Research Of Nutrient Absorption Of Cyclamen Under The Facility Cultivation And Effect Of Calcium On Cyclamen High-quality Flower Formation

Cyclamen (cyclamen persicum L.), also called Tu'er Flower, Yipin Guan, etc, belongs to corm flower of Cyclamen genus, Primula malacoides Franch family. By virtue of peculiar hereditary variability of C. persicum, it is a kind of flower fostered through selection generation after generation and intraspecific hybridization and cultivation. This flower has special flower forms, abundant flower color, and long florescence. In developed countries such as America, Europe, Japan, etc., the related industrialization production technology of different varieties has been formed. In our country, the planting history of the cyclamen is short and the industrialized culture just starts. Because of lack of corresponding technical research, the breeds introduced abroad cannot realize the localization in the aspects of seed, culturemedium, and fertilizer. The problems such as low commodity rate, high production cost and lack of management skills of the high-quality cyclamen generally exist. In order to accelerate the sustainable development of cyclamen industry of our country, this research, based on the technological status quo of domestic and international industrialization production of cyclamen, investigates the nutrient absorption rule of cyclamen under the cultivation conditions, different fertilizer mode impact on the growth and development and quality, and calcium influence on the development of flowers and the formation of high-quality flowers. The main results are summarized as follows:â… . Growth and development characteristics and nutrient absorption rules of Cyclamen cultivated under facility conditionsAiming at the problems of blind fertilizer application, low fertilizer utilization ratio, high production cost, obstruction of growth and development, difficulty of the improvement of output and quality, etc., the growth and development characteristics and nutrient absorption rules of the main cultivated cyclamen breeds in our country have been studied and the following results are obtained:1. The study on the growth rules of three cultivars (S3, M1, NP3) of cyclamen of our country shows that, under the testing conditions, the growth and development of three cultivar breeds are slow before the over-summer period (August 21) due to the influence of high temperature stress; The number of leaves accounts for 30～40% of the total number, and the dry matter weight only accounts for 9.8% - 15.5% of the total number. However, after the over-summer period, cyclamen resumes to grow rapidly, leaf emergence accelerates, the number of leaves rapidly adds, and the accumulation of dry matter accelerates, but there are differences on the repair capacity among the breeds, wherein M1＞NP3＞S3, and M1 firstly starts into the full florescence, S3 is the last and NP3 is in the middle; when reaching the period of commodity (January 12), the maximum number of leaf for S3 is 83, for M1 is 84, and for NP3 is 81, all of which exceed the requirements of leaves of choice cyclamen; the maximum of dry mater accumulation for S3 is 49.9g·plant^-1, for M1 is 43.2 g·plant^-1, and for NP3 is 42.2 g·plant^-1; and the total number of flowers for S3 is 23, for M1 is 31, for NP3 is 29.2. The determination of the nutrient requirements in the whole breeding time of the three cultivars of cyclamen shows that, under the cultivation conditions, the requirements of nitrogen, phosphorus and potassium for S3 are respectively 1257.25mg·plant^-1, 218.79mg·plant^-1, 1171.69mg·plant^-1, the ratio between them is 5.7:1:5.4, and the total amount of the three elements is 2647.73 mg·plant^-1; the requirements of nitrogen, phosphorus and potassium for M1 are respectively 1214.14mg·plant^-1, 222.13mg·plant^-1, 1292.66mg·plant^-1, the ratio between them is 5.8:1:5.7, and the total amount of the three elements is 2170.831 mg·plant^-1; while the requirements of nitrogen, phosphorus and potassium for NP3 are respectively 1003.78mg·plant^-1, 174.231mg·plant^-1, 992.82mg·plant^-1, the ratio between them is 5.5:1:5.8, and the total amount of the three elements is 2728.93 mg·plant^-1; comparing the required amount of the three elements for the three breeds, the result is M1＞S3＞NP3. The requirements of calcium, magnesium for S3 are respectively 184.50 mg·plant^-1, 85:40mg·plant^-1; for M1 are respectively. 