Abstract：Selecting 25 Chinese onion materials and adopting nutrient solutions with 2 nitrogen levels，
one of normal 14.0 mmol·L-1 and the other of mionectic 2.8 mmol·L-1，this experiment conducted hydroponic
treatment and comprehensive evaluation on low nitrogen tolerance of Chinese onion in seedling stage，
and screened out indicators for quickly evaluating low-nitrogen-tolerant Chinese onion in seedling stage，
hoping to provide references for identification of low-nitrogen-tolerant Chinese onions in seedling stage．
The results showed that there were different differences in 25 Chinese onion materials’ responses to low
nitrogen environment．According to the abilities of low nitrogen resistance，the test materials were divided
into 3 categories．Seven varieties of ‘Tianmingyiben’，‘Lucongza No.1’，‘Biancong’，‘Jicong No.1’，
‘Jiujingdacong’，‘Ribendongyue’ and ‘Shaocong’ were tolerant to low nitrogen．Eight varieties including
‘Liaocong No. 8’，‘Baoguanyuanzang’，‘Yuanzang’，‘Jicong No. 2’，‘Jucongwang’，‘Xincong No. 2’，
‘Zhangqiudawutong’ and‘ Qingye No. 1’ were moderate low-nitrogen-tolerant varieties.‘ Zhangqiutiegan’，
‘Hancong No. 1’，‘Qingza No. 2’，‘Lucongza No. 5’，‘Liaocong 16-12’，‘Tieganwutongwang’，
‘Lingbaidacong’，‘Hanfengjucong 90 bai’，‘Changyiqiubao’ and ‘Dugenjucong’，etc. 10 varieties were
low nitrogen sensitive varieties．The screened out relative shoot dry weight，relative root-shoot ratio，relative
root fresh weight，relative root length，relative stem diameter，and relative shoot nitrogen content could be
indicators for evaluating low-nitrogen-tolerance of Chinese onion in seedling stage．
