Peter Bulli

• PhD
• Faculty Member at Jaramogi Oginga Odinga University of Science and Technology

House crickets ( Acheta domesticus ) and field crickets ( Gryllus bimaculatus ) are among the commonly reared insects for human and animal consumption. However, the potential contamination of rearing facilities with microbes poses a serious threat to sustainability of production of these insects, especially in poorer regions of the world where stra...

This study aimed to evaluate the influence of the prickly pear cactus on the socio-economic status of pastoral livelihoods of rangelands in the Northern Rift Valley of Kenya. The prickly pear cactus (Opuntia stricta) is one of the most widespread and naturalized invasive species in the arid and semi-arid areas of Kenya, with serious negative conseq...

Chironomidae commonly inhabits most aquatic habitats and often dominate aquatic insect communities in abundance and species richness. Despite their ecological importance, the diversity and distribution of chironomids in the Lake Victoria ecosystem of Kenya have not been studied to date. Here we report on the diversity and distribution of adult Chir...

Background: The challenge to food security posed by climate change and coupled with the substantial rise in the global population, necessitate a shift in crop improvement programmes towards developing crop cultivars with stable and high yield potentials across a wide range of agro-ecological conditions. Methods: New high yielding crop varieties wit...

Objective: This study aims to assess the effects of cricket frass biofertilizer on the growth and yield potential of spring onion (Allium fistulosum L.) and its residual effects on physicochemical properties of the soil in greenhouse and field conditions. Methods: 7 treatments namely cricket frass (0t/Ha, 5t/Ha, 10t/Ha, 15t/Ha, and 20t/Ha), poultry...

Integrated Crop-Livestock Farming Systems (ICLFS) are globally recognized for their contributions to improving agricultural sustainability. These systems also play a big role in conservation and Climate-Smart Agriculture (CSA) since they reduce greenhouse gas (GHG) emissions, thus assisting in coping with the effects of climate change. This study a...

Stripe rust, or yellow rust (Puccinia striiformis Westend. f. sp. tritic), is a disease of wheat (Triticum aestivum L.) historically causing significant economic losses in cooler growing regions. Novel isolates of stripe rust with increased tolerance for high temperatures were detected in the United States circa 2000. This increased heat tolerance...

Stem rust is one of the most damaging diseases of wheat. The recent emergence of the stem rust Ug99 race group poses a serious threat to world wheat production. Utilization of genetic resistance in cultivar development is the optimal way to control stem rust. Here we report association mapping of stem rust resistance in a global spring wheat germpl...

Genome-wide association mapping is a powerful tool for dissecting the relationship between phenotypes and genetic variants in diverse populations. With the improved cost efficiency of highthroughput genotyping platforms, association mapping is a desirable method of mining populations for favorable alleles that hold value for crop improvement. Stem...

Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici Erikss. (Pst) remains one of the most significant diseases of wheat worldwide. We investigated stripe rust resistance by genome-wide association analysis (GWAS) in 959 spring wheat accessions from the United States Department of Agriculture-Agricultural Research Service National Sm...

SNP markers tagging QTL for resistance to stripe rust under field condition in a global collection of spring wheat accessions identified based on marker-wise P value < 0.01 in at least two environments for both IT and SEV in the GWAS test. (DOCX)

Estimation of the most likely number of clusters in the germplasm panel based on the Bayesian clustering model in structure software. Mean of Estimated Log-likelihood and the magnitude of delta K (ΔK) were plotted against K values based on five independent runs and K ranging from 1 to 10. (PPTX)

Allelic frequency of the markers linked to previously mapped stripe rust resistance genes in the spring wheat association mapping panel. (PPTX)

Summary of stepwise regression analysis. Parameter estimate, reduction in the residual sum of squares (SS), test statistic and significance level are reported. (DOCX)

Pearson’s correlation coefficients between the five test environments for stripe rust infection types (IT) and severity (SEV). (DOCX)

Virulence/avirulence formula of the stripe rust isolates used for seedling resistance screening. (DOCX)

ABSTRACT Harnessing diversity from germplasm collections is more feasible than ever due to the development of lower-cost and higher-throughput genotyping methods. At the same time, the cost of phenotyping is still generally high, so efficient methods to sample and exploit useful diversity are needed. Genomic selection (GS) has the potential to enha...

Key message: Genome-wide association analysis in tetraploid wheat revealed novel and diverse loci for seedling and field resistance to stripe rust in elite spring durum wheat accessions from worldwide. Improving resistance to stripe rust, caused by Puccinia striiformis f. sp. tritici, is a major objective for wheat breeding. To identify effective...