203.51 mg·plant^-1, 97.05mg·plant^-1; while for NP3 are respectively 273.21 mg·plant^-1, 127.14mg·plant^-1; comparing the total amount of calcium and magnesium for the three breeds, the result is NP3＞M1＞S3. The requirements of microelement for cyclamen are also different between different breeds. For the total amount, M1 is greater than S3, NP3.3. Investigation on the nutrient, absorption rules of cyclamen in different cultivation period shows that, under the testing conditions, the absorption amount of nitrogen, phosphorus and potassium before over-summer period is relatively less, accounting for 5.3～7.9%, 7.0～14.4%, 4.8～7.7% of the total absorption amount of nitrogen phosphorus and potassium respectively. But there are differences among the varieties. The absorption accumulation amount of M1 and NP3 is greater than S3 during the early period; the absorption accumulation rate is relatively less for S3 and slowly increases for M1 and NP3; the absorption of nitrogen, phosphorus and potassium of cyclamen greatly increases after over-summer period, and the rules of absorption and accumulation keeps pace with the growth and development of cyclamen. The absorption trends of calcium, magnesium and microelements are similar to the absorption of nitrogen, phosphorus and potassium.â…¡. Research on the growth and nutrient absorption and utilization under different fertilization modesThree different fertilization modes are established based on the nutrient absorption characteristics and production requirements of cyclamen cultivated in the different facilities. The following results have been obtained on the three different breeds:1. Based on the nutrient absorption rules and growth of testing conditions, three fertilizer supply modes are established. Compared with fertilizer supply model, Mode 2 and mode 3 can obviously decrease the high temperature stress during the over-summer period, resume the growth more quickly, and increase leaves earlier and more; accumulates and increases dry matters rapidly, splits up more bud, blooms early and neatly with less flowers below leaves, and quality flower increases. Among them, mode 3 is superior to mode 2; for the three varieties, the influence effects of M1, NP3 are superior to S3.2. Analysis of different fertilization supply modes effects on the nutrient absorption shows that, different fertilizer supply modes have similar effects on the nitrogen absorptions; that the impacts of mode 1 is greater than mode 3, and mode 3 is greater than mode 2. For mode 1, too much nitrogen absorption is not good for the development of cyclamen. However, the effects on element of phosphorus are inconsistent among different varieties: for S3, mode 2＞mode 3＞mode 1, for NP3, mode 1＞mode 3＞mode 2, but for M1, there is no obvious difference on the phosphorus absorption under the three modes. Among them, for NP3, the surplus absorption in phosphorus under mode 1 influences the development and growth and bloom quality of cyclamen. As to the impacts on potassium, calcium, magnesium, mode 2 and mode 3 are higher than mode 1. For the impact on absorption of the microelements, there are differences among the modes and among the breeds. But as a whole, the fertilizer supply mode 2 is more favorable to the absorption of microelements.3. Calculation on the nutrient utilization ratio under different fertilizer supply modes obviously shows that, compared with mode 1, mode 2 and mode 3 have obviously improved the utilization ratio of the nitrogen phosphorus and potassium nutrients, among them the utilization ratio of nitrogen has been increased by 1.9～2.5 times, utilization ratio of phosphorus by 3.5～4.6 times, while utilization ratio of potassium has been increased by 2.2～3.3 times. But for the impact on nutrient utilization ratio of different fertile modes, there are some differences among the breeds.4. Under the facilities culture conditions in the southeast of China, high-temperature stress makes a great influence on the growth of development of cyclamen, which leads to the reduction of output and bad quality. It is an important restricting factor for the production of high-quality cyclamen. How to clarify the stress physiology and improve the capacity of resisting high-temperatures stress is the question that cyclamen producers care about very much. Through the study on biochemical and physiological index on relevant cell membrane steady and soluble sugar contents of root activity, SOD enzyme activity of the leaf, MDA content, it shows that, the capability