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

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

Response of soybean (Glycine max L.) genotypes to varying levels of phosphorus for yield and related traits under acid soils of western Ethiopia

Low availability of soil phosphorus (P) is one of the major limiting factors for soybean production on acidic soils of the tropics. The objectives of this study were to assess the interaction of soybean genotypes (G) with levels of P, and identify genotypes that are responsive to high P and tolerant to low P conditions. A total of 36 soybean genotypes were evaluated under three levels of P (0, 100, and 200 kg ha-1) in three locations (L) of Western Ethiopia in split plot design with P levels as main plots, and genotypes as subplots. The individual locations analysis, revealed that the genotypes X phosphorus interaction for grain yield was significant (P<0.05) at Assosa. The genotypes showed highly significant differences for most of the studied traits in all the locations. The combined analysis revealed that there was significant G, and LXG interactions for most of the traits. Essex-1, IAC 11 and AGS-3-1 were the best performing genotypes on 200 kg ha-1 P; while IAC 11, AA-7138, G 9945 and Hawassa 04 exhibited tolerance to low P. AMMI analysis for grain yield at Assossa revealed that zero and 200 kg ha-1 were highly interactive with the genotypes. Genotypes: AA-7138, PR-142 (26) and H 3 were stable genotypes across the P levels with relatively high main effect; and hence, such genotypes are useful in breeding soybeans for consistent response to varying P conditions

Response of pigeon pea genotypes to different races of Fusarium udum and the mode of gene action responsible for disease inheritance

To develop high yielding Fusarium wilt resistant varieties, it is essential to identify new sources of resistance that can withstand multiple races of the pathogen. The aim of this study was to identify [Fusarium udum (L.) Millsp.] races occurring in the study fields, determine reaction of pigeon pea hybrids to the different isolates and establish the mode of gene action responsible for Fusarium wilt inheritance. Field and pot experiments were conducted during 2009 and 2010. A root-dip inoculation and transplantation technique in pots and sowing in a wilt-sick field were used for studying the reactions of 54 pigeon pea genotypes to F. udum isolates. Field evaluation was done in the infested plot in a 9 x 6 alpha lattice design with two replications. Purification of the isolates on potato dextrose agar identified three isolates and were designated as ISO-A, ISO-B, and ISO-C. The isolates produced whitish to light pink or orange mycelia. Purple was predominant on the substrate, but whitish to light pink were also identified. Pot inoculation trials with the three isolates identified seven genotypes (ICPB2043, ICP12012, ICP13092, ICPA2039xICP13092, ICPA2043xICP12012, ICPA2043xICP13092, and ICPA2043xICP9135) resistant to all the isolates. Under field evaluation, seven genotypes (ICPA2039xICP13092, ICPA2039xAsha, ICPA2043xICP12012, ICPA2043xICP13092, ICPA2043xICEAP557, ICPB2043, and Maruti) were moderately resistant. The cytoplasmic male sterile (A) line, A2043, showed resistance to the three isolates. The resistant hybrid, ICPA2943xICP12012 had the highest negative SCA that was highly significant for all the isolates in the field.Keywords: Fusarium udum, pigeon pea genotypes, pigeon pea isolates, Kenya, wilt-sick fieldJ. Trop. Microbiol. Biotechnol. 8:9-19

Diversity in tanzanian pigeonpea [cajanus cajan (l.) Millsp.] Landraces

A total of 123 Pigeonpea landraces were collected from four major pigeonpea production areas in Tanzania. The accessions grown at Ilonga (Tanzania) and Kabete and Kampi ya Mawe (Kenya) were characterized for diversity using 16 qualitative and 14 quantitative traits. In the Northern Highlands, pigeonpea is grown mainly as a cash crop for export. Farmers mainly rely on self saved seed, but seed is also obtained from other sources. Significant polymorphism in qualitative traits was recorded in base flower colour, pod colour, flowering pattern, streak pattern, seed colour and seed shape. Northern Highlands collections exhibited lowest diversity in these traits, an indication of selection response to market preferences. Principal component and cluster analysis separated the variability in the germplasm based on days to flower, days to maturity, plant height, number of primary and secondary branches and number of racemes/ plant. Overall, two distinct diversity clusters were evident with Coastal, Eastern and Southern accessions in one cluster and Northern Highlands accessions in another cluster. Further studies, using molecular techniques is essential to confirm the diversity groups identified and also to identify genetic markers for insect pests and disease resistanc