Comprehensive assessment of drought resistance and recovery in kiwifruit genotypes using multivariate analysis
Bao, Wen-Wu, Xi Chen, Ruo-Nan Li, Min Li, Cui-Juan Xie, Meng-Ru Dou, Kang-Zhuang Zhang, Jian Wang, Zhi-Xiong Gao, Zhan-De Liu and Yan Xu
Plant Journal
https://doi.org/10.1111/tpj.16746
ABSTRACT
As global climate change persists, ongoing warming exposes plants, including kiwifruit, to repeated cycles of drought stress and rewatering, necessitating the identification of drought-resistant genotypes for breeding purposes. To better understand the physiological mechanisms underlying drought resistance and recovery in kiwifruit, moderate (40-45% field capacity) and severe (25-30% field capacity) drought stresses were applied, followed by rewatering (80-85% field capacity) to eight kiwifruit rootstocks in this study. We then conducted a multivariate analysis of 20 indices for the assessment of drought resistance and recovery capabilities. Additionally, we identified four principal components, each playing a vital role in coping with diverse water conditions. Three optimal indicator groups were pinpointed, enhancing precision in kiwifruit drought resistance and recovery assessment and simplifying the evaluation system. Finally, MX-1 and HW were identified as representative rootstocks for future research on kiwifruit's responses to moderate and severe drought stresses. This study not only enhances our understanding of the response mechanisms of kiwifruit rootstocks to progressive drought stress and recovery but also provides theoretical guidance for reliable screening of drought-adaptive kiwifruit genotypes. In conclusion, we conducted a multivariate analysis to comprehensively investigate the physiological mechanisms underlying drought adaption and to identify reliable indicators and methods suitable for evaluating drought resistance and recovery capabilities in kiwifruit rootstock germplasm. Our findings will not only advance our understanding of kiwifruit's responses to water stress but also facilitate the identification of drought-adaptive genotypes in future kiwifruit production.