| Summary: | 碩士 === 國立中興大學 === 園藝學系 === 90 === The objective of this experiment was to investigate the graft incompatibility between ‘Fuyu’ and D. japonica. It is general believed that the ‘Fuyu’ persimmon could produce certain toxic chemical compound which can be transported via phloem to the root of D. japonica. The toxic principle is harmful to the development of the root system of D. japonica during graftage by affecting mineral nutrients uptake and translocation.
Among the various combination of scions and rootstocks, the compatibility between D. japonica scion grafted on the same rootstock performed relatively better than ‘Fuyu’ grafted onto D. japonica. The former had rapid growth rate, more carbohydrate and cells fusion quicker at the grafting union. In contrast, the latter combination had a lower growth rate, more starch and less carbohydrate in the scion leaves. Total phenolic compounds content of Fuyu/D. japonica were higher than D. japonica/D. japonica in the stem.
Tissue samples (1%, 5%, 10 % barks) of D. japonica, ‘Fuyu’, ‘Bull Heart’ were extracted with deionized water (use water as a check). Bark extracts were used to treat the seeds of D. japonica. The root growth of the seedling was slightly inhibited by 1% of bark extract and was significantly inhibited at 10 %. The affected cells were brown in color and shrunken at the root apex. The symptom seemed to show that water transport was affected. Chemical analysis showed that the soluble tannin, total phenolic compounds and soluble protein content were high in the seedling root with 10 % Fuyu bark extract treatment. It is presumed that Fuyu bark extract contain certain kind of phenolic compound which was responsible for the inhibition of seedling root growth.
Experiment data indicated that no difference was found between 1% and 10% Fuyu bark extract on seeds germination, but growth of seedlings of D. japonica were significantly inhibited. Dry and fresh weights of D. japonica were less than the control while total phenolic compound was higher after 1% or 10% bark extracts treatment.
Results of peroxidase activity and electrophoresis showed different enzyme activities and band patterns due to the dissimilarity in varieties. Primary results disclosed that there was no significant relationship between peroxidase isozyme pattern and graft compatibility.
D.japonica, ‘Hiratanaenashi, ‘Bull Heart’, ‘Fuyu’ persimmon shoots were collected separately at leaf abscission and pre-bud bursting stage. Electrolyte leakages from the deep-freezed (-22.5℃) tissues were determined. Results of leaf abscission indicated that D. japonica had the highest leakage level but the lowest starch content while Fuyu had the lowest leakage but with the highest starch. This seemed to indicate a positive relation between cold hardness and starch content. Samples before bud bursting showed that ‘Hiratanenashi’ and ‘Fuyu’ had the lowest electrolyte leakage and highest soluble sugar content also indicated a positive relationship between the cold hardness and soluble carbohydrate.
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