C.N.A. de Sousa, A.L. Barcellos, A.M. Prestes, E.N. Guarienti, E.P Gomes, J.C.S. Moreira, J.F. Sartori, L. de J.A. Del Duca, P.L. Scheeren, S.D. dos A. e Silva, and W.I. Linhares.
The wheat cultivar `EMBRAPA 40' was selected from the cross `PF 7650/NS 18-78//CNT 8/PF 7577' made in Mexico in 1979 and bulked in the F6 generation as a line (PF 84316) in 1984 using the mass method. EMBRAPA 40 was released for cultivation in the state of Rio Grande do Sul in 1995. This variety yielded 2,812 kg/ha, 1 % over the average of the check cultivars according to the average of 66 trials conducted in Rio Grande do Sul from 1992-94. EMBRAPA 40 is an early, tall spring wheat with some tendency to lodge. This cultivar is susceptible to powdery mildew, but resistant to all races of Puccinia graminis tritici found in Brazil. EMBRAPA 40 is susceptible to some races of P. recondita, but, so far, has good field resistance to leaf rust and is moderately resistant to soilborne mosaic virus. This cultivar has good resistance to sprouting and moderate tolerance to aluminum toxicity. The industrial quality of EMBRAPA 40 is considered good, and it has the high molecular weight glutenin subunits 5+10 and 17+18.
1995 Wheat Cultivar Yield Trials in Passo Fundo, Brazil.
J.C.S. Moreira and C.N.A. de Sousa.
About 350 wheat genotypes were tested in 19 yield
trials at the National Research Center for Wheat of EMBRAPA in
Passo Fundo, Rio Grande do Sul, Brazil, during 1995. The process
for releasing a new cultivar in Rio Grande do Sul, the southernmost
Brazilian state, was described in the 1986 Annual Wheat Newsletter
(32:38-39).
The climatic conditions in Passo Fundo during the
wheat growing season (June to November) were not good for wheat.
A drought lasted through much of the growing season. Plants had
a poor growth and the yield was low. Disease was less than in
previous years.
The field trials were in a rotation area (2 years
without wheat) with fertilizer applications of 12.5 kg/ha N, 63
kg/ha P205, 50 kg/ha P205, 50 kg/ha K2O, and 45 kg/ha N as top-dressing.
The trials were conducted in a no-till system. No fungicides
were used in most trials.
The cultivars used as controls in 1995 were BR 23,
CEP 24, and EMBRAPA 16. The cultivar EMBRAPA 16 is the main cultivar
grown in Rio Grande do Sul, occupying about 100,000 ha (30 %)
of the growing area in this state. For several years BR 23 was
the main cultivar grown in this region of Brazil.
No entry exceeded the yield of the three local checks
in the South Central Brazilian Trial. Cultivars that yielded more
than EMBRAPA 16 in trials in Passo Fundo, RS, are listed in Table
2.
Table 2. Cultivars with higher yield than EMBRAPA 16 in trials in Passo Fundo, RS, in 1995.
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Yield % of
Cultivar Pedigree kg/ha EMBRAPA 16
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1. Cultivar State Trialówithout fungicide.
BR 23 CC/ALD SIB/3/IA5 54-20/COP//CNT 8 2,743 106
BR 35 IAC 5*2/3/CNT 783/LD//IAC 5/Hadden 2,721 106
RS 1-Fenix PF 70100/J 15157-69 2,701 105
2. Cultivar State Trialówith fungicide.
BR 23 CC/ALD SIB/3/IA5 54-20/COP//CNT 8 3,046 111
BR 35 IAC 5*2/3/CNT 783/LD//IAC 5/Hadden 3,173 115
RS 1-Fenix PF 70100/J 15157-69 2,780 101
3. South Brazilian Trialówithout fungicide.
PF 9099 PF 82252/BR 35//IA 7998/PF 8550 2,667 103
BR 23 CC/ALD SIB/3/IA5 54-20/COP//CNT 8 2,661
103
4. South Brazilian Trialówith fungicide.
CEP 9168 CEP 8435/CEP 17//BR 23 2,723 102
ORL 91256 BR23/PF 869107 S 2,738 103
BR 23 CC/ALD SIB/3/IA5 54-20/COP//CNT 8 2,991
112
Table 2 (Cont). Cultivars with higher yield than EMBRAPA 16 in trials in Passo Fundo, RS,in 1995.
