Studies On In Vitro Preservation Of Potato Germplasm

Potato is one of vegetative vegetables.The conservation of potato germplasm with traditional method needs to replant every year.This method is not only easily affected by some natural disasters,diseases and insect pests,but also needs a lot of labor,money and material.As the germplasm exchange becomes more often and introduction of new germplasm has been become one important part of the breeding programme in China,conservation of germplasm raises an issue of importance for the breeding.In order to solve those problems,the preservation in vitro of potato was explored in this paper.Internodes slow growth conservation of Japanese potato strain 06-10 were studied in this experiment.The cryopreservation method of potato germplasm was also studied.The main results were as follows:1 It showed that MS+IAA0.5mg/L+KT0.1mg/L medium with 20g/L sorbitol restricted in vitro growth of the plantlets efficiently and conserved for over 5 months,the high survival rate of 93.75%was achieved.2 It showed that MS+IAA0.5mg/L+KT0.1mg/L medium with 70,90g/L sucrose restricted in vitro growth of the plantlets efficiently and conserved for over 5 months,the high survival rate of 87.5%was achieved.3 Otherwise,the MS+IAA0.5mg/L+KT0.1mg/L medium with 10,13g/L agar could not restrict the growth of in vitro plantlets effectively.4 It showed that MS+IAA0.5mg/L+KT0.1mg/L medium with 200mg/L CCC and 4mg/L ABA restricted in vitro growth of the plantlets efficiently and conserved for over 5 months,the high survival rate of 81.25%were achieved.5 Internodes of Japanese potato strain 06-10 wes successfully cryopreserved with the vitrification technique.The suitable procedure was established as follows:Internodes about 10mm in length were precultured on MS medium with 0.5mol/L sucrose for 3 days and then detached the internodes with the size of 2～3mm were pretreated with 60%PVS₂ for 20min under room temperature,and then dehyrated with a vitrification solution of 100%PVS₂ for 40 minutes at 0℃.After the new vitrification solution was replaced,the internodes were plunged into liquid nitrogen directly.After one day,the materials were taken off from liquid nitrogen and then thawed rapidly in the water bath at 40℃for 2min,the internodes were washed with 1.2mol/L sucrose solution for 20min.Then the internodes were plated on MS medium supplemented with IAA0.5mg/L+KT0.1mg/L+GA₃0.3mg/L and cultrued in darkness for 7 days and then transfered to normal condition for about 15 days.The higest survival rate of internodes after cryopreservation was 88.87%.