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Kimani P.M.,Egerton University | Wachira F.,Association for Strengthening Agricultural Research in Eastern and Central Africa ASARECA | Cheruiyot E.K.,Egerton University | Owuoche J.,Egerton University | Kimani E.,Kenya Agricultural Research Institute
Australian Journal of Crop Science | Year: 2014

Genetic diversity plays an important role in selection of parental stocks in plant breeding. Sorghum [Sorghum bicolor (L.) Moench] breeding initiatives have been constrained by lack of information on genetic diversity of cultivated accessions which would otherwise guide in the choice of heterotic parents for hybridization. This study was carried out to determine genetic diversity of sorghum accessions collected from Africa and ICRISAT using simple sequence repeats (SSR) of microsatellite marker. Thirty sorghum SSR markers were used to assess the genetic diversity of 134 sorghum accessions. The number of alleles per microsatellite locus in the 134 sorghum accessions ranged between 2 to 22, with a total of 259 different alleles having been amplified. The greatest number of alleles was found at the locus 3590e705f67911e0b58c0010185a4b14 with 22 alleles. The average Polymorphism Information Content (PIC) for all the assayed sorghum accessions was 0.55. Expected heterozygosity of population ranged between 2.91 for Sudan and 1.58 for Central Africa. Pairwise population comparisons for genetic identity were derived based on Nei's. Genetic identity of the populations ranged from 0.36 for Central Africa and Northern Africa to 0.93 between Eastern Africa and Rwanda. Analysis of Molecular Variance (AMOVA) revealed that 75% of the molecular variation in sorghum accessions was due to within individual populations while 25% of the total variation was partitioned among populations. There was low population differentiation due to either continuous exchange of genes between sorghum populations largely by germplasm exchange or no intense selection processes. The diversity observed within sorghum accession from Sudan and East African region could be useful in improvement of sorghum for various traits. Source

Mungube E.O.,Kenya Agricultural Research Institute | Njarui D.M.G.,Kenya Agricultural Research Institute | Gatheru M.,Kenya Agricultural Research Institute | Kabirizi J.,National Livestock Resources Research Institute NaLIRRI | Ndikumana J.,Association for Strengthening Agricultural Research in Eastern and Central Africa ASARECA
Livestock Research for Rural Development | Year: 2014

The dairy sub-sector in the semi-arid zones of Kenya is constrained by inadequate feeds, inappropriate breeds, inaccessibility and high cost of artificial insemination (AI) services, high incidence of animal diseases and inaccessible credit services. A study with the objective of identifying important reproductive and animal health challenges in smallholder dairy farms of semi-arid Kenya was conducted between September and December 2013. A pre-tested questionnaire was developed and administered to 73 respondents in the three study sites. The mean age of heifers at first service was 28.1±10.8 months, 25.5±9.0 months and 22.4±5.8 months in Machakos, Wote and Wamunuyu, respectively. There was significant difference (P<0.05) between mean age of heifers at first service from Wamunyu compared to those from Machakos and Wote. Artificial insemination charges per cow/insemination averaged Ksh 1620 ((USD$ 20) in the study areas. Heat detection was done by herd owners (89.2%), bulls/other cattle (1.4%) and both herd owners and cattle (9.5%). Mean calving intervals (CI) in the studied sites were 12.7±1.1, 13.7±3.0 and 14.3±3.7 months for Machakos, Wote and Wamunyu, respectively. The CI in the 3 sites were not significantly different (P>0.005). The average milk production for the lactating dairy cows in the three sites was 6 litres/cow/day. Milk productivity was negatively correlated with lactation phase stage. East Coast fever and anaplasmosis, pneumonia, mastitis, foot and mouth disease and eye conditions were reported as prevalent diseases in the study herds. Further prospective studies should be carried out to evaluate other key reproductive parameters and relationship between nutrition and infertility. Source

Omer R.A.,Kenyatta University | Omer R.A.,Agriculture Research Corporation ARC | Matheka J.M.,Kenyatta University | Runo S.,Kenyatta University | And 5 more authors.
Biotechnology | Year: 2012

