolerance for further research.