17 research outputs found

    Profits and Efficiency along Pearl Millet Market Chain: A Value Addition Approach

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    Pearl millet is the most commonly used millet around the world. However, in Kenya, little information exists concerning the distributional implication of pearl millet market structure, market channel efficiency and its determinants. As a result, the characteristics of pearl millet value chain have remained scanty in the literature. This paper characterizes Kenya’s pearl millet value chain focusing on its structure, functions and trade within the production areas (Mbeere district) and the final markets (Nairobi) of Kenya. Data was obtained from 255 market actors (120 producers, 2 rural agents/ brokers, 25 traders, 8 processors and 100 consumers) between August-September 2012 and analysis done using value addition approach and a multiple regression models. Evidence showed that high returns to participation accrued to processors compared to producers and traders despite their limited functions. Transport costs, border taxes and commission charges were major components of marketing cost. Pearl millet market channel efficiency was positively influenced by level of education and whether an actor undertook value addition activities before selling positively influenced. Keywords: Mbeere district, Market channel efficiency, Final markets, pearl mille

    INTROGRESSION OF DROUGHT TOLERANCE ROOT TRAITS INTO KENYAN COMMERCIAL CHICKPEA VARIETIES USING MARKER ASSISTED BACKCROSSING

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    Roots play critical roles in enhancing drought tolerance, more so under terminal drought conditions. The objective of this study was to introgress drought tolerant root traits into Kenyan chickpea varieties through marker assisted backcrossing (MABC). Eight simple sequence repeat (SSR) markers, linked to quantitative trait loci (QTL) for root traits, were used to screen parents at ICRISAT in India, and 1144 single nucleotide polymorphic (SNPs) markers at Legume Genomics Centre in the United Kingdom. Crosses were made between two selected varieties, ICCV 92944 (Chania Desi II) and ICCV 00108 (LDT 068); and ICC 4958, QTL donor parent. Polymorphic SSR and SNP markers were used to select offspring with root QTL at F1, BC1F1, and BC2F1, and later advanced to BC2F3. BC2F3 families were evaluated for root traits at Egerton University in Kenya in a pot experiment under rain shelter. The BC2F3 families were significantly (P<0.05) different for root dry weight (RDW), shoot dry weight (SDW), total plant dry weight (PDW), and root to shoot dry weight (R/S) ratio (R/S) for Chania Desi II x ICC 4958; while R/S was significantly different for LDT 068 x ICC 4958. Root length density (RLD) and RDW were positively and significantly (P<0.05) correlated with most of the traits, indicating its usefulness in the indirect selection of these traits. The utilisation of MABC is an effective and efficient method of introgressing complex root traits into commercial lines, expected to improve yields under drought. There is need for deployment of marker-assisted breeding in difficult to phenotypically select traits.Les racines jouent un r\uf4le essentiel dans l\u2019am\ue9lioration de la tol\ue9rance \ue0 la s\ue9cheresse, plus encore en cas de s\ue9cheresse terminale. L\u2019objectif de cette \ue9tude \ue9tait d\u2019introduire des traits de racine tol\ue9rants \ue0 la s\ue9cheresse dans des vari\ue9t\ue9s Kenyannes de chickpea par r\ue9trocroisement assist\ue9 par marqueurs (MABC). Huit marqueurs de r\ue9p\ue9tition de s\ue9quence simple (SSR), li\ue9s \ue0 des locus de traits quantitatifs (QTL) pour les traits racinaires, ont \ue9t\ue9 utilis\ue9s pour s\ue9lectionner les parents \ue0 l\u2019ICRISAT en Inde, et 1144 marqueurs polymorphes \ue0 un seul nucl\ue9otide (SNP) au Legume Genomics Center au Royaume-Uni. Des croisements ont \ue9t\ue9 r\ue9alis\ue9s entre deux vari\ue9t\ue9s s\ue9lectionn\ue9es, ICCV 92944 (Chania Desi II) et ICCV 00108 (LDT 068) ; et ICC 4958, parent donneur QTL. Des marqueurs SSR et SNP polymorphes ont \ue9t\ue9 utilis\ue9s pour s\ue9lectionner la prog\ue9niture avec un QTL racine \ue0 F1, BC1F1 et BC2F1, puis avanc\ue9 \ue0 BC2F3. Les familles BC2F3 ont \ue9t\ue9 \ue9valu\ue9es pour les traits racinaires \ue0 l\u2019Universit\ue9 d\u2019Egerton au Kenya dans une exp\ue9rience en pot sous abri contre la pluie. Les familles BC2F3 \ue9taient significativement diff\ue9rentes (P<0,05) pour le poids sec des racines (RDW), le poids sec des pousses (SDW), le poids sec total de la plante (PDW) et le rapport poids sec des racines sur les pousses (R/S) (R/S ) pour Chania Desi II x ICC 4958\ua0; tandis que R/S \ue9tait significativement diff\ue9rent pour LDT 068 x ICC 4958. La densit\ue9 de longueur des racines (RLD) et RDW \ue9taient corr\ue9l\ue9es positivement et significativement (P < 0,05) avec la plupart des traits, indiquant son utilit\ue9 dans la s\ue9lection indirecte de ces traits. L\u2019utilisation de MABC est une m\ue9thode efficace et efficiente d\u2019introgression de traits racinaires complexes dans des lign\ue9es commerciales, cens\ue9e am\ue9liorer les rendements en p\ue9riode de s\ue9cheresse. Il est n\ue9cessaire de d\ue9ployer la s\ue9lection assist\ue9e par marqueurs dans les caract\ue8res difficiles \ue0 s\ue9lectionner ph\ue9notypiquement

