Progress and future prospects in groundnut improvement to feed Africa in the face of technological advancements

Crop productivity is crucial in meeting food demands to feed the growing population in the face of endemic biotic and abiotic stresses. Technological advancement and its application to boost crop productivity would be a pathway towards ensuring food and nutrition security. Dryland legumes including groundnut are suitable in diversification of farming systems as insurance crops to ensure productivity. Crop improvement is one of the pillars towards enhancing productivity by delivering products and services based on demand articulation such as high yielding resilient varieties that are nutrient dense to address the global nutrition agenda. Recent advancements in molecular technology has made it possible to sequence the groundnut genome, develop genetic maps and identification of quantitative trait loci (QTLs) for key traits of importance. These new developments need to be exploited to accelerate the design and development of quality products that fits within the African farming systems. The low genotyping cost has opened avenues for research centers in African countries to embrace the use of genomic selection tools in breeding. This should enhance efficiency in exploiting the wild genetic resource base, broadening the narrow genetic base of groundnut and fast tracking variety release. The use of molecular tools in breeding and wide hybridization techniques coupled with high throughput phenotyping is a new dawn to breeding programs and this would contribute significantly to food security and poverty alleviation in the long run. However, the success in the modernization of breeding for efficiency will be underpinned by pro-active engagement among different actors in the national, regional and international arena to leverage resources and expertise in the omics era for sustained outcomes. Healthy working partnerships are also key to the delivery and utilization of such technologies coupled with learning and feedback for product improvement

Farmers perceptions on dual-purpose sorghum and its potential in Zambia

Food feed crops play a cardinal role in mixed crop-livestock production systems yet views of farmers on their usage are limited. Farmers perceptions in predominant sorghum growing areas of Zambia were solicited on socio-economic factors affecting sorghum production, awareness and willingness to adopt dual-purpose sorghum cultivars for food and feed. Preferred traits of a model dual-purpose cultivar were identified. The aim of the study was to generate information that would support the genetic improvement of dual-purpose sorghum. Questionnaires were used to generate this information. Results showed that less than 50% of sorghum growing SSFs had limited knowledge on the use of sorghum to produce feed silage; however, there was full awareness among the LSFs. Among other traits, farmers ideal variety should combine high grain yield potential (100 %) with high biomass (100 % of LSFs and 80 % of SSFs) and high stem sugar content (100 % of LSF and 70 % of SSFs). All the SSFs and 20 % of the LSFs indicated that adequate production could be hampered by low grain yield, poor access to improved seed and unavailability of farmers- preferred cultivars. DOI: http://dx.doi.org/10.3329/ijarit.v4i2.22654 Int. J. Agril. Res. Innov. & Tech. 4 (2): 76-81, December, 201

