Evaluation of Nitrogen Tolerance in Nine Naked Oat Varieties:A Seeding Stage Study
This study aimed to investigate the growth,physiological responses,and nitrogen tolerance of nine naked oat(Avena nuda L.)varieties under low nitrogen(0.4 mmol/L,LN)and control(4 mmol/L,CK)conditions for 21 days.Morphological and physiological indices were measured and analyzed.Under low nitrogen conditions,compared to the control group,the results showed as follows:(1)Root length and bio-mass decreased,with WDY5 exhibiting the largest decline in shoot dry weight.Plant height decreased in all varieties except ZY8.(2)Nitrate assimilation-related enzymes(nitrate reductase glutamine synthase,gluta-mate dehydrogenase),osmoregulatory substances,and nitrogen content decreased,while stress markers(glutamate synthetase activity,superoxide anion,hydrogen peroxide,malondialdehyde)increased,with QY3 showing the least malondialdehyde accumulation.(3)Principal component analysis revealed five princi-pal components explaining 91.76%of the variance contribution.Cluster analysis categorized the varieties into three groups:three low-nitrogen tolerant,five medium-low-nitrogen tolerant,and one low-nitrogen-sensitive(WDY5).The Z-value analysis confirmed QY3 as the most tolerant and WDY5 as the most sensi-tive variety to low nitrogen stress.