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

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.

Features of colorectal cancer in China stratified by anatomic sites:A hospital-based study conducted in university-affiliated hospitals from 2014 to 2018

Objective:The clinical and biological characteristics of colorectal cancer have been found to differ depending on the anatomic site of the cancer.However,for Chinese patients,there is limited information on the proportion of cases at each site and the related features.In this study,we explored the location,distribution and other features of colorectal cancers at each anatomic site in Chinese patients.Methods:We conducted a hospital-based study using hospitalization summary reports from 10 Peking University-affiliated hospitals from 2014 to 2018;the reports covered a total of 2,097,347 hospitalizations.Incident cases were chosen as the study population,and their epidemiological features were further analyzed.Results:A total of 20,739 colorectal cancer patients were identified.Rectum was the most common location(48.3%)of the cancer,whereas the proportions of patients with distal and proximal colon cancer were 24.5%and18.6%,respectively.Patients with rectal cancer were predominantly male and were the youngest for all anatomical sites(each P<0.001).The highest proportion of emergency admissions,the longest hospital stays and the highest hospitalization costs were found in patients with proximal colon cancer(each P<0.001).The proximal colon cancer subgroup included the highest proportions of patients with medical histories of cholecystectomy,cholecystolithiasis and/or gallbladder polyps and appendectomy(P=0.009,P<0.001 and P<0.001,respectively).The distal colon cancer subgroup included the highest proportions of patients with medical histories of diabetes and hypertension(P<0.001,respectively).Conclusions:The patterns of colorectal cancer observed in this study differ from those reported for Western patients and show a significantly higher proportion of patients with rectal cancer.Different epidemiological features were also found based on anatomic sites.Further studies based on tumor location should be conducted to facilitate more accurate screening and treatment.