Preface

Tomato production is limited by abiotic and biotic factors (fungi, bacteria, viruses, and nem‐ atodes). There are however various methods currently employed to address these challeng‐ es. This book "Recent Advances in Tomato Breeding and Production" focuses on two main themes: (i) disease and pest management in tomato production, and (ii) breeding tools and improvement of the tomato. These themes will be expanded on to include tomato breeding/ production methods e.g., application of grafting techniques for disease control, where a scion of a susceptible plant is grafted onto a resistant root-stock against a biotic agent, the use of integrated management methods, e.g., good agronomic practices (GAPs), application of plant botanical extracts with fungicidal properties, and biological control agents such as *Trichoderma harzianum* to manage damping-off in tomato seedlings. Plant growth promoting Rizobacteria (PGPR) e.g., *Pseudomonas s*pp. and *Bacillus* sp. enhance growth and develop‐ ment of tomato plants and also provide protection against plant pathogens. Other chapters will focus on germplasm collection and screening, through morphological and molecular characterization for identification of resistance to biotic and abiotic stress. Modern-day to‐ mato cultivation makes use of soilless media and controlled environments e.g., hydroponics, simple high tunnel structures, and automated screen and greenhouses. Marker assisted se‐ lection (MAS) is a conventional breeding tool where molecular markers linked to specific traits are identified. Other strategies include marker assisted backcrossing and recurrent se‐ lection for tomato breeding against stress. These studies can be complemented with under‐ standing of the genotype x environment interactions for varietal development. I believe the chapters will be useful to university students and researchers.

Many thanks to the IntechOpen book department and Ms. Romina Skomersic (Author Serv‐ ice Manager), for the opportunity to work on this project. All authors of the book chapters are highly acknowledged for their valuable contributions.

#### **Dr. Seloame Tatu Nyaku**

Department of Crop Science College of Basic and Applied Sciences (CBAS) University of Ghana, Ghana

West Africa Centre for Crop Improvement (WACCI) College of Basic and Applied Sciences (CBAS) University of Ghana, Ghana

> **Dr. Agyemang Danquah** College of Basic and Applied Sciences (CBAS) University of Ghana, Ghana

**Section 1**

**Disease and Pest Management in Tomato**

**Production**

**Disease and Pest Management in Tomato Production**

**Chapter 1**

**Provisional chapter**

**Grafting: An Effective Strategy for Nematode**

**Grafting: An Effective Strategy for Nematode** 

DOI: 10.5772/intechopen.82774

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.

Grafting is the deliberate joining together of a scion and rootstock, taken from different but compatible plants, which are taxonomically close, to produce a composite plant. The scion, which forms the top portion, is selected for its desirable attributes, such as better yields, bigger fruit sizes, or preferred flavor. The rootstock onto which the scion is grafted is selected for reasons such as its vigorous growth and resistance/tolerance to soilborne diseases and pathogens as well as its ability to withstand soil extremes [1]. The technique of grafting vegetables originated from Japan and Korea in the late 1920s. The first record of an interspecific graft for increased yield and pest and disease control was reported in Japan between

**Keywords:** grafting, root-knot nematode, tomato, management, rootstock

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

**Management in Tomato Genotypes**

**Management in Tomato Genotypes**

Seloame Tatu Nyaku and Naalamle Amissah

Seloame Tatu Nyaku and Naalamle Amissah

Additional information is available at the end of the chapter

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.82774

**Abstract**

**1. Introduction**

#### **Chapter 1 Provisional chapter**

#### **Grafting: An Effective Strategy for Nematode Management in Tomato Genotypes Grafting: An Effective Strategy for Nematode Management in Tomato Genotypes**

DOI: 10.5772/intechopen.82774

Seloame Tatu Nyaku and Naalamle Amissah Seloame Tatu Nyaku and Naalamle Amissah

Additional information is available at the end of the chapter Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.82774

#### **Abstract**

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.

**Keywords:** grafting, root-knot nematode, tomato, management, rootstock

#### **1. Introduction**

Grafting is the deliberate joining together of a scion and rootstock, taken from different but compatible plants, which are taxonomically close, to produce a composite plant. The scion, which forms the top portion, is selected for its desirable attributes, such as better yields, bigger fruit sizes, or preferred flavor. The rootstock onto which the scion is grafted is selected for reasons such as its vigorous growth and resistance/tolerance to soilborne diseases and pathogens as well as its ability to withstand soil extremes [1]. The technique of grafting vegetables originated from Japan and Korea in the late 1920s. The first record of an interspecific graft for increased yield and pest and disease control was reported in Japan between

