Louisiana State University Agricultural Center

Department of Agronomy, 104 Madison B, Sturgis Hall, Baton Rouge, LA 70803-2110 USA. S.A. Harrison, C.A. Clark, P.D. Colyer, C.A. Hollier, J.S. Russin, R.W. Schneider, B.L. Tillman, and J.D. Thompson.

Wheat breeding and variety testing. The wheat breeding program completed its tenth year in 1994. Emphasis continues to be on development of high-yielding lines with good test weight and resistance to leaf rust, Septoria leaf and glume blotch, and bacterial streak. The oat breeding program is concentrating on lodging (culm rot), crown rust, stem rust, and barley yellow dwarf resistance. Short and hull-less types also are targeted. About 300 new wheat crosses were added in 1994. The switch from pedigree selection to mass selection for the F₂ and F₃ generations led to planting of about 24,000 F₄ head rows in November, 1994. The F₂ and F₃ populations for 1994-95 include 1,200 75 square-foot plots (about 3/each of 400 crosses). Half of these were planted in mid-October (3 weeks earlier than normal) to evaluate potential to select lines that do not head out early when planted early. Some spring x winter populations set seed in December and January. These should be frozen out in February. Harvested heads will be planted later than normal in 1995 to select for low-vernalization lines. This should result in a high proportion of photoperiodic lines that can be planted over a broader range of dates. Eight wheat lines have been advanced to statewide performance trials for 1995 and an additional 387 lines will be evaluated in preliminary yield trials. About 50,000 total head rows were planted in the fall. The oat breeding project includes 20 lines in statewide yield trials and about 8,000 head rows. Breeder seed increases of superior lines was initiated for 1995. (Harrison, Thompson, and Tillman)

Wheat diseases and fungicide evaluation in North Louisiana. For the second consecutive year, disease severity on winter wheat in northern Louisiana was very low. The incidences of bacterial blight (Xanthomonas campestris pv. translucens) and leaf rust (Puccinia recondita f. sp. tritici) were very low, while the severities of Septoria leaf and glume blotch (Septoria spp.) were moderate. Leaf rust developed on susceptible varieties very late in the growing season and probably had little effect on yield. A field trial of labelled and experimental fungicides for the control of foliar diseases of wheat (cv. Florida 302) was conducted at the Red River Research Station in Bossier City. The severity of leaf rust was low, with the untreated control averaging only 13 % rust on the flag leaf at Feekes' stage 10.8. Eight of 10 fungicide treatments reduced leaf rust compared with the untreated control. The severity of leaf rust in plots treated with Kocide 101 and the experimental fungicide, SAN 619 at 1.27 oz product/acre, was not significantly different from that in the untreated control. There were significant differences in the severity of leaf blotch occurred among fungicide treatments. Grain yields, which averaged 53.3 bu/acre, were not significantly different among treatments. (Colyer)

Wheat production in 1994. Wheat was harvested from 66,592 acres by 589 producers, a drop from the 98,804 acres harvested by 711 producers in 1993. Yields for 1994 averaged 37.03 bushels per acre, an increase from 26.08 bushels per acre, resulting in a total production of 2,465,838 bushels, down from the 2,576,467 bushel crop of 1993. The gross farm value of the 1994 crop was estimated at $8,013,976. The reduction in acreage was caused by adversities in planting conditions and late-season freezes from the season before. The increase in yield per acre was due to good growing conditions and lower than normal disease pressure. Yield losses from leaf rust were about 2 %, whereas losses from the stem and stripe rusts were <1 %. Other leaf and glume diseases caused negligible losses. Total yield loss from a combination of all diseases was <5 %. (Hollier)

