Association studies between grain yield and agronomic traits of a MARS maize (Zea mays L.) population under drought and non-stress condition

Folusho A Bankole,Gedil Melaku,Abebe Menkir,Oloruntoba Olakojo,Gbadebo Olaoye

doi:10.14720/aas.2019.114.1.9

Folusho A Bankole, Gedil Melaku + Show 3 more

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https://doi.org/10.14720/aas.2019.114.1.9

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Abstract

The study aimed at examining the associations between yield and other traits under drought stress and non-stress conditions. A total of 150 MARS testcrosses were evaluated under both conditions at the International Institute of Tropical Agriculture substation for two years under during the dry season. Genotypic and phenotypic correlation, multiple stepwise regression and path co-efficient analyses were carried out to examine the relationship among the traits under both environments. Results showed anthesis-silking interval, days to silking, husk cover and plant aspect were significantly associated with yield under drought condition at both genotypic and phenotypic levels. Yield was positively correlated with plant and ear height but had a negative correlation with plant and ear aspect at both levels under well-watered condition. Regression analysis showed that ears per plant, plant aspect, ear aspect, days to silking, leaf death and plant height had a direct effect on yield, contributing a total of 71.1 % of observed variation under drought, while ears per plant, ear aspect, plant aspect, days to pollen shed, days to silking and plant height contributed about 31.42 % to yield under well-watered conditions. The study concluded that these traits be used as selection criteria as it will aid improvement of maize yield.

Highlights

Maize (Zea mays L.) is presently the second most abundant crop in the world (Ort and Long, 2014) and it has a higher yield potential compared with rice and wheat theoretically, being a C4 plant (Gong et al, 2015)
The genotypic and phenotypic correlations between grain yield, the primary trait of selection, and other agronomic traits for the marker assisted recurrent selection (MARS) testcrosses under drought stress and well-watered conditions are presented in Tables 1 and 2 respectively
Significant (ρ ≤ 0.01) but negative genotypic and phenotypic correlations were observed between grain yield (GY) and flowering traits viz: anthesis silking interval (ASI), days to anthesis (DP) and silking (DS) under drought stress condition

Summary

Introduction

Maize (Zea mays L.) is presently the second most abundant crop in the world (Ort and Long, 2014) and it has a higher yield potential compared with rice and wheat theoretically, being a C4 plant (Gong et al, 2015). In comparison to other abiotic stress factors, drought is the causative factor for the major losses recorded in crop production (Ober, 2008) Maize has it origin in the tropics, it is extremely prone to drought and heat, at silk emergence and/or when flowers are ready for pollination (Boyer and Westgate, 2004; Lobell et al, 2011, 2014; Frey et al, 2015). A gross limitation in crop production worldwide has been predicted as a result of changes in climate, extreme temperatures and drought (Cooper et al, 2014; Frey et al, 2015; Horton et al, 2015) It becomes more difficult for a small-scale producer of maize with little or no access to irrigation facilities, who plants varieties that are susceptible to drought stress in sub-Saharan Africa to survive these myriads of challenges (Derera et al, 2008)

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