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Variability of Grain‐Filling Traits in Early Maturing CIMMYT Tropical Maize Inbred Lines
Author(s) -
Gasura Edmore,
Setimela Peter S.,
Tarekegne Amsal,
Icishahayo David,
Edema Richard,
Gibson Paul T.,
Okori Patrick
Publication year - 2014
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 - 10.2135/cropsci2013.07.0441
Subject(s) - germplasm , biology , inbred strain , heritability , agronomy , zea mays , grain yield , poaceae , genetic variability , genotype , genetics , gene
ABSTRACT Grain‐filling rate (GFR), effective grain‐filling duration (EGFD), and total grain‐filling duration (TGFD) are important physiological traits of maize ( Zea mays L.) grain yield (GY) formation. To devise effective breeding strategies, the genetic nature of these traits is a prerequisite for improvement in early maturing maize. A study was conducted at CIMMYT‐Zimbabwe using an α‐lattice design with two replications in two environments to investigate the genetic variability of grain‐filling traits in 18 early maturing tropical maize inbred lines derived from CIMMYT germplasm. Highly significant differences were observed for GY, thousand‐grain weight (TGW), GFR, EGFD, TGFD, kernels per row (KR), and rows per cob (RC). The broad‐sense coefficient of genetic determination (the fixed parent equivalent of broad‐sense heritability) was above 70% for all of the traits. The highest GY was obtained from the inbred line T032‐30 (79.2 g plant –1 ) and the lowest from inbred line CML506 (37.6 g plant –1 ), respectively. Therefore, selecting for higher GFR and longer TGFD, especially the EGFD, can increase GY of early maize without extending days to physiological maturity (DPM).