John Omondi

Dr. John Omondi


Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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27 January 2021 in Plants
Verified
Journal Article
Open access
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ASAigerim Soltabayeva
Aigerim Soltabayeva
AOAssel Ongaltay
Assel Ongaltay
JOJohn Omondi
John Omondi
SSSudhakar Srivastava
Sudhakar Srivastava
Plant growth and development is adversely affected by different kind of stresses. One of the major abiotic stresses, salinity, causes complex changes in plants by influencing the interactions of genes. The modulated genetic regulation perturbs metabolic balance, which may alter plant’s physiology and eventually causing yield losses. To improve agricultural output, researchers have concentrated on identification, characterization and selection of salt tolerant varieties and genotypes, although, most of these varieties are less adopted for commercial production. Nowadays, phenotyping plants through Machine learning (deep learning) approaches that analyze the images of plant leaves to predict biotic and abiotic damage on plant leaves have increased. Here, we review salinity stress related markers on molecular, physiological and morphological levels for crops such as maize, rice, ryegrass, tomato, salicornia, wheat and model plant, Arabidopsis. The combined analysis of data from stress markers on different levels together with image data are important for understanding the impact of salt stress on plants.

10 October 2022 in Plants
Verified
Journal Article
Open access
PDF file
ASAigerim Soltabayeva
Aigerim Soltabayeva
NDNurbanu Dauletova
Nurbanu Dauletova
SSSymbat Serik
Symbat Serik
MSMargulan Sandybek
Margulan Sandybek
JOJohn Omondi
John Omondi
SSSudhakar Srivastava
Sudhakar Srivastava
Plants live under different biotic and abiotic stress conditions, and, to cope with the adversity and severity, plants have well-developed resistance mechanisms. The mechanism starts with perception of the stimuli followed by molecular, biochemical, and physiological adaptive measures. The family of LRR-RLKs (leucine-rich repeat receptor-like kinases) is one such group that perceives biotic and abiotic stimuli and also plays important roles in different biological processes of development. This has been mostly studied in the model plant, Arabidopsis thaliana, and to some extent in other plants, such as Solanum lycopersicum, Nicotiana benthamiana, Brassica napus, Oryza sativa, Triticum aestivum, Hordeum vulgare, Brachypodium distachyon, Medicago truncatula, Gossypium barbadense, Phaseolus vulgaris, Solanum tuberosum, and Malus robusta. Most LRR-RLKs tend to form different combinations of LRR-RLKs-complexes (dimer, trimer, and tetramers), and some of them were observed as important receptors in immune responses, cell death, and plant development processes. However, less is known about the function(s) of LRR-RLKs in response to abiotic and biotic stresses. Here, we give recent updates about LRR-RLK receptors, specifically focusing on their involvement in biotic and abiotic stresses in the model plant, A. thaliana. Furthermore, the recent studies on LRR-RLKs that are homologous in other plants is also reviewed in relation to their role in triggering stress response processes against biotic and abiotic stimuli and/or in exploring their additional function(s). Furthermore, we present the interactions and combinations among LRR-RLK receptors that have been confirmed through experiments. Moreover, based on GENEINVESTIGATOR microarray database analysis, we predict some potential LRR-RLK genes involved in certain biotic and abiotic stresses whose function and mechanism may be explored.

13 December 2019 in Physiologia Plantarum
Verified
Journal Article
Closed access
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JOJohn Omondi
John Omondi
NLNaftali Lazarovitch
Naftali Lazarovitch
SRShimon Rachmilevitch
Shimon Rachmilevitch
TKTitaya Kukew
Titaya Kukew
UYUri Yermiyahu
Uri Yermiyahu
HYHagai Yasuor
Hagai Yasuor

7 July 2023 in Frontiers in Agronomy
Verified
Journal Article
Open access
JOJohn Omondi
John Omondi
SMSiyabusa Mkuhlani
Siyabusa Mkuhlani
JMJane Mugo
Jane Mugo
ACAmaral Machaculeha Chibeba
Amaral Machaculeha Chibeba
MCMazvita Sheila Chiduwa
Mazvita Sheila Chiduwa
INIsaiah Nyagumbo
Isaiah Nyagumbo
Introduction: Smallholder farmers in Sub-Saharan Africa (SSA) are increasingly producing soybean for food, feed, cash, and soil fertility improvement. Yet, the difference between the smallholder farmers’ yield and either the attainable in research fields or the potential from crop models is wide. Reasons for the yield gap include low to nonapplication of appropriate fertilizers and inoculants, late planting, low plant populations, recycling seeds, etc.Methods: Here, we reviewed the literature on the yield gap and the technologies for narrowing it and modelled yields through the right sowing dates and suitable high-yielding varieties in APSIM.Results and Discussion: Results highlighted that between 2010 and 2020 in SSA, soybean production increased; however, it was through an expansion in the cropped area rather than a yield increase per hectare. Also, the actual smallholder farmers’ yield was 3.8, 2.2, and 2.3 times lower than the attainable yield in Malawi, Zambia, and Mozambique, respectively. Through inoculants, soybean yield increased by 23.8%. Coupling this with either 40 kg ha−1 of P or 60 kg ha−1 of K boosted the yields by 89.1% and 26.0%, respectively. Overall, application of 21–30 kg ha-1 of P to soybean in SSA could increase yields by about 48.2%. Furthermore, sowing at the right time increased soybean yield by 300%. Although these technologies enhance soybean yields, they are not fully embraced by smallholder farmers. Hence, refining and bundling them in a digital advisory tool will enhance the availability of the correct information to smallholder farmers at the right time and improve soybean yields per unit area.

20 August 2019 in Journal of Plant Nutrition
Verified
Journal Article
Closed access
JOJohn Omondi
John Omondi
NLNaftali Lazarovitch
Naftali Lazarovitch
SRShimon Rachmilevitch
Shimon Rachmilevitch
UYUri Yermiyahu
Uri Yermiyahu
The objective of this study was to determine the effect of phosphorus applied through fertigation on growth and root yield of cassava. This was achieved through a greenhouse pot-experiment consisting of 1, 4, 7, 10, 20 and 30 mg P L−1. Increasing P from 1 to 30 mg P L−1 realized a 57.1 and 150.0% increase in leaf blade P in 2014 and 2015, respectively. Similarly, chlorophyll content and shoot growth increased as P concentration in solution increased. However, leaf stomatal conductance and net photosynthesis reached a maximum in 7 and 20 mg P L−1 in 2014 and 2015, respectively. This trend of stomatal conductance and net photosynthesis was consistent with that of dry root yield and storage roots numbers. Regressing dry root yield against storage root numbers showed that R2 = 0.80. Phosphorus encourages formation of storage roots and the duration of cassava’s growth affects the amount of P required for maximum root yield.

2 July 2018 in Journal of Plant Nutrition and Soil Science
Verified
Journal Article
Closed access
PDF file
JOJohn Omondi
John Omondi
NLNaftali Lazarovitch
Naftali Lazarovitch
SRShimon Rachmilevitch
Shimon Rachmilevitch
SBSteve Boahen
Steve Boahen
PNPheneas Ntawuruhunga
Pheneas Ntawuruhunga
UYUri Yermiyahu
Uri Yermiyahu