Incidence, Distribution and Characteristics of Major Tomato Leaf ...

Incidence, distribution and characteristics of major tomato leaf curl and mosaic virus diseases
-------------------------------------ATCGGTGTCCCTCAA----AGCT 19
CTATGGCAATCGGTGTATCGGTGTCTTACTTATACCTGGACACCTAATGGCTATTTG-GT 78
AATTTCATAAATGTTCATTGCAATTCAAAATTCAAAATTCAAAAATCAAATCATTAAAGC 138
GGGCATCCGTATAATATTACCGGATGGCCGCGCCTTTTCCTTTTATGTGGTCCCCACGAG 198
GGTTACACAGACGTCACTGTCAACCAATCAAATTGCATCCTCAAACGTTAGATAAGTGTG 258
CATTTGTCTTTATATACTT----------------------------------------- 277
Figure 3.14: Partial DNA sequence of TYLCV-UG (RL5 DNA), 277 bp of the intergenic region (IR)
amplified using specific primers PTYIRv21 and PTYIRc715, after primer and overap segments are worked
on.
3.3.2.1.3 Host Range of Tomato Yellow Leaf Curl Viruses
ToLCV-UG was subsequently detected in Euphorbia heterophylla, Physalis floridana
and Desmodium spp. (Table 3.13a). At least six weed species associated with the tomato
agro-ecosystem were confirmed to be infected by TYLCV-UG, that is, Desmodium spp.,
Commelina benghalensis, Conyza floribunda, Crassocephalum spp., Euphorbia
heterophylla and Ageratum conyzoides, as shown in Table 3.13b. Healthy samples of
these plants tested negative.
Table 3.13: Samples of alternative hosts that tested positive to (a) ToLCV-UG; and (b)
TYLCV-UG (strain of TYLCV-Is, TYLCV-IR and TYLCV-SR)
(a) ToLCV-UG
Sample Code/ Alternative Host Test result (DNA hybridisation)
Collection Date
ToLCV-UG
IG14/24.03.98 Euphorbia heterophylla +++¹
IG17/24.03.98 Physalis floridana +++
MBl/28.04.98 Desmodium spp. +
IG1 positive Lycopersicon esculentum +++
HTS negative weed sample -²
¹Positive to test virus; ² negative to test virus
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