of resisting high-temperature stress of mode 2 and mode 3 is greater than that of the regular mode 1, which can be also demonstrated by the fact of the characteristics of leaf and bud growth conditions of cyclamen during the over-summer period, the rapid growth and quick stepping into the prosperous growth period in advance after over-summer period, and forming of large high-quality flowers.Considering the above descriptions and the production practice, for S3, there is no obvious difference in growth and development under the fertilizer supply between mode 2 and mode 3, and it is simple for fertilizing and application in mode 2, so mode 2 can be chosen for fertilizing in the production; the growth conditions of NP3, and M1 are obviously better than mode 2. Not only the leaf growth and bud splitting up is quickly after over-summer period, but also the products can come into the markets in advance with excellent quality, so mode 3 can be chosen for fertilizing in the production.â…¢. Research on the mechanism of floral organs development and high-quality flower formation influenced by calcium nutrition1. Under the water culture condition, the absorption of calcium is closely related to the floral organs development. When the concentration of calcium is Ommol L^-1, 2.5 mmol L^-1 and 5 mmol L^-1 respectively in nutrient solution, the absorption rates of calcium are steadily around -0.6mg plant^-1 d^-1, 5mg plant^-1 d^-1 and 15 mg plant^-1 d^-1 respectively; the corresponding contents of calcium in the floral organs are respectively 3.372g kg^-1d.wt, 6.341 g kg^-1 d.wt and 8.697 g kg^-1 d.wt; the corresponding bloom quantity are 3, 8 and 12 respectively; the average height of pedicel is 20.2cm, 24.7cm and 28.3cm respectively. Therefore, the increase of calcium concentration within a certain scope can improve the quality of blooming. The improvement of nitrogen concentration will obviously inhibit the absorption of calcium. The average absorption rate of calcium is 2.5 mg plant^-1 d^-1, the content of calcium in floral organs is 3.784 g kg^-1d.wt, and the height of pedicel is even 19.8% lower than that under the condition of calcium deficiency. The increase of boron concentration in the nutrient solution has no obvious influence on the absorption of calcium, but it accelerates the quantity of blooming, and the ratio between calcium and boron in the floral organs is close to the results of the group treated with 5mmol L^-1 calcium.2. The result of SEM scan shows that under the acalcerosis treatment and high nitrogen treatment for the floral organs containing relatively lower calcium, the vascular tissue of scape is small with irregular cell arrangement and indistinct difference of medullary ray, xylem and phloem. However, under the treatment for other flower organs containing higher calcium, the cell in the vascular tissue of scape which is regularly arranged, is clear, and there is distinct difference in medullary ray, xylem and phloem. Moreover, annular and thickening vessel element can be observed, of which the treatment for 5mmol L^-1 calcium is the most obvious. Therefore, one of the reasons that calcium has influence on the growth of flower organs is that it has influence on the growth of the scape cell.3. TEM ultrastructure shows that under the acalcerosis treatment and high nitrogen treatment, the chloroplast, chondriosome and cell nucleus of the scape cell will be damaged obviously. Under acalcerosis treatment, the thickness of cell wall is exceptionally inhomogeneous and broken, but under high nitrogen treatment, although there is no breakage of cell wall and cell membrane, the cell wall is very thin. Under the treatment of other flower organs with relatively high calcium concentration, the cell structure is normal, and the organelle is complete without any breakage. As the increase by 5mmol L^-1 of calcium concentration, the cell structure becomes clearer and more complete compared with the treatment group of 2.5mmol L^-1 calcium.4. The results for the cytochemistry allocation of calcium shows that, the cell wall and intercellular space in the scape cell are the main distribution places of Ca²⁺, which are also distributing in the cell membrane, nuclear membrane and cytoplasm with a little amount. Under 5mmol L^-1 calcium treatment, there will be maximum amount of Ca²⁺ precipitation grain, and there will be little Ca²⁺ precipitation grain under the acalcerosis treatment and high nitrogen treatment. The distribution