Induction of callus from explants is a critical process in regeneration, micropropagation and transformation of plants. Formation of callus from plant tissues on culture is affected by different factors. This study sought to establish the effect of genotype, source of explants and auxin concentration on callus induction from different Sudanese maize genotypes (222F, Hudiba-1, 441, Giza-2, PR5655 and Mojtamma-45). Callus induction of the six maize varieties was investigated using mature embryos, leaf disks and shoot tips as explants and different concentrations of the auxin; 2,4-dichlorophenoxyacetic acid (2,4-D), ranging from 0 to 10 mg L -1. The highest callus, induction frequency was observed in shoot tips while the lowest was observed in mature embryos. Leaf disks gave a higher callus induction frequency than mature embryos and lower than shoot tips. Concentrations of 2,4-D of 2 mg L -1 gave the highest callus induction for most genotypes while 0 and 10 mg L -1 gave the lowest callus induction for all the genotypes. © 2012 Asian Network for Scientific Information. Source

Afari-Sefa V.,The World Vegetable Center | Chagomoka T.,The World Vegetable Center | Karanja D.K.,CABI Inc | Njeru E.,The World Vegetable Center | And 4 more authors.
Acta Horticulturae | Year: 2013

The growing scourge of malnutrition due to unhealthy and imbalanced diets has led to increased public health awareness and advocacy for diversifying diets with highly nutritious indigenous vegetables and fruits. Several studies have shown that indigenous vegetables rich in micronutrients, vitamins, antioxidants, and other health-related phytochemicals with antibiotic, probiotic and prebiotic properties can play a key role in addressing human nutrition and development. However, a major reason for the low adoption of indigenous vegetables from Africa is the inability of formal, centralized seed production systems to meet their complex and diverse seed requirements. Drawing on experiences in Tanzania with amaranth, African nightshade and African eggplant, this paper provides a preliminary assessment of the viability of seed production under two farmer-led seed enterprise models, namely, contract seed production with seed companies, and the community-led Quality Declared Seed production systems. Both are examined as strategies for economically viable and sustainable distribution and promotion of indigenous vegetable crops. The assessment is based on participatory learning, action research and outcome mapping tools. Preliminary analysis shows that on average community seed producers have a lower input cost and higher returns than contract seed growers. While seed companies operate in a dynamic business environment and have profit-oriented motives that might contravene development objectives envisaged under the proposed seed contract model, the community seed production system may also encounter challenges in identifying and establishing viable market linkages. The two farmer led seed enterprise models investigated have potential for higher income earning opportunities at both the farmer and community levels. Inaccessibility of indigenous vegetable germplasm, lack of technical know-how, institutional bottlenecks, lack of strong collaborative links between seed sector stakeholders, and the need for an enabling national seed policy and regulatory environment must be addressed to successfully implement and scale up this approach. Source

Masembe C.,Makerere University | Isabirye B.E.,Makerere University | Isabirye B.E.,Association for Strengthening Agricultural Research in Eastern and Central Africa ASARECA | Rwomushana I.,Association for Strengthening Agricultural Research in Eastern and Central Africa ASARECA | And 2 more authors.
Plant Protection Science | Year: 2016

The potential impact of future climate change on fruit fly species distribution was assessed in Uganda using two general circulation models (HADCM and CCCMA) and two future predicted CO2 emission scenarios (A2 and B2), under both full and no species dispersal modes. Future ranges were overall projected to decline by 25.4% by year 2050. Under full-dispersal, D. ciliatus > C. cosyra > B. invadens ranges were predicted to increase, while the rest are likely to decrease. In the no-dispersal scenario, a significant average decrease in size of niches is predicted. Range losses are predicted higher under B2 than A2. Future niches will likely shift to northern Uganda. The results should assist in the development of climate change adaptive pest management strategies. © 2015, Czech Academy of Agricultural Sciences. All rights reserved. Source

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