Study On Radiation Induced Dwarf Mutant Of Zoysia Matrella

Zoysia matrella (L.)Merr, namely manilagrass, is an excellent warm-season turfgrass species, which has fine, colour and lustre with leaves green, grass, long green period, strong resistance, resistance to trample, and are widely used in most areas of southern China. Dwarf is an important indicator in turfgrass production application, because it can improve planting density, make fμl 1 use of land space, enhance the photosynthetic efficiency, low cutting rate and more and more attention.This experiment using 100 Gy 60Co-y irradiation embryonic callus of Zoysia matrella regenerated by the field screening dwarf mutant plants (DW) and control (CK) as the experimental material, the plant genetic stability test, field determination of phenotypic traits, leaf anatomical shape analysis, physiological and biochemical and the analysis of the plant endogenous hormone, in order to find 60Co-γ irradiation induced dwarf mutation mechanism of Zoysia matrella. The main resμl ts were as follows:1.100 Gy 60Co-y irradiation callus of Zoysia matrella and phenotypic selection, field for a year and a half of phenotype observation, found a dwarf mutant plant, by pruning transplanting half a year, dwarf mutant plants still keep good character, have certain genetic stability.2. Phenotypic traits analysis of the dwarf mutant plant (DW) and control (CK) plant found that the DW plant and CK plants on phenotypic differences, mainly displays in: compared with CK, the average leaf length 9.45 cm, shorter 43%, the average blade width 0.12 cm, width of 41.66%, the average between the stem length is 1.03 cm, shorter 27.32%, average between stem diameter of 0.16 cm, coarsen 50%, the average grass height 7.03 cm, shorter 31%.3.The physiological and biochemical detection:DW plant, POD, SOD enzyme is CK increased significantly, the CAT enzyme activity difference was not significant, but there are still high, show that during the period of growth, DW dwarfed by a certain stress, the stress condition, O2- and H2O2 content increased, plant active oxygen in the body accumμl ation and clearing system to adjust to a certain extent, the peroxidase activity increased.DW of leaf chlorophyll content, significant difference, have certain relevance with phenotypic index observation. Protein content difference was not significant, its function mechanism is unclear.4.Endogenous hormone content detection, gibberellic acid (GAs) and auxin (IAA) level decreased, but no significant difference in GAs, significant difference was found in IAA, abscisic acid (ABA) levels also significantly reduced at the same time, the ABA/IAA ratio increased, this also shows the mechanism of the DW dwarf mutant strains may be the absence of IAA mutant.5.The blade of DW and CK of paraffin crosscut slice observation, DW plant vascμl ar tissue density loose, chlorophyll content increased, palisade tissue thickness is significantly smaller than that of CK, palisade tissue and spongy tissue proportion on the high side, plant chlorophyll content increased in the body also illustrates the DW plant photosynthesis intensity, leaf color is significantly more green.