Fungicide evaluations. Field tests of labelled and experimental fungicides were conducted on rust-susceptible Coker 9877 at Baton Rouge, Alexandria, and Bossier City. Leaf disease pressure was low at all locations. Of the labelled compounds, Tilt, Bayleton, and Bayleton + Manzate 200 provided limited control of leaf rust and Septoria leaf blotch. Fusarium head scab was present at low levels in plots but was not controlled by these fungicides. Only one experimental compound, RH7592 (Rohm & Haas), was tested this year. As in previous years, foliar disease control with this material rivalled or exceeded that provided by the standard recommended compounds. (Russin)

Bacterial suspensions on seed. Wheat (FFR 525) seed were treated with each of eight bacteria suspensions that previously were effective in reducing seedling disease in water-seeded rice. Emergence in the field was recorded at 15 and 30 days after planting and compared to nontreated and fungicide treated controls. Relative to the fungicide control, three bacterial isolates accelerated emergence at 15 days after planting, and seven of eight isolates resulted in higher emergence at 30 days after planting. (Schneider)

Bacterial streak research on soft red winter wheat. Field studies conducted over several year-locations showed that ratings of black chaff and bacterial streak symptoms caused by X. campestris pv. translucens were not correlated. Greenhouse studies confirmed this. Greenhouse results showed that Florida 304 is susceptible to bacterial streak, but resistant to black chaff and that Coker 9877 is susceptible to black chaff, but is intermediate in reaction to bacterial streak. The cultivar Terral 101 is resistant to both symptoms, whereas the F₆ breeding line LA85426 is susceptible to both symptoms. Our research indicates that certain genotypes can be resistant to black chaff but susceptible to bacterial streak and vice versa. Yield loss has been associated with bacterial streak but not black chaff. Therefore, it appears that breeders should focus on breeding for resistant to bacterial streak. The inheritance of resistance to bacterial streak in winter wheat breeding populations at the Louisiana Agricultural Experiment Station is quantitative. In three F₂-derived populations, heritability (parent-offspring regression) of resistance averaged 0.34. Residual variance was 2 to 4 times as large as genotype by environment interaction variance. Average entry mean heritabilities increased from 0.31 to 0.46 using 3 replications and 1 environment and from 0.31 to 0.55 using 1 replication and 3 environments. Out of 380 wheat lines screened over 2 years, 57 have shown resistance in Louisiana. The only soft red winter wheat cultivar among the group was Terral 101, which is the most resistant cultivar yet identified in Louisiana. GA 22 triticale also was very resistant in our tests. The group of 57 will undergo a final field screening in 1995. (Tillman, Harrison, Clark, and Russin)

Personnel. Barry Tillman completed his Ph.D. in the wheat breeding program in December, 1994. He is currently publishing results of his research on bacterial streak of wheat. Dr. Tubajika Kyembi joined the wheat pathology program as a postdoctoral associate. He will follow up on the research on bacterial streak of wheat and work on other diseases of wheat.

Publications. Shah SA, Harrison SA, Boquet DJ, Colyer PD, and Moore SH. 1994. Management effects on yield and yield components of late-planted wheat. Crop Sci 34:1298-1303. Harrison SA et al. 1994. Performance of small grain varieties in Louisiana, 1993-94. LAES Mimeo Series No. 90. 92 p. Russin JS, Tillman BL, and Harrison SA. 1994. Supplemental spring nitrogen reduces severity of black chaff in Louisiana. Biol and Cul Tests. Tillman BA. 1994. Breeding wheat for resistance to bacterial leaf streak caused by Xanthomonas campestris pv. translucens. Ph.D. dissertation, Louisiana State University.

MINNESOTA

Cereal Rust Laboratory, USDA-ARS

University of Minnesota, St. Paul, MN 55108, USA. D.L. Long, K.J. Leonard, D.V. McVey, M.E. Hughes, D.H. Casper, and J.J. Roberts.