    Screening for host plant resistance to Helicoverpa armigera in selected chickpea (Cicer arietinum L) genotypes in Kenya

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    Hellicoverpa armigera (poad borer) is a major pest of chickpea (Cicer aurientinum) in many areas of the world, In Kenya, it causes up to 80% yield losses of the crop

    Marker assisted backcross breeding to enhance drought tolerance in Kenyan chickpea (Cicer arietinum L.) germplasm

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    Drought is the number one constraint in chickpea production. In the past, breeding efforts to improve terminal drought tolerance have been hindered by its quantitative genetic basis and poor understanding of the physiological basis of yield in water-limited conditions

    An overview of chickpea breeding programs in Kenya

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    Chickpea is a new crop in Kenya and its potential has not been fully utilized. The chickpea grain yields generally range between 1.2 to 3.5 tons/ha at farmers‟ fields, indicating that chickpea has a potential of becoming an important export crop in Kenya. The chickpea breeding program in Kenya is still at infant stage and being established with support from International Crops Research Institute for the Semi-Arid Tropics (ICRISAT). Four chickpea varieties have been recently released from the breeding material supplied by ICRISAT. Efforts are being made on evaluation of germplasm and breeding lines, application of modern molecular breeding tools and techniques in chickpea breeding and establishment of effective seed system for establishing a sustainable chickpea production system in the country

    Achievements and prospects of genomics-assisted breeding in three legume crops of the semi-arid tropics

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    Advances in next-generation sequencing and genotyping technologies have enabled generation of large-scale genomic resources such as molecular markers, transcript reads and BAC-end sequences (BESs) in chickpea, pigeonpea and groundnut, three major legume crops of the semi-arid tropics. Comprehensive transcriptome assemblies and genome sequences have either been developed or underway in these crops. Based on these resources, dense genetic maps, QTL maps as well as physical maps for these legume species have also been developed. As a result, these crops have graduated from ‘orphan’ or ‘less-studied’ crops to ‘genomic resources rich’ crops. This article summarizes above mentioned advances in genomics and genomics-assisted breeding applications in the form of marker-assisted selection (MAS) for hybrid purity assessment in pigeonpea; marker-assisted backcrossing (MABC) for introgressing QTL region for drought-tolerance related traits, Fusarium wilt (FW) resistance and Ascochyta blight (AB) resistance in chickpea; late leaf spot (LLS), leaf rust and nematode resistance in groundnut. We critically present the case of use of other modern breeding approaches like marker-assisted recurrent selection (MARS) and genomic selection (GS) to utilize the full potential of genomics-assisted breeding for developing superior cultivars with enhanced tolerance to various environmental stresses. In addition, this article recommends the use of advanced- backcross (AB-backcross) breeding and development of specialized populations such as multi-parents advanced generation intercross (MAGIC) for creating new variations that will help developing superior lines with broadened genetic base. In summary, we propose the use of integrated genomics and breeding approach in these legume crops to enhance crop productivity in marginal environments ensuring food security in developing countries

