Abstract: To know the effect of drought stress induced by polyethylene glycol 8000(PEG-8000)on growth indicators of potato plantlets in vitro,eleven main potato varieties in China were evaluated by adding 5%,10%,15% and 20%(W:V)of PEG-8000 to Murashige-Skoog solid medium respectively with do not contain PEG-8000 as the control.Seven characters:plant height,root length,shoot fresh weight,root fresh weight,shoot dry weight,root dry weight and plant water content,were measured and analyzed.The results indicated that all potato plantlets in vitro showed more severe drought stress,when facing with increasing concentration of PEG.Under 15% PEG-8000 stress,the eleven varieties showed the largest differences and all growth indicators were lower than that in control condition,therefore 15%PEG-8000 was the best concentration to simulate drought stress for potato plantlets in vitro.Under such stress,the relative values of indicators were also analyzed,the results showed that the average of relative root fresh weight was 26.9%,was decreased most and had the largest variation coefficient of 50.6%,the relative root fresh weight was the most sensitive to drought stress among all indicators.By clustering analysis,the 11 cultivars were divided into 3 groups at Euclidean distance of 40.The effects induced by drought stress among the three groups are gradually increased:group Ⅰ contains Bashu 10,Gaoyuan 7,Kexin 1 and Jinshu 2;groupⅡcontains Zhongshu 2 and Zhongshu 20;group Ⅲ contains Zhongshu 3,Atlantic,Favorita and Epoka.After clustering analysis and plant water content analysis,Bashu 10 and Gaoyuan 7 could be classified as drought tolerant varieties.

Key words: Potato, PEG-8000, Drought, stress, Growth, indicators

CLC Number: 

• S532.01