Study On The Enlargement Mechanism And Regulation Technology Of Tuberous Root Of Ficus Microcarpa L.f.

? Ficus microcarpa ( China root ) is one of ornamental plants of Ficus microcarpa, which is belong to Ficus retusa, the main position for appreciation is root tuber which is formating by seedling growth through hypocoty enlargement.The study on Ficus microcarpa mainly concentrated in cultivation techniques, controlling and preventing the insect pests diseases et al, as to researches in the problems of etiolated and deciduous of the Ficus microcarpa during storage transportation, artistic modeling, maintenance of bonsai. However, about study on mechanism of enlargement and regulation technology of tuberous root of Ficus microcarpa, which has not been reported up to now. To unfold the mechanism of enlargement and regulation technology of tuberous root of Ficus microcarpa, not only can promote the understanding of enlargement mechanism of tuberous root, but also can guide the production of Ficus microcarpa, shorten production period, reduce production cost, improve the ornamental quality of tuberous root. Therefore, carrying out researching in it will have great theoretical value and practical meaning.? In this experimental study, the young seedling of Ficus microcarpawas selected as the research matierials, To research the changes rule in physiology of the total soluble sugar, starch in the leaves; and the lignin, cellulose and endogenous hormones in the tuberous toot, according to histological anatomy, to observed the swollen progress in tuberous root by Conventional paraffin sectioning technology. Using plant growth regulator, carried on Enlargment regulation technology of tuberous root, The main research results were as follows:1. The observations of paraffin section showed that, the different internal structures have been obtained in roots ,which is inspite enlargement root or not enlargement one. First of all, not enlargement root mainly persented primary growth,however, in the enlargement tuberous root ,it had been appeared the typical secondary structure. The vascular cambium and cork cambium proceed a series of activities, which has produced secondary vascular tissues and periderm. And caused tuberous root to expande constantly, In addition, in the secondary xylem and parenchyma cells of the expanded tuberous root, also found that the production of accessory cambium and the existence of starch grains. They common played a role in promoting the tuberous roots further expanded. The experiment also showed that the major enlargement part of the tuberous root was secondary xylem. In addition, the Storage and accumulation of starch grains Were also one of the important reason in promoting enlargement of the tuberous root.2. The research showed that the endogene hormone ZR, GA3, IAA, and ABA in the tuberous root, the content of ZR was the highest in the 4 kinds of hormone. particularly, at early stage and at the first expanding stage of tuberous root growth, it showed that ZR was able to help promote cell division, so it was closely related with the tuberous root expending. The content of GA3 in the tuberous root followed by ZR, the content of ABA was the fewest. Different illumination conditions, the content of endogenous hormone in the tuberous root there was a difference, which showed that the illumination effected the tuberous root growth and development.3. The research of the carbohydrate (total soluble sugar, starch, lignin and cellulose)in the tuberous root of Ficus microcarpa, the results showed that, the content of the carbohydrate was different amount when it was in different stage of root swell ratios and different tuberous root diameter. The content of the total soluble sugar, starch increased at the prior root expansion period, the content of total soluble sugar decreased at enlargment of tuberous root later period, the content of starch increased slowly. The illumination effected the content of the total soluble sugar and starch. The expansion of young seedling root at the prior period, the content of the lignin and cellulose in the tuberous root increased with the diameter increased, but what the later period decreased.4. With four kinds of growth regulators of BR, 6-BA, PP333 and GA3 in different concentrations sprayed the plants of Ficus microcarpa. The results indicated that the concentration of 0.001 mg/L and 0.05 mg/L BR in enlargement of the tuberous root , which have played the best role in promoting. Compared to the CK, the increases amplitude reached percentage of 47.23 and 47.53, respectively. All reached extremely significant levels (p= 0.01). The inhibit effect of PP333 on the aerial part of Ficus microcarpa is significant. with the concentration (50 mg/L~1000 mg/L) of the increased expansion of the root role in promoting, The improving effect of aerial part of Ficus microcarpa is significant; at a lower concentration (5 mg/L), the enlargement of the tuberous root was more obvious. GA3 on plant height on the ground with a clear role in promoting growth, but the effect of swelling was not obvious.