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Yield % of
Cultivar Pedigree kg/ha EMBRAPA 16
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5. Regional Yield Trial.
SA 9252 RS 4/2* Minuano 82 2,651 104
SA 9458 PF 82250/RS 1 2,630 103
BR 23 CC/ALD SIB/3/IA5 54-20/COP//CNT 8 2,991
112
6. Multilocation Preliminary Trials (5 sites with lines in 2nd year of test). Data from
Passo Fundo.
PF 92140 BR 35/PF 85946/3/PF 772003*2/PF 813//PF 83899
2,670 106
PF 92141 BR 35/PF 85946/3/PF 772003*2/PF 813//PF 33899
2,554 101
PF 92231 CEP 14/BR 23//CEP 19 2,609 103
PF 92392 BR 35*3//BR 14*2/Largo 2,592 103
PF 92398 BR 35*4/3/PF 839100//BR 14*2/CI 17959 2,595 103
PF 92569 BR 35*2/PF 85437 2,844 113
PF 92570 BR 35*2/PF 85437 2,632 104
7. Preliminary trials (1st year trial - 11 preliminary lines, 235 lines).
5th Preliminary trial.
PF 940097 PF 8619/BR 35 2,346 101
PF 940099 PF 8619/BR 35 2,857 101
PF 940110 PF 83743/PF 813019//PF 84296/PF 83743 3,122 111
7th Preliminary trial.
PF 940156 BR 34/PF 8545 2,123 102
PF 940159 BR 35/PF 8596/3/PF 772003*2/PF 813//PF 8399 2,256 103
PF 940176 PF 8569/3/VS 73-98//PF 802014//PF 802014/F 29-76
2,186 105
PF 940181 BR 35*2/Coker 80-33 2,207 106
PF 940182 PF 87511*2/Coker 80-33 2,318 111
PF 940184 PF 87511*2/Coker 80-33 2,218 106
8th Preliminary trial.
PF 940200 PF 87511*2/Coker 80-33 2,736 121
PF 940201 PF 87511*2/Coker 80-33 2,844 126
PF 940202 PF 87511*2/Coker 80-33 2,622 116
PF 940207 BR 35/TP 2,549 113
PF 940212 Coker 762/BR 23//Coker 762/BR 14 2,707 120
9th Preliminary trial.
PF 940266 BR 23//CEP 19//PF 35490 2,574 102
8. High Technology Trial (with fungicide and a high amount of nitrogen).
ORL 9128 PF 869107 S/BAU S 3,169 120
PF 86242 HLN/CNT 7//Amigo/CNT 7 2,850 108
SA 9458 PF 82250/RS 1 2,950 112
BR 23 CC/ALD SIB/3/IAS 54-20/COP//CNT 8 2,709 103
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Observations on cultivar resistance to scab.
C.N.A. de Sousa.
Scab (Fusarium graminearum, syn. Gibberella
zeae) was an important disease in the crossing block conducted
in the field in Passo Fundo, Rio Grande do Sul, Brazil, for the
last 3 years. A survey through simple observation was done, although
it is not an easy task to take notes on this disease. The best
lines (cross in parentheses) of those lines observed for 3 years
in the crossing block were Ning 8331, PF 84511 (Butui/PAT 73g2),
PF 859114 (CNT 10//LD*3/NBAY), PF 89156 (Sulivan/PF 79777), PF
9099 (PF 82252/BR 35//IA 7998/PF 8550), PF 90132 (VS 73-598/BR
6), Toropi, Trigo BR 32, and Wuhan 3. Era, GD 88158, Oasis, PF
9052 (PF 8237//LAP 689/3*CNT 10), and PF 83145 (CEP 14/PF 79547)
were the best of the lines tested for 2 years.
A survey for the presence of Ne genes.
C.N.A. de Sousa.
In 1995, a survey was made to determine the presence
of the Ne1 and Ne2 genes in several Brazilian cultivars.