The rusts of wheat in the United States in 1994. Stem rust (Puccinia graminis f. sp. tritici). Overwintering stem rust sites were found on susceptible wheat cultivars in southern Texas and Louisiana. During the last week in March, traces of stem rust were found in a field of Mit wheat located southwest of Houston, Texas. Rust collected from this field was identified as race Pgt-QCCJ. Stem rust in southern Texas and Louisiana was less severe in 1994 than in 1993. In March, 1994, moisture conditions (less rainfall and fewer dews) and cool nighttime temperatures (less than 40 F) were not favorable for rust development. In late April, in central Texas and southern Louisiana, traces of stem rust were found in wheat plots. During late May, light amounts of wheat stem rust were observed in north central Texas plots at harvest. By the first week in May, 5 % stem rust severities were observed throughout the state of Louisiana. By the third week in May, light amounts of wheat stem rust were scattered throughout the lower Mississippi Valley wheat growing area. In all of these areas, losses to wheat stem rust were minimal, but these fields and plots did provide stem rust inoculum for susceptible wheat and barley farther north. In early June, traces of stem rust were observed on McNair 701 (susceptible host) in a south central Kansas plot. By the third week in June, a focus of 10 % wheat stem rust severity was found in a northwestern Kansas plot of McNair 701, and traces of stem rust were found on Karl. The hot, dry weather in late May and early June in Kansas was not conducive for rust increase. In mid-July, traces of stem rust were found in plots of the winter wheat Norstar and the susceptible spring wheat Max in southeastern North Dakota. In late July, traces of stem rust were found in plots in west central Minnesota and central and northwestern North Dakota. Commercial spring and durum wheat cultivars in this area have a high level of stem rust resistance, so losses to stem rust were negligible. Stem rust development throughout the Great Plains was less than normal. The cool, dry conditions in late winter in the southern plains and hot, dry weather in late May and early June in the central plains were not conducive for rust increase. Traces of wheat stem rust were reported first in the northern soft red winter wheat area in west central Indiana and east central Illinois in mid-June, but losses were negligible, because the crop was close to harvest. In late July, in west central Colorado, severe stem rust was found on the cultivar Stephens at harvest time. This was the first time wheat stem rust was found at this location on the west slope of the Rocky Mountains. In early July, traces of wheat stem rust were reported in an eastern Washington plot but none was reported in fields. Seven Pgt-races were identified from 49 wheat collections made in the U.S. in 1994 (Table 1). Race Pgt-TPMK was the predominant race identified this year, as it was from 1974-1989 and 1992-1993. It comprised 41 % of the isolates in 1994 compared to 74 % in 1993, 53 % in 1992, and 36 % in 1991. Pgt-QFCS comprised 24 % of the isolates in 1994, 16 % in 1993, 21 % in 1992, and 14 % in 1991. Pgt-QCCJ, the barley attacking race, comprised 26% of the isolates in 1994, 8 % in 1993, 21 % in 1992, and 14 % in 1991. This race was identified from collections made in Texas, Minnesota, North Dakota, and Washington. Table 1. Races of Puccinia graminis f. sp. tritici identified from wheat in 1994. __________________________________________________________________________________________ Number of Percentage of isolates of Pgt- race¹ ________________ _________________________________________________ State Source collections isolates QCCJ QFCS RCRS RKQQ RTQQ TMLK TPMK __________________________________________________________________________________________ AR Field 1 3 - - - - - - 100 Nursery 3 9 - - - - - - 100 CO Nursery 1 3 - 67 - - 33 - - IL Field 1 3 - - - - - - 100 IN Field 1 3 - - - - - - 100 Nursery 1 3 - - - - - - 100 KS Nursery 2 6 - 100 - - - - - LA Nursery 6 18 - - - 6 - - 94 MN Nursery 6 16 38 19 - 19 6 - 19 MS Field 1 2 - 100 - - - - - Nursery 1 3 - - - - - - 100 ND Nursery 19 55 45 38 9 4 - - 4 NE Nursery 1 3 - - - - - - 100 TX Field 1 3 67 - - - - - 33 Nursery 3 7 - - - - - - 100 WA Nursery 1 3 100 - - - - - - __________________________________________________________________________________________ U.S.² Field 5 14 14 14 - - - - 71 Nursery 43 123 25 26 4 5 2 - 38 Total 48 137 24 25 4 4 1 - 42 __________________________________________________________________________________________ ¹ Pgt-race code, after Roelfs and Martens, Phytopathology 78:526-533. Set four consisted of Sr9a, 9d, 10, and Tmp. ² U.S. totals do not include collection from Washington, because the population in this area is considered to be sexual. Wheat leaf rust (Puccinia recondita f. sp. tritici). In late March, wheat leaf rust was widespread but less severe than normal in fields and plots across southern Texas (Fig. 1). Generally, leaf rust overwinters throughout southern Texas. Later planting (December), lack of moisture, and cool temperatures are factors other than resistance that restricted the rust development. In some north central Texas fields, leaf rust overwintered and by late March, severe rust was noted on the lower leaves. The lack of moisture in April delayed further leaf rust development throughout most of Texas. By the last week in April, only light leaf rust was found on flag leaves in fields and plots in north central Texas and southwestern Oklahoma. By the third week in May, 20 % leaf rust readings were observed on flag leaves in a few fields in north central Oklahoma and 1 % leaf rust severities were observed on flag leaves of T. cylindricum (Ae. cylindrica) across central and western Oklahoma. Losses to wheat leaf rust were light in the southern plains this year (Table 2). The amount of leaf rust that overwintered in Kansas during 1993-94 was the least observed in the past 15 years. Cool weather in late March and early April was not conducive for rust development. In early April, freezing temperatures in western Kansas killed leaf tissue infected with rust, thus delaying the local rust buildup. By early May, traces of leaf rust were found in central Kansas. In a field of Karl in central Kansas, a few pustules were found on flag leaves, but none was found on lower leaves, which meant the rust developed from spores blown into the field from an external source. In the long distance spread of rust, the spores are typically brought down with rain and deposited on leaves. During the third week in May, traces of leaf rust were found on flag leaves in plots and fields throughout central, south central and southwestern Kansas. Leaf rust was much lighter in this area than last year, because very little leaf rust overwintered, temperatures were cooler than normal in the early spring, and moisture was less than normal. In northern Kansas, final leaf rust severities were light, because dry hot conditions pushed the crop to quick maturity. In early June, leaf rust was light in southern Nebraska fields on the flag leaves at the late milk stage. During the third week in June, trace to 20 % leaf rust severities were observed in winter wheat fields in