NATIONAL RESEARCH CENTER FOR WHEAT - EMBRAPA
Centro Nacional de Pesquisa de Trigo, BR 285, Km 174, Caixa Postal 451, 99001-970, Passo Fundo, Rio Grande do Sul, Brazil.
Survey on hybrid necrosis in Brazilian wheat cultivars.
C.N.A. de Sousa
Thirteen wheat cultivars from Brazil were tested in Passo Fundo in 1998 for hybrid necrosis (gene Ne2) through crosses using Ne1 genotypes. With a few exceptions, the gene Ne2 is associated with the Lr13. The Ne1 genotypes used for the test were Spica-lp942 (an Australian bread wheat); PF 89419 (a Brazilian bread wheat); and the durum wheats Hercules (Canada), Karim (Tunisia), and Rascon 10 and Sord 4 (Mexico). The information obtained in 1998 is presented in Table 1.
Embrapa 24 was tested in 1993 and IAPAR 53 was tested in 1997. Both cultivars had hybrid necrosis in these tests. Brazilian wheat cultivars Alegrete, Embrapa 24, Fepagro-RS 15, Fundacep 29, IAPAR 28, IAPAR 53, IAS 54, Pitana, and Trigo BR 4 seem to possess the gene Lr13.
The gene Lr13 alone appears ineffective against leaf
rust under the present Brazilian field conditions but seems to
function in combination with Lr13 plus Lr34, as
found in the Brazilian cultivars Frontana and Trigo BR 23. These
cultivars survived under farm conditions for a great number of
years. Frontana has been recommended in Brazil for 48 years, from
1940 to 1987, and Trigo BR 23, released in 1987, is still under
recommendation.
| Cultivar | Year of release in Brazil | Hybrid necrosis, 1998 test * | Presence of Lr13 ** | Leaf rust in Passo Fundo, 1998 |
|---|---|---|---|---|
| Alegrete | 1949 | yes | + | 30S - MS |
| Coodetec101 | 1997 | no | - | 10 MS |
| Embrapa 24 | 1993 | yes | + | 80S |
| Embrapa 41 | 1995 | no | - | 60S |
| Fepagro-RS 15 | 1998 | yes | + | 20 MR |
| Fundacep 29 | 1997 | yes | + | 10MR - MS |
| IAPAR 28 | 1998 | yes | + | 1MS |
| IAPAR 53 | 1992 | yes | + | 5R |
| IAPAR 84 | 1998 | no | - | 5MR - MS |
| IAS 54 | 1970 | yes | + | 80S |
| OCEPAR 22 | 1994 | no | - | 50MS |
| Pitana | --- | yes | + | 0 - 1MS |
| Trigo BR 4 | 1979 | yes | + | 0 |
| * in the F1 population of cross with Ne1 genotypes. | ||||
| ** a '+' means that the cultivar must have the gene Lr13, according to the linkage with the gene Ne2. | ||||
1998 wheat cultivar yield trials in Passo Fundo, state
of Rio Grande do Sul, Brazil.
J.C.S. Moreira and C.N.A. de Sousa.
Thirty-six yield trials were conducted at the National Research Center for Wheat, an unit of Embrapa in Passo Fundo, Brazil, testing about 460 spring cultivars of bread wheat.
Above-normal rainfall prevailed in June, July, and August during the wheat season in Passo Fundo (June to November). However, the rainfall was below normal in September, October, and November during flowering and harvest. Low yields were observed in some regions, and high yields in others. An average yield of 1,600 kg/ha was estimated for the state of Rio Grande do Sul, which is an increase of 30 % compared to 1997. Some lines and cultivars yielded more than 5,000 kg/ha in trials in Vacaria (170 km from Passo Fundo) and more than 4,000 kg/ha in Lagoa Vermelha (90 km from Passo Fundo).
High moisture at the beginning of the season favored diseases
and contributed to decreased yields in some regions. The trials
were conducted in a rotation area. Check cultivars used in 1998
were BR 23, CEP 24, and CEP 27. The cultivar Embrapa 16 occupied
a greater area in Rio Grande do Sul in 1998 (108,000 ha), followed
by CEP 24 and CEP 27 with 76,000 and 59,000 ha, respectively.