GENETIC DIVERSITY AMONG SORGHUM LANDRACES OF SOUTHWESTERN HIGHLANDS OF UGANDA

Sorghum ( Sorghum bicolor L. Moench) is an economic and staple crop in sub-Saharan Africa. The genetic diversity in its germplasm is an invaluable aid for its crop improvement. The objective of this study was to assess the existing genetic diversity among sorghum landraces in the southwestern highlands of Uganda. A total of 47 sorghum landraces, collected from southwestern highlands of Uganda, were characterised using 12 qualitative and 13 quantitative traits. The study was conducted at Kachwekano Research Farm in Kabale District, at an altitude of 2,223 m above sea level, during growing season of December 2014 to August 2015. Panicle shape and compactness were the most varied qualitative traits. Grain yield (1.23 to 11.31 t ha-1) and plant height (144.7 to 351.6 cm) were among quantitative traits that showed high variability. Days to 50% flowering (115 to 130 days) showed the least variability. Results of UPGMA cluster analysis generated a dendrogram with three clusters. Panicle weight, leaf width, stem girth, exertion length, peduncle length, panicle shape and compactness, glume colour and threshability were major traits responsible for the observed clustering (P<0.001). Principal Component Analysis revealed the largest variation contributors.Le sorgho ( Sorghum bicolor L. Moench) est une culture vivri\ue8re de grande consommation en Afrique au sud du Sahara. La diversit\ue9 g\ue9n\ue9tique au sein de son germplasm est d\u2019une valeur incalculable pour la production de semences am\ue9lior\ue9es. L\u2019objectif de la pr\ue9sente \ue9tude \ue9tait d\u2019\ue9valuer la diversit\ue9 existante au sein des cultivars des plateaux du Sud-ouest d\u2019Ouganda. Au total, 47 accessions de sorgho, collect\ue9es des plateaux du Sud-ouest d\u2019Ouganda, ont \ue9t\ue9 caract\ue9ris\ue9es en se servant de 12 traits quantitatifs et de 13 traits qualitatifs. L\u2019\ue9tude s\u2019est d\ue9roul\ue9e \ue0 la ferme de recherche de Kachwekano dans le district de Kabal\ue9, zone situ\ue9e \ue0 2223m d\u2019altitude, pendant la saison culturales de Decembre 2014 \ue0 Ao\ufbt 2015. La forme des panicules, et leur densit\ue9 \ue9taient les traits qualitatifs les plus diversifi\ue9s. Le rendement en grains (1,23 \ue0 11,31 t ha-1) et la hauteur des plants (144,7 \ue0 351,6 cm) \ue9taient les traits quantitatifs ayant pr\ue9sent\ue9 une grande variabilit\ue9. Le d\ue9lai de 50% de floraison (115 \ue0 130 jours) \ue9tait le trait le moins variable. La classification num\ue9rique a g\ue9n\ue9r\ue9 un dendrogramme avec trois groupes. Le poids des panicules, la largeur des feuilles, la circonf\ue9rence de la tige, la longeur des insertions, la longueur des p\ue9doncules, la forme des panicules et leur densit\ue9, la couleur de la glume et la facilit\ue9 au d\ue9corticage \ue9taient les traits majeurs ayant contribu\ue9 \ue0 la r\ue9partition en groupes (P<0.001). L\u2019analyse en composantes principales a r\ue9v\ue9l\ue9 les contributeurs \ue0 la plus grande variabilit\ue9

Morphological Diversity of Tropical Common bean Germplasm

Common bean ( Phaseolus vulgaris L.) landraces and varieties grown by farmers in the tropics are a major source of genes and genetic diversity for bean improvement. These materials are, however, threatened by genetic erosion. In this study, we sought to understand the current state of genetic diversity of common bean in Uganda, using the available collection consisting of 284 bean accessions. A field experiment was conducted at the National Crops Resources Research Institute in Namulonge, Uganda. The level of morphological variation estimated with the Shannon Weaver diversity index (H), ranged from 0.47 to 0.58, with an overall mean of 0.56\ub10.19, an indicator of moderate genetic diversity. Principal component analysis (PCA) clustered the germplasm into three major groups (G1, G2 and G3). The genotypes differed mostly for growth habit, pod cross-section, pod curvature, hypocotyl colour, days to flowering, node number on the main stem, number of flower buds, and 100 seed weight.Les cultivars et vari\ue9t\ue9s de haricot commun ( Phaseolus vulgaris L.) cultiv\ue9s par les fermiers dans les tropiques son tune source majeur de \ue8nes et diversit\ue9 g\ue9n\ue9tique pour l\u2019am\ue9lioration du haricot. Ce materiel est, par ailleurs, handicap\ue9 par une \ue9rosion g\ue9n\ue9tique. Le but de cette \ue9tude est de comprendre la situation courante de la diversit\ue9 g\ue9n\ue9tique du haricot commun en Ouganda, en utilisant la collection disponible de 284 accessions de haricots. Un essai \ue9tait conduit au National Crops Resources Research Institute \ue0 Namulonge, Ouganda. Le niveau de variation morphologique estim\ue9 \ue0 l\u2019aide de l\u2019indice de diversit\ue9 de Shannon Weaver (H),variait de 0.47 \ue0 0.58, avec une moyenne g\ue9n\ue9rale de 0.56\ub10.19, un indicateur de diversit\ue9 g\ue9n\ue9tique mod\ue9r\ue9. L\u2019analyse de la composante principale (PCA) a group\ue9 le germplasme en trois groupes majeurs (G1, G2 et G3). Les g\ue9notypes differaient plus par l\u2019habitude de croissance, la section des gousses, la courbature des gousses, la couleur de l\u2019hypocotyle, les jours \ue0 la floraison, le nombre de nodes sur la tige principale, le nombre de bourgeon des fleurs et le poids de 100 graines

