Identification of bread wheat genotypes with superior grain yield and agronomic traits through evaluation under rust epiphytotic conditions in Kenya

Elizabeth Akinyi Msundi,Ravi Prakash Singh,Mandeep Singh Randhawa,James Otieno Owuoche,Godwin Macharia,Maurice Edwards Oyoo

doi:10.1038/s41598-021-00785-7

Abstract

Bread wheat (Triticum aestivum L.) cultivars adapted to specific environments and resistant to prevalent pathogens are preferred for obtaining high yield. This study aimed to identify wheat genotypes with superior grain yield (GY) and yield associated traits from 168 genotypes of International Maize and Wheat Improvement Center’s 13th Stem Rust Resistance Screening Nursery evaluated over two seasons during 2019 and 2020 under high disease pressure of both stem rust (SR) and yellow rust (YR) in a 21 × 8 α-lattice design with 3 replications in Kenya. Effects due to seasons were significant for YRAud, SRAud, 1000-kernel weight (TKW), days to heading (DH), plant height (PH) and number of spikelets spike−1 (SS), while genotypes and genotypes × season interaction effects were significant for all traits except number of kernels spike−1. Respectively, heritability values of 0.95, 0.93, 0.87, 0.86, 0.77 and 0.75 were observed for area under disease progress curve for SR (SRAud), YR (YRAud), TKW, DH, biomass (BM) and GY. Path analysis showed positive direct effects on GY via PH, SS, BM, and TKW. Biplot analysis identified 16 genotypes with superior desirable traits GY, BM and harvest index. The SR contributed the highest reduction in GY and TKW while YR contributed the most reduction in BM. These identified genotypes with superior GY combined with adequate resistance to both SR and YR are potentially valuable resources for improvement of locally adapted wheat cultivars.

Highlights

Wheat (Triticum aestivum L.) is an important cereal food crop worldwide and it accounts for 21% of the global food demand with more than 80% of the global population depending on it as a source of protein and calories[1]
Significant effects due to seasons indicated that seasonal conditions that prevailed in main season 2019 (MS2019) were entirely different from off season 2020 (OS2020) and this influenced the performance of wheat genotypes over growing seasons in different years
The mean monthly rainfall and temperature was higher in OS2020 than in MS2019, creating conducive relative humidity for rust infection that resulted in yield reduction

Summary

Introduction

Wheat (Triticum aestivum L.) is an important cereal food crop worldwide and it accounts for 21% of the global food demand with more than 80% of the global population depending on it as a source of protein and calories[1]. Raising and/or maintaining wheat yield to their potential in farmers’ fields through conventional practices in absence of resistant cultivars, would require use of high rates of fungicides and fertilizers which can increase production costs and adversely affect the ecosystem[22,23]. This necessitates development of sustainable high yielding cropping practices[22]

Objectives

Methods

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Conclusion