Studies On The Cutting Propagation And Rooting Mechanism Of Cinnamomum Petrophilum

Cinnamomum petrophilum, which is a evergreen tree belonging to Cinnamomum, Lauraceae, and the leaves contain the highest safrole in the around the world. It is also one of the special economic species of Sichuan province. In order to obtain a better utilization of the genetic characteristics of high safrole yielding, it is necessary to cultivate a fast-growing, high yield and high quality C. petrophilum species. Moreover, it is necessary to take another reproduction of a large nursery by cuttage propagation.Studying on cutting propagation and rooting mechanism of the C. petrophilum could solve the production technical difficulties of a large number of seedling work, and guide the rapid propagation, breeding and scientific cultivation of the C. petrophilum. This study will provide a theoretical basis and technical reference for another plants’ rapid propagationThis study was analyzed the effects of different substrates, cutting seasons and growth regulator of different matrix on cutting rooting of C. petrophilum, and the nutrition level in root, the enzyme activity in the process and anatomic structure change were discussed in the present study. A relatively perfect system of cutting breeding technology was formed, and the rooting mechanism was illustrated in detail. The main results were as follows:(1) A significant difference of survival rate of cuttage was found among different substrates of C. petrophilum. Therein to, the formula of nutrition soil+sand (1:1) or sand+ loam (1:1) were performed well in the test, the cuttage survival rate was higher, which were 46.1%,34.9% respectively. However, compared with the matrix formulation, cuttage survival rate were lower as the cutting medium were made by a single loam or sand.(2)The cuttage survival rate of C. petrophilum was affected significantly by seasons. The cutting survival rate was highest in the early March, while the number of adventitious roots were least; followed in mid-October; the lowest survival rate for cuttage propagation was in summer, in fact, the maximum number of adventitious roots were found in summer. In addition, there was no obvious relationship between the number of adventitious roots and the cuttage survival rate.(3) The cuttage survival rate and rooting quality of C. petrophilum were significantly affected by plant growth regulators and their concentrations. The results of different kind of growth regulator treatment showed that, NAA treatment had the best effect on the cottage rate and rooting quality, followed by IAA, and ABT; Different concentration of growth regulator treatment results indicated that, the survival rate and rooting quality best as the cuttings base were soaked in concentration of 400 mg/L NAA soaking for 2 h.(4) The starch content, soluble protein content and soluble sugar content in the base portion of the cutting changed with the rooting process. The soluble sugar, soluble protein, starch content of cuttings were decreased in the early phase (0-45 d). The soluble sugar, soluble protein and starch content of cutting treated by IAA, NAA, ABT decreased much more than that for the controls. In the metaphase of treatment (45-60 d), both of the treatment group and controls cuttings presented a increase trend in sugar and protein content, while starch content continued decreasing, the amplitude changes greater than that of the control group. In the later cutting period (60-75 d), compared with the metaphase of cutting, the soluble sugar, soluble protein content in the cuttings base portion decreased, while the starch content increased.(5) In the rooting process of C. petrophilum during in the early phase of cutting period (0-45 d), the POD, PPO activity increased gradually, and then reached a peak in the 45th day. Moreover, MDA content in the cuttings cortex increased gradually, the controls increased more than treatment group. In the metaphase and later stage (45-75 d), with the formation of adventitious root and decomposition of phenolic compounds, POD, PPO activity decreased, MDA content in cuttings cortex decreased gradually, and the treatment group decreased significantly than that for controls.(6) The anatomical observations showed that C. petrophilum belongs to the species, which is hard to root by cottage propagation. The primary tectonic stem has a ring of thick tissue, therefore, this maybe relate to difficult adventitious roots. There is no latent root primordium of adventitious roots from the cross section of stem, which were mainly caused by the induction of root base. The root base originated from the pith parenchyma.