Performance of Tomato Lines and Hybrids Combining Resistance to Septoria Leaf Spot and Late Blight and Tolerance to Early Blight

Transcription

1 Performance of Tomato Lines and Hybrids Combining Resistance to Septoria Leaf Spot and Late Blight and Tolerance to Early Blight Martha A. Mutschler and Stella Zitter Dept. of Plant Breeding Tom Zitter, Dept. of Plant Pathology Cornell University, Ithaca NY 26th TDW Ithaca, NY - Oct 12, 2011 Kelly Ivors, Dept/ of Plant Pathology NSCU, Mills River, NC

2 Defoliating Diseases of Tomato in Temperate Climates Late blight (Phytophthora infestans) LB Early blight (Alternaria tomatophila) EB Septoria Leaf spot (Septoria lycopersici) SLS All cause severe defoliation & loss of yield and quality Which disease predominates is a factor of weather conditions, other horticultural factors Must control SLS as well as EB and LB to protect yield & fruit quality, and reduce reliance on fungicides Recovered SLS resistance from old breeding populations from V. Poysa (work in early1990s)

3 Impacts of SLS Resistance Resistant Supersonic: Susceptible 0.6 mm lesion length 2.1 mm lesion length 0.3 pycnidia/lesion 1.6 pycnidiospores/lesion 14 pycnidia/lesion 70 pycnidiospores/lesion

4 LB/EB/SLS Tomato Lines SLS resistance of line was combined with LB resistance (Ph2 + Ph3) and EB tolerance of NC33EB-1 17 F4 lines created with all 3 disease control traits Some LB/EB/SLS lines crossed with NC33EB-1 creating hybrids homozygous for LB resistance and EB tolerance genes, and heterozygous for SLS resistance These lines and hybrids used in 2010 & 2011 trials What is impact of combined resistance on disease expression? Are any horticultural issues associated with SLS resistance (linkage drag)?

5 SLS Response in Homozygous SLS-R Tomato Lines (Ho) vs. the Heterozygous SLS-R Hybrids (He): 2010 Entry AUDPC a,b length Lesion (mm) b No. of pycnidia per lesion b,c NC33EB-1 (Su) a 1.40 a 7.78 a SLS F4 sel x NC33EB-1 (He) b 0.70 b 3.63 b SLS F4 sel (Ho) b 0.67 b 2.24 c NC33EB-1 (Su) a 1.40 a 7.78 a SLS F4 sel x NC33EB-1 (He) b 0.72 b 2.81 b SLS F4 sel (Ho) b 0.63 c 1.90 c NC33EB-1 (Su) a 1.40 a 7.78 a SLS F4 sel x NC33EB-1 (He) b 0.72 b 3.50 b SLS F4 sel (Ho) b 0.67 c 2.27 c a Area Under Disease Progress Curve. Disease ratings were taking using Horsfall-Barratt scale and then converted to % using Elanco formula prior to the analysis. b Levels not connected by same letter are significantly different at 0.05 level by Tukey-Kramer HSD. c values are the avg of 15 lesions selected at random per leaf.

6 Disease Progress Curve on Tomatoes With and Without SLS-R: 2010 Inoculated Trial, Ithaca % Defoliation Mt. Merit (SLS-S) xNC33EB1 (SLS-S) xNC33EB1 (He SLS-R) (Ho SLS-R) Days after inoculation

7 SLS AUDPC on Tomatoes With and Without SLS-R: 2010 Inoculated Trial, Ithaca Cumulative AUDPC Mt Merit (SLS-S) a xNC33EB-1 (SLS-S) a x NC33EB-1 (He SLS-R) b (Ho SLS-R) b Days after inoculation

8 Fruit Size of LB/EB/SLS Resistant Lines and Parental Controls, 2010 Ithaca, NY Entry Mean fruit weight (g) a Entry (continued) Mean fruit weight (g) a a defgh ab efgh abc cdefg NC33EB abcd efgh abcde fgh abcdef gh abcdef gh bcdefg i cdefg , SLS 54.1 i cdefgh a Levels not connected by same letter are significantly different at 0.05 level by Tukey-Kramer HSD

9 Fruit Size of LB/EB/SLS Resistant FM Hybrids and Parental Controls, 2010 Ithaca, NY a Levels not connected by same letter are significantly different at 0.05 level by Tukey-Kramer HSD

10 Fruit Size of LB/EB and LB/EB/SLS Resistant Hybrids and Controls, 2010 Fletcher NC Entry SLS CU x NC33EB-1 SLS CU x NC33EB-1 SLS CU x NC33EB-1 Total Weight Tons/A Marketable weight tons/a CULL weight tons/a 61.5 ab 42.4 ab 19.1 b 71.5 a 44.1 a 27.3 a 61.4 ab 46.0 a 15.4 bcd CU X NC33EB bc 33.2 b 17.7 bc CU X NC33EB bc 36.7 ab 14.3 bcd CU X NC33EB c 39.3 ab 9.1 d CU x NC33EB c 33.5 b 12.2 bcd Mt Fresh 48.8 c 39.6 ab 9.3 d Mt Fresh 49.9 c 38.7 ab 11.2 cd a Levels not connected by same letter are significantly different at 0.05 level by Tukey-Kramer HSD

11 2011 Trial of Hybrids Under Organic Production 2011 trial on the Freeville organic farm in coop. with Dr. M. Mazourek and Mike Glos, Trial intended to evaluate hybrids for plant and fruit performance under organic production conditions. During July this plot suffered natural infection by Septoria leaf spot and Early blight. The first symptoms were in lower leaves of several plants scattered in the plot, with rapid spread throughout the plot and up the trellised plants during August. Natural infection provided an excellent demonstration of the impact of disease control.

