Research On Breeding Excellent New Strains Of Special Potato

Potato is grain and vegetable crops,which plays an important role in agricultural production in China.With the in-depth implementation of the strategy of national potato staple food,the demand for special processing potato varieties is constantly increasing,while which bred in our country is rarely and can not meet the requirements of the production development.In order to cultivate excellent new varieties of special processing potato which is suitable for processing potato granule,high starch and chip etc,we combined potato materials‘1867'and‘MB09'which has good quality and high yield introduced from abroad with domestic potato varieties‘Longshu 6'and‘Longshu 7'which has high disease resistance and strong adaptability,and successfully obtained the F1 seeds of three cross combinations‘1867×Longshu 6',‘MB09×Longshu 6'and‘MB09×Longshu 7',and then obtained the hybrids F₁ clonal population via greenhouse nursery.This study emphatically carried out some research on the following 5 aspects:SSR identification of individual authenticity of hybrids F₁ clonal population,chromosome configuration and pollen fertility analysis of F₂ clonal population,excellent strain breeding and characters analysis such as yield and quality of F₃ clonal population,AFLP analysis of heredity difference of F₄ clonal population,as well as evaluation of potato yield and quality and identification of potato black scurf resistance and storability of 5 special excellent new strains.The main results are as follows:1.A total of 76 individuals of hybrids F₁ clonal population of three cross combinations‘1867×Longshu 7',‘MB09×Longshu 7'and‘MB09×Longshu 6'were identified as true hybrids using four screened suitable SSR primers S25?S118?C57 and STI047.2.Determine the chromosome pairing configuration and pollen fertility of 27excellent lines of F₂ clonal population of three cross combinations,and the relationship between bivalent frequency and pollen fertility rate.The lines with the pollen fertility rate below 50%?A4,A10,A12,A14,A19,A23,A30,B1,B13,B14,B15,C2,C21 and C22?are suitable as female parent to further cross and utilize,and the lines with the pollen fertility rate above 50%are suitable as male parent to cross and utilize.3.In the present study,17 out of 27 excellent hybrid lines of F₃ clonal population were selected,with good tuber shape,eye shallow,tidy and concentrated tuber,good quality,high yield and commodity potato rate,of which hybrid lines A10,A12,A14,A21,A23,A26 and A29 from cross combination‘1867×Longshu 7',B1,B2,B7,B13,B14,B15 and B20 from‘MB09×Longshu 7'and C2,C21 and C22 from‘MB09×Longshu 6'.4.The correlation analysis shows that the yield per plant has a positive correlation with plant height,main stalk number,tuber number per plant,average tuber weight,and commodity potato rate,while a significantly negative correlation with number of plant branch,and the average tuber weight has a extremely significantly negative correlation with tuber number per plant.And there is a extremely significantly positive correlation between tuber starch and the dry-matter content,and the reducing sugar content has a significantly negative correlation with protein,starch and dry-matter content,respectively.5.Using 10 AFLP suitable primer combinations to amplify 17 excellent hybrid lines of F₄ clonal population and their parents,a total of 277 pleomorphic loci were amplified,the pleomorphic rate was 87.29%,the average polymorphic information content was0.5617,the Nei's gene diversity index was 0.3623,and the shannon index was 0.5407.6.The average genetic distance?GD?of 17 excellent hybrid lines of F₄ clonal population and their parents was 0.528,and the materials were classified into four categories based on GD value of 0.51:line A10,A12,A21,A29 and female parent‘1867'as a category;line A14,A23,A26,B13,B14,male parent‘Longshu 6'and‘Longshu 7'as a category;line B1,B2,B7,B15,B20,C22 and parent‘MB09'as a category;and line C2and C21 as a category.7.A total of 5 excellent new strains with outstanding target characteristics of special potato,A14,A21,A29,B2 and C21,were selected from 17 excellent potato lines,which has good tuber shape,shallow eye,high yield and commodity potato rate.The strain A29has high starch,strain A14 and A21 are suitable for granules processing new strain,strain B2 is suitable for chip processing,and C21 is suitable for french fry processing.8.The results of potato chip inoculation showed that new strain A14,A21,A29 and B2 inherited strong black scurf resistance from male parent‘Longshu 7',and new strain C21 inherited relative strong black scurf resistance from male parent‘Longshu 6'.9.After stored five months,the tuber germination rate of all the potato new strains was low,and the descend range of starch and dry matter content as well as the rising range of reducing sugar were also sluggish,since the new strains inherited strong storability from their male parent.10.Tubers germination rate shows a extremely significantly negative correlation with starch and dry-matter content,while a extremely significantly positive correlation with reducing sugar.The starch,dry-matter content and reducing sugar can be used as a important indicator for evaluating storability of different potato materials.