Evaluation of drought resistance in Iris germanica L. based on subordination function and principal component analysis

Abstract

Drought is one of the major environment stresses that have a wide range of impact on plants. In this study, seven physiological indexes including the content of soluble protein (SP), chlorophyll (Chl) and malondialdehyde (MDA), superoxide dismutase (SOD) and peroxidase (POD) activities, leaf relative water content (RWC), rate of water loss (RWL) from excised leaves were measured in leaves of Iris germanica before and after the drought treatment. It was found that the content of MDA and SP, POD and SOD activity increased, while RWL and RWC decreased in response to drought stress. Based on the subordinate function values of seven physiological indexes, seven single indexes were transformed into three principal components namely damage degree, active oxygen removal ability and moisture condition and the composite score (F value) of each iris variety was calculated by principal component analysis (PCA). Based on the F values, 10 iris cultivars could be divided into three groups by cluster analysis (CA): drought-resistance (2 varieties), medium drought-resistance (5 varieties), and low drought-resistance (3 varieties). Meanwhile, optimum regression equation was constructed. Therefore, this work provides a comprehensive and reliable method for evaluating drought resistance in the varieties of Iris germanica.

Screening of Key Drought Tolerance Indices for Cotton at the Flowering and Boll Setting Stage Using the Dimension Reduction Method

“…In rice, corn and wheat, PCA is used for drought resistance analysis and evaluation, and relevant drought resistance indicators have been determined. PCA can explain and describe the important indicators of drought resistance and salt tolerance in germplasm (Bo et al, 2017;Negrão et al, 2017;Kakar et al, 2019). Ayalew et al (2011) identified three principal components through PCA, which accounted for 70% of the total variation in 14 agronomic traits.…”

“…Drought stress reduces yield because it affects crop growth and physiological metabolism (Nagy et al, 2013;Liu et al, 2015), which includes many drought resistance indicators, and it is difficult to consider all indicators when analyzing macropopulations. However, PCA can be used to determine the weight of each indicator and finds some principal components that can control all variables (Ali et al, 2014;Chen et al, 2014;Wijewardana et al, 2016;Bo et al, 2017;Füzy et al, 2019). It can reduce the number of measurement indicators and improve measurement efficiency.…”

Adaptive changes in root morphological traits of Gramineae and Leguminosae seedlings in the ecological restoration of the semiarid region of northwest China

“…The drought tolerance responses of different species to a specific indicator will not necessarily be the same. A single indicator cannot comprehensively or accurately reflect the strength of drought tolerance (Wei, Fu, Qin, Xing, & Wang, 2017). Therefore, this study used RM, RL, RA, RV, tips, LA, and 10 other indicators to identify the drought tolerance of the different species; these indicators have been widely used (Qiao et al, 2019;Zhang, Shi, Wang, & Zhao, 2018).…”

Evaluation of saline-alkali and drought tolerance in maize varieties

“…The method of membership function was used to comprehensively evaluate the drought tolerance and saline-alkali tolerance of each maize varieties during mature period (Chen 2002, Shi et al 2010, Bo et al 2017.…”