Chemical Changes during Maize Tissue Aging and Its Relationship with Mediterranean Corn Borer Resistance

The
Mediterranean corn borer (MCB), Sesamia nonagrioides Lef, is an important pest of maize in temperate areas, causing significant
stalk lodging and yield losses. The main goals of this study were
to determine possible changes in chemical traits (phenols, flavonoids,
anthocyanins, sugars, fibers, and lignin) during plant development
after the flowering stage and to assess how those traits may differ
in diverse genotypes of maize, such as MCB resistant and susceptible.
Higher values for some particular traits in more mature tissues seemed
to increase their effectiveness against the MCB attack. A decreased
amount of borer damage in the field was recorded in the resistant
inbred line and in older tissues (7.90 cm vs 31.70 cm as the mean
for the stalk tunnel length). In accordance with these results, the
resistant inbred line showed a higher degree of hemicellulose cross-linkage
(due to ferulic and diferulic acids), higher soluble sugar content,
and higher stalk strength. The use of resistant varieties and early
sowings is highly recommended as an integrated approach to reduce
the yield losses produced by this pest.

地中海玉米螟（Mediterranean corn borer, MCB），学名Sesamia nonagrioides Lef.，是温带地区玉米的重要害虫，可引发严重的茎秆倒伏与产量损失。本研究的核心目标有二：一是明确开花期后植株发育过程中各类化学性状（酚类、黄酮类、花青素、糖类、纤维及木质素）的动态变化；二是评估上述性状在不同玉米基因型——如抗地中海玉米螟与感虫基因型——间的差异。研究发现，成熟组织中部分特定性状的更高水平，可显著提升其抵御地中海玉米螟侵染的效能。田间试验结果显示，抗螟自交系及较老组织的螟害程度均有所降低，二者茎秆隧道长度均值分别为7.90 cm与31.70 cm。与上述结果相吻合，该抗螟自交系表现出更高的半纤维素交联度（源于阿魏酸与二阿魏酸）、更高的可溶性糖含量以及更强的茎秆强度。综上，推广抗虫品种并适期早播，可作为综合防控手段有效降低该害虫引发的产量损失。