Gene action of blast disease reaction and grain yield traits in finger millet

Gene action of blast reaction, yield and yield associated traits in finger millet were studied using a 4x4 North Carolina Design II mating scheme. The four female and four male parents and their 16 crosses were evaluated at Alupe and Kakamega in western Kenya in a randomized complete block design under both artificially induced and natural disease pressure. General combining ability (GCA) and specific combining ability (SCA) estimates of the traits were calculated to determine the genotypes breeding value. The GCA variance predominated over SCA variance for all traits except finger width hence these traits can be improved through selection. With high, desirable GCA effects, male parent KNE 392 and female parents KNE 744 and IE 11 are suitable for blast resistance breeding while male parent Okhale 1 is suitable for grain yield improvement. The frequency distribution for the segregating F2 generation for the three blast types differed within and between crosses which could be due to differences in gene numbers or gene combinations being expressed in the different parents used. Convergent crossing or gene pyramiding for durable resistance could be possible

Natural out-crossing in dwarf pigeonpea

Natural out-crossing rate in pigeonpea was studied at 1CRISAT Center using plant stature (tall plants in dwarf progenies) as the genetic marker. The data indicated natural out-crossing rates of 9.7% to 24.1 % with a pooled value of 13.1% in the six populations studied. These data were comparable to earlier studies at the same site using stem colour and growth habit as genetic markers in tall pigeonpea cultivars thus suggesting that foraging of insect pollination vectors is not influenced by plant type. The implications of natural out-crossing on breeding and maintenance of genetic purity of cultivars is discussed

Genetic diversity assessment of farmers’ and improved potato (Solanum tuberosum) cultivars from Eritrea using simple sequence repeat (SSR) markers

Sixty three potato clones (51 farmers’ and 12 varieties) from Eritrea, 18 and 12 varieties from Kenya and Rwanda, respectively were characterized using 12 highly polymorphic simple sequence repeat (SSR) markers. The study was designed to assess the genetic diversity and varietal distinctness among the different samples. In total, 91 alleles ranging between 2 (STM1053) to 13 (STM0031) alleles per marker were scored. All but 97.8 SSR markers were highly polymorphic with an average PIC value of 0.87 (0.51 to 0.98). All of the 51 farmers’ cultivars were clearly distinct from each other. Samples from Eritrea showed the highest genetic diversity as explained by the diversity index (h). The principal coordinate analysis (PCoA) revealed that the local farmers’ Eritrean samples are different from the Kenyan, Rwandese and even the imported varieties. Genetic distance analysis generated three clusters correlating with the PCoA findings. Cluster I consisted of 45 samples with 6 sub-clusters; Cluster II consisted of 29 samples with a majority (26) from Eritrea while cluster III consisted of 19 samples. Potato materials from Eritrea appeared to cluster separately from the other samples, which reflects a contribution from the Tuberosum germplasm prominent in temperate regions, unlike from the Andigenum germplasm for Kenyan and Rwandan potato materials. Most of the Eritrean samples in cluster I are farmers’ cultivars with intermediate maturity, good performance and better tuber quality characteristics. Cluster II contains mainly the imported variety from Eritrea characterized by late emergence and late maturity. The Kenyan and Rwandese were grouped mainly in Cluster III. In summary, the farmers’ cultivars are distinct from the Kenyan and Rwandese materials and represent more genetic diversity than the varieties imported into Eritrea. This finding is of interest to national breeding program to use the farmer’s materials as source of genetic variation for traits of interest.Keywords: Potato, simple sequence repeat (SSR), principal coordinate analysis (PCoA), cluster analysis, Eritrea, multivariat

Diversity in Tanzanian pigeonpea [Cajanus cajan (L.) Millsp.] landraces and their response to environments

A total of 123 pigeonpea landraces collected from farmers' fields in four pigeonpea growing regions of Tanzania were characterized and evaluated for 16 qualitative and 14 quantitative descriptors, and their response across three pigeonpea growing environments in Tanzania and Kenya determined. Polymorphism in the qualitative traits was relatively low among accessions and across collection regions. Collections from the northern highlands exhibited lower diversity in qualitative descriptors, especially physical grain characters, relative to the other three regions, an indication of farmer selection in response to market preferences. There were significant differences in agronomic traits among accessions and in genotype-by-environment interaction (GEI). High broad-sense heritability was recorded for days to flower, days to maturity, plant height, raceme number and 100 seed mass. Principal component analysis and clustering separated variability among the accessions according to days to flower, days to maturity, plant height, number of primary and secondary branches, and number of racemes per plant. There was close clustering within and between materials from the coastal zone, eastern plains and southern plains with the northern accessions distinctly separated and with wide dispersion within them. Overall, two diversity clusters were evident with coastal, eastern and southern landraces in one diversity cluster and northern highlands landraces in another cluster. This diversity grouping established potential heterotic groups which may be used in crosses to generate new cultivars adapted to different pigeonpea growing environments with consumer acceptability. The grouping may also form a basis of forming a core collection of this germplasm representing the variability available

Variation for Agro-Morphological Traits among Kabuli Chickpea (Cicer arietinum L.) Genotypes

