Establishment Of Regeneration System For Self-compatible Pear 'Jin Zhui'

Asia are the regions with the longest and most productive pear cultivation history in the world,and China is also one of the most important origins of pears.The‘white pears',‘sand pears',‘ussurian pear'and xinjiang pears that are commonly cultivated in production are all native to China.Pears have a highly self-incompatibility,although this feature limits the inbreeding of pears and is beneficial to species diversity,but it is not true for the production of pears,which are fruits and seeds for harvested crops,Self-incompatibility undoubtedly increases production investment.On the other hand,pear incompatibility and long juvenility time delay pear breeding time,and it can promote pear cultivation innovation and variety selection through genetic transformation technology mainly based on plant tissue culture and tissue regeneration.An effective way to achieve pear genetic engineering breeding.In this experiment,we studied the self-incompatibility of pears,studied the growth characteristics of pollen tubes,combined with the fruit setting rate,and selected self-compatible varieties.On the one hand,the method of preliminarily verifying the self-incompatibility of pears was determined,and the self-compatible pear varieties were finally screened out.On the other hand,On the other hand,self-intergrity pear varieties were used as materials to optimize the pear subculture system,and an efficient regeneration system for self-compatible pear varieties was established.It provides theoretical basis and reference for studies on the rapid propagation,detoxification and genetic transformation of pear cultivars with affinity..The main findings are summarized below:1.In this experiment,the experiment carried out pollen tube in situ fluorescence microscopy of 256 pear varieties that were bagged.According to the intensity analysis of R value,there are 6 varieties,most likely self-compatible varieties.These are 'Yanzhuangyali','Akizuki','54S-135','Jinzhui','Duoguohuanghua',and 'Mansoo'.By investigating the self-pollination rate of varieties with different R values,it was found that the fruit set rate of the late show was zero,and the set rates of 'Jinzhui' and 'Akizuki' were all higher than 20%.Other self-affinity intensities are not as strong as those of self-cultivated kits,the rate of seed setting is extremely low,which is a self-incompatible species.The reliability of the method for the initial screening of self-compatible breeds by using R values in massive resources was verified.2.In this experiment,primary culture of selected self-compatibility cultivars was conducted,and it was found that 'Jin zhui' is suitable as a regeneration system material,through the selection of different hormone ratios in subculture media.The best subculture medium for 'Jinzhui' Pear was MS+1.0 mg·L-1 6-BA+0.2 mg-L-1 6-BA+30 g·L-1 sucrose+7.5 g·L-1 agar,the mean bud proliferation rate was 1.44 and the browning rate was the lowest at this time.In this experiment,primary culture of selected self-compatibility cultivars was conducted,and it was found that 'Jinzhui' is suitable as a regenerative system material,through the selection of different hormone ratios in subculture media.The suitable medium for the regeneration of the leaves of 'Jinzhui' is NN69+2.0 mg·L-1 TDZ+0.4 mg·L-1 IBA.The regeneration rate reached 100%,the average number of buds per leaf was 2.11,the callus rate reached 100%,and the browning rate was 0;the inverting of the far axis was conducive to increase the leaf regeneration rate;the most suitable dark culture time was 21 days.