Ongoing Field Evaluations of Tomato Yellow Leaf Curl Virus Resistant Varieties for Screenhouse Consideration Sugano, J., G. Spinelli, L. Okumura, J. Silva, J. Uyeda, T. Radovich, R. Corrales and K.H Wang University of Hawaii at Manoa, College of Tropical Agriculture and Human Resources SUMMARY A field trial in May 2018 showed that weekly applications of organic crop protection chemicals in combination with screenhouse systems did not suffice in minimizing plant viruses from affecting tomatoes. The highpoint of screenhouse systems is its ability to physically keep out larger pests such as fruit flies, Chinese rose beetles, birds, and Lepidoptera pests. The limitation is the management of small insect pests as they can move in and out of the screen units as they have the ability to vector plant viruses. Chemical spray applications are not an effective way to manage plant vectors and viruses. Adoption of a virus resistant varieties helps to heighten the efficacy of pest and disease management within screen systems. Tomatoes (Solanum lycopersicum) are an important economical crop for many small and large-scale producers in Hawaii. Tomato Yellow Leaf Curl Virus (TYLCV) is a devastating disease of tomato worldwide (Melzer, et al, 2009). Susceptible varieties become chlorotic with interveinal discoloring, stunted due to shortened internodes, leaflets curl or cup upwards at the leaf margins and suffer from reduced fruit set due to premature flower abortion. TYLCV is transmitted by sweet potato (Bemisia tabaci) and silverleaf (Bemisia argentifolii) whiteflies but is not transmitted by the greenhouse whitefly (Trialeurodes vaporariorum). TYLCV is not spread through mechanical means. VARIETIES SCREENED BY UH CTAHR FROM 2009-2018 WITH TYLCV RESISTANCE IN HAWAII Varieties with tolerance to TYLCV strains on Oahu based on tissue blot test: Beef Steak Type (12): Adonis, PIK Ripe 461, Mochomo (Roma), Pamela, Sacramento, VT-62940, VT- 62966, Tovi Star, Tovi Roca, VT-62966, Yaqui, Xaman (Roma) and Tygress. Specialty Type (5): Grape: 72618, Rona, Merlot (disc.) Cherry: Felicity, Hathor, Sarina ** In a previous screenhouse field trial (5/2018), Sacramento tested positive for tomato spotted wilt virus (TSWV), cucumber mosaic virus (CMV), and tobacco mosaic virus (TMV).
METHODOLOGY Since 2009, UH CTAHR has been screening new commercially available tomato varieties for putative resistance to the Tomato Yellow Leaf Curl Virus (TYLCV). We installed an observational field trial at the Waimanalo Research Station in July 2018 in an open field. All varieties received the same amount of fertilizer and irrigation. Weekly applications of sulfur were applied as a preventative fungicidal spray due to heavy rains and storms. Spinosad, Bacillus thuringiensis, and Azadirachtin insecticides were rotated and used for fruit fly and small insect control. exit was used as an adjuvant for spray applications. There were no marketable fruits due to excessive fruit fly and pinworm damage. Visual assessments of TYLCV symptoms were conducted on a monthly basis. Paramount Seed varieties took 4 months to bear flowers and fruits. Variety Seed Company Percent Affected by TYLCV Certified Organic Fruit Set Cardinal Beefsteak Paramount Seeds 0% No Moderate Cypress Seminis Seeds 0% No Heavy DRD 8537 Seminis Seeds 100% No Heavy Ekin Beefsteak Paramount Seeds 0% No Moderate Kewalo UH Seed Lab 100% No Poor Owl Beefsteak Paramount Seeds 0% No Moderate Skyway Johnny Seeds 90% YES Poor Southern Ripe Seminis Seeds 100% No Poor SV3543TE Seminis Seeds 0% No Heavy SVTD2310 Seminis Seeds 0% No Moderate SVTD3418 Seminis Seeds 100% No Low SVTE6653 Seminis Seeds 0% No Moderate SVTE8444 Seminis Seeds 0% No Moderate NOTE: Per our CTAHR virologist, Dr. Mike Melzer, 'Skyway' had PCR amplification consistent with infection by the TYLCV-IL strain. We will re-test Skyway in 2019. TYLCV-IL strain is the strain of the virus which we have found previously in Hawaii. 'DRD8537' also had a faint amplification, but it was larger than expected for either the -IL or -MLD strains of TYLCV. Dr. Melzer pointed out that the TYLCV resistance genes are more tolerant of infection, but they are not immune. Other plant stresses on the plant can cause the virus titre to increase and symptoms may appear. SEED COMPANY INFORMATION Cardinal Beefsteak: Cardinal Beefsteak tomato is an indeterminate variety with a vigorous plant and short internodes. Cardinal produces 4 to 5 large fruits per cluster. Fruits are high quality,
