Index screening and tolerance evaluation of low nitrogen stress in seed-ling stage of Cucurbita moschata
Excessive application of nitrogen fertilizer is one of the major causes of soil degradation and environmental pollution.The selection of high-yielding varieties with strong low-nitrogen tolerance is of great significance for the efficient production in Cucurbita moschata.In this study,eight germplasm were used as experimental materials,and two treatments of suitable nitrogen(7.0 mmol·L-1)and low nitrogen(0.7 mmol·L-1)were set up in hydroponics to determine the low nitrogen tolerance coefficients of 18 traits in the seedling stage.The comprehensive evaluation system was estab-lished by using the methods of principal component,subordinate function and regression analysis.The results showed that the low nitrogen tolerance coefficients of different germplasm indicators differed significantly.The principal component analysis showed that the index characterizing plant biomass and photosynthesis were closely related to the low nitrogen tolerance ability,and that the four index,including root dry mass,root fresh mass,root volume and seedling index,could be used as index of the tolerance identification.Regression analysis was used to establish a predictive equation for low nitrogen tolerance in seedlings D'=0.950 9-0.121 2X1-0.207 7X2+0.134 1X3-0.078 2X4(R2=0.957,average estimation accu-racy 96.5％).One germplasm with strong low-nitrogen tolerance were finally obtained,namely Cmo19(Shibing Nan-gua).This study initially realized the high-throughput screening and identification of low nitrogen tolerance germplasm resources in Cucurbita moschata during the seedling stage,which provided a theoretical basis for the selection and breed-ing of nitrogen-efficient varieties of Cucurbita moschata and the study related mechanisms.
万方数据
维普