The objectives of this study were to evaluate genetic variation among kabuli chickpea genotypes and to determine the relationships among agronomic traits with seed yield. Field experiments were conducted during the long and short rain seasons of 2013 using alpha lattice design in triplicate. Data on agro-morphological traits were recorded using descriptors for chickpea and analysed using SAS 2013 and Genstat 2014. There were highly significant (p < 0.001) variations among genotypes and genotype by environment interactions for all studied traits. The top five high yielding genotypes were ICCV 05315, ICC 13461, ICCV 07313, ICC 13764 and ICCV 00302. Genotypes ranking for most agronomic traits varied across environments which indicated a crossover type of genotype by environment interactions. Evaluated genotypes were polymorphic for six qualitative traits. Seed yield ha-1 was positively and significantly (p < 0.05) correlated with biomass yield ha-1, pods plant-1, plant canopy width and secondary branches plant-1. These characters could be used for indirect selection of high yielding genotypes. The first principal component explained 57% of the total variation and was associated with days to 50% flowering and podding, plant canopy width, plant height, number of primary and secondary branches plant-1, days to 75% maturity, number of pods plant-1 and biomass yield ha-1 as positive contributors. The documented information on genetic variation and association of agronomic traits with seed yield can be exploited to devise suitable breeding strategies and chickpea germplasm conservation

Exploiting Genetic Diversity for Adaptation and Mitigation of Climate Change: A Case of Finger Millet in East Africa

With the reality of global climate change there is a need to exploit the variation in the germplasm in order to develop genotypes adapted to these changes. This requires breeding and selection of crops at strategically selected locations along a rainfall/temperature gradient to enable farmers select desired cultivars. Eighty one finger millet germplasm lines from East Africa were evaluated in eight environments spread across Kenya, Tanzania and Uganda for adaptation, grain yield stability using the additive main effects and multiplicative interaction (AMMI) ANOVA and Genotype and Genotype x Environment (GGE) models and blast reaction under artificial and natural inoculation. Lanet 2012 long rains, Serere 2012 long rains and Miwaleni 2012 long rains were found to be the most discriminating environments for the low temperature, sub-humid mid-altitude and dry lowland areas, respectively. Alupe 2012 long rains was the ideal environment for blast selection. Seven genotypes were identified for yield stability across the eight environments whereas nine genotypes had specific adaptation. Nine genotypes were identified with resistance to three blast types. However, one and two genotypes had high resistance only to leaf and neck blast, respectively. Two resistant and 12 moderately resistant genotypes to blast attained the highest grain yields and had varied maturity, plant heights and grain colour. This will provide farmers the opportunity to select genotypes appropriate to their target agro-ecologies with desired end-uses. The East African finger millet germplasm has high potential as a source of climate smart high yielding and blast resistant genotypes for direct production and/or breeding

Exploiting Genetic Diversity for Adaptation and Mitigation of Climate Change: A Case of Finger Millet in East Africa

Eighty one finger millet germplasm accessions from East Africa were evaluated in eight environments in Kenya, Tanzania and Uganda for adaptation and grain yield stability, genotype and genotype x environment (GGE) models. Lanet 2012 long rains, Serere 2012 long rains and Miwaleni 2012 long rains were found to be the most discriminating environments for the low temperature, sub-humid mid-altitude and dry lowland areas, respectively. Seven genotypes were identifi ed for yield stability across the eight environments, whereas nine genotypes had specifi c adaptation. Fourteen genotypes attained the highest grain yield and had varied maturity, plant heights and grain colour. This will provide farmers the opportunity to select genotypes appropriate to their target agroecologies with desired traits. The East African fi nger millet germplasm has high potential as a source of climate smart, high yielding genotypes for direct production and/or breeding

The Hominin Sites and Paleolakes Drilling Project:Inferring the environmental context of human evolution from eastern African rift lake deposits

Funding for the HSPDP has been provided by ICDP, NSF (grants EAR-1123942, BCS-1241859, and EAR-1338553), NERC (grant NE/K014560/1), DFG priority program SPP 1006, DFG-CRC-806 “Our way to Europe”, the University of Cologne (Germany), the Hong Kong Research Grants Council (grant no. HKBU201912), the Peter Buck Fund for Human Origins Research (Smithsonian), the William H. Donner Foundation, the Ruth and Vernon Taylor Foundation, Whitney and Betty MacMillan, and the Smithsonian’s Human Origins Program.The role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered around the study of outcrop sediments and fossils adjacent to where fossil hominins (ancestors or close relatives of modern humans) are found, or from the study of deep sea drill cores. However, outcrop sediments are often highly weathered and thus are unsuitable for some types of paleoclimatic records, and deep sea core records come from long distances away from the actual fossil and stone tool remains. The Hominin Sites and Paleolakes Drilling Project (HSPDP) was developed to address these issues. The project has focused its efforts on the eastern African Rift Valley, where much of the evidence for early hominins has been recovered. We have collected about 2 km of sediment drill core from six basins in Kenya and Ethiopia, in lake deposits immediately adjacent to important fossil hominin and archaeological sites. Collectively these cores cover in time many of the key transitions and critical intervals in human evolutionary history over the last 4 Ma, such as the earliest stone tools, the origin of our own genus Homo, and the earliest anatomically modern Homo sapiens. Here we document the initial field, physical property, and core description results of the 2012–2014 HSPDP coring campaign.Publisher PDFPeer reviewe

Effects of biofertilizer containing N-fixer, P and K solubilizers and AM fungi on maize growth: A greenhouse trial.

An in vitro study was undertaken to evaluate the compatibility of indigenous plant growth promoting rhizobacteria (PGPR) with commonly used inorganic and organic sources of fertilizers in tea plantations. The nitrogenous, phosphatic and potash fertilizers used for this study were urea, rock phosphate and muriate of potash, respectively. The organic sources of fertilizers neem cake, composted coir pith and vermicompost were also used. PGPRs such as nitrogen fixer; Azospirillum lipoferum, Phosphate Solubilizing Bacteria (PSB); Pseudomonas putida, Potassium Solubilizing Bacteria (KSB); Burkholderia cepacia and Pseudomonas putida were used for compatibility study. Results were indicated that PGPRs preferred the coir pith and they proved their higher colony establishment in the formulation except Azospirillum spp. that preferred vermicompost for their establishment. The optimum dose of neem cake powder