    Response of Bread Wheat Genotypes to Drought Simulation Under a Mobile Rain Shelter in Kenya

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    Selection of drought tolerant wheat genotypes for Arid and Semi-arid lands (ASALS) of Kenya, which consist of 83% of total land area, can provide alternative agricultural land for expansion. To reduce cost of dryland research, simulated drought under a rain shelter offers a good alternative for screening because marginal areas are vast and widespread. Four moisture regimes which simulated terminal, early, mid- and late- season droughts were created under the mobile rain shelter at Njoro in 1998/99, by applying drip irrigation (i) up to seedling stage (70 mm) (ii) through tillering (82 mm) (iii) up to anthesis (94 mm) and (iv) grain filling (106 mm), respectively, to determine drought responses of five wheat varieties (Duma, R748, R830, R831 and R833) and identify drought tolerant genotypes. Control watering regime had 118 mm applied at all stages. Yield and yield components in each season and the two seasons combined showed significant difference (P<0.05 and 0.01, respectively). Early drought during seedling stage and tillering caused significant reduction in plant heights, tiller number and number of reproductive tillers. However, drought from anthesis and grain filling to maturity caused significant (P<0.05) reduction in ear length (16.9%), spikelets/head (14.3%), 1000-kernel weights (22.4%) and an increase in the number of sterile florets/head (28.3%), compared to control. Seedling and reproductive stage (anthesis and grain filling) droughts caused the highest grain yield reduction (25 and 67%, respectively), indicating that they were the most critical stages in moisture requirement compared to control. Genotype R748 out-performed Duma (check) in all moisture regimes, and was recommended for field testing and participatory evaluation. From this study, it is possible to select drought tolerant cultivars using mobile rain shelters by drought simulations in Kenya.La sélection des génotypes tolérant a la sécheresse pour les terres arides et semi-arides (ASALS) du Kenya, lesquelles consistent a 83% de la surface de terre, peut pourvenir de terre pour l&apos;expansion agricole. Pour réduire le coût de la recherche dans les régions arides, la sécheresse simulée a l&apos;abris de la pluie offre une bonne alternative pour la sélection parce que les aires marginales sont vastes et éparpillées. Pour les régimes humides qui sont simulés a l&apos;état terminal, matinal, en pleine et en retard des saisons séches étaient crées sous un abri mobile a Njoro entre 1998/1999, par application de l&apos;irrigation par goutte 1) jusqu&apos;a l&apos; étape de semis (70 mm) ii) a travers le labourage (82 mm), iii) jusqu&apos;a l&apos;étape d&apos;anthere (94 mm) et iv) graine nourrissante (106 mm), respectivement pour déterminer les réponses a la sécheresse aux cinq variétés de blé (Duma, R748, R830, R831 et R833) et identifier les génotypes tolérant la sécheresse. Le contrôle du régime en eau avait 118 mm appliqués a toutes les étapes. Les composants de la production et du rendement dans chaque saison et les deux saisons combinées ont montré une différence significative (P<0,005 et 0,01 respectivement). La sécheresse matinale durant l&apos;étape de semis et de labeur a causé une réduction significative en hauteurs de plante en nombre de laboureurs et nombre de laboureurs reproductifs. Cependant, la sécheresse à partir de maturité d&apos;anthere et graine nourrissante a causé une réduction significative (P<0,05) en longueur d&apos;épi (16,9%), de pointes/ tête (14,3%), poids de 1000 grains (22,4%) et croissance dans le nombre de fleurons steriles / tête (28,3%) comparée au contrôle. L&apos;étape de semis et reproductive (anthere et graine nourrissante) de sécheresse a causé la réduction la plus élevée en rendement de graines (25 a 67%, respectivement)., indiquant qu&apos;elles étaient les étapes les plus critique en humidité requise comparée au contrôle. Le génotype R748 donne une mauvaise performance en tous les régimes humides, et était recommendé pour les test sur terrain et l&apos;évaluation participative. De cette étude, il est possible de sélectionner les variétés tolérantes a la sécheresse en utilisant les abris mobiles pour simuler la sécheresse au Kenya