12 Fruit Size of LB/EB and LB/EB/SLS Resistant Hybrids and Controls, 2011 Freeville, NY Levels not connected by same letter are significantly different at 0.05 level by Tukey-Kramer HSD Major source of unmarketable fruit in all entries was blossom end rot. In coop. with Dr. M. Mazourek and Mike Glos

13 Fruit Analysis: 2011 Freeville Organic Trial Early Blight tolerance associated with smaller fruit, so compare fruit size and yield of LB/EB/SLS hybrids with LB/EB hybrids with same male parents. Fruit weights of LB/EB/SLS hybrids no smaller than that of LB/EB hybrids. Yield of LB/EB/SLS hybrids no smaller than that of LB/EB hybrids. LB/EB/SLS hybrids tend to have less BER, higher % marketable fruit. Fruit weights of the LB/EB (166 to 179g) and LB/EB/SLS hybrids (150 to 186g) are moderate, ranging between that of Legend (146g) to less than that of Mt Fresh (254 g).

14 Percentages of EB and SLS Lesions: 2011 Freeville Organic Trial No signs of late blight observed in any entry in this trial.

15 Naturally Occurring Diseases in 2011 Organic Trial The weather conditions from mid July forward were more favorable to Septoria leaf spot than to early blight spread. 80 to 95% of the identifiable lesions from analysis of leaf samples from all entries were caused by Septoria leaf spot Only 0.0 to 4.8% of identifiable lesions were caused by early blight. No late blight observed until after experiment completed.

16 SLS Disease Progress Curve of Hybrids With/ Without SLS Resistance: Natural Infection Mt. Fresh Plus (Full S) x (SLS-S) x (SLS-S) x (SLS-S) x (He SLS-R) x (He SLS-R) x (He SLS-R) x (He SLS-R) % Defoliation /2 8/8 8/17 8/23 8/29 9/06 Evaluation dates

17 Rain and Temperature data Freeville, NY Rain (mm) Temperature (C 0 ) July August September 0.0

18 AUDPC of SLS on Tomato Hybrids With/Without SLS Resistance Under Natural Infection Cumulative AUDPC FINAL AUDPC Mt. Fresh Plus (Full S) a x (SLS-S) ab x (SLS-S) b x (SLS-S) b x (He SLS-R) c x (He SLS-R) c x (He SLS-R) c x (He SLS-R) c 0.0 8/2 8/8 8/17 8/23 8/29 9/06 Evaluation dates

19 Heavy Defoliation of SLS Susceptible Control Mount Fresh Plus and LB/EB Hybrids Susceptible for SLS Fully Susceptible Control, Mountain Fresh As of Aug 24th: Susceptible control nearly fully defoliated Two SLS susceptible Hybrids that are LB resistant/eb tolerant LB/EB hybrids only slightly less disease, high level of defoliation

20 Reduced Defoliation of LB/EB Hybrids Also Resistant for SLS Fully Susceptible Control, Mountain Fresh As of Aug 24th: Susceptible control nearly fully defoliated Two SLS resistant hybrids that are also LB resistant/eb tolerant SLS/LB/EB hybrids much less disease, low level of defoliation

21 Summary For SLS/LB/EB Lines and Hybrids SLS resistance decreases production of pycnidia/pycnidiospores, decreases rate of disease spread/defoliation Extremely heavy inoculation can cause extreme lesion numbers, defoliate SLS resistant plants (2010, and prior years) Disease progress is strongly reduced in the Ho SLS resistant line (2010) and in the He SLS resistant hybrid (2010, 2011) compared to susceptible controls SLS resistance in He SLS plants, was equal to that of the Ho SLS plants in the field (2010) After disease is advanced in susceptible plants, disease accelerates in neighboring He SLS plants, possibly due to heavy inoculum load from susceptible plants Fruit size and yields of the SLS/LB/EB lines and hybrids does not indicated linkage drag issues with SLS resistance gene (2010, 2011)

22 Summary: Continuing Work Completing the analysis of 2011 results from multiple regional trials Planning 2012 test of SLS disease progress in plots with only SLS heterozygous and homozygous resistant entries, vs. plots including susceptible plants Can SLS gene be mapped using data from mapping population being genotyped through SOLCAP project Create and test SLS marker. Select and release best LB/EB/SLS lines for breeding, creation of LB/EB/SLS hybrids.

23 Septoria Leaf Spot Contributors Martha A. Mutschler Lab DNA work: Darlene DeJong Res. Support. Thomas Zitter Lab Stephen Southwick, Richard Gaisser Germplasm Contribution: Dr. Vaino Poysa A special thank you for : Brian Leckie for help with computer programs Marshall Hayes for help with Access program Kent Loeffler, for photography This work supported in part with funds from NE Regional IPM grant, gifts from the Vegetable Breeding Institute, Hatch funds.