firm and have a long shelf life. Suitable for the greenhouse and open field. Highly resistant to: ToMV 1/ Vd/ Va. Intermediate resistance: Ma/ Mi/ Mj/ TYLCV/TSWV. Cypress: (formerly SV4483TD): SV4483TD is a fresh market determinate round tomato that has the potential to yield more than other varieties in the market. Excellent disease resistance package not currently available in competitor varieties [TYLCV; TSWV; F3]. Highly resistant to: TSWV/TYLCV/Aal/Fo//Sbl/Sl/Ss/Va/Vd. DRD 8537: Hybrid tomato growth rate determined from a strong plant with good leaf coverage. Its resistance to TYLCV provides adaptability to high pressure areas viral diseases in the early or late stages. This variety, with a comprehensive package of resistors, generates high yields of excellent quality fruit, firm and long shelf life. Highly resistant to: ToMV:0-2/Ff:A-E/Fol:0-2/Va:0/Vd. ; Intermediate resistance: TYLCV. Ekin: Ekin is a medium to large beefsteak tomato. Ekin has early maturity producing firm, round tomatoes with good color. For Open field production. Disease Resistance; Intermediate resistance: TYLCV/MA/ Mi/ Mj. HR: ToMV/ Fol/ Va/ Vd. Seed from this supplier is Thiram treated as standard. Kewalo: Kewalo is a determinate tomato plant with uniform ripening. Fruits approx. 6-8oz. Matures in 75-80 days. It is tolerant to bacterial wilt as well as tobacco mosaic virus. Resistant to the common root knot nematode, fusarium wilt, gray leaf spot and one strain of spotted wilt virus. Kewalo is highly susceptible to TYLCV. Owl Beefsteak: Owl Beefsteak tomato is an indeterminate variety with a vigorous plant and short internodes. Owl produces 4 to 5 large fruits per cluster. Fruits are high quality, firm and have a long shelf life. Owl is suitable for Spring season in the greenhouse and open field. Highly resistant to: ToMV/ Vd/ Va. Intermediate resistance: Ma/ Mi/ Mj/ TYLCV/TSWV. Skyway: Skyway is a large organic beefsteak-type with broad disease resistance for the South. Attractive, red, moderately ribbed, 8-12 oz. tomatoes. Skyway's multiple resistances keep the vigorous plants healthy. Very good flavor and fruit quality. High resistance to fusarium wilt (Fol) races 0-2, tomato apex necrotic virus, verticillium wilt; and intermediate resistance to nematodes, tomato spotted wilt virus (TSWV), and tomato yellow leaf curl virus (TYLCV). Determinate. Organically grown. Southern Ripe: Southern Ripe s (SV5685TD) diseases package makes this variety able to yield good quality fruit in spite of the disease pressure. Highly resistant to: TSWV/Aal/Fol/ For/Sbl/Sl/Ss/Va/Vd//Ma/Mi/Mj. Does not have TYLCV protection. SV3543TE (Roma): SV3543TE hybrid is an option for growers that is looking short cycles and earliness. Plant is not very compact like Pony (HM) variety, because SV3543TE presents medium vigor; but the great advantage is the yield and fruit size stand against pony. Also, it is a good alternative for the growers that present problems with F3 because this variety has resistance
for this disease. TYLC resistance is an advantage in areas where this disease is present. Besides, is possible to grow in stacked and not stacked conditions. Is a good option to start season in Sinaloa state. For central, is a good alternative for hot season. Highly resistant to: ToMV:0-2/ToTV/TYLCV/Ff:A-E/Fol/Sbl/Sl/Ss/Va/Vd. Semi compact plant, F3 and TYLCV resistance, high percentage of extra size fruit and medium earliness. SVTD2310: Improved variety; Highly resistant to: TYLCV/Aal/Fol/For/Sbl/Sl/Ss/Va/Vd. SVTD3418: SVTD3418 is a main season tomato with excellent heat set ability and strong tolerance to bacterial leaf spot. Due to the presence of the crimson gene, fruit display deeper phenotypic expression of red flesh and gel color, whether harvested mature green and gassed or harvested vine ripe. Growers who appreciate the horticultural benefits of Florida 91 will want to try some SVTD3418 to experience to the genetic improvements in fruit color and quality; Highly resistant to: Aal/Fol/Sbl/Sl/Ss/Va/Vd. Does not have TYLCV protection. SVTE6653 (Roma): Was advanced for west and central México to compete with Pony express (HM) and Galilea (HZ). Compact plant, good fruit size and good earliness. (TY+TSWV+Fus3); Highly resistant to: ToMV:2/ToTV/TSWV/TYLCV/Fol//Sbl/Sl/Ss/Va/Vd. SVTE8444 (Roma): Good plant Vigor, High Average Fruit Weight, Competitive Yield. Highly resistant to: ToMV:2/ToTV/TYLCV/Ff:E/Fol//For/Sbl/Sl/Ss/Va/Vd. PATHOGEN: SCIENTIFIC NAME ENGLISH COMMON NAME CODE RACES / STRAINS CODES (US / CANADA) VIRUS Tomato torrado virus Tomato torrado ToTV ToTV Tomato mosaic virus Tomato mosaic ToMV 0,1,2 ToMV:0-2 Tomato spotted wilt virus Tomato spotted TSWV TSWV Tomato yellow leaf curl virus wilt Tomato yellow leaf curl TYLCV TYLCV BACTERIA Pseudomonas syringae pv. tomato Bacterial speck Pst 0 Pst:0 FUNGI Alternaria alternata f. sp. lycopersici Passalora fulvum (ex Fulvia fulvum; ex Cladosporium fulvum) Fusarium oxysporum f. sp. lycopersici Alternaria stem canker Aal Aal Leaf mold Ff A,B,C,D, Ff:A-E E Fusarium wilt Fol 1-3 (US) Fol:1 (US) Fol:1,2 (US) Fol:1-3(US)
Fusarium oxysporum f. sp. radicislycopersici Fusarium crown For For and root rot Oidium neolycopersici (ex Oidium Powdery mildew On On lycopersicum) Verticillium albo-atrum Verticillium wilt Va 1 (US) Va:1 (US) Verticillium dahliae Verticillium wilt Vd 1 (US) Vd:1 (US) Pyricularia grisea Grey leaf spot Sbl/Sl/Ss NEMATODE Meloidogyne arenaria Root-knot Ma Ma Meloidogyne incognita Root-knot Mi Mi Meloidogyne javanica Root-knot Mj Mj