Together, these genes promote hybrid necrosis. Simple crosses
were made using genotypes with the Nel or Ne2 genes
and the cultivar to be tested. When crosses between a cultivar
with Ne1 and another with Ne2 are made, hybrid necrosis
occurs in the F1 generation. The main reason for this survey is
that the Ne2 gene is located near the Lr13 gene
for adult-plant leaf rust resistance. Lr13 seems to
be important in combination with other genes for leaf rust resistance.
Brazilian cultivars EMBRAPA 16, PF 9099, Trigo BR 18, Trigo BR
35, Trigo BR 43, and C306 (BRA) exhibited hybrid necrosis in the
F1 when crossed with Ne1 lines, indicating the presence
of the Ne2 gene and, by extension, gene Lr13. PF
844003 and PF 89419 have the Ne1 gene, which is a rare
trait among Brazilian wheats. Cultivars CEP 27, Colonias, IAPAR
17, OCEPAR 10, PF 88305, PF 89230, PF 92432, PF 9323, and Trigo
BR 42 do not have either Nel or Ne2. CEP 24, EMBRAPA
27, EMBRAPA 40, PF 79547, PF 9132, PF 9210, PF 9234, PF 92349,
PF 93113, PF 9325, Trigo BR 20, and Trigo BR 36 do not have the
Ne2 gene and were not tested for Ne1.
A.M. Prestes, P.L. Scheeren, C.N.A. de Sousa, M. Barbosa, and L.R. Goulart.
The reaction of more than 300 entries of wheat, comprising
a crossing block and final wheat yield trials, were evaluated
in 1994 and 1995 for resistance to SBMV under field conditions
at Passo Fundo, in the state of Rio Grande do Sul, Brazil. The
disease is endemic in the northern part of the state and may cause
severe losses to susceptible cultivars.
A nursery was established in a field where SBMV was
severe in previous years. All cultivars were sown in double rows,
2 m long, after a rain when soil was still very wet. Evaluation
was based on symptomatology using a 0(zero) to 5 scale considering
the severity of symptoms, stunting, and rosette formation.
Considering the 2-year evaluations, a few cultivars had good resistance to SBMV (Table 3). EMBRAPA 16, the widest grown commercial variety in the southern state, was the most resistant cultivar. EMBRAPA 15, ENBRAPA 40, BR 32, and BR 38 were moderately resistant. Among the foreign germplasm, Amigo and Century were the most resistant, whereas Coker 762, Coker 80-33, Coker 97-33, Florida 301, Hadden, Hunter, Era, Newganes, Oasis, and Tivoli were susceptible.
Table 3. A few examples of soilborne mosaic virus-resistant cultivars from the 1994-95
nursery.
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Cultivar Pedigree Score
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Amigo Gaucho/TCS/63PC42-4/3/Teewon (BC)/4/... 0
Century Tanya/TAM W101/Amigo 0
EMBRAPA 15 CNT 10/BR 35//PF 75172/Tifton 2
EMBRAPA 16 HLN/CNT 7//Amigo/CNT 7 0
EMBRAPA 40 PF 7650/NS 18-78//CNT 8/PF 7577 2
Frontana Fronteira/Mentana 2
TRIGO BR 4 IAS 20*3/Sinvalocho Gama 1
TRIGO BR 8 IAS 20/TP//PF 70100 2
TRIGO BR 32 IAS 60/Indus//IAS 62/3/ALD SIB/4/IAS 59 2
TRIGO BR 36 JUP 73*3/Amigo 1
Toropi (check) PE 8//FN 1971-37/QNA-A 5
Florida 301 (check) Holley/3/Olesen//Arthur 71 5
Coker 762 (check) Unknown 4
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The resistance of EMBRAPA 16 and of a number of other
cultivars may come from Amigo. Studies involving reciprocal crosses
of EMBRAPA 16 with the susceptible cultivars BR 23, BR 35, and
EMBRAPA 27 indicated that the resistance in these crosses was
governed by two dominant genes with interacting effects. Additional
studies to determine the inheritance of resistance to SBMV are
in progress.