Prioritization of feasible physiological parameters in drought tolerance evaluation in sorghum: a grey relational analysis

Abstract

Identification and evaluation of drought tolerant germplasm is the primary step for sorghum (Sorghum bicolor L. Moench) breeding and utilization under drought conditions. The objective of this study was to use a grey relational analysis to investigate the role of feasible physiological parameters in evaluating drought tolerance in sorghum. Four sorghum varieties were cultivated in pots with two water treatments, including normal watering (75-80% of the soil moisture capacity) and water deficit (45-50% of the soil moisture capacity), which occurred at jointing stage, anthesis and filling stage, respectively. Drought tolerance index of yield was used as the key indicator to evaluate sorghum performance under drought. The grey relational degree of the investigated parameters decreased in the order of transpiration rate, stomatal conductance, photosynthetic rate, soluble sugar content, proline content, relative water content, activity of catalase, activity of superoxide dismutase and activity of peroxidase, implying that drought tolerance for guaranteeing sorghum yield formation was the most related to gas exchange parameters. Water content was a very sensitive parameter of plant growth under drought stress and was more important as compared to the activities of antioxidant enzymes. Results of this research suggested that feasible physiological parameters could be used in the evaluation of drought tolerance to improve the efficiency and accuracy of selection.

Activities of Key Enzymes Involved in Starch Accumulation In Sorghum (Sorghum Bicolor L. Moench) Grains With Different Starch Contents

“…Sorghum is considered as a multipurpose crop that provides food, feed, and raw materials for wine, fuel and industrial starch (Wang et al 2015a). Starch is the main component of sorghum grains, which determines the quality of sorghum grains and has an important influence on grain yield, palatability and grain brewing (Xiao et al 2019).…”

The Role of Deep Roots in Sorghum Yield Production under Drought Conditions

“…Sorghum is mainly planted in arid and semiarid regions of Asia and Africa, and the planting area in these regions accounts for 85% of the worldwide planting area according to 2018 data [27]. However, filling stage is the most important period for yield production, at which drought can lead to severe decline of yield in sorghum [28]. Sorghum can feed at least 5 million people in these areas due to its unique drought adaptability [29][30][31], and sorghum roots play an important role in its drought tolerance [32].…”

“…Wang et al reported that a higher root activity has been found in the stay green sorghum B35 as compared to non-green-stayed sorghum Sanchisan and is considered as one of the drought-resistant mechanisms under drought conditions [33]. Photosynthetic parameters and osmotic adjustment ability are the principal factors associated with sorghum yield under drought conditions [28]. However, research on root systems is time consuming, expensive, and difficult because plant roots are hidden under the ground.…”