Growth, leaf δ¹³C and gene expression of latitudinal bermudagrass species under different drought levels

The issue of drought resulting from global warming has prompted plants to exhibit appropriate stress tolerance strategies in response to environmental changes. Water use efficiency is of particular significance in the context of drought stress. Plants displaying higher water use efficiency accumulates greater dry matter (negative δ¹³C values), photosynthesizing more efficiently, and resisting drought stress more effectively. Such plants have sufficient potential for community succession. The objective of this study was to investigate the changes in bermudagrass among different indicators under different degrees of drought, and the relationship between them. Additionally, the correlation between leaf δ¹³C and latitude among climate change was explored. The findings indicated that the germplasm resources in high-latitude regions exhibited robust drought tolerance, attributable to the prevailing environmental conditions, including limited precipitation, water scarcity, ample sunshine, and low temperatures. Among mild (soil moisture content of 55 ± 5%), moderate (soil water content of 35 ± 5%), and severe drought (soil moisture content of 25 ± 5%), the moderate conditions showed an increased growth. Under drought conditions, the dehydrin gene exhibited high expression levels in the low latitude region (Zhongshan), while the CdL96, COP1 and CdL79 genes demonstrated high expression levels in the high latitude region (Xinyang), and the CdL44 gene exhibited high expression levels in the middle latitude region (Linxiang), indicating that the germplasm resources in the high latitude region have stronger drought adaptability.