不同氮源浓度配比对苹果砧木G935试管苗生长及扩繁的影响研究OA

[Objective]Apple rootstock G935 seedlings in vitro were selected,and the concentration ratios of KNO3 and NH4NO3 in MS medium were adjusted to screen for the nitrogen source levels most conducive to the efficient propagation and high-quality growth of G935 test-tube seedlings.This provides theoretical support and formula optimization for establishing an efficient rapid propagation system for this rootstock.[Methods]Test-tube seedlings of apple rootstock G935 were used as the material,with stem segments bearing 2.0 cm leaves as the explants.Based on MS medium,five different concentration treat-ments of KNO3 and NH4NO3 were designed,with the control CK(standard MS nitrogen source:KNO3 1.9 g/L,NH4NO3 1.65 g/L).After five weeks of culture,five growth indices of the explants(propagation coefficient,plant height,internode length,stem diameter,chlorophyll)were measured and subjected to principal component analysis.[Results]Moderate reduc-tion in the total amount and proportion of nitrogen sources significantly affected the growth performance of G935 test-tube seedlings.Among them,treatment T2(KNO3 1.3 g/L+NH4NO3 1.1 g/L)showed the best performance in the compre-hensive index evaluation,especially in achieving the optimal balance in the propagation coefficient,internode length control,and chlorophyll content.The results of principal component analysis further confirmed that treatment T2 had the highest com-prehensive evaluation value.[Conclusion]A theoretical basis and practical reference are provided for the optimization of nitro-gen nutrition in the efficient in vitro rapid propagation system of apple rootstock.