Effects Of Gibberellin And Cytokinin On Tillers Morphology And Physiology Of Cynodon Dactylon L.

Tillering is a biological characteristic of grasses and tiller number is one of the key indicators for turfgrass density evaluation.As the most widely used warm-season turfgrass,Cynodon dactylon L.has extremely high ornamental value.The high-density Cynodon dactylon L.species is the first choice for golf courses and football fields.There are no in-depth reports on tillering of Cynodon dactylon L.,As the only Cynodon dactylon L.material with high cold resistance,As the only Cynodon dactylon L.material with high cold resistance,Xinjiang Cynodon dactylon L.has a small number of tillers,but it can survive the winter safely;Therefore,this study used Cynodon dactylon（L.）Pers.’Xinnong No.1’as the material to observe the morphology of tiller buds;spray gibberellin（GA₃）and cytokinin（6-BA）,to conduct in-depth research on the changes of physiology and endogenous hormones during the occurrence of Cynodon dactylon L.tillers in different periods.The result is as follows:（1）Cynodon dactylon L.forms tiller primordia at the three-leaf stage,and breaks through the mother stem after forming tiller buds at the eight-leaf stage.Spraying 1 1μmol·L^-1of GA₃and 6-BA can advance the formation of tiller buds of Cynodon dactylon L.,and form new tiller buds at the seven-leaf stage and six-leaf stage.Observation of the anatomical structure of tiller buds at leaf stage under different hormone treatments,it was found that the thickness of epidermis,cortex and vascular bundle diameter were 6-BA>GA₃>CK,It shows that both hormones can promote the tissue structure of Cynodon dactylon L.（2）Spray 1μmol·L^-1of 6-BA and GA₃at the three-leaf stage,five-leaf stage and seven-leaf stage of Cynodon dactylon L.,Spraying 6-BA promoted the growth of tillers,It was found that spraying 6-BA at the three-leaf stage had the best effect,and the number of tillers was 1.2 times that of CK.After spraying 6-BA,the activities of POD,SOD and CAT increased,and the content of MDA decreased.However,the activities of POD,SOD and CAT began to decrease after spraying GA₃at the five-leaf stage and seven-leaf stage,which led to the increase of MDA content and inhibited the occurrence of tillering.The correlation analysis of spraying hormones showed that the activity of antioxidant enzymes had a significant effect on the occurrence of tillering.Among them,the tillering ability of Cynodon dactylon L.increased with the enhancement of POD activity after 6-BA treatment.However,after GA₃treatment,it was found that the tillering ability of Cynodon dactylon L.began to weaken with the increase of CAT activity.After 6-BA treatment,the tiller number of Cynodon dactylon L.increased with the increase of the content of osmotic adjustment substances,However,after GA₃treatment,the content of osmotic adjustment substances decreased,resulting in a decrease in tiller number,It indicated that hormones changed the content of osmotic regulators while maintaining tiller growth.（3）The effect of spraying exogenous hormones on the content of endogenous hormones in the tiller nodes of Cynodon dactylon L.Spraying 6-BA increased the ZR content in tiller nodes,decreased the contents of IAA,GA₃and ABA,and decreased the ratio of IAA/ZR.However,spraying GA₃at the five-leaf stage and seven-leaf stage increased the contents of IAA and GA₃in tiller nodes,but decreased the content of ZR,resulting in an increase in the ratio of IAA/ZR;The test results showed that IAA and ZR played a key role in the occurrence of Cynodon dactylon L.tillering.Exogenous hormones mainly affected tillering by affecting the contents of endogenous hormones IAA and ZR and regulating the ratio of IAA/ZR.In summary,this study preliminarily clarified the specific time node of tiller bud formation,and revealed the morphological change process of Cynodon dactylon L tiller.To analyze the changes of physiological indexes and endogenous hormones in the tiller nodes of Cynodon dactylon L in different growth stages,and to master the regulation of hormones regulating the tiller of Cynodon dactylon L,It is of great significance for the cultivation of new multi-tiller Cynodon dactylon L varieties with hormone regulation.