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

Early BlightMartha A. Mutschler and Stella Zitter

Dept. of Plant BreedingTom Zitter, Dept. of Plant Pathology

Cornell University, Ithaca NY

Kelly Ivors, Dept/ of Plant Pathology

NSCU, Mills River, NC

26th TDW Ithaca, NY - Oct 12, 2011

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)

Impacts of SLS Resistance

Supersonic: Susceptible

2.1 mm lesion length

071733-1 Resistant

0.6 mm lesion length

0.3 pycnidia/lesion1.6 pycnidiospores/lesion

14 pycnidia/lesion 70 pycnidiospores/lesion

LB/EB/SLS Tomato Lines

SLS resistance of line 071733-1 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)?

SLS Response in Homozygous SLS-R Tomato Lines (Ho) vs. the Heterozygous SLS-R Hybrids (He): 2010

Entry AUDPCa,bLesion length (mm)b

No. of pycnidia per

lesionb,c

NC33EB-1 (Su) 738.3 a 1.40 a 7.78 aSLS F4 sel 097225-2 x NC33EB-1 (He) 337.5 b 0.70 b 3.63 b

SLS F4 sel 097225-2 (Ho) 332.2 b 0.67 b 2.24 cNC33EB-1 (Su) 738.3 a 1.40 a 7.78 a

SLS F4 sel 097234-3 x NC33EB-1 (He) 386.7 b 0.72 b 2.81 bSLS F4 sel 097234-3 (Ho) 284.7 b 0.63 c 1.90 c

NC33EB-1 (Su) 738.3 a 1.40 a 7.78 aSLS F4 sel 097236-5 x NC33EB-1 (He) 372.7 b 0.72 b 3.50 b

SLS F4 sel 097236-5 (Ho) 379.7 b 0.67 c 2.27 caArea Under Disease Progress Curve. Disease ratings were taking using Horsfall-Barratt scale and then converted to % using Elanco formula prior to the analysis.bLevels not connected by same letter are significantly different at 0.05 level by Tukey-Kramer HSD.cvalues are the avg of 15 lesions selected at random per leaf.

Disease Progress Curve on Tomatoes With and Without SLS-R: 2010 Inoculated Trial, Ithaca

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Mt. Merit (SLS-S) 071009xNC33EB1 (SLS-S) 097225-2xNC33EB1 (He SLS-R) 097225-2 (Ho SLS-R)

SLS AUDPC on Tomatoes With and Without SLS-R: 2010 Inoculated Trial, Ithaca

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Mt Merit (SLS-S) 1402.4 a071009xNC33EB-1 (SLS-S) 1275.4 a097225-2 x NC33EB-1 (He SLS-R) 681.0 b097225-2 (Ho SLS-R) 561.9 b

Fruit Size of LB/EB/SLS Resistant Lines and Parental Controls, 2010 Ithaca, NY

aLevels not connected by same letter are significantly different at 0.05 level by Tukey-Kramer HSD

Entry Mean fruit weight (g)a Entry (continued) Mean fruit weight

(g)a

097236-5 255.5 a 097243-2 166.3 defgh

097181-4 245.3 ab 097234-4 159.1 efgh

097234-3 231.4 abc 097245-3 148.8 cdefg

NC33EB-1 228.3 abcd 097105-4 148.3 efgh

097212-2 206.1 abcde 097252-3 137.4 fgh

097223-1 198.5 abcdef 097021-4 132.1 gh

097225-2 198.4 abcdef 097245-5 124.3 gh

097067-5 185.4 bcdefg 097258-5 118.9 i

097154-5 182.0 cdefg 071733-1, SLS 54.1 i

097272-1 178.8 cdefgh

aLevels not connected by same letter are significantly different at 0.05 level by Tukey-Kramer HSD

Fruit Size of LB/EB/SLS Resistant FM Hybrids and Parental Controls, 2010 Ithaca, NY

Fruit Size of LB/EB and LB/EB/SLS Resistant Hybrids and Controls, 2010 Fletcher NC

Entry Total Weight Tons/A

Marketable weight tons/A

CULL weight tons/A

SLS CU097225-2 x NC33EB-1 61.5 ab 42.4 ab 19.1 b

SLS CU097234-3 x NC33EB-1 71.5 a 44.1 a 27.3 a

SLS CU097236-5 x NC33EB-1 61.4 ab 46.0 a 15.4 bcd

CU071002 X NC33EB-1 50.9 bc 33.2 b 17.7 bc

CU071008 X NC33EB-1 51.0 bc 36.7 ab 14.3 bcd

CU071009 X NC33EB-1 48.4 c 39.3 ab 9.1 d

CU048143-7x NC33EB-1 45.6 c 33.5 b 12.2 bcd

Mt Fresh 48.8 c 39.6 ab 9.3 dMt Fresh 49.9 c 38.7 ab 11.2 cd

aLevels not connected by same letter are significantly different at 0.05 level by Tukey-Kramer HSD

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 .

2011 Trial of Hybrids Under Organic Production

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

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).

Percentages of EB and SLS Lesions: 2011 Freeville Organic Trial

No signs of late blight observed in any entry in this 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.

Naturally Occurring Diseases in 2011 Organic Trial

SLS Disease Progress Curve of Hybrids With/ Without SLS Resistance: Natural Infection - 2011

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Mt. Fresh Plus (Full S) 101259 x 101251 (SLS-S) 101258 x 101251 (SLS-S) 101260 x 101251 (SLS-S) 101256 x 101251 (He SLS-R) 101253 x 101251 (He SLS-R) 101252 x 101251 (He SLS-R) 101254 x 101251 (He SLS-R)

Rain and Temperature data – Freeville, NY

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AUDPC of SLS on Tomato Hybrids With/Without SLS Resistance Under Natural Infection - 2011

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Mt. Fresh Plus (Full S) 2473.4 a101258 x 101251 (SLS-S) 2050.8 ab101259 x 101251 (SLS-S) 1979.3 b101260 x 101251 (SLS-S) 1833.5 b101254 x 101251 (He SLS-R) 870.5 c101252 x 101251 (He SLS-R) 866.1 c 101256 x 101251 (He SLS-R) 864.5 c101253 x 101251 (He SLS-R) 842.4 c

FINAL AUDPC

Heavy Defoliation of SLS Susceptible Control Mount Fresh Plus and LB/EB Hybrids Susceptible for SLS

Fully Susceptible Control, Mountain Fresh

Two SLS susceptible Hybrids that are LB resistant/EB tolerant

As of Aug 24th:

Susceptible control nearly fully defoliated

LB/EB hybrids only slightly less disease, high level of defoliation

Reduced Defoliation of LB/EB Hybrids Also Resistant for SLS

Fully Susceptible Control, Mountain Fresh

Two SLS resistant hybrids that are also LB resistant/EB tolerant

As of Aug 24th:

Susceptible control nearly fully defoliated

SLS/LB/EB hybrids much less disease, low level of defoliation

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)

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.

Septoria Leaf Spot ContributorsMartha A. Mutschler Lab

DNA work: Darlene DeJong

Res. Support. Stephen Southwick, Richard Gaisser

Thomas Zitter Lab

Germplasm Contribution: Dr. Vaino PoysaA 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.