**Author details**

sequencing analysis showed two genes, which were identical to each other (Mi-1.1 and Mi-1.2), which also confers resistance to three species of root-knot nematodes namely *M. arenaria, M.* 

Several DNA markers have been developed for the detection of the Mi gene in plants using polymerase chain reaction (PCR) amplifications. Devran et al. [50] screened for the Mi gene using gene specific primers C1/2 (5′-cagtgaagtggaagtgatga-3′) and C2S4 (5′-ctaagaggaatctcatcacagg-3′) for screening F2 tomato plants for the root-knot nematode resistance gene. A 1.6 kb amplification product was amplified in these containing the Mi-1.2 gene in the 3′ region; how-

Similarly, in another study, the Mi-1.2 gene was introgressed into *S. melongena* to confer resistance to *M. javanica* and aphids. The study revealed that the transgenic eggplant was able to confer resistance to *M. javanica* but not aphids [51]. In confirming the presence of the Mi-1.2 gene in the transgenic eggplant, a reverse-transcription polymerase chain reaction assay with the Mi specific primers C2D1 (5′-ctagaa agtctgtttgtgtctaacaaagg-3′) and C2S4 (5′-ctaagaggaatctcatcacagg-3′) amplified a single PCR band of 915 bp, which was present but absent in

A study in Morocco by Mehrach et al*.* [52] to detect the Mi-1.2 gene in 14 begomovirus-resistant breeding lines with known resistance was also undertaken using a two-step PCR approach. The primer pairs PM3Fb/PM3Rb and REX primers used in a multiplex PCR amplified a band of 720 bp for both susceptible and resistant varieties; however, the resistant varieties (Motelle and Better Boy) showed an additional band of 500 bp, indicating the presence of the Mi gene

In distinguishing between heterozygous and homozygous plant cultivars with the Mi-1.2 gene, the primer pairs of PMiF3/PMiR3 amplified a single unique band of 350 bp for the susceptible cultivars (Moneymaker and Daniella). However, 550 and 350 bp fragments for both the homozygous and heterozygous plant resistant cultivars "Motelle" and "Better Boy"

Farmers are the ultimate beneficiaries of grafted plants; therefore, healthy grafted seedlings production is important at affordable prices. The high costs involved in the grafting process are due to high labor requirements, grafting input costs, and seeds of rootstock. These associated costs therefore limit the usage of grafted plants by growers or farmers. Grafting costs can be reduced through training of selected farmers from farmer groups, who will in turn train other farmers (trainer of trainers). Information related to this technology can be passed on to farmers and other interested stakeholders through extension programs, for example, workshops, fairs, field days, and on-farm trials. There is also the need for undertaking extensive disease diagnosis in specific areas and feedback given to farmers. Tomato rootstock breeding efforts can lead to production of rootstocks to specific environments, pests and diseases, and

ever, it was found to be absent in the susceptible F2 plants.

*javanica,* and *M. incognita.*

12 Recent Advances in Tomato Breeding and Production

the nontransgenic *S. melongena.*

were amplified, respectively.

in those cultivars.

**9. Conclusions**

other abiotic stresses.

Seloame Tatu Nyaku1,2\* and Naalamle Amissah1,2

\*Address all correspondence to: seloame.nyaku@gmail.com

1 Department of Crop Science, College of Basic and Applied Sciences, University of Ghana, Legon, Ghana

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