south central Nebraska and southeastern South Dakota. Damage varied with local conditions, but some fields suffered losses in yield. During late June, traces of leaf rust were observed in spring wheat fields in west central Minnesota and 10 % severities were found in plots of the susceptible cultivar Baart in southern Minnesota and southeastern North Dakota. Most infections were on the lower leaves. During late June in southeastern North Dakota winter wheat plots, trace-5 % severities were observed at the 1/4 berry stage. In early July, severities of 5-60 % were common on flag leaves in plots of susceptible winter wheat in east central Minnesota and southeastern North Dakota. In late July in the northern Great Plains, 40 % severities were common in susceptible spring wheat plots, whereas only traces were noted in fields. Because resistance, only traces of leaf rust developed; therefore, losses were minimal in the spring wheat areas (Table 3). No rust was reported on durum wheat. During early April, leaf rust severities were generally light throughout Louisiana (Fig. 1). During November to January, the temperatures were cooler than normal, which didn't allow the rust to increase as it did during the winter of 1992-93. No leaf rust was found in southern Louisiana CK 9877 plots, in contrast to 1993 when rust was severe in these plots. In mid-April, severe leaf rust was reported in susceptible plots in southern Louisiana, and light amounts of leaf rust were found in east central Arkansas fields. By late May, in northeastern Arkansas, leaf rust severities ranged from traces to 50 % in plots and traces to 10 % in fields. These rust-infected plants provided leaf rust inoculum for susceptible wheat farther north. From southern Mississippi to southern Georgia, winter rainfall was above normal, creating favorable conditions for rust infection. However, cooler than normal temperatures in November slowed rust establishment, and very little development occurred in the coldest months of December and January. By early April, leaf rust severities were generally light on susceptible southern soft red winter wheat in plots and fields from southern Mississippi to southern Georgia. Then drier than normal conditions and cool temperatures slowed leaf rust spore production and movement in much of this area. By the first week in May, leaf rust severities ranged from traces to 90 % in wheat plots and fields at the soft dough stage from the Florida panhandle to east central Louisiana. Throughout the southern soft red winter wheat area, leaf rust losses were light except for a few isolated cases. Table 2. Estimated losses in winter wheat from rust in 1994 (T = Trace). _____________________________________________________________________________________________ Losses from ___________________________________________________ Stem rust Leaf rust Stripe rust 1,000s Production ______________ ______________ ______________ acres Yield 1,000s 1,000 1,000 1,000 State harvested bu/acre bu % bushels % bushels % bushels _____________________________________________________________________________________________ AL 95 48.0 4,560 0.0 0.0 1.0 46.1 AR 880 46.0 40,480 T T 0.5 203.4 0.0 0.0 CA 510 80.0 40,800 0.0 0.0 5.0 2,147.4 T T CO 2,550 30.0 76,500 T T T T 0.0 0.0 FL 15 42.0 630 0.0 0 2.0 12.9 GA 400 51.0 20,400 0.0 0.0 1.0 206.1 ID 790 72.0 56,880 0.0 0.0 0.1 56.7 0.1 56.7 IL 900 56.0 50,400 T T 1.0 509.0 0.0 0.0 IN 630 61.0 38,430 T T 2.0 784.3 0.0 0.0 IA 45 47.0 2,115 0.0 0.0 T T KS 11,400 38.0 433,200 0.001 4.4 1.0 4,375.8 0.0 0.0 KY 450 60.0 27,000 0.0 0.0 1.0 272.7 LA 70 37.0 2,590 T T 2.0 52.9 T T MI 580 53.0 30,740 0.0 0.0 