Identification and Classification of Sorghum Cultivars for Drought Resistance during Germination Stage Based on Principal Components Analysis and Self Organizing Map Cluster Analysis

Abstract

PEG-6000 was used to simulate drought stress environment in artificial climate chamber for studying the effects of different concentrations of PEG-6000(80,120,150,and 175 g L–1) on the response of 31 sorghum cultivars at germination stage,with the objectives of screening drought-resistant cultivars and exploring methods suitable for assessing drought-resistance of sorghum cultivars.Through principal component analysis(PCA) and Self-Organizing-Map(SOM) cluster analysis,the drought-resistance of 31 sorghum cultivars was evaluated.PCA showed that relative bud length,relative root length and drought-resistance index during germination had the maximum weight in values,and were used as the main indices for evaluating and ranking the drought-resistant capabilities of 31 sorghum cultivars.Five groups of drought-resistance capabilities of 31 sorghum cultivars were detected based on SOM cluster analysis:four cultivars including Jiza 305 were highly drought-resistant,four cultivars including HL8 were drought-resistant,eight cultivars including Liaoza 10 were medium drought-resistant,seven cultivars including Jinza 103 were drought-sensitive and eight cultivars including Jinza 93 were highly drought-sensitive.In conclusion,relative bud length,relative root length and germination drought-resistance index can be used as indices for identifying drought-resistance in sorghum,and SOM cluster analysis is an important method for classifying drought-resistance.