Identification of early and extra-early maturing tropical maize inbred lines resistant to

Autor: Alejandro Ortega-Beltran, A.O. Talabi, Faith A. Bankole, R.O. Akinwale, Baffour Badu-Apraku, Ranajit Bandyopadhyay, Babatope Samuel Ajayo, M. A. B. Fakorede
Rok vydání: 2021
Předmět:
0106 biological sciences
Germplasm
DS
days to 50% silking
food.ingredient
EASP
ear aspect
Growing season
Biology
Plant disease resistance
EEM
extra-early maturing
GYLD
grain yield
01 natural sciences
ASI
anthesis-silking interval
food
Inbred strain
Perspectives in Crop Protection
Index selection
EM
early maturing
SSA
sub-Saharan Africa
BI
base index
Hybrid
EPP
number of ears per plant
G × T
genotype × trait
Disease resistance
PHT
plant height
SAS
statistical analysis system
Inoculation
PASP
plant aspect
Germplasm screening
RL
root lodging
food and beverages
DA
days to 50% anthesis
TURC2WAI
disease score 2 weeks after inoculation
Low N
low soil nitrogen
Exserohilum
WCA
West and central Africa
IITA
International Institute of Tropical Agriculture
010602 entomology
TURC
average disease severity score
EHT
ear height
PSI
percentage severity index
Agronomy
Sustainable food production
G × E
genotype by environment
Agronomy and Crop Science
TURC6WAI
disease score 6 weeks after inoculation
010606 plant biology & botany
HUSK
husk cover
SL
stalk lodging
Zdroj: Crop Protection (Guildford, Surrey)
ISSN: 0261-2194
Popis: Northern corn leaf blight (NCLB) incited by the fungus Exserohilum turcicum is a foliar disease that significantly limits maize production and productivity in West and Central Africa (WCA), particularly in the mid-altitudes but during the last decade it has become a menace in lowland agro-ecologies. The most economical and environmentally friendly disease management strategy is the cultivation of maize varieties resistant or tolerant to NCLB. However, no early maturing (EM) and extra-early maturing (EEM) NCLB resistant varieties are commercially available in WCA. One hundred inbred lines each of EM and EEM derived from tropical maize germplasm were inoculated with a virulent isolate of E. turcicum at five locations in Nigeria during the 2017 and 2018 growing seasons. The objective of the study was to identify promising NCLB resistant lines and to investigate inter-relationships among the traits. Analysis of variance revealed highly significant genotype and genotype by environment (G × E) interactions for disease severity, grain yield (GYLD), and other agronomic traits. The average disease severity (TURC) values ranged from 1.9 to 5.8 and 2.9 to 5.7 for the EM and EEM inbred lines, respectively. The levels of reaction of the inbred lines to NCLB ranged from highly resistant to highly susceptible. Stepwise regression analysis showed that ears per plant, ear and plant aspects were significantly influenced by the disease scores. Ears per plant, ear and plant aspects, TURC and GYLD traits were employed to develop a base index (BI) for selecting NCLB resistant inbred lines for hybrid development. TZEI 135 and TZEEI 1 were outstanding in GYLD and also had the highest positive BI values in the EM and EEM inbred lines, respectively. The identification of NCLB resistant lines in this study has set the premise for development of NCLB resistant hybrids for WCA as well as the improvement of tropical maize breeding populations for NCLB resistance.
Highlights • Protocol for inoculum production and inoculation of maize with E. turcicum for resistance screening of pathogen developed. • Early and extra-early maize inbred lines with resistance to E. turcicum and adapted to the tropics have been identified. • A base index for selecting maize inbred lines for resistance to E. turcicum with desirable agronomic traits developed in IITA.
Databáze: OpenAIRE
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