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

watermelons [*Citrullus lanatus* (Thunb.) Matsum and Nakai] as scion and squash (*Cucurbita moschata* Duch.) The watermelon grafting technique was then widely introduced to farmers in Japan and Korea between the 1920s and 1930s; later, the technique was extended to grafting of other vegetable crops *Cucumis sativus* L. [2] and *Solanum melongena* L. in the 1950s [2] and then to *Lycopersicon esculentum* Mill [1].

to nematodes, flooding, salinity, extreme temperatures, and increased yield production. Tomato and eggplants are the most grafted plants in the Solanaceous family, although crops

Grafting: An Effective Strategy for Nematode Management in Tomato Genotypes

http://dx.doi.org/10.5772/intechopen.82774

5

The most common rootstocks used for commercial tomato grafting are hybrids (F1) or interspecific hybrids, which have been specifically bred for resistance against pathogens and other diseases such as nematodes, *Verticillium* wilt, and *Fusarium* wilt. Hybrids are produced by crossing selected tomato varieties with other wild *Solanum* species with the genetic ability to

In Europe, tomato hybrids are used as rootstocks compared to other *Solanum* spp., because of their high level of genetic improvements [17]. There are other plants that share the same family with tomato (*Solanum torvum, S. aethiopicum*, and *S. macrocarpon*); these can serve as rootstocks for their tolerance to waterlogged and drought conditions, *Fusarium* wilt, and root knot nematode infestation [13]. Most eggplant lines utilized will graft successfully with tomato lines. Rootstocks selected should be resistant to bacterial wilt (caused by, for example, *Ralstonia solanacearum*) and other soilborne diseases. The Asian Vegetable Research and Development Centre (AVRDC) recommends eggplant accessions EG195 and EG203, which are resistant to flooding, bacterial wilt, root-knot nematode (*Meloidogyne incognita*), tomato *Fusarium* wilt (caused by *Fusarium oxysporum* f.sp. *lycopersici*), and southern blight (caused by *Sclerotium rolfsii*) [13]. Grafting of a tomato variety "Pectomec" onto *S. aethiopicum* and *S. macrocarpon* in the University of Ghana Farm, Legon provided resistance to *Fusarium* wilt caused by *Fusarium oxysporum*; however, nongrafted tomato plants had a disease intensity of 46% (**Table 1**) and were highly diseased [19] (**Figure 1**). Grafting success of the tomato variety "Pectomec" onto *S. aethiopicum*, *S. lycopersicon "*Mongal F1," and *S. macrocarpon* was poor with

An ideal rootstock for tomato grafting should not only be resistant to pathogens, but also have high compatibility with the scion of tomato, with the ability to express a high level of vigorousness and resistance to pest and diseases. Rootstocks with very high levels of vigorousness compared to the scion may result in the tomato grafts being more vegetative with less fruit yield and quality [20]. Rootstocks selected should be resistant to bacterial wilt and other soilborne diseases. The tomato line (Hawaii 7996) has a high level of resistance to bacterial

In developing countries, the use of tomato hybrids as rootstocks is limited because of the costs of imported hybrid seeds. Therefore, the use of eggplants as rootstocks is the most common

NRP = Number of recording plants; NDRP = Number of diseased recorded plants; DI = Disease intensity (%); P/SA = Pectomech grafted onto *Solanum aethiopicum*; P/SM = Pectomech grafted *Solanum macrocarpon.* Agyeman [19].

of the cucurbitaceous family (melon) are also utilized [17].

offer resistance to specific diseases and pathogen infection [18].

the rootstock *S. lycopersicon "*Mongal F1" [19] (**Table 2**).

wilt and *Fusarium* wilt and is a recommended variety by AVRDC [13].

**Treatment NRP NDRP DI (%)** Control 24 11 46 P/SM 24 0 0 P/SA 24 0 0

**Table 1.** *Fusarium* wilt disease intensity of grafted and nongrafted tomato plants onto solanum rootstocks.

Vegetable grafting is implored to impart resistance to soilborne pathogens, for example, nematodes [1, 3] and increase yields [3] and tolerance to abiotic stress conditions [4–8].

Tolerance to soilborne diseases is one of the main reasons why vegetable grafting is practiced. Rootstocks are selected based on their tolerance to common vegetable production diseases caused by *Verticillium*, *Phytophthora*, *Fusarium*, and nematodes [3, 9–11].

Vegetable grafting has been shown to increase fruit yields of vegetables such as tomato and eggplants and enhances nutrient uptake together with improved water use efficiency [3, 12]. An improved water use efficiency and nutrient uptake enables grafted plants to withstand short dry spells and also increase photosynthetic activity. Eggplant rootstocks have the ability to withstand flooding conditions for several days [13].