1.0 310.5 MN 37 29.0 1,073 0.0 0.0 T T MS 160 40.0 6,400 0.0 0.0 2.0 130.6 0.0 0.0 MO 1,100 45.0 49,500 0.0 0.0 2.0 248.7 0.0 0.0 MT 1,850 35.0 64,750 0.0 0.0 T T 0.1 64.8 NE 2,100 34.0 71,400 0.0 0.0 0.5 358.8 NM 230 24.0 5,520 0.0 0.0 0.0 0.0 NY 115 53.0 6,095 0.0 0.0 T T NC 620 49.0 30,380 0.0 0.0 2.0 620.0 0.0 0.0 ND 38 33.0 1,254 0.0 0.0 T T 0.0 0.0 OH 1,180 58.0 68,440 0.0 0.0 T T OK 5,300 27.0 143,100 0.0 0.0 1.0 1,445.5 0.0 0.0 OR 870 64.0 55,680 0.0 0.0 0.1 55.8 0.1 55.8 PA 165 48.0 7,920 0.0 0.0 T T SC 360 50.0 18,000 0.0 0.0 1.0 181.8 SD 1,350 32.0 43,200 0.0 0.0 T T TN 300 50.0 15,000 T T 1.0 151.5 TX 2,900 26.0 75,400 T T T T 0.0 0.0 VA 250 56.0 14,000 0.0 0.0 T T WA 2,300 54.0 124,200 T T 0.1 124.4 0.1 124.4 WV 10 55.0 550 0.0 0.0 T T WI 130 59.0 7,670 0.0 0.0 T T WY 180 24.0 4,320 0.0 0.0 T T _____________________________________________________________________________________________ Total of above 40,860 1,638,577 4.4 12,294.9 301.7 Average 40.1 T 0.74 0.02 U.S. Total 41,365 40.2 1,664,883 _____________________________________________________________________________________________ Table 3. Estimated losses in spring and durum wheat from rust in 1994 (T = Trace). _____________________________________________________________________________________________ SPRING WHEAT Losses from ___________________________________________________ Stem rust Leaf rust Stripe rust 1,000s Production ______________ ______________ ______________ acres Yield 1,000s 1,000 1,000 1,000 State harvested bu/acre bu % bushels % bushels % bushels _____________________________________________________________________________________________ CO 42 77.0 3,234 0.0 0.0 T T 0.0 0.0 ID 620 70.0 43,400 0.0 0.0 T T T T MN 2,500 28.0 70,000 0.0 0.0 T T MT 3,300 55.0 99,000 0.0 0.0 0.0 0.0 T T ND 8,850 31.5 278,775 0.0 0.0 T T OR 58 50.0 2,900 0.0 0.0 0.1 2.9 T T SD 1,980 26.0 51,480 0.0 T T T UT 22 46.0 1,012 0.0 0.0 0.0 0.0 WA 245 40.0 9,800 T T 0.1 9.2 0.1 9.2 WI 9 30.0 270 0.0 0.0 0.0 0.0 WY 17 37.0 629 0.0 0.0 0.0 0.0 _____________________________________________________________________________________________ Total of above 17,643 560,500 T 12.1 9.2 Average 31.8 T 0.002 0.002 U.S. Total 17,647 31.8 560,720 _____________________________________________________________________________________________ DURUM WHEAT Losses due to ___________________________________________________ Stem rust Leaf rust Stripe rust 1,000s Production ______________ ______________ ______________ acres Yield 1,000s 1,000 1,000 1,000 State harvested bu/acre bu % bushels % bushels % bushels _____________________________________________________________________________________________ AZ 94 91.0 8,554 0.0 0.0 0.0 0.0 CA 59 95.0 5,605 0.0 0.0 0.0 0.0 0.0 0.0 MN 35 25.0 875 0.0 0.0 0.0 0.0 MT 178 30.0 5,340 0.0 0.0 0.0 0.0 0.0 0.0 ND 2,250 32.5 73,125 0.0 0.0 0.0 0.0 SD 23 26.0 598 0.0 0.0 0.0 0.0 _____________________________________________________________________________________________ Total of above 2,639 94,097 0.0 0.0 0.0 Average 35.7 0.0 0.0 0.0 U.S. Total 2,639 35.7 94,097 _____________________________________________________________________________________________ In mid-June, in the northern soft red winter wheat area, traces of leaf rust were observed in fields and traces to 10 % in nurseries at the soft dough stage. This was much less leaf rust than normal for this area because of less inoculum arriving from the south; drier than normal conditions; and no rust overwintering, which was related to later than normal fall planting. In early July, light leaf rust was found on winter wheat in central and western New York. In these areas, losses