| Lycoris radiata, which has stout flower stems, gorgeous color, high medical value and strong resistance, is considered to be of great development potential. But the research on cut-flower cultivation technology is seriously lagged behind. This paper takes four-year-old asexual bulbs of L. radiata as the subject and studies its floral development physiology and cut-flower cultivation techniques by examining its growth phenology, anatomical structure, development physiology, storage physiology, and cut-flower cultivation techniques. The results are supposed to provide some reference for the exploitation and flower development study of L. radiata.The main contents and results are as follows:1. Phenological observations and the anatomical structure show that such structural features as thinner palisade tissue, osteoporosis sponge tissue and the convex shape feature of epidermal cells explains its capacity to adapt to the damp environment. The whole growth and development period of L. radiata includes the following stages:the period of flower bud differentiation(from late March to mid May), floral organ development period(from late May to early July), bolting period(from mid to late August), blossoming stage (from early September to early October), leaf sprouting stage (from mid to late October)and green leaf stage (from November to March), and leaf scorch stage((from late March to early May). In addition, the growth and development of L.radiata are greatly affected by the environmental temperature.It’s is at the respectively sprouting-leaf atage, vigorous growth stage, the slow growth stage, leaf yellowing stage, and leaf blight stage when the temperature ranges respectively from18.3℃to21.8℃, from10.6℃to14.8℃from5℃to9℃, from22.1℃to25℃, and from25℃to31℃. On the other hand, when it is respectively in the period of flower primordium, perianth form, and floral organ development, only when the temperature is also respectively below12.88℃,17.3℃～23.35℃, and25℃～30℃. In addition, the continuous high temperature or the temperature difference of1.69℃between the soil and air is probably necessary for its lower bud differentiation.2. Studies on developmental physiology of L. radiata’s bulbs show that the content of soluble sugar and soluble protein in bulbs changes when it’s at different developmental stages as well as the activities of SOD and POD. In which, the content of soluble sugar and soluble protein both tend to increase gradually at the stage of flower bud differentiation to maintain relatively stable in floral development period, and to decrease significantly in the green period. But, the activities of SOD and POD decrease during flower bud differentiation period and they increase gradually during the floral development to green period. Studies of endogenous hormones content in the process of bulb development show that the peak sequence of five kinds of endogenous hormones content appears orderly as following:IAAâ†'GAâ†'ZRâ†'ABAâ†'IPA. There is a negative correlation between IAA, ABA, and ZR, and there is a positive correlation between ABA, IPA and GA content in bulb bud. The result shows the relatively high ratio of IAA/GA, IAA/ZR, GA/IPA content and ABA/GA, ZR/iPA accelerate flower bud differentiation, and high ABA/GA, ZR/IPA, ABA/ZR accelerate flower bud development, blossom and leaf sprouting.3. The test of bulb storage shows that temperature and storage time both have an obvious influence on the florescence and quality of cut-flower of Lycoris radiata. Although the treatment of5℃cold storage significantly delays its florescence and leaf sprouting period. At the same time it also reduces accordingly the length of scape and leaf. The processing of14℃helps sprout leaves ahead of29days, but not blossom before spring. However, The high temperature (22℃～26℃) storage blooms ahead of10to16days. In addition, the quality of cut-flowers decreases with a longer storage time under the same storage temperature(the lower blossom rate, the shorter florescence).4. Bulb storage physiological studies suggest that the change trends about the soluble sugar content, soluble protein content, POD activity, SOD activity, and MDA content during storage are similar. That is, they decrease with the increasing temperature and time. But the temperatures of their peak are different.On the other hand, the IAA/ZR, ZR/iPA and AB A/G A play an important role in the process of breaking dormancy. At low temperature of5℃to14℃, the contents of IAA, ABA, and IPA increase with temperature and so does storage time. and the change trend about ABA/GA is similar. While, the content and the with temperature and storage time increase, while the change trends of GA and ZR are the opposite. The contents of IAA and ABA are respectively negative correlation to that of ZR.5. The experiment of cut-flower cultivation shows that three factors can be effective in promoting the growth of leaves, flowering delay, flowering uniformity, the quality of cut-flowers.The performance of effect by the strength is as the following: shading>fertilization> shading*fertilization. In four kinds of shading, the shading of45%has the best effect comprehensively. Because it not only has the highest rate of blossom(66.76%), the highest number of bulbs (67.75), and the biggist fresh weight(1184.5g), the root number and the length of roots are also the biggest, and the quality of cut-flowers is the best. For example, compared to the control, its average scape length, flower diameter, basic coarse, carotid diameter and the number of floret are respectively more6.31cm,0.3cm,0.03cm,0.02cm,0.13).In12fertilization treatments, the effect of B3on the quality of bulbs is the best (the average diameter is largest,3.55cm). Its total number of bulbs is biggest (61.5particles) and the flower number per scape is most. However, the quality of cut-flower of B12(Shading45%+Organic manure2.6kg·plt-1+N11.7g+P10.76g+K35.8g) is the best. Its average length, the flower number of every flower sequence, the flower diameter, the basic crude and the neck roughness of scape are significantly greater than that of the control.In all treatments, the processing of A2B3(Shading45%+Organic manure2.6kg·plot-1) has the biggest production of cut-flower(104.43branch·m-2), the maximum diameter of bulb, the largest number of root, and coarse scape. However, the processing of A2B12(Shading45%+Organic manure2.6kg·plot-1+N11.7g+P10.76g+K35.8g) has the superior quality of cut-flower(such as the longest scape, the flower number per scape), the biggest leaf area and bulb weight. Overall, the promoting effect of A2B12is best.In conclusion, Lycoris radiata has some characteristics in leaf structure of adapting to the damp environment, and it nourishes with humus-rich sandy loam. Therefore, during its cut-flower cultivation, the moderate shade (45%), chemical fertilizer application amount of organic fertilizer (3.25kg·m-2) is the effectively way to cultivate the excellent quality and high yield cut-flowers, as well as delaying flowering and improving its blossom uniformity. In addition, the development of flower and leaf is mainly controlled by the balance of hormones ratio, and the requirement on the temperature in different stage of the flower bud differentiation and development is not same, the process is significantly affected by the environmental temperature. The specific remains to be further research. |
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