Abstract
Stem rust (<i>Puccinia graminis</i> f. sp <i>tritici</i>) is a destructive disease of wheat (<i>Triticum aestivum</i> L.) making it a major challenge to wheat production in Kenya as well as other wheat growing countries. Due to this, mutation breeding has been as a source of increasing variability and confers specific improvement to the Kenyan varieties without significantly altering its phenotype. The objective of this study was to determine adult plant resistance of wheat mutant lines to stem rust across three different locations. The study area was in three locations, Nakuru County (Njoro and Mau Narok) and Meru County (Timau) during 2015-2016 cropping season. Sixty three mutant lines and six checks (NJBWII, Duma and Kwale, Kingbird, Robin and Cacuke) were evaluated under field conditions with three replications in an alpha lattice (23 rows by 3 columns) design. Mean for area under disease progress curve and coefficient of infection revealed that Duma200gry (1026), Duma200gry (1124) were best disease performers. The calculated variance (<i>Si</i>) distinguished stable genotypes in terms of disease and yield which included Duma100gry (995) and Kwale100gry (1483), respectively. There was positive effect of dosage 400gry on the mutant lines in terms of disease, yield and 1000 kernel weight, mostly with the Duma mutant lines. The mean grain yield for the genotypes ranged from 5.5 to 14.1 t ha<sup>-1</sup>. Genotype, location and genotype by location interaction for the area under disease progress curve, coefficient of infection and yield were significant at P< 0.01 and P<0.001. There was a negative correlation displayed between yield and disease components. R-Square values revealed 0.1508 and 0.3911 of the variation in yield was contributed by the disease severity and area under disease progress curve, respectively. Considering the best lines both in disease and yield can be taken for further screening in breeding programmes.
Highlights
Ug99 (TTKSK) race and its variants have been resulting to huge wheat yield losses which can go up to 100% in most of Kenya wheat growing areas and worldwide [1, 13, 26, 30, 31]
A combined analysis of variance procedure was used to identify the existence of disease resistance, genotype*environment interaction (GEI) and stability from replicated multi-location trials
Of the total variance of coefficient of infection (CI), the site main effect accounted for 30.60%, genotype 23.45% and the site by genotype interaction 22.63%
Summary
Ug99 (TTKSK) race and its variants have been resulting to huge wheat yield losses which can go up to 100% in most of Kenya wheat growing areas and worldwide [1, 13, 26, 30, 31]. Mutation induction is one of the techniques that have been employed to create variation within wheat varieties [11, 17]. Some of these variations have been achieved using physical mutagens, like X-rays, gamma-rays, neutrons and chemical mutagens. Wheat (Triticum aestivum L.) is one of the major food crops in the world. [6] estimated that the world wheat production had risen to 700 million tonnes in the year 2011 from 553.92 million tonnes in 2003/2004, 607 million in 2007 and 655.7 million tonnes in 2010. In Kenya, wheat is second important crop after maize with an annual
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
