Research On Embryonic Callus Induction And Effect Of ABA On Somatic Embryogenesis Of Lilium Leucanthum (Baker) Baker

The resource of Lilium varieties is rich,Its flower type is unique,in the flower market,It has very important value.But in our country Lilium depends on importing from the Netherlands,Japan and other countries for a long time,made our international market position lower.Our country is the main origin of Lilium,germplasm resources is rich,but with the continuous development of urbanization,many wild Lilium is dwindling even become extinct,because they can't get protection,.Therefore,effective preservation and utilization of germplasm resources in our country become a key problem to be solved.This article mainly use?Lilium leucanthum?bulbs as the experimental material,through the induction of embryonic callus,establish the somatic embryo regeneration system;On this basis,based on long-term transgenerational callus materials,combined with morphological,histological observation,discuss adding ABA embryogenesis and development of the body in the process of physiological and biochemical characteristics and the influence of endogenous hormones.For Lilium leucanthum germplasm resources preservation and body mechanism of embryogenesis provide theoretical basis for the study,the results showed that:?1?Induction of embryonic callus under light conditions the best medium for MS+TDZ 0.5 mg/L+1.0 mg/L NAA+2,4-d 0.05 mg/L,induction rate was62.690%;Dark under the condition of embryonic callus induction of the best medium for MS+TDZ 0.5 mg/L+1.5 mg/L NAA+2,4-d 0.1 mg/L,the induction rate was59.423%.Embryo healthy seedlings roots of optimum culture medium for 1/2 ms+NAA 0.2 mg/L+AC 1 g/L,training after 60 d,seedling to the peat:vermiculite:pearlite=1:1:1 in matrix,the survival rate of 90%.?2?Morphology on embryonic callus shows it is yellowish green or dark green,granular;Non-embryo callus is loose,fragile,and water damage.observed by paraffin section observation,embryonic callus has big and thick cytoplasm,nucleus and cells contain abundant starch grains,cell diameter of about 50 to 80 um.Non-embryo callus cells,did not see obvious nucleus,diameter of about 100¹80 um.?3?Add in the culture medium of low concentration ABA training,Lilium leucanthum callus can be gradually transformed into embryonic callus,and the normal development of embryo,globular embryo,heart embryo,torpedo embryo and cotyledon embryo development and eventually grow into a complete plant.?4?ABA increased SOD activity and played a fundamental role in cell differentiation and development.At the later stage of somatic embryo development,the activity of SOD increased,the activity of POD and CAT decreased,and the content of MDA was significantly lower than that of the control group?CK?.It can be seen that ABA had a positive effect on the antioxidant enzyme system of somatic embryo in the process of regulating the normal development of somatic embryo.In early somatic embryogenesis,the increase of proline in aba-treated callus plays an important role in regulating cell osmotic potential and stabilizing protein structure.Starch accumulation peaked in torpedo embryo stage,which provided material basis for callus differentiation and embryo development.The soluble protein in the body of lilium yichang had a peak value in the early embryo formation stage,but the soluble sugar had a low value.It was speculated that the cell metabolism was strong in the early embryo stage,and the soluble sugar in the body of lilium yichang was transformed into RNA and protein,which introduced the accumulation of protein and further promoted cell division and differentiation.?5?ABA treatment effectively prevented the accumulation of IAA hormone to toxic levels.Because of ABA regulation,GA₃ in lily callus of yichang was increased during morphogenesis,which promoted the normal growth of seedlings.The early development of somatic embryo may require a small amount of cytokinin.However,higher levels of cytokinins may contribute to the differentiation and normal maturation of somatic embryos at the later stage of somatic embryo development.ABA treatment at a moderate level significantly promoted somatic embryo differentiation and development.In the middle and late stages of somatic embryo development,the increased ABA/IAA ratio is conducive to the continuous development and maturation of somatic embryo.High IAA/ZT ratio can promote the formation of callus,while low IAA/ZT is more suitable for the differentiation of callus.