to wheat leaf rust were minimal. In late April, light amounts of wheat leaf rust were found in the Central Valley of California. By mid-May, leaf rust was widespread and severe on susceptible cultivars in fields and nurseries. By the fourth week in May, leaf rust had increased to severe levels in plots and fields in the Sacramento Valley of California. A 5 % loss from leaf rust occurred in California in fields of susceptible cultivars (Table 2). By early June, severe leaf rust was observed in plots at Corvallis, Oregon, and light rust was found in the Pullman, Washington area. In early July, light leaf rust was found on winter wheat in the Gallatin Valley in Montana. In 1994, eight new races were identified: LBG-10,18; MCD-10; MFC-10; MFR-10; MGD-10; PMM-10,18; PMR-10,18; and PNM-10 (Tables 4 and 5). The Lr 9 and 26 virulence combination (PM-) was identified for the first time in the U.S. population from rusted collections made in Pennsylvania. Race MBR-10 was the most frequently identified race in 1994, comprising 36.2 % of the population, whereas in 1993, it comprised only 6 % of the population. Race MBG-10, the most frequently identified race during the last 5 years, comprised 15.7 % of the population. Forty Prt-races comprised the other 48.1 % of the U.S. population. Wheat stripe rust (Puccinia striiformis). In late March, 5 % severities were observed on the soft red winter wheat cultivar Coker 9835 in the Uvalde nursery in southern Texas. High temperatures retarded further development in this nursery. There were no reports of wheat stripe rust being found this year in the southern Mississippi River Valley wheat-growing area. During the second week in April, traces of wheat stripe rust were found in the Davis, California nurseries. During the last week in April, wheat stripe rust was found in the Central Valley, California nurseries. By the second week in May, severe wheat stripe rust was found in San Joaquin and Sacramento Valley plots in California. Stripe rust was more widespread in California than it had been in the last 2 years. During mid-April, significant amounts of stripe rust were observed in northwestern Washington wheat plots. Severities of 80 % were found on the most susceptible lines in the Mount Vernon nursery. By late May, stripe rust was severe in northwestern Washington plots and in some fields that were susceptible to stripe rust. In eastern Washington, stripe rust was light this year because of lower than normal rainfall and higher than normal springtime temperatures. Throughout the Pacific Northwest, losses from to stripe rust were lighter than normal. During the first week in July, traces of wheat stripe rust were found in the Gallatin valley in Montana. Losses from rust. Acreage harvested and yield production records are based on 1994 Annual Crop Summary, Agricultural Statistics Board, USDA. Loss data are summaries of estimates made by personnel of the State Departments of Agriculture, University Extension and research projects, Agriculture Research Service, USDA, and the Cereal Rust Laboratory. Losses for 1994 are shown in Tables 2 and 3. Losses were calculated for each rust as follows: (Production) X (Percent loss) Loss (specific rust) = _______________________________ (100%) - (Percent loss from rusts) Losses were indicated as a trace when the disease was present, but no fields were know to have suffered significant losses. When a few fields suffered measurable losses, this was reflected as a percent of the state's production. Zeros indicate that the disease was not reported in that state during the season. Blanks for stripe rust indicate that the disease was not