| Lilium distichum and Lilium cernuum Komar.,originated from northeast China,are rare wild lilies resources,which feature prominently in unique color and highly resistant to abiotic stresses.However,both of two lily species flowers are small,plants are susceptible to get disease,and the coefficient of reproduction are low.Polyploidy,characterized by large organ,strong plant and strong resistance,is one of the most effective ways to cultivate new germplasm with robust characters in lilies.The conventional polyploidy breeding,however,leads to a large number of chimeras.Somatic embryo originated from single cell,which is quite genetically stable,high-efficiency propagate and avoiding chimera formation as an excellent material for polyploid breeding.For the first time,the study using both of which the lilies scales and somatic embryos servered as the target tissues,are accomplished the ployploid inducement by means of soaking method and mixed culture method with different concentration of colchicine.Comprehensively through morphological observation,root tip chromosome count and stomatal observation,obtain new species with good cultivation characteristics and improve reproduction coefficient.The main results are showed as follows:1.Induceing somatic embyro and histological examination in two Lilium species.Results indicated that the combination of 1.0 mg·L~-11 picloram and 0.2 mg·L~-11 NAA increased the amount of embryogenic callusthat formed with a maximum on 89.8%and 91.2%of all explants.Histological examination confirmed the somatic embryogenesis of two species Lilium are different,It is indirect regeneration in Lilium distichum and direct regeneration in Lilium cernuum Komar.with no embryogenic callus stage.Somatic embryos were originated via both the exogenous and the endogenous origin in Lilium distichum and Lilium cernuumKomar.,The exogenous origin pattern accounted for 89%and 65%,respectively2.This study are accomplished the ployploid inducement by means of soaking method and mixed culture method with different concentration of colchicine.Results indicated that when colchicine concentration is from 0.01%-0.1%,With the increase of concentration,With the rise of the concentration of colchicines,the suvival rate of the explants is decreasing.When 0.1%colchicine solution for 72 h in soaking method,0.1%colchicine solution for 20 d in mixed culture method,the death rate is 100%.In terms of inducing effect,with long culture time and great toxicity,mixed culture method has higher lethality rate.While soaking method,with relevant lower lethality rate,which increases the inducing rate of polyploidy,is the best method to induce the lily polyploidy.3.The polyploidy of these two lilium has been identified by root tip chromosomes method,the results indicated that the diploid chromosomes and tetraploid chromosomes of these two lily species are respectively 24 and 48,also there is no chimerism.Through identification,it can be found that polyploidy can be induced by scales or somatic embyro,but the effect of somatic embyro induction is better,especially in 0.05%colchicine solution for 48 h in Lilium distichum and in 0.05%colchicine solution for 24 h in Lilium cernuum Komar.,that the induction rates of tetraploid plants are 28.57%and23.08%,respectively.4.Comprehensively through morphological observation and stomatal observation shows that the tetraploid plants developed larger,thicker leaves and stronger root system.Moreover,the tetraploid stoma of Lilium distichum and Lilium cernuum Komar.is 1.63-fold and 2-fold greater than its diploid stoma.The optimal project substance to culture these two lily species is 1/3 turf and 1/3 vermiculite and1/3 riversand.Compared with diploid plants,tetraploid plants and notable difference in appearance and stronger. |
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