Appraisal of Artificial Screening Techniques of Tomato to Accurately Reflect Field Performance of the Late Blight Resistance

Abstract

Late blight (LB) caused by the oomycete Phytophthora infestans continues to thwart global tomato production, while only few resistant cultivars have been introduced locally. In order to gain from the released tomato germplasm with LB resistance, we compared the 5-year field performance of LB resistance in several tomato cultigens, with the results of controlled conditions testing (i.e., detached leaflet/leaf, whole plant). In case of these artificial screening techniques, the effects of plant age and inoculum concentration were additionally considered. In the field trials, LA 1033, L 3707, L 3708 displayed the highest LB resistance, and could be used for cultivar development under Polish conditions. Of the three methods using controlled conditions, the detached leaf and the whole plant tests had the highest correlation with thefield experiments. The plant age effect on LB resistance in tomato reported here, irrespective of the cultigen tested or inoculum concentration used, makes it important to standardize the test parameters when screening for resistance. Our results help show why other reports disagree on LB resistance in tomato.

Assessment of Tomato Advanced Lines to Resistance of Late Blight

“…Result showed that the 11, 17, 19, 24 and 29 genotypes were categorized as highly resistant (PDI 0.01 -10), resistant (PDI 10.01 -25), moderately resistant (PDI 25.01 -40), susceptible (PDI 40.01 -60) and highly susceptible (PDI > 60.01), respectively (Table 1). These results were in agreement with the findings of Gopal and Singh (2003), Govers (2005), Irzhansky and Cohen (2006), Nowicki et al, (2012), Nowicki et al, (2013), Forbes et al, (2014) and Nowakowska et al, (2014).…”

Virulence and aggressiveness of Phytophthora infestans isolates collected in Poland from potato and tomato plants identified no strong specificity

“…However, substantial infection of Ph-3 carrying hosts in detached leaflets may reflect a higher sensitivity of leaflets of this genotype than the whole seedlings. Resistance expression of this genotype is age sensitive as discussed by Nowakowska et al (2014). In the present study, virulence frequencies were higher among virulent T isolates than P isolates for tomato differentials that include Ph-2, namely West Virginia'63 (Ph-2), West Virginia 700 (Ph-1, Ph-2), Ottawa 30 (Ph-1, Ph-2), and BALU-30 (Ph-1, Ph-2, and fruit resistance).…”

Comparative transcriptome analysis between resistant and susceptible tomato allows the identification of lncRNA16397 conferring resistance to Phytophthora infestans by co‐expressing glutaredoxin

“…The wild tomato Solanum pimpinellifolium is one of the closest relatives to cultivated tomato, and its trait of disease resistance has been introduced into cultivated tomato (Darwin et al, 2003;Tomato Genome Consortium, 2012;Strickler et al, 2015). Among all S. pimpinellifolium accessions, one line (L3708) has been identified to be highly resistant to a wide range of P. infestans isolates (Chunwongse et al, 1998;Nowakowska et al, 2014;Zhang et al, 2014a). Another cultivated tomato, S. lycopersicum Zaofen No.2, is a susceptible accession to a variety of pathogens including P. infestans (Wang et al, 2006(Wang et al, , 2015aGao et al, 2011;Guo et al, 2013;.…”