Exploring the influence of various TY resistance marker combinations and resistance mechanisms on TYLCV accumulation in tomato plants
Creators: name: Hsieh, CH
name: Eybishitz A, Yen J
Publisher: name: World Vegetable Center
Year: 2024
Subjects: subject: tomato
subject: TOMATO YELLOW LEAF CURL VIRUS
subject: LEAF CURLS
subject: RESISTANT VARIETIES
subject: Tomato
subject: Tomato Yellow Leaf Curl Virus (TYLCV)
subject: Begomovirus
subject: Geminiviridae family
subject: Monopartite ssDNA
subject: Bipartite ssDNA
subject: Yield loss
subject: Genetic recombination
subject: Virus mutation
subject: Bemisia tabaci (whitefly)
subject: Disease symptoms
subject: Leaf curling
subject: Yellow mosaic
subject: Stunted growth
subject: Resistant genes
subject: Gene pyramiding
subject: Ty resistance genes (Ty1, Ty2, Ty3, Ty4, Ty5, Ty6)
subject: Allelic genes (Ty1/3)
subject: TYLCTHV strain
subject: Breeding for resistance
subject: Virus accumulation

description: Tomato is the second most important vegetable in the world, but it faces numerous diseases (Prabhandakavi et al., 2019). One of disease is Tomato yellow leaf curl virus (TYLCV), belonging to the genus Begomovirus in the family Geminiviridae and can be classified based on its genomic structure into two types: the virus has a single circular single-stranded DNA (ssDNA) molecule is monopartite and two separate circular ssDNA is bipartite. (Zhe et al., 2021) TYLCV causes up to 100% yield loss in tomatoes (Kaushal et al., 2020), and have various strains with high mutation and high genetic recombination, allowing it to spread and adapt to many area. TYLCV is transmitted by silverleaf (Bemisia tabaci), which has a broad host range, but only tomatoes exhibit symptoms of the disease (Zhe et al., 2021). Symptoms of TYLCV include cup-sharped curling of the upper leaves, interveinal yellowing, stunted growth, and a drastic reduction in fruit yield. Early in the disease, the upper leaves exhibit yellow mosaic, followed by curling of the young upper leaves. In severe cases, the upper leaves become completely yellow, curl, and deform, young leaf size is reduced, and the plant stunted growth with shortened internodes. (Lin et al., 2017; H. C. Prasanna et al., 2015; Gill et al., 2018). Physical or chemical biological control methods have shown limited effectiveness against TYLCV. Many studies indicate that the most effective control strategy is breeding tomatoes with resistant genes and gene pyramided can be used to enhance resistance against TYLCV (Prabhandakavi et al., 2019; Prasanna et al., 2015). Currently identified resistance genes include Ty1, Ty2, Ty3, Ty4, Ty5, and Ty6. Ty1 and Ty3 are allelic, denoted as Ty1/3, and are the most commonly used genes in tomato breeding due to their resistance to various strains (Zhe et al, 2021). Ty2 has been found to be overcome by TYLCTHV (Tsai et al., 2013). The gene Ty5 is recessive and provides good resistance to TYLCV, but its effectiveness is lower against some bipartite begomoviruses. Reference indicates that Ty6 of has high resistance to both TYLCTHV and ToCTWV (Gill et al., 2018). This research purpose is exploring influence of various Ty gene pyramided on TYLCV symptoms and virus accumulation, and we focus on the strain TYLCTHV.