    Wheat Productivity Improvement in the Drought Prone Areas of Kenya

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    In search for superior wheat ( Triticum aestivum L.) varieties for the marginal areas of Kenya various breeding methods have been applied. These include introductions, mutation and the doubled haploid technique. The application of doubled haploid (DH) technique in breeding for drought tolerance has proved to be very effective and efficient for such complex characters as drought. This study was aimed at evaluating and validating doubled haploid lines (DHs) that were developed in 2000 using the chromosome elimination technique. The resulting lines have also been compared with other lines introduced from CIMMYT and two mutants developed in Njoro. The lines were tested in multi-locational trials in 2002 and repeated in 2003. The sites were Lanet, Mogotio, Naivasha, Mweiga, Kajiado and Katumani. The results show that the DHs were as good as the conventionally developed lines and had a better performance in yield than the check variety Chozi and Duma. One of the DHs had average yield of 1.7 t ha-1, which was not significantly different from Chozi with the same mean yield and R960 with a mean yield of 2.0 t ha-1. The DH technique therefore saves time of breeding without compromising quality of the output

    Marker assisted backcross breeding to enhance drought tolerance in Kenyan chickpea (Cicer arietinum L.) germplasm

    No full text
    Drought is the number one constraint in chickpea production. In the past, breeding efforts to improve terminal drought tolerance have been hindered by its quantitative genetic basis and poor understanding of the physiological basis of yield in water-limited conditions

    Achievements and prospects of genomics-assisted breeding in three legume crops of the semi-arid tropics

    Get PDF
    Advances in next-generation sequencing and genotyping technologies have enabled generation of large-scale genomic resources such as molecular markers, transcript reads and BAC-end sequences (BESs) in chickpea, pigeonpea and groundnut, three major legume crops of the semi-arid tropics. Comprehensive transcriptome assemblies and genome sequences have either been developed or underway in these crops. Based on these resources, dense genetic maps, QTL maps as well as physical maps for these legume species have also been developed. As a result, these crops have graduated from ‘orphan’ or ‘less-studied’ crops to ‘genomic resources rich’ crops. This article summarizes the above-mentioned advances in genomics and genomics-assisted breeding applications in the form of marker-assisted selection (MAS) for hybrid purity assessment in pigeonpea; marker-assisted backcrossing (MABC) for introgressing QTL region for drought-tolerance related traits, Fusarium wilt (FW) resistance and Ascochyta blight (AB) resistance in chickpea; late leaf spot (LLS), leaf rust and nematode resistance in groundnut. We critically present the case of use of other modern breeding approaches like marker-assisted recurrent selection (MARS) and genomic selection (GS) to utilize the full potential of genomics-assisted breeding for developing superior cultivars with enhanced tolerance to various environmental stresses. In addition, this article recommends the use of advanced-backcross (AB-backcross) breeding and development of specialized populations such as multi-parents advanced generation intercross (MAGIC) for creating new variations that will help in developing superior lines with broadened genetic base. In summary, we propose the use of integrated genomics and breeding approach in these legume crops to enhance crop productivity in marginal environments ensuring food security in developing countries
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