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Integrating nitrogen and water‐soluble carbohydrates dynamics in maize: A comparison of hybrids from different decades
Author(s) -
Fernandez Javier A.,
Messina Carlos D.,
Rotundo José L.,
Ciampitti Ignacio A.
Publication year - 2020
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.1002/csc2.20338
Subject(s) - biology , hybrid , germplasm , agronomy , grain yield , genetic gain , poaceae , zea mays , yield (engineering) , genetic variation , biochemistry , materials science , metallurgy , gene
During a century of maize ( Zea mays L.) breeding, yield genetic gain was largely determined by increased reproductive resilience under stress and establishment of sink size (number of grains per unit area). Considering grains as competing sinks for C and N assimilates, understanding changes in the C and N economy can provide insights to define selection criteria towards a sustained yield improvement. A cognitive framework to define such criteria may consist in connecting the water‐soluble carbohydrates (WSC) and N dynamics in stem and leaves with the reproductive sink strength during post‐flowering. The objectives of this study were to advance such framework by (a) quantifying grain N demand and remobilization capacity in two hybrids as affected by N availability, and (b) formalizing how the interplay between N and WSC remobilization influence grain growth. Single cross hybrids 3394 and P1197 (released in 1991 and 2014) were evaluated to represent keystone phases of germplasm development (conventional and molecular breeding eras). P1197 outyielded 3394 consistently under high N supply, and its better N utilization efficiency was reflected through a lower grain N concentration. Under high N, the ability to maintain a greater leaf area during late grain‐filling for P1197 resulted in a reduced leaf N remobilization. Although yield was not limited by C supply, 3394 exposed greater remobilization of WSC during late grain‐filling. This study contributes to advance the development of a relevant C to N framework to further analyze drivers of genetic yield gain and assist in selection strategies in maize.