| Lily is a perennial herbaceous bulbous flower of Lilium in Liliaceae.It is widely loved by people because of its large and gorgeous flowers and unique fragrance.It is one of the five fresh cut flowers in the world.China is the origin center of Lily in the world.However,the development of lily industry in China is slow,the obstacles of distant hybridization and the lack of technology seriously hinder the breeding of new varieties in China,which has become the key technical bottleneck of lily industry.OT（Oriental hybrids×Trumpet hybrids）has the advantages of strong resistance,large flowers and unique fragrance.However,its laterally growing flowers hinder the transportation of cut flowers.Oriental lily hybrid lines also have large flowers and aromatic smell,and the flowers grow upright,but the resistance is relatively poor,which is not suitable for China’s climate and cultivation environmental conditions.Using OT series Lily and Oriental lily as parents for cross breeding can combine the excellent characters of their parents and cultivate new varieties with strong resistance,upright flowers and strong adaptability.In this study,OT series Lily’Robina’（triploid）was used as female parent and Oriental Lily’Sorbonne’（diploid）was used as male parent.The mechanism of distant hybridization obstacle and Hybridization Compatibility between’Robina’and’Sorbonne’were explored by measuring the pollen germination rate of parents,the stigma activity of female parent,the growth state of pollen tube in pistil,the embryo rate of hybrid seeds and the sowing of hybrid seeds;Through the exploration of embryo rescue conditions such as inoculation mode,embryo age,medium components and light conditions,an efficient embryo rescue scheme was established to lay a foundation for future breeding work;SSR and chromosome technology were used to identify the hybrid authenticity of the seedlings of hybrid offspring,and to explore the law of chromosome segregation of female parents.The main results are as follows:1.Analysis of Hybridization Compatibility and distant hybridization obstacles between’Robina’and’Sorbonne’.The pollen germination rate of parents was measured by liquid culture method.The pollen germination rate of’Sorbonne’was68.15%,which can be used in hybridization experiment.The results of’Robina’stigma acceptability test showed that it had the strongest acceptability on the day of flowering.Pollen tube fluorescence observation,seed embryo rate statistics and hybrid seed planting results show that the pollen tube of’Sorbonne’can grow normally and locate to the ovule pore.After pollination,seeds with embryo and endosperm morphology can be obtained,and the embryo rate is 27.09%.However,the sowing germination rate of hybrid seeds is very low,only 6.3%,and the germination time is long,so it is determined as post fertilization obstacle.2.Establishment of embryo rescue system of‘Robina’בSorbonne’hybrid combination.The culture medium,embryo age,inoculation method and light conditions affecting the efficiency of embryo rescue were screened.The results showed that the best embryo rescue scheme was as follows:seeds of 90DAP were peeled and inoculated on culture medium 2.215 g·L-1 MS powder+60 g·L-1 sucrose+4.6 g·L-1 agar powder for dark culture.3.Hybrid authenticity identification.The hybrid authenticity of the germinated seedlings after embryo rescue was identified by SSR molecular marker technology and chromosome technology.The results showed that 15 of the 19seedlings examined by SSR were true hybrid offspring,and the remaining 4 needs to be further identified.The chromosome numbers of 61 seedlings were counted.The results showed that the number ranged from 24 to 35,mainly concentrated in28 and 30,and most of them were aneuploidy.In this study,through the analysis of the compatibility of the hybrid‘Robina’בSorbonne’,it was found that there was a serious post-fertilization obstacle in this hybrid combination,and embryo culture was needed to overcome this obstacle.Then,through the screening of various factors affecting embryo culture,the optimum embryo culture conditions were determined as follows:90 days after pollination,the hybrid seeds were peeled and inoculated in MS based medium for dark culture,and the identification of hybrid authenticity showed that the real hybrid offspring seedlings were obtained. |
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