Research On Cutting Rooting Physiology And Tissue Culture Of Melliodendron Xylocarpum

Melliodendron xylocarpum Hand.-Mazz.is a deciduous tree of the genus Melliodendron Hand.-Mazz.in the Styracaceae DC.&Spreng,It has beautiful flower shape,peculiar fruit shape and high oil content,and has both ornamental value and economic value.For a long time,the main method of propagation of the fruit is seed propagation,but its seed germination is difficult,resulting in the production and utilization of the fruit being limited.In this paper,we studied the physiology of rooting cuttings and tissue culture of M.xylocarpum to provide a scientific basis for asexual propagation and domestication of the fruit,and the main findings are as follows:1.The orthogonal experiment design of L₉（3⁴）with three factors and three levels was used to explore the effects of the type,concentration and treatment time of plant growth regulators on the rooting of M.xylocarpum cuttings.The type,concentration,and treatment time of plant growth regulators have a very significant effect on the rooting rate of M.xylocarpum cuttings（P<0.01）,among which the type of plant growth regulator is the main influencing factor,and the plant growth regulator with the highest rooting rate is 200 mg/L ABT-1 treatment for 20 min,the rooting rate was 62.22%.2.The age of the mother tree,the substrate,and the location of the cuttings all have a significant impact on the rooting of the M.xylocarpum cuttings.Comparing the rooting conditions of the cuttings produced by the 1-year-old,5-year-old and 10-year-old mother trees,the rooting rate of the cuttings of the 5-year-old mother trees is significantly higher than that of the 1-year-old and 10-year-old mother trees.,was 47.78%.Vermiculite is the most suitable substrate for M.xylocarpum cutting rooting,and the rooting rate was 45.56%,which was significantly higher than the treatment of perlite,river sand and vermiculite+perlite+river sand（1:1:1）group;the cuttings with the highest rooting rate were the upper and middle parts of the branches,and the rooting rate and root growth index were better than those of the cuttings collected from the lower part of the branches.3.The cuttings were soaked in 1000 mg/L NAA,IBA,and ABT-1 for 30 s,and water was used as the control to observe the rooting type and anatomical structure of the cuttings,and to detect the changes in soluble protein content,soluble sugar content,MDA content,SOD and POD activity in the rooting process of the cuttings.The result showed that treatment of plant growth regulators could increase the content of the soluble sugar and soluble protein,reduce the content of MDA,and significantly increase the SOD and POD activities in the rooting process,thus promoting the rooting of the plugs.Morphological and microscopic observation of the cuttings of Melliodendron xylocarpum showed that the root type was callus root type,root primordium type was induced root primordium and adventit root type.Adventitious root formation can be divided into three stages:callus formation stage,adventitious root formation stage and adventitious root elongation stage.4.The Melliodendron xylocarpum stem segments were screened for sterilization method,and the best sterilization effect was achieved by using 75%alcohol solution for30 s followed by 0.1%Hg Cl₂for 3 min,and the contamination rate was 33.33%.The gyroscopic fruit stem segments could germinate in MS+1 mg/L 6-BA medium,and the highest proliferation coefficient of 2.67 was obtained in MS+2 mg/L 6-BA+0.5 mg/L NAA enrichment medium.5.Tissue culture was carried out with the leaves of gyro fruit as explants.It was found that the optimal disinfection treatment was to soak in 75%alcohol solution for 30 s and then soak in 0.1%Hg Cl2 for 3 min,and the contamination rate could be as low as 0.Callus appeared after 41 days of culture in gyro fruit leaves.The medium formula with the highest induction rate was MS+2 mg/L NAA,and the induction rate was 33.33%.