Cultivars and lines that yielded more than 4 % greater than the
best check in the trials at Passo Fundo are in Table 2.
| Cultivar | Cross | Yield (kg/ha) | % ofcheck |
|---|---|---|---|
| 1. Cultivar State Trial (without fungicide). | |||
| BRS 49 | BR 35/PF 83619//PF 858/PF 8550 |
2,720 |
115 |
| RS 1-FENIX | PF 70100/J 15157-69 |
2,608 |
110 |
| BR 23 (check) | CC/ALD SIB/3/IAS 54-20/COP//CNT 8 |
2,584 |
100 |
| 2. Cultivar State Trial (with fungicide). | |||
No cultivar produced more than check BR 23 (2,981 KG/HA) |
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| 3. South Brazilian Trial (without fungicide). | |||
| PF 9293 | PF 83899/PF813//F27141 |
2,903 |
126 |
| PF 92140 | BR 35/PF 8596/3/PF 772003*2/PF 813//PF 83899 |
2,836 |
123 |
| ORL 94363 | PF 87512//PF 869107 'S'/BAGULA 'S' |
2,709 |
117 |
| CEP 9483 | CEP 8720//PVN/ANI 'S'/3/CEP 8749 |
2,476 |
116 |
| PF 92231 | CEP 14/BR 23//CEP 19 |
2,661 |
115 |
| CEP 93113 | CEP 85155/3/CEP 7780*2//H499.71A/ 4*JUP73/4/BR 23 |
2,622 |
114 |
| CEP 9499 | TNMU/5/BR 35/4/IAC 5*6/CI 15243//IAC 5*6/AGA/3/IAC 5*6/AG//IAC 5*6/AGA |
2,600 |
113 |
| ORL 94364 | PF 87512//PF 869107 'S'/Bagula 'S' |
2,589 |
112 |
| PF 940097 | PF 8619/BR 35 |
2,459 |
107 |
| SA 9642 | - | 2,434 | 106 |
| ORL 94346 | PF 8944/BUCK Bagual//BR 23/Embrapa 27 | 2,411 | 105 |
| BR 23 (check) | CC/ALD SIB/3/IAS 54-20/COP//CNT 8 | 2,307 | 100 |
| 4. South Brazilian Trial (with fungicide). | |||
| PF 9293 | PF 83899/PF813//F 27141 |
3,221 |
107 |
| BR 23 (check) | CC/ALD SIB/3/IAS 54-20/COP//CNT 8 |
3,010 |
100 |
| 5. Regional Yield Trial (lines that yielded more then 5 % when compared to the best check). | |||
| PF 950419 | BR 32/PF 869120 |
2,443 |
118 |
| CEP 9567 | PF 85235/SA 8615/5/CEP 8879/4/KLAT/Soren//PSN SIB/3/BOW SIB |
2,406 |
116 |
| PF 950351 | BR 32/PF 869120 |
2,401 |
116 |
| ORL 95688 | BR 23/Embrapa 27//R 26-4/PF 889300 |
2,364 |
114 |
| CEP 9545 | CEP 8749/Embrapa 27 |
2,317 |
112 |
| CEP 94129 | Shanghai 8/CEP 8361//CEP 8435/CEP 17 |
2,272 |
109 |
| PF 940328 | BR 32/PF 869120 |
2,245 |
108 |
| CEP 954 | BAU SIB/CEP 83128//Embrapa 27 |
2,214 |
107 |
| BR 23 (check) | CC/ALD SIB/3/IAS 54-20/COP//CNT 8 |
2,078 |
100 |
| 6. Multilocation Preliminary Yield Trials (5 sites with lines in the 2nd year of test). Data from Passo Fundo. | |||
| PF 960188 | PF 87899/EMB 16 |
3,015 |
129 |
| PF 960198 | PF 87107/2*IAC 13 |
2,715 |
116 |
| PF 960009 | CEP 24/PF 87116//FN/BR 23 |
2,683 |
115 |
| PF 960181 | F32302//F32044/PF 9545 |
2,625 |
113 |
| PF 960411 | EMB 27/Klein Orion | 2,518 | 108 |
| PF 960343 | EMB 27*2/Klein H 3450 C 3131 | 2,512 | 108 |
| PF 960112 | EMB 27/PF 859114 | 2,508 | 108 |
| PF 960147 | EMB 40/EMB 27 | 2,508 | 108 |
| PF 960149 | EMB 40/EMB 27 | 2,497 | 107 |
| PF 960296 | BR 4/BH 1146//VEE SIB/PAT 7392 | 2,495 | 107 |
| PF 960044 | PF 87373/PF 85202 | 2,473 | 107 |
| BR 23 (check) | CC/ALD SIB/3/IAS 54-20/COP//CNT 8 | 2,329 | 107 |
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7. Preliminary Yield Trials (280 new lines tested in 13 trials).
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