Mesophyll Protoplast Culture And Fusion Of Dihaploid Strains And Diploid Wild Species Of Potato

Potato (Solanum tuberosum L.) is the only crop used both as food and vegetable.Protoplast culture and somatic hybridization is the important procedure of analytical-synthetic breeding of potato and the important way to transfer resistant properties of wild species into cultivar of potato.In this reseach,three anther derived dihaploid strains and three diploid wild species were used as the donor tissues to investigate the protoplast culture and somatic hybridization of potato.The effect of some outside factors such as vaccum infiltration,cold pretreament,browning inhibitor were also discussed.The results showed as follows:The treatment of vaccum infiltration on donor tissues could improve the yield and reduce the broken ratio of proptoplasts.There were less impurities in the protoplasts when they were cultured.There was an intimate relationship between the yield, viability, plating effeciency of protoplast and the donor tissues' variety and genotypes.The protoplast'yield,quality and plating effeciency of dihaploid strains were all better than diploid wild species'.2-10 was the best,its protoplast yield was 5.83×106/g fresh leaves,viability was 61.02% and plating effeciency was 32%.CW-2-3 was the worst,its protoplast yield was 0.31×106/g fresh leaves,viability was 16.40% and plating effeciency was 0%.The cold 2d-pretreatment with the tube plantlets of CW-2-7 could improve its plating efficiency of protoplast.With 4℃ pretreament,the plating effeciency of protoplast was the highest compared with 15℃ and Room Temperature.The browning rates were very different with different genotypes,and diploid wild species'browning rates were all higher than the dihaploid strains'.The browning rates of CW-2-3 was the highest,18.33%;2-10's browning rate was the lowest,9%.But the addition of AgNO3 into the culture medium of protoplast could prevent its browning,and the best concentration of AgNO3 was 0.6mg/L. NAA or 6-BA could cause the browning of mesoplyll protoplasts of potato.But when they were cooperated,they could prevent the browning of protoplasts.The browning rates of NAA1.2mg/L were the highest among the three NAA concentration levels. The variances of protoplast browning rates were all siginificant in the three 6-BA concentration levels.The protoplasts browning rates of 6-BA0.6mg/L were the highest,17.33%.The chemical fusion by PEG method and electro-fusion were between CW-2-7 and 2-10.The results showed that the best temperature was 30℃ and the best pH was 9.0 in the chemical fusion.The best parameters of electro-fusion was:AC125V/cm,DC0.75KV/cm,PW40μs.With those parameters of electro-fusion,no side-effect was found on the protoplast viability.Regenerated plantlets from three dihaploid strains and one diploid wild species were got by the isolation and culture of mesophyll protoplast of potato.