Key message: We identified 15 potentially novel loci in addition to previously characterized leaf rust resistance genes from 1032 spring wheat accessions. Targeted AM subset panels were instrumental in revealing interesting loci. Leaf rust is a common disease of wheat, consistently reducing yields in many wheat-growing regions of the world. Althou...

Global wheat production is consistently challenged by leaf, stem, and stripe rust epidemics, and millions of hectares experience moderate to severe epidemics annually. In order to identify and map effective rust resistance loci, survey the frequency of known resistance genes in global germplasm, and to investigate improved germplasm utilization str...

Stripe rust (Puccinia striiformis Westend f. sp. tritici) is a devastating disease for wheat (Triticum aestivum L.) production worldwide. Yr5 is a race‐specific resistance gene, effective to all races that have been identified in the United States. Therefore, it has been increasingly used for US cultivar development. The goal of this study was to i...

Virulence shifts in populations of Puccinia striiformis f. sp. tritici (Pst), the causal pathogen of wheat stripe rust, are a major challenge to resistance breeding. The majority of known resistance genes are already ineffective against current races of Pst, necessitating the identification and introgression of new sources of resistance. Germplasm...

Knowledge of available genetic variation and population structure is important for utilization of core collections and in understanding the genetic basis of diverse physiological, agronomic, and morphological traits. Here we report the results of genetic characterization and association mapping for resistance to stripe rust, caused by Puccinia stri...

The recently identified Puccinia graminis f. sp. tritici (Pgt) race TTKSK (Ug99) poses a severe threat to global wheat production because of its broad virulence on several widely deployed resistance genes. Additional virulences have been detected in the Ug99 group of races, and the spread of this race group has been documented across wheat growing...

Stripe rust, caused by the fungus Puccinia striiformis f. sp. tritici, is a widespread and major threat to wheat production in the Pacific Northwest of the US and the world. Identifying new sources of resistance and incorporating multiple genes into elite cultivars is required to ensure durable protection against the dynamics of pathogen virulence....

Hexaploid bread wheat (Triticum aestivum) is a staple cereal crop that provides approximately 20% of calories for the global human population. Wheat stem rust (Puccinia graminis f. sp. tritici), especially the Ug99 race group which is prevalent in east Africa, threatens food security in many countries. The persistent arms race between plant pathoge...

Developing wheat cultivars adapted to the Pacific Northwest region is challenging due to stripe rust epidemics that are often triggered by emergence of new virulent races of the fungal pathogen, Puccinia striiformis f. sp. tritici. As part of the Triticeae Co-ordinated Agricultural Project (TCAP) funded by the USDA-NIFA, the wheat improvement progr...

Winter wheat Druchamp has both high-temperature adult-plant (HTAP) resistance and all-stage resistance to stripe rust caused by Puccinia striiformis f. sp. tritici (Pst). The HTAP resistance in Druchamp is durable as the variety has been resistant in adult-plant stage since it was introduced from France to the United States in late 1940s. To map th...

New races of Puccinia striiformis f. sp. tritici (Pst), the causal pathogen of wheat stripe rust, show high virulence to previously deployed resistance genes and are responsible for large yield losses worldwide. To identify new sources of resistance we performed a genome-wide association study (GWAS) using a worldwide collection of 1,000 spring whe...

New races of Puccinia striiformis f. sp. tritici (Pst), the causal pathogen of wheat stripe rust, show high virulence to previously deployed resistance genes and are responsible for large yield losses worldwide. To identify new sources of resistance we performed a genome-wide association study (GWAS) using a worldwide collection of 1,000 spring whe...

The recently characterised and mapped adult plant resistance gene Lr67 contributes to the breeding of durable resistance against multiple fungal pathogens of wheat. Lack of tightly linked markers has so far prevented widespread use of Lr67 in breeding programmes. Exhaustive screening of available SSR markers and 9,000 gene-associated SNPs using bul...

Stripe (yellow) rust of wheat, caused by Puccinia striiformis f.sp. tritici (PST), is an ubiquitous, polycyclic wheat disease capable of long-distance migrations and rapid evolution of host-pathogen interaction mechanisms. The major negative impact on wheat production stimulates a continuous search for effective resistance genes, either belonging t...

epidemics. Washington State is a stripe rust hotspot and an ideal location for extensive germplasm screening and genetic analyses. Over 5,000 accessions of spring and winter wheat from around the world were screened for reaction to stripe rust at multiple locations in Washington State from 2011-2013. Field evaluations of the first 1,000 spring whea...

In this research, a recombinant inbred line (RIL) population derived from cross between a leaf rust- and stripe rust-susceptible spring wheat ‘Avocet S’ and a slow leaf- and stripe-rusting resistant spring wheat ‘Amadina’ was used to postulate and map leaf rust seedling resistance genes, identify quantitative trait loci (QTL) for slow-rusting resis...