amount of Ca²⁺ precipitation grain in the intercellular space of the new added boron is relatively small, while the amount and volume of Ca²⁺ grain on the cell wall increases. Take a section of the scape cell for EDS energy spectrum analysis, and measure the comparative calcium content of scape cell under different calcium conditions. The measurement result is comparatively consistent with the result of cytochemistry allocation of calcium. Under 5mmol L^-1 calcium treatment, the Ca/O ratio of high density electronic body in the scape cell is relatively high. The order of the Ca/O ratio under all kinds of treatment should be Ca₀＜+Ca+N＜+Ca＜+Ca+B＜++Ca.5. Absorption and transportation of Ca²⁺ are closely related to the activity of Ca²⁺-ATPase. Under Calcium-deficiency treatment, the calcium contents in all organs of cyclamen decrease obviously, calcium concentration in cells also reduces and activities of Ca²⁺ -ATPase in all organs also markedly decease. This may cause disorder of Ca²⁺ messenger system. Increase of calcium concentration from external source can improve calcium contents in all organs and obviously promote the activity of Ca²⁺ -ATPase. Increase of nitrogen supply inhibits the absorption of calcium and also decreases the activity of Ca²⁺ -ATPase.6. The changes of contents of all components in cell wall of cyclamen under conditions with different calcium supply are analyze and measured. The result indicates that with the increase of calcium content in organs, the cellulose content obviously increases. The cellulose content in cell wall under calcium-deficiency and nitrogen-efficiency is about 1/3 of that under treatment with comparatively high calcium content. However, the contents of pectin and hemicellulose decrease with the increase of calcium concentration. The increase of nitrogen supply makes the proportion of hemicellulose reach 65.6%, With the increase of calcium content in flower organs, the content of aldehydic acid increases in pectin, decreases, in cellulose and changes without regular rules in hemicellulose. The rule of change of total sugar content is similar to that of change of aldehydic acid content. The content of protein increases in hemicellulose, decreases in cellulose and changes a little in pectin. Therefore, calcium supply has direct effect on growth of organs of cyclamen and changes of structure of cell wall. 7. The different calcium condition can obviously affect the cyclamen flower organ endogene hormone content. At the calcium absorption normal treatment, IAA, ZTs and GA3 content are increasing along with the floral elongates to blossoms. At the treatments with lacking the calcium and the calcium absorption blocked, the gibberelin class matter content drops suddenly during the period of floral elongates to blossoms. It may cause the pedicel elongation to be blocked. The change of the IAA content level was opposite within the lacking calcium treatment and the calcium supply sufficient treatment. It also possibly causes the abnormal phenomenon of pedicel curving etc. At the same time, the lower content of growth hormone class matter is possibly the imperfect primary factor of vascular tissue growth during later period of pedicel growth. At the treatment with high calcium content supplying, both the IAA and the ZTs content are higher and the incrassation phenomenon of vessel is obviously. Maybe, there are some corresponding relations.8. Under different facility cultivation condition, studies on the influence of difficult calcium-supplying methods and different calcium resources on cyclamen-blooming show that, stopping the external supply of calcium has greater impact on the quality of cyclamen-blooming, with the height only about 2cm higher than the leave which is beyond the need of the cyclamen goods. CaEDTA is more effective than Ca(NO₃)₂ to promote cyclamen's absorption of calcium, as well as to improve cyclamen-blooming quality. Due to different calcium-supplying methods, tremendous differences exist in calcium content of nutrition organ of the cyclamen, for example, as to calcium supplied by root method, calcium content of root is higher than corm, which is higher than leaves. However it turns out to be different for calcium sprayed on leaves method, with which the calcium content of leaves is higher than root, and root higher than corm. Nevertheless, there is no obvious difference in calcium content in its floral organs resulted from different calcium-supplying methods.