GENETIC ANALYSIS OF MAIZE KERNEL WEIGHT: RESPONSE TO NITROGEN AVAILABILITY

HISSE, I.R.; D'ANDREA, K.E.; OTEGUI, M.E.

Pergamino

Congreso; XI Congreso Nacional del Maíz; 2018

AIANBA

Knowing the proportion of additive effects is of interest for breeding purposes since they are the predictable portion of genetic variance. The main objective of this work was to assess the combining ability and heterosis levels for maize kernel weight (KW) and its physiological determinants under contrasting N conditions. For this purpose, 6 parental inbred lines and all possible F1 hybrids were evaluated in the field in a complete diallel mating design, at two contrasting N levels during 2013-14 and 2014-15. We found (i) significant general combining ability (GCA) effects for most traits, and specific combining ability effects for KW, grain-filling duration, maximum water content and moisture content at physiological maturity; (ii) high proportion of additive genetic variance (σ > 0.75) for all the traits, with greater values at low than at high N level; (iii) lower additive effects as well as lower GCA-inbred performance correlation values for KW than for its physiological determinants; and (iv) a superior heterosis for KW, in addition to a greater heterosis at high than at low N level for all the traits. Selection process would be more efficient on secondary traits of KW than on KW itself, as well as under low N condition