Abstract
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 and 10％polyethylene glycol 6000(PEG6000)as the control(CK)and DS treatment,respectively.An analysis of 23 above-ground 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 length-lower,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 length-lower,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.
基金项目
National Natural Science Foundation of China(31871569)
National Natural Science Foundation of China(32172120)
Natural Science Foundation of Hebei Province,China(C2020204066)
国家科技期刊平台
NSTL
万方数据