Phenotypic diversity within Ugandan yam (Dioscorea species) germplasm collection

Open Access JournalA proper understanding of the diversity of the available germplasm is an initial step for the genetic improvement of a crop through breeding. However, there is limited information on the diversity of Uganda’s yam germplasm. The study sought to characterize the diversity of yam germplasm utilized for decades in Uganda together with germplasm recently introduced from West Africa using phenotypic traits. A germplasm collection of 291 genotypes was characterized using 28 phenotypic traits. Data were subjected to multivariate analysis using principal component analysis and cluster analysis. The traits assessed were informative and discriminating, with 62% of the total variation explained among the first six principal components. Results showed that the important phenotypic traits contributing to most of the variability among the genotypes were leaves, flowering, and tuber traits. Ugandan genotypes were identified with amorphous tuber shapes compared to West African genotypes. The study has shown that there is ample phenotypic variability within the major yam genotypes in Uganda yam germplasm that can be used for genetic improvement. More in-depth molecular and biochemical studies to further understand the diversity are recommended. The preprint was made available by research square in the following link: “https://www.researchsquare.com/article/rs-1518551/v1.

Current status of groundnut improvement in Uganda

In Uganda, groundnut (Arachis hypogaea L) is the second most important legume after beans. Groundnuts is cultivated on nearly 260,000 ha, representing 24.6% of the total arable land. On-farm pod yields are low, averaging 800 kg/ha of dry pods, compared to on-station potential yields of 3,000kg/ha. Sales from current production could potentially generate $344 million to the producers who are largely small-scale farmers. The yield gaps are attributed to a combination of biotic, abiotic, cultural and political factors. Since the 1920s, research efforts have released 24 varieties, the most recent commercial varieties being the Serenut 1-14 series. These varieties have overcome some of the mentioned production constraints. However, varied growing agroecologies, land tenure systems, diverse market preferences, and emerging stresses call for continuous research. Current research agenda includes breeding for high oleic, leafminer resistance, confectionery, aflatoxin tolerance, drought tolerance, early to medium maturing varieties, high yielding, and rosette disease resistant varieties. We have initiated Marker Assisted Selection for high oleic breeding and adopted BMS for Digitalization of data capture, management, analyses and storage. Recently developed regeneration protocol will aid in introgressing additional traits across taxa. The bimodal rainfall pattern and active hybridization programme increases our breeding cycles. To date, the groundnut breeding program has an active breeding pipeline frequently releasing varieties and lines which have already been shared with National Programs across Africa, Haiti and the USA with many additional National Programs making requests. We have strong partnerships in Research and Development among the African Countries, USAID, ICRISAT, and BMGF

Phenotypic and genotypic screening for rust resistance in common bean germplasm in Uganda

Peer Revie

Genetic diversity and population structure of Peronosclerospora sorghi isolates of Sorghum in Uganda

Sorghum is the third most important staple cereal crop in Uganda after maize and millet. Downy mildew disease is one of the most devastating fungal diseases which limits the production and productivity of the crop. The disease is caused by an obligate fungus, Peronosclerospora sorghi (Weston & Uppal) with varying symptoms. Information on the genetic diversity and population structure of P.sorghi in sorghum is imperative for the screening and selection for resistant genotypes and further monitoring possible mutant(s) of the pathogen. Isolates of P. sorghi infecting sorghum are difficult to discriminate when morphological descriptors are used. The use of molecular markers is efficient, and reliably precised for characterizing P. sorghi isolates. This study was undertaken to assess the level of genetic diversity and population structure that exist in P. sorghi isolates in Uganda. A total of 195 P. sorghi isolates, sampled from 13 different geographic populations from 10 different regions (agro-ecological zones) was used. Eleven (11) molecular markers, comprising of four Random amplified microsatellite (RAM) and seven (7) Inter-Simple Sequence Repeat (ISSR) markers were used in this study. The analysis of molecular variation (AMOVA) based on 11 microsatellite markers showed significant (P < 0.001) intra-population (88.9 %, PhiPT = 0.111) and inter-population (8.4 %, PhiPR = 0.083) genetic variation, while the genetic variation among regions (2.7 %, PhiRT = 0.022) was not significant. The highest genetic similarity value (0.987 = 98.7 %) was recorded between Pader and Lira populations and the lowest genetic similarity (0.913 = 91.3 %) was observed between Namutumba and Arua populations. The mean Nei's genetic diversity index (H) and Shannon Information Index (I) were 0.308 and 0.471 respectively. Seven distinct cluster groups were formed from the 195 P. sorghi isolates based on their genetic similarity. Mantel test revealed no association between genetic differentiation and geographical distance (R2 = 0.0026, p = 0.02) within the 13 geographic populations

