Abstract:

In order to study the correlation between stem traits and the formation of elasticity and density tolerance of maize,and further reveal the mechanism of lodging resistance,6 maize varieties with different lodging resistance were selected as materials,and 3 planting densities of 6.0×10⁴,7.5×10⁴ and 9.0×10⁴ plants/ha were set.The stem pull lodging angle in the field was used as the evaluation index of elasticity,and the morphological characteristics between plants and basal nodes.The internode anatomical structure,material accumulation and mechanical characteristics were analyzed.The results showed that plant height,ear height,basal internode length,thickness,epidermal thickness,crusty tissue thickness,total vascular bundle,sheath area of small vascular bundle,fresh weight per unit length,dry weight per unit length and content of each component,puncture and folding strength had significant effects on the stem pull lodging angle,among which internode diameter(r=0.521^**)and dry weight per unit length(r=0.562^**)had the greatest effects.The greater the planting density,the smaller the internode diameter,the thickness of the hard skin tissue,the total number of vascular bundles,the fresh weight per unit length,the dry weight,the content of each component,the lodging resistance,the worse the elasticity of the stem.There were significant differences in stem traits among different varieties.The elasticity related traits of Lishou 1,Chuangyu 107,Jingnongke 728 and MC278 were better than those of other varieties,and the variation amplitude was smaller with the increase of density,so the elasticity and density tolerance were stronger.Traits such as internode diameter and dry weight per unit length had significant effects on stem pull lodging angle, that was stalk elasticity,and the variation amplitude of these traits after densification determined the density tolerance of stalk.

Key words: Maize, Stalk, Elasticity, Density tolerance, Pull lodging angle