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Common bean (Phaseolus vulgaris) is a rich source of protein, vitamins, and micronutrients and is an important crop for food security throughout Latin America, Asia, and Africa. Among tropical and subtropical regions of the world, where the majority of beans are grown, yield losses due to the pathogenic fungus Pseudocercospora griseola, causing angular leaf spot (ALS), can be as high as 80%. The strategic use of marker-assisted selection (MAS) to pyramid multiple resistance genes into a single genetic background with preferred morphological and cooking characteristics is being implemented by six research groups throughout East Africa that make up the African Bean Consortium (ABC). Identifying unique markers that are polymorphic among multiple parents is a major source of marker attrition. In this study, an illustration of how 22 DNA sequences physically linked to the Phg-2 ALS resistance locus were identified using the PhaseolusGenes marker database and checked for amplification and polymorphism among 16 ABC breeding parents are given. Only three polymorphic markers could be identified following this procedure; one (g796), showed a polymorphism present only in the ALS resistance donor, Mexico 54. The PCR protocol developed to identify the g796 polymorphism was validated among five laboratories. Furthermore, co-segregation analysis of the marker and ALS resistance phenotype in a population of 100 F 2 individuals from the cross between French bean (that is, green bean) genotype Amy and ALS resistance donor Mexico 54 showed the marker is genetically linked (3 cM) to the Phg-2 locus, in addition to being physically linked. This study suggests that in the near future, genetic resequencing data of diverse common bean accessions, compiled within an easily accessible database, will facilitate identification of markers for MAS, marker/trait association, and candidate gene identification.

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Pigeonpea is an important pulse crop that has gained importance in semi-arid tropics, although its yield potential has not been fully realized due to biotic and abiotic stresses that limit its production. Insect pest complex of pod borer (Helicoverpa armigera), sucking bug (Clavigralla tomentosicollis) and pod fly (Melanagromyza cholcosoma) are the major limiting factors to its production causing up Original Research Article

Aims: For an effective potato breeding strategy, knowledge of the genetic parameters of traits, such as heritabilities and genetic correlations are essential, hence the need to assess the genetic variability estimates of yield-related traits in Irish potato mutants Study Design: At M1V1 generation, there was no replication of the mutant minitubers because each does not maintain the same genetical constitution after irradiation. In M1V2 and M1V3 generation the tubers were replicated 3 times in alpha lattice design. Place and Duration of Study:Irradiation was done at the Plant Genetics and Breeding Laboratories (PGBL) at IAEA/FAO Seibersdorf, Vienna, Austria. After mutation induction, the mutant microtubers (consisting of Asante, Mpya and Sherekea) were was transported to Kenya, University of Eldoret for establishment between April 2015 and March 2017. Methodology: A total of 30 tubers each of the three potatoes was sent for irradiation. Two in-vitro radio-sensitivity tests were developed involving different tissues: Irradiation of in vitro nodal cuttings Original Research Article(without leaf) followed by in vitro shoot propagation and irradiation of in vitro nodal cuttings (with leaf) followed by direct in vitro micro-tuber production. After mutation induction, a total of 570 mutant microtubers (Asante 230, Mpya 160, Sherekea 180) were developed from the three potato varieties and was transported to Kenya, University of Eldoret for the establishment. The M1V1 microtubers were established in the greenhouse while M1V2 and M1V3 generations of mutants were planted at the at the University of Eldoret research field. Results: It showed that the highest positive heritability percentage (H 2 ) estimates in Mpya and Sherekea mutants were in plant height with 81.51% and 87.7% respectively. Conclusion: Tuber number exhibited high heritability estimates displaying that induced mutation was successful in the development of new potato genotypes which be used in future breeding programs.

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Artemisia annua is the source of artemisinin, an antimalarial drug which is effective against multidrug-resistant strains of plasmodium, the malarial parasite. Malaria has serious effects on morbidity and mortality thus negatively impacting on agricultural production and food security. Although artemisinin has been found to be a useful medicine; its production is very low in comparison with what is actually needed to treat the worldwide threat of malaria. On the other hand, the lower content (0.01%-0.8%, dry weight) of artemisinin found in leaves and flowers of A. annua has seriously limited its commercialization. Currently there are only two varieties of A. annua present in Kenya; hence there is a need to increase its diversity. The objective of the current study was to determine the effect of mutation on agronomical traits and artemisinin production by parents and mutant (M2) A. annua plants in Kenya Agricultural and Livestock Research Organisation (KALRO) Njoro and the University of Eldoret (UoE). Seeds of two varieties of Artemesia annua varartemis and varanamed were sent to Vienna Austria for irradiation at the International Atomic Energy Agency (IAEA) at a dosage of 150 gray. The M1 seeds were multiplied at the University of Eldoret farm. The harvested seeds were planted in replicate at the University of Eldoret and Njoro (KALRO). The results showed that mutation had significant effect on agronomical traits (P-value < 0.001). Mutant varieties and lines showed wide variation in terms of agronomical traits (crown length, stem length, plant height and stem diameter) and yield of artemisinin. The following lines showed superiority in artemisinin production; Artemis line 1, 2 and 9 with an average mean of 58.843, 58.393 and 69.192 µg/l, respectively while Anamed line 2, 3, 5 and 8 with an average of 56.268, 51.704, 53.557 and 54.448 µg/l, respectively. The effect of mutation on both agronomical traits and production of the artemisinin content appeared to occur randomly and was also dependent on environmental factors in the different ecological zones. Higher means in agronomical traits was observed in UoE while production of artemisinin content was enhanced in Njoro. The artemisinin yield in A. annua crops was negatively correlated with leaf traits, shoot and stem characteristics. Leaf traits had positive correlations with shoot and stem characteristics. It is recommended that superior lines be advanced in generations for further stability and evaluation of its efficacy in treatment of malaria.

French bean (Phaseolus vulgaris L.) is a very important protein component of the diets of the majority of the population globally and in Kenya. It is a major vegetable export crop (48%) and income earner to the smallholder farmers who constitute more than 80% of producers in Kenya. However commercial varieties presently grown have the potential to produce more yields of above 1800 kgha -1 but are limited by pests and disease. Among the diseases is anthracnose incited by Colletotrichum lindemuthianum (sacc.et. magn.) Lams. Scrip which causes a severe rapidly developing disease that can bring about complete plant defoliation and extensive yield and or quality loss. Studies were conducted to identify commercial varieties of French beans which are resistant to anthracnose disease. The objective of this study was to screen commercial varieties of French beans in controlled environmental conditions (glasshouse) for resistance to anthracnose disease. This was achieved through evaluation of incidence and phenotypic variation in anthracnose virulence among the bean varieties in relation to yields. Ten bean varieties were used during the study, among them were two controls;