AGRONOMIC QUALITIES OF GENETIC PYRAMIDS OF COMMON BEAN DEVELOPED FOR MULTIPLE-DISEASE-RESISTANCE

Multiple co-infections by different pathogens on common bean ( Phaseolus vulgaris L.) affect its productivity and cause complete crop loss in susceptible varieties. Therefore, gene pyramiding using marker assisted selection (MAS) and backcrossing, provide alternative cost-effective control measures to bean diseases. However, in the process of developing pyramids, linkage drags were likely to affect the qualities of progeny lines, hence, special attention was paid to this situation. The objective of this study was thus to assess the agronomic qualities of advanced genetic pyramids developed from a four-way cross for multiple disease resistance. The disease resistance genes (R) pyramided from four parents were: Co42 and Co-5 from G2333; Phg-2 from MEX54; Pythium ultimum Dennis from MLB49-89A and I &amp; bc3 from MCM5001. The progeny lines were planted in an incomplete block design, and replicated thrice for two seasons (2015A and 2015B) in fields at CIAT, Kawanda in Uganda. Agronomic traits were highly heritable (0.6), except number of pods per plant (&lt; 0.3). Backcrossing generated high-yielding bean lines, with 270 - 290 seed per plant and early maturity (95-100 days). Nine superior lines with desirable qualities, such as earliness (95 days), high seed rate (290 seeds per plant), and climbing ability, were obtained. Pyramiding R genes did not affect yield traits, except time to flowering and number of flower buds per plant due to transgressive segregation.Les co-infections multiples par de diff\ue9rents pathog\ue8nes sur le haricot commun ( Phaseolus vulgaris L.) affectent sa productivit\ue9 et causent la perte totale des vari\ue9t\ue9s susceptibles de la culture. Par cons\ue9quent, la pyramide des g\ue8nes en utilisant la s\ue9lection assist\ue9e par des marqueurs (MAS) et le r\ue9trocroisement, fournissent des mesures alternatives de contr\uf4le moins ch\ue8res des maladies du haricot. N\ue9anmoins, dans le processus du d\ue9veloppement des pyramides, les poids des liaisons affectent probablement les qualit\ue9s des lign\ue9es de prog\ue9nitures, de ce fait, une attention particuli\ue8re \ue9tait port\ue9e \ue0 cette situation. L\u2019objectif de cette \ue9tude \ue9tait d\u2019\ue9valuer les qualit\ue9s agronomiques des pyramides g\ue9n\ue9tiques avanc\ue9es d\ue9velopp\ue9es d\u2019un croisement de quatre parents pour la r\ue9sistance aux maladies multiples. Les g\ue8nes pyramid\ue9s de r\ue9sistance (R) \ue0 la maladie de quatre parents \ue9taient\ua0: Co42 et Co-5 de G2333; Phg-2 de MEX54; Pythium ultimum Dennis de MLB49-89A et I &amp; bc3 de MCM5001. Les lign\ue9es de prog\ue9nitures \ue9taient plant\ue9es en arrangement de block incomplet et r\ue9pliqu\ue9 trois fois pendant deux saisons (2015A et 2015B) dans les champs \ue0 CIAT, Kawanda en Ouganda. Les traits agronomiques \ue9taient hautement h\ue9ritables (0,6), \ue0 l\u2019exception du nombre de gousses par plant (&lt;0.3). Le r\ue9trocroisement a g\ue9n\ue9r\ue9 des lign\ue9es d\u2019haricot \ue0 haut rendement, avec 270-290 graines par plant et \ue0 maturit\ue9 pr\ue9coce (95-100 jours). Neuf lign\ue9es sup\ue9rieures avec des qualit\ue9s d\ue9sirables, telles que la pr\ue9cocit\ue9 (95 jours), taux de graines \ue9lev\ue9s (290 graines par plant) et l\u2019habilit\ue9 grimpante, \ue9taient obtenues. La pyramide des g\ue8nes R n\u2019avait pas affect\ue9 les traits li\ue9s au rendement, \ue0 l\u2019exception de la p\ue9riode de floraison et le nombre de bougeons de fleurs par plant d\ufb \ue0 la s\ue9gr\ue9gation transgressive