Agronomic performance of maize populations divergently selected for diferulate cross-linkage

Abstract

The direct response of a divergent selection programme for total cell wall ester-linked diferulate concentration in maize pith stalk tissues and its indirect effect on cell wall degradability and corn borer resistance have been previously evaluated. Since increased total diferulate concentration is expected to improve crop performance in response to corn borers, the objective of the present research was to evaluate the indirect response of the divergent selection for diferulates on agronomic traits under corn borer infestation. For this purpose, five maize populations with contrasting total diferulate concentrations were evaluated four environments for performance under protected and infested conditions. Measured traits were: days to anthesis, days to silking, plant height, stalk lodging, grain moisture at harvest and grain yield. High diferulate populations showed a significant reduction in anthesis (precocity), and were 11 cm taller than the starting population, while low diferulate populations were 9 cm shorter, and showed nearly 1 t/ha lower grain yield than the original and high diferulate populations. The analysis showed that cycles of selection were positively correlated with flowering, plant height and grain yield. The infestations with borers produced >1 t/ha of reduction in grain yield; although the higher diferulate populations showed a better performance under infestation than the low diferulate populations. This positive effect on the grain yield by increasing diferulate content can be considered an extra in order to breed for resistance to corn borers.