Effects Of Heterologous Grafting On Interspecific Hybridization Affinity Of Potato And Its Embryo Development Dynamics

In order to create wild potato and cultivated potato hybrids,In this study,five grafting methods were adopted: "grafting contemporary,maternal clone,cumulative grafting I,cumulative grafting II,parental clone",fruit setting rate and seed setting rate of grafted plant and control group were calculated,study on the effect of grafting on the interspecific cross compatibility of wild materials of jizhangshu 8,jizhangshu 12 and diploid.In order to screen out the best grafting method and cross combination with strong affinity,obtaining distant hybrid seeds,provide new intermediate materials for potato breeding.The development of hybrid embryos of jizhangshu 8,jizhangshu 12 and diploid wild materials at different stages were further observed by paraffin section,in order to put forward the node of embryo abortion and find out the reason of embryo abortion.The results lay a solid theoretical foundation for accumulating data of distant hybrid embryo rescue technology of potato.The main results are as follows:1.Grafting contemporary in the experiment of distant hybridization of jizhangshu 8 and jizhangshu 12 with diploid materials,both of them have positive effects on improving fruit setting rate and single fruit setting rate.The percentage of hybrid backseat fruit and the percentage of single fruit bearing were generally increased in multiple groups of experiments: The highest fruit setting rate of jizhangshu 8 grafting group increased from 32.6% to 47.4%.The highest seed setting rate of single fruit increased from 0% to 9.1%.The highest fruit setting rate of jizhangshu 12 grafting group increased from 21.2% to 59.8%.The highest seed setting rate of single fruit increased from 68.6% to 1234.7%.Grafting contemporary can effectively promote the compatibility of wild and cultivated species.It can be effectively applied to the hybrid cultivation and breeding of jizhangshu 8、jizhangshu 12 and wild species.2.The parental clonal pattern played a positive role in the fruit setting rate and fruit setting rate of distant hybridization between jizhangshu 8 and diploid materials.The highest fruit setting rate of grafting group increased from 1.2% to 19.2%,the highest seed setting rate of single fruit increased from 25% to 100%.The parental clonal system can be effectively applied to the hybrid cultivation and breeding of jizhangshu 8 and wild species.3.The effects of three grafting methods cumulative grafting I,cumulative grafting II and maternal clone,on promoting the fruit setting rate and fruit setting rate of jizhangshu 8 and diploid materials were not good.At the same time,the effect of jizhangshu 12 on fruit setting rate was not good.There was no significant effect on improving the seed setting rate of single fruit of jizhangshu 12 and diploid materials by four grafting methods: cumulative grafting I,cumulative grafting II,maternal clones and parental clones.4.The cross section of interspecific hybrid embryo was observed 8 days after pollination,and it was found that the hybrid embryo was in the initial stage of formation,unfixed form,embryo and endosperm are in the state of initiation and development;There was no cell differentiation in most hybrid embryos 12 days after pollination,However,a few embryos developed into torpedo type;19 days after pollination,most of the hybrid embryos were aborted.The best period of embryo rescue could not be earlier than 8 days after pollination,no later than 19 d after pollination,the best time for embryo rescue is about 12 days after pollination.