Studies On Asexual Propagation And Bulb Technique Of Lilium Asiatic Hybrids

Lilium spp.is a bulbous perennial herbaceous flower,a liliaceous plant and one species of Lilium.It has tall and straight stems,large petals of varying colors,with elegance and fragrance.Due to its tenacious vitality and rich artistic value,it tends to be regarded as the symbol of purity,bright and happiness.Its Chinese pronunciation "baihe" also sounds like eternal love,happiness and prosperity.In addition,its bulbs possess high values for food and medical purpose,which has made it one of the best bulb flowers and the world's fifth largest cut flower.Asian Lilium "Prato" is one of excellent cultivars in Asiatic lily hybrids.It possesses orange-red flowers,no scent,and high resistance,and can be cultivated in overwintering outdoor in northeast China region.This experiment aims to discuss three issues,featuring the optimal reproductive condition of two approaches of asexual reproduction,the connection between carbohydrate metabolism of mother scale and new bulblet and development,growth and expansion of new bulblet in the process of scale cutting propagation,and the third one,the morphology change of mother scales and new bulblet growth during the above process,by using the method of anatomy.This experiment could offer theoretical reference and practical guidance for factory production of Lilium spp.bulbs.Main results of this research are as follows:(1)Compared among outer,middle and inner scales of Prato,the outer ones are the best for cutting propagation,which has higher growth rate and seedlings strength than the middle and inner ones.Through selecting different bulk materials of Prato's scales,the dosages of plant growth regulators,processing time and cutting positions of scales,the results show significant differences among these factors,and Prato grows the best in Q10 treatment,featuring turf soil plus vermiculite(1:1)as bulk materials,100 mg/L 6-BA + 100 mg/L IBA as plant growth regulator,3 hours of processing time,and the cutting at the bottom of the scales.The influence ability of each factor is from the strong to the weak,which is:the position of the scale>the kind and concentration of plant growth regulator>treatment time>the matrix of cuttage.(2)The experiment adopted the middle and outer scales as explants,and the 15 min as best sterilization time,the most suitable medium for the induction of new bulblets:MS + 1.5 mg/L 6-BA + 0.2 mg/L NAA,and concluded that the differentiation rate was 84%and the number of adventitious bud to 148.(3)In the process of cutting,the amount of carbohydrates in mother scales decreased on the whole,while in new bulblets increased at the beginning(0-21 d),which shows that the development of new bulblets,to a large extent,depends on the consumption of carbohydrates in mother scales,and this development is also a process of accumulation of carbohydrate.In the middle of the cuttings(21-41 d),the amount of carbohydrates in mother scales and the new bulblets were both in a relatively stable state.In the later period(after 42 d),the amount of carbohydrates in mother scales decreased again,while that in new bulblets obviously increased,which shows that in the expansion stage of new bulblets,they require a large consumption of carbohydrates from the mother scales.(4)Prato's cormels germinated in the parenchyma cells of inside 10 layers of paraxial incision.The development process of cormels was successively initiating stage,apical meristem formation stage,leaf primordium formation stage and bulblet formation stage.