Abstract: Eighteen cucumber (Cucumis sativus L. ) inbred lines were used to evaluate their low light tolerance based on growth, physiological and biochemistrical indexes at seedling stage. The low light condition was simulated by block light net. The result indicated that thirteen character indexes of different cucumber materials showed significant difference by usingmultip le variance analysis. Factor analysis indicated that the thirteen character indexes could be characterized into five main factors, and the accumulative contribution rate hit
to 85.62%. Cluster analysis based on factor scores after varimax rotation showed that eighteen cucumber inbred lineswere classified into four categories: The best low light tolerantmaterials including M₂₂, M₄₃, M_a9,
and stronger low light tolerant inbred lines includingM8 , M11 , M3 , M4 and M₃₄, moderately sensitive materials including M₁₂, M₂₁, M₁₄, M₂, M_a1 and M₂₈, whereas low light sensitive materials including M₁₀, M₄₄, M₃₂ and M₃₆. Under low light stress, stronger inbred lines have bigger low light tolerant index and smaller fall in pohotosynthetic rate. The method of combination of low light tolerant index and other factors such as photosynthesis and growth is effective to identify low light tolerance in cucumber.

Key words: cucumber, low light tolerance, factor analysis, cluster analysis