reported or does not occur annually in that state. Trace amounts were not included in the calculation of totals and averages. Table 4. Prt code and corresponding virulence formula for wheat leaf rust collections made in 1994. ___________________________________________________________________________________________ Prt code¹ Virulence formula² Prt code¹ Virulence formula² ___________________________________________________________________________________________ CBG-10 3, 10, 11 MFC-10 1, 3, 10, 24, 26, 30 CCB-10 3, 10, 26 MFR-10 1, 3, 3ka, 10, 11, 24, 26, 30 FBM-10 2c, 3, 3ka, 10, 30 MGD-10 1, 3, 10, 16, 17 FBR-10 2c, 3, 3ka, 10, 11, 30 NBB-10, 18 1, 3, 10, 18 FBR-10, 18 2c, 3, 3ka, 10, 11, 18, 30 PBB-10, 18 1, 2c, 3, 10, 18 KFB-10 2a, 2c, 3, 10, 24, 26 PBD-10 1, 2c, 3, 10, 17 LBG-10 1, 10, 11 PBG-10 1, 2c, 3, 10, 11 LBG-10, 18 1, 10, 11, 18 PBM-10, 18 1, 2c, 3, 3ka, 10, 18, 30 MBB-10 1, 3, 10 PBR-10, 18 1, 2c, 3, 3ka, 10, 11, 18, 30 MBD-10 1, 3, 10, 17 PLM-10, 18 1, 2c, 3, 3ka, 9, 10, 18, 30 MBG 1, 3, 11 PMM-10, 18 1, 2c, 3, 3ka, 9, 10, 18, 26, 30 MBG-10 1, 3, 10, 11 PMR-10, 18 1, 2c, 3, 3ka, 9, 10, 11, 18, 26, 30 MBR 1, 3, 3ka, 11, 30 PNM-10 1, 2c, 3, 3ka, 9, 10, 24, 30 MBR-10 1, 3, 3ka, 10, 11, 30 PNM-10, 18 1, 2c, 3, 3ka, 9, 10, 18, 24, 30 MCB-10 1, 3, 10, 26 TBD-10 1, 2a, 2c, 3, 10, 17 MCD-10 1, 3, 10, 17, 26 TBG-10 1, 2a, 2c, 3, 10, 11 MCG-10 1, 3, 10, 11, 26 TDB-10 1, 2a, 2c, 3, 10, 24 MCR-10 1, 3, 3ka, 10, 11, 26, 30 TDG-10 1, 2a, 2c, 3, 10, 11, 24 MDB-10 1, 3, 10, 24 TFB-10 1, 2a, 2c, 3, 10, 24, 26 MDR-10 1, 3, 3ka, 10, 11, 24, 30 TFG-10 1, 2a, 2c, 3, 10, 11, 24, 26 MFB-10 1, 3, 10, 24, 26 TLG-18 1, 2a, 2c, 3, 9, 11, 18 ____________________________________________________________________________________________ ¹ Prt code plus Lr10 and 18 near-isogenic supplementals. ² Resistances evaluated: Lr1, 2a, 2c, 3, 9, 16, 24, 26, 3ka, 11, 17, 30, 10, and 18. Table 5. Races of Puccinia recondita f. sp. tritici identified from wheat collections in 1994¹. _____________________________________________________________________________________________________ Percent of isolates per state by area² AL AR FL GA LA MS NC VA PA NY IL IN KY TX OK KS NE MN SD ND MT CA OR US __________________ __________ __________ _________ ______ ______ ______________ ___ ___ ___ CBG-10,18 20 0.3 CCB-10 8 0.3 FBM-18 60 8 1.2 FBR-18 4 0.1 FBR-10,18 13 0.1 KFB-10 1 0.1 LBG-10 30 0.9 LBG-10,18 5 0.1 MBB-10 3 4 4 25 3 4 19 5 2.5 MBD-10 5 0.3 MBG 10 13 0.3 MBG-10 41 40 75 62 29 25 30 13 25 11 9 11 2 28 1 8 19 15 15.7 MBR 4 17 0.9 MBR-10 31 22 25 15 33 42 38 30 20 21 38 18 45 61 67 48 28 63 50 3 36.2 MCB-10 8 17 44 10 2.9 MCD-10 3 6 0.6 MCG-10 9 0.4 MCR-10 2 2 0.3 MDB-10 3 6 5 1.6 MDR-10 3 12 8 0.9 MFB-10 4 8 15 7 2 3 9 16 9 5.7 MFC-10 8 0.3 MFR-10 2 5 6 1.3 MGD-10 3 0.3 NBB-10,18 30 0.9 PBB-10,18 2 0.1 PBD-10 1 0.1 PBG-10 5 0.1 PBM-10,18 10 0.1 PBR-10,18 7 33 100 0.9 PLM-10,18 3 0.1 PMM-10,18 33 0.3 PMR-10,18 17 0.1 PNM-10 8 0.3 PNM-10,18 2 13 0.6 TBD-10 3 1 0.4 TBG-10 8 10 17 3 1 2 6 2 1 17 2.0 TDB-10 22 4 10 18 23 10 8 14 12 16 8 11.7 TDG-10 3 4 4 17 8 25 22 3.8 TFB-10 3 4 12 3 5 1 8 2.5 TFG-10 3 4 1 2 3 0.7 TLG-18 7 8 25 2 1.0 _____________________________________________________________________________________________________ Number of isolates 29 45 4 26 24 12 8 10 6 2 10 24 8 73 107 41 36 58 25 67 12 32 20 683 _____________________________________________________________________________________________________ ¹ States grouped according to agroecological area (Plant Dis 76:495-499). ² U.S. total includes four additional isolates from two collections: South Carolina, TLG-18 (2 isolates); and Tennessee, MBG-10 (2 isolates).