Screening of Tomato Lines for Late Blight Resistance 

Xingyue Gong, MHS seminar
Under the direction of Dr. Dilip Panthee
Monday, March 23, 2020, at 9:00 am
Join Zoom Meeting: https://ncsu.zoom.us/j/244590315
Meeting ID: 244 590 0315

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Abstract

Late blight caused by the oomycete Phytophthora infestans (Mont.) de Bary is the serious disease of tomato in North Carolina (NC). Identification and utilization of genetic resources resistant to P. infestans in tomato is the most important way to develop late bight resistant tomato cultivars. Tomato lines were evaluated for late blight resistance under field condition at Mountain Research Station, Waynesville, NC where natural inoculum pressure of late blight was extremely high during the summer. Data were collected on late blight resistance and other horticultural and physiological traits. Data analysis revealed that the late blight score was significantly correlated with plant vigor, height, node number, and growth type. The 16 traits were reduced to three major components by principal component analysis, which accounted for 71.3% of the phenotypic variation. Additionally, the tomato germplasm of 179 lines was classified into six clusters at the genetic distance of 2.3 by the average linkage of the hierarchical clustering method. Our late blight trial had 7.2% of lines with no LB disease, 8.5% were highly resistant with up to 20% blighted leaf area, 11.3% were resistant with around 40% blighted leaf area, 26.7% were moderately resistant with around 60% blighted leaf area, 22.9% were susceptible with around 80% blighted leaf area and 23.4% were highly susceptible with infected leaves on the whole plant. Based on the average LB score, we found that 13385-GR2-005_F5, 13385-GR1-013_F5, NC 10331_F4_205-2, 13385- GR2-015_F5_W and 13385-GR3-019_F5_W were the top 5 tomato late blight resistant lines. These lines may be useful for further tomato breeding program.