Real time PCR mediated determination of the spontaneous occurrence of Sorghum bicolor alleles in wild sorghum populations

The study evaluates the utility of Real Time PCR (RT-PCR) in quantitative and qualitative analysis of alleles in sorghum populations and the spontaneous occurrence of Sorghum bicolor alleles in wild populations of sorghum. Leaf and seed material from wild sorghum accesions were sampled in Homabay, Siaya and Busia counties to represent Western Kenya sorghum producing regions. A second sampling was done on S2 populations of S. bicolor, Sorghum halepense and Sorghum sudanense maintained in the greenhouse. Crop loci were evaluated in all materials using a LightCycler® 2.0 system. Real Time PCR was effective in qualitative and quantitative determination of crop alleles in both crop and weedy backgrounds of S. sudanense, S. halepense and S. verticilliflorum. Crossing point values ranged between 19.7 from 30 ng template to 35.9 from 0.015 pg of template on locus SB1764. Melting peaks analysis ranged between 83.29 to 88°C on locus SB1764 and between 86.01 to 80.88°C on locus SB3420 effectively differentiating the 4 species. RealTime-PCR was successful in quantitative and qualitative analysis of specific crop alleles from loci SB1764 and SB3420 from seed and leaf DNA. Spontaneous occurrence of crop and rare alleles in wild sorghum populations growing in sympatry with crop cultivars showed the presence of crop and rare alleles in wild sorghum populations. Means of wild populations from lower midland1 (LM1), LM2, LM3 and LM4 AEZs were not significantly different. It is therefore vital to test S. bicolor seeds and other plant materials in transit, at entry points and populations of growing plants for foreign genes including transgenes using RT-PCR. Keywords: Real time polymerase chain reaction (PCR), Sorghum bicolor, Sorghum halepense, Sorghum sudanense

Effects of nitrogen and phosphorus fertiliser on growth and yield of ironweed (Vernonia galamesis)

No Abstract Available E. Afr. Agric. For. J. 2003 69(2), 109-11

Genomic interventions to improve resilience of pigeonpea in changing climate

Pigeonpea is an important food legume crop for rainfed agriculture in developing countries, particularly in India. Productivity gains in pigeonpea have remained static, and the challenge of improving pigeonpea yield is further aggravated by increasingly uncertain climatic conditions. Improved pigeonpea cultivars with favourable traits, allowing them to cope with climatic adversities, are urgently required. Modern genomic technologies have the potential to rapidly improve breeding traits that confer resistance to biotic and abiotic stresses. Recent advances in pigeonpea genomics have led to the development of large-scale genomic tools to accelerate breeding programs. Availability of high-density genotyping assays and high-throughput phenotyping platforms motivate researchers to adopt new breeding techniques like genomic selection (GS) for improving complex traits. Accurate GS predictions inferred from multilocation and multiyear data sets also open new avenues for ‘remote breeding’ which is very much required to achieve genotype selection for future climates. Speed breeding pigeonpea with deployment of rapid generation advancement (RGA) technologies will improve our capacity to breed cultivars endowed with resilient traits. Once such climate-resilient cultivars are in place, their rapid dissemination to farmer’s fields will be required to witness the real impact. Equally important will be the acceleration of varietal turnover to keep pace with the unpredictably changing climatic conditions so that cultivars are constantly optimized for the climatic conditions at any given time

How to understand the complexity of product quality and the challenges in differentiating between organically and conventionally grown products—exemplified by fresh and heat-processed carrots (Daucus carota L.)

Quality traits are highly focused upon in the marketing of organic food products. There is a need to define and measure quality as consumers seem to have preconceived notions about the superior health value and taste of organic compared to non-organic products. A commonly held opinion among many consumer groups is that organic farming guarantees optimum quality, despite the fact that this remains unproven. The aim of this paper is to contribute to a better understanding of the complexity of quality traits in a plant-based food product, using carrots as an example. Selected designated quality aspects are presented to describe the complexity of quality and discuss the challenges of using these aspects in differentiating between organic and conventional products. The paper concludes we have insufficient tools to be able to adequately authenticate organically produced carrots. The same may be the case for most vegetables and fruit products. Suggestions for further studies include the soil and location aspect (terroir), in order to trace a product back to its origin in an organically or conventionally farmed field by finding a unique fingerprint for chemical constituents of sample