Seloame Tatu Nyaku

By Seloame T. Nyaku, Yonathan Tilahun, Kathy Lawrence, Venkateswara R. Sripathi, Abreeotta J. Williams and Govind C. Sharma

Among major nematode pests of Upland, cotton production is the reniform nematode, which is a serious threat in various cotton-producing regions. The availability of germplasm lines with tolerance or resistance to this menacing pest is a valued asset. To date, various laboratories and research institutions have collaborated to transfer the reniform nematode resistance from wild gene pools of cotton into widely cultivated Upland cotton, which have led to positive results. This chapter focuses on the current status of these introgressions and resistance mechanisms in cotton. In this overview, four major themes are being pursed: (1) tolerance mechanisms in cotton to the reniform nematode, (2) genotype evaluations, (3) introgression of reniform resistance into Upland cotton, and (4) functional analysis of reniform infection in Upland cotton. Genetic resistance in Upland cotton to the reniform nematode is the only practical solution because conventional control measures are the most cost-effective and environmentally sustainable and therefore have been and will be actively pursued. Resistance genes, if successfully introgressed into crop plants from wild relatives, should complement management of the reniform nematode with traditional methods.

Part of the book: Cotton Research

By Seloame Tatu Nyaku, Antoine Affokpon, Agyemang Danquah and Francis Collison Brentu

Nematodes are very diverse and parasitize various plants including vegetables, and their management is of concern. Biological control of nematodes provides an environmentally friendly management option and there are various micro‐soil‐borne organisms which can be considered for this purpose. The primary goal of this chapter is to provide a review on the progress made so far, in application of biological control agents in nematode management in vegetables, cereals, and root and tuber crops. This chapter will be divided into five (5) sections: (1) herbivore‐induced plant volatiles, (2) root exudates and nematode control, (3) inhibitory metabolites in bacteria for nematode management, (4) fungi and symbiotic reprogramming in host cells, and (5) fungi antagonists of nematodes.

Part of the book: Nematology

By Seloame Tatu Nyaku and Naalamle Amissah

Research focus currently relies on combinations of environmentally friendly approaches among which is grafting for pathogen management. Grafting has potential to provide resistance to multiple soilborne pathogens, for example, nematodes, after a susceptible plant (scion) is united with resistant rootstocks. Sources of resistant rootstocks include species from the same family or closely related species, hybrids, and weeds. This chapter focuses on the following themes: (1) grafting and cost implications, (2) rootstock selection and tomato grafting against root-knot nematodes, (3) grafting techniques and requirements and graft union formation, (4) fruit quality of grafted plants, and (5) screening of rootstocks against root-knot nematode and identification of markers linked to Mi gene in rootstocks. Tomato rootstock breeding efforts, if coordinated properly, can lead to production of rootstocks, which can be adapted to specific environments and abiotic stresses.

Part of the book: Recent Advances in Tomato Breeding and Production