B.R. Kerry’s research while affiliated with Rothamsted Research and other places

By 2050, Africa's population is projected to exceed two billion. Africa will have to increase food production more than 50% in the coming 50 years to meet the nutritional requirements of its growing population. Nowhere is the need to increase agricultural productivity more pertinent than in much of sub-Saharan Africa where it is currently static or declining. Optimal pest management will be essential, because intensification of any system creates heightened selection pressures for pests. Plant-parasitic nematodes and their damage potential are intertwined with intensified systems and can be an indicator of unsustainable practices. As soil pests, nematodes are commonly overlooked or misdiagnosed, particularly where appropriate expertise and knowledge transfer systems are meager or inadequately funded. Nematode damage to roots results in less efficient root systems that are less able to access nutrients and water, which can resemble symptoms typical of water or nutrient deficiency, leading to misdiagnosis of the underlying cause. Damage in subsistence agriculture is exacerbated by growing crops on degraded soils and in areas of low water retention where strong root growth is vital. This review focuses on the current knowledge of economically important nematode pests affecting key crops, nematode control methods, and the research and development needs for sustainable management, stakeholder involvement and capacity building in the context of crop security in East and Southern Africa, especially Kenya, Tanzania, Uganda and Zimbabwe. This article is protected by copyright. All rights reserved.

By 2050, Africa's population is projected to exceed 2 billion. Africa will have to increase food production more than 50% in the coming 50 years to meet the nutritional requirements of its growing population. Nowhere is the need to increase agricultural productivity more pertinent than in much of Sub-Saharan Africa, where it is currently static or declining. Optimal pest management will be essential, because intensification of any system creates heightened selection pressures for pests. Plant-parasitic nematodes and their damage potential are intertwined with intensified systems and can be an indicator of unsustainable practices. As soil pests, nematodes are commonly overlooked or misdiagnosed, particularly where appropriate expertise and knowledge transfer systems are meager or inadequately funded. Nematode damage to roots results in less efficient root systems that are less able to access nutrients and water, which can produce symptoms typical of water or nutrient deficiency, leading to misdiagnosis of the underlying cause. Damage in subsistence agriculture is exacerbated by growing crops on degraded soils and in areas of low water retention where strong root growth is vital. This review focuses on the current knowledge of economically important nematode pests affecting key crops, nematode control methods and the research and development needs for sustainable management, stakeholder involvement and capacity building in the context of crop security in East and Southern Africa, especially Kenya, Tanzania, Uganda and Zimbabwe.

Studies on the use of Pochonia chlamydosporia isolates as biological control agents of root-knot nematodes (RKN, Meloidogyne spp.), showed that their efficacy relies on selected key factors such as fungal proliferation in soil, establishment in the rhizosphere, and ability to parasitize RKN eggs. A pot experiment was conducted to evaluate the performance of a Portuguese P. chlamydosporia isolate (Pc2) and of a non-native isolate (Pc10) against M. chitwoodi in a potato-maize-potato-potato crop rotation. The growth of P. chlamydosporia in soil and roots was monitored throughout the experiment by assessing the numbers of colony forming units (cfu). The prevalence in M. chitwoodi eggs and nematode reproduction was measured at the end of each crop. The cfu/g of soil varied over time and was particularly low for both isolates during the spring and summer 2009, when temperatures above 30°C were registered. Native isolate Pc2 was more effective in establishing in soil than Pc10. Growth and survival of the fungus did not seem to depend on the presence of nematode or host plant species. Establishment of P. chlamydosporia in soil was slow and was only achieved after the full cropping sequence. The two P. chlamydosporia isolates revealed subtle differences in host preference, plant compatibility, or tolerance to abiotic conditions that may affect their efficacy as biocontrol agents in a long-lasting management programme.

Oligonucleotides used for qRT-PCR. (DOCX)

Gene expression analysis of MAP-1 and 2 selected TDFs during the A. thaliana - M. icognita interaction using different endogenous gene: Gene expression analysis by qRT-PCR of A, MAP-1 , B, P57E2 and C, P16AB6 during the pathogenic interaction (1 biological repeat) using 3 different endogenous reference genes: actin, elongation factor 1 (EF1) and glyceraldehyde 3-phosphate dehydrogenase (GPDH). (TIF)

Summary of the 63 transcript-derived fragments (TDF)a. a Differential expression between ARE- and H2O-treated Meloidogyne incognita infective juveniles b Presence (Y) or absence (N) of signal peptide (SP) was determined by using SignalP software. When no full cDNA or protein sequence was available, the presence of a SP was not determined (Na). c Putative localisation of the protein corresponding to the TDF was analysed using WoLF PSORT software. Only 1 predicted localisation was reported when the score was superior at 18. d Proteins were classified by family using the classification published in Bellafiore et al., 2008. (1 = proteins interacting with actin/microtubules, 2 = proteins interacting with nucleic acids, 3 = post-translational modifications, protein turnover, and chaperone functions, 4 = metabolism, 5 = signal transduction, 6 = proteins synthesis and secretion, 7 = detoxification, 8 = cell wall modification enzymes, 9 = others) e Gene expression is reported for ARE-treated nematodes in comparison to H2O-treated nematodes (2 biological repeats). (DOCX)

Mean ΔCT for statistical comparison. LSD = Least significant difference, degree of freedom (df) = 19 except for P16EF1 and P17AB3 (df = 18) (DOCX)

Transcript-derived fragments sequences. (DOCX)