Increasing root-lower characteristics improves drought tolerance in cotton cultivars at the seedling stage  

作　　者：Congcong Guo Hongchun Sun Xiaoyuan Bao Lingxiao Zhu Yongjiang Zhang Ke Zhang Anchang Li Zhiying Bai Liantao Liu Cundong Li 

机构地区：[1]State Key Laboratory of North China Crop Improvement and Regulation/Key Laboratory of Crop Growth Regulation of Hebei Province/College of Agronomy,Hebei Agricultural University,Baoding 071001,China

出　　处：《Journal of Integrative Agriculture》2024年第7期2242-2254,共13页农业科学学报（英文版）

基　　金：the National Natural Science Foundation of China(31871569 and 32172120);the Natural Science Foundation of Hebei Province,China(C2020204066)。

摘　　要：Drought is an important abiotic stress factor in cotton production.The root system architecture(RSA)of cotton shows high plasticity which can alleviate drought-related stress under drought stress(DS)conditions;however,this alleviation is cultivar dependent.Therefore,this study estimated the genetic variability of RSA in cotton under DS.Using the paper-based growth system,we assessed the RSA variability in 80 cotton cultivars at the seedling stage,with 0 and10%polyethylene glycol 6000(PEG6000)as the control(CK)and DS treatment,respectively.An analysis of 23 aboveground and root traits in the 80 cotton cultivars revealed different responses to DS.On the 10th day after DS treatment,the degree of variation in the RSA traits under DS(5–55%)was greater than that of CK(5–49%).The 80 cultivars were divided into drought-tolerant cultivars(group 1),intermediate drought-tolerant cultivars(group 2),and drought-sensitive cultivars(group 3)based on their comprehensive evaluation values of drought resistance.Under DS,the root lengthlower,root area-lower,root volume-lower,and root length density-lower were significantly reduced by 63,71,76,and 4%in the drought-sensitive cultivars compared to CK.Notably,the drought-tolerant cultivars maintained their root lengthlower,root area-lower,root volume-lower,and root length density–lower attributes.Compared to CK,the root diameter(0–2 mm)-lower increased by 21%in group 1 but decreased by 3 and 64%in groups 2 and 3,respectively,under DS.Additionally,the drought-tolerant cultivars displayed a plastic response under DS that was characterized by an increase in the root-lower characteristics.Drought resistance was positively correlated with the root area-lower and root length density-lower.Overall,the RSA of the different cotton cultivars varied greatly under DS.Therefore,important root traits,such as the root-lower traits,provide great insights for exploring whether drought-tolerant cotton cultivars can effectively withstand adverse environments.

关 键 词：COTTON root system architecture drought stress cultivars variability root-lower 

分 类 号：S562[农业科学—作物学]