Studies On Regeneration Of Potato And Genetic Stability Of Their Regenerated Plantlets

Establish a regeneration system of potato is utilize the theory that a living plantcell have an omnipotent quality, it can redifferentiate a new plant through the phase ofcallus. It provides a foundation for many other researches, especially the transgenetechnique developed in recent years, which is depends on a highly stable regenerationsystem. But the somaclonal variations are often occured in the process of plant tissueculture. In order to know the process of potato's regeneration and variation inregeneration plant, make a foundation for other reseaches. This research take 10different kinds of potato varieties as experimental material, firstly, study theinfluencing factors in the process of regenerating on the potato variety of Da xiyang,such as the category and concentration of hormone,the days of culture for callus, andthen apply the regeneration system to other 9 varieties to compare the regenerationdifferences among different genotypes; finally, mensurate the genetic variation ofvariety of Da xiyang'regenerated plant. The results are as follows:1. The optimal medium for callus induction from leaves and stem segments ofpotato variety Da xiyang were MS+6-BA2.5mg/L+NAA0.3mg/L and MS+6-BA2.5mg/L+NAA0.4mg/L respectively, the callus induction rates all reached 100%; Theoptimal medium for adventitious bud differentiation from leaf-derived calluses andstem segment-derived calluses was found to be MS+6-BA5.0mg/L+NAA0.1 mg/L+GA₃ 10mg/L, adventitious bud differentiation rate reached 100% and 73.3%respectively. Apply this regeneration system to other 9 varieties, the result indicatethat there are biggish differences among the regeneration of different genotype, thesystem is adequate for 2 kinds only.2. 2,4-D is good for callus induction, but it has retarding effect on adventitiousbud differentiation; and using IAA has negative effects on induction of callus, butthere are highly frequency of adventitious bud differentiations on the callus thatinduced using IAA. Compare with the status of adventitious bud differentiation fromcallus that cultured for different days, shows that the leaf-derived callus that culturedfor 14 days used for adventitious bud differentiation is the best, but the stem segment-derived callus that cultured tbr 21 days used for adventitious buddifferentiation is better then others; and the adventitious bud differentiation rate ofleaf-derived callus is higher than stem segment-derived callus's.3. At the same time, the receach find that the GA₃ is requisite in adventitious buddifferentiation. There have't had adventitious bud differentiation in the culturemedium which do not have GA₃, it have adventitious bud differentiation as long asthere are GA₃ in the culture medium, but the optimal concentration is 10mg/L.4. Through the observation of agronomic character, there are no big variation inthe 100 regenerated plants. Only a few plant have small changes in same characters orlarge changes happened in individual characters in few cases. Through the RAPDanalysis, only one regenerated plant from leaf-derived callus and four plants fromstem segement-derived callus have variation in the 100 regenerated plants, that is tosay that the variation in regenerated plants is not common.