Effects Of Plant Growth Substances On Rooting Rate And Seedling Growth Of 'Fengdan' Peony

Paeonia ostii T. Hong et J. X. Zhang, the widely cultivated tree peony variety in China with traditionally medicinal and ornamental value, has become the emerging oilseed crop in recent years on account of high seed setting rate and oil yielding rate and good oil quality. The effects of trichokonins(TKs), gibberellin(GA3) and ethephon(ETH) on seed rooting rate and main nutrients in radicle of Paeonia ostii ‘Feng Dan'were studied in this research.We also observed the root-shoot ratio and several organic matters contents in leaves of the oil tree peony seedlings by employing trichokonins, naphthylacetic acid(NAA) and indoleacetic acid(IAA). Moreover, the root characteristics in response to TKs,NAA and IAA were analyzed using Win RHIZO root analysis system. The main results are as follows:1. After soaking seeds with trichokonins, GA3 and ethephon in different concentrations for 24 hours, the tree peony seed rooting rate, the first seed rooting time mildew rate and soluble protein, soluble sugar, root activity, nitrate reductase activity showed significant response to the treatments of trichokonins and GA3. However, under the treatments of ethephon, no significant different was found in seed rooting rate, the first time of seed take root, mildew rate and soluble protein content, while soluble sugar content,root activity and nitrate reductase activity of the peony changed significantly. During the rooting period of tree peony, the shortest first seed rooting time was observed as 50 days with the lowest seed deterioration rate under 2.5 mg/L trichokonins treatment, which 8days earlier than that in the control. Moreover, the seed rooting rate was 89.48% under the treatment of 300 mg/L GA3. On the contrary, the ethephon with the concentration from 5mg/L to 85 mg/L delayed the first seed rooting time, reduced the rooting rate and raised the mildew rate. During the rooting process of tree peony, the treatments of trichokonins with0.25 mg/L and 2.5 mg/L obtained the highest content of soluble protein and soluble sugar,root activity and nitrate reductase activity of the radicle. The similar results were observed under the treatments of 200 mg/L and 300 mg/L GA3. However, our results also showed that ethephon significantly reduced the soluble protein content.2. The significant differences were found in the root-shoot ratio, soluble proteincontent, soluble sugar content, chlorophy and N, P, K content, while the electric conductivity showed no significant changes under different plant growth substances treatments. The treatments of 0.25 mg/L or 2.5 mg/L trichokonins significantly increased the root-shoot ratio, soluble protein content, soluble sugar content, chlorophy content and the N, P, K content. The above indicators were also significantly increased under conditions of NAA with 25 mg/L or 45 mg/L, and IAA with 25 mg/L or 45 mg/L,respectively. The results indicated that trichokonins showed the best treatment effect on the tree peony seedlings, while the NAA and IAA also had certain promotion functions.3. The root characteristics were scanned and analyzed using Win RHIZO root analysis system after the spraying treatment of trichokonins, NAA and IAA on the tree peony seedlings. The results showed that the total root length, total projection area, total surface area, root average diameter, total volume, root number changed significantly among different treatments. The highest total root length, total surface area, total volume and root number of tree peony seedlings were observed in the treatment of 0.25 mg/L trichokonins,while the total projection area was the highest under conditions of 2.5 mg/L trichokonins.As for the NAA and IAA, the total root length, total projection area, total surface area, total volume, root number of tree peony seedling were up to the peak in the concentration of 25mg/L. The trichokonins showed the best treatment effect in comparison with the other two plant growth substances.