ITEMS FROM BRAZIL

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.

Reaction of wheat cultivars released by Embrapa in relation to aluminum toxicity in acid soils. [p. 33]

Cantídio N.A. de Sousa.

Acid soils are prevalent in most wheat-growing areas in Brazil. Resistance/tolerance to aluminum toxicity is a general objective in the wheat-breeding program of Embrapa (Brazilian Agricultural Research Corporation) that develops new wheat lines and cultivars in research centers located in Passo Fundo, Pelotas, Londrina, Dourados, and Planaltina. Susceptible cultivars also are released, because there are areas without an aluminum (Al)-toxicity problem. Genotypes are tested in the field and by screening in the laboratory in order to evaluate their reaction to Al toxicity.

Cultivars were evaluated by Embrapa in the field between 1989 and 2000 and the results are presented in Table 1. The methodology was described in Plant Breed 117:217-221, 1998. Trials were grown each year and replicated three times. Plant response to Al in acid soil was evaluated visually on the above-ground parts of plants at maturity and, in some instances, before heading. The susceptibility index to Al toxicity in each year was calculated as the mean of the observations made during the given year. The general index presented in Table 1 is the average of the index of 4 or more years. The most resistant cultivars, with a susceptibility index to aluminum lower than 1.25 were BRS 49, CNT 1, Trigo BR 25, Trigo BR 35, and IAC 5-Maring (resistant check). The most susceptible cultivars were Anahuac 75 (susceptible check) and Trigo BR 36-Ianomami.

Table 1. Cultivar, year of release, susceptibility index in the field, and reaction to aluminum toxicity.

Cultivar	Year of release in Brazil	Al3+-susceptibility index	Al3+ reaction *
BRS 49	1996	1.16	R
BRS 119	1997	1.72	MR
BRS 120	1997	2.22	MR
BRS 176	1999	1.60	MR
BRS 177	1999	1.82	MR
BRS 179	1999	1.30	R
BRS 192	2000	1.67	MR
BRS 194	2000	1.34	R
CNT 1	1975	1.08	R
CNT 8	1976	1.84	MR
CNT 10	1977	1.28	R
Embrapa 15	1992	1.26	R
Embrapa 16	1992	1.53	MR
Embrapa 21	1993	2.33	MR
Embrapa 22	1993	2.63	MR
Embrapa 24	1993	1.42	R
Embrapa 27	1994	1.81	MR
Embrapa 40	1995	2.22	MR
Embrapa 41-Ofaié	1995	2.35	MR
Embrapa 42­Nambiquara	1995	2.56	MS
Embrapa 52	1996	1.48	R
Trigo BR 2	1979	2.12	MR
Trigo BR 10-Formosa	1983	2.53	MS
Trigo BR 12-Aruanã	1985	2.81	MS
Trigo BR 15	1985	1.29	R
Trigo BR 16-Rio Verde	1986	1.77	MR
Trigo BR 17-Caiuá	1986	2.75	MS
Trigo BR 18-Terena	1986	2.21	MR
Trigo BR 23	1987	1.39	R
Trigo BR 24	1988	1.79	MR
Trigo BR 25	1988	1.08	R
Trigo BR 26-São Gotardo	1988	3.14	MS
Trigo BR 32	1988	1.43	R
Trigo BR 33-Guará	1989	2.42	MR
Trigo BR 35	1989	1.01	R
Trigo BR 36-Ianomami	1990	3.87	S
Trigo BR 38	1990	1.91	MR
Trigo BR 39-Paraúna	1991	2.44	MR
Trigo BR 40-Tuiúca	1991	2.46	MR
Trigo BR 43	1991	1.50	R
Anahuac 75 **	1981	4.31	S
IAC 5-Maringá ***	1966	1.07	R
* R = resistant, MR = moderately resistant; MS = moderately susceptible, and S = susceptible. ** Susceptible check cultivar. *** Resistant/tolerant check cultivar.

Genetic wheat improvement for durable resistance to disease. [p. 33-35]

Leo J.A. Del Duca, Amarilis L. Barcellos, Cantídio N.A. Sousa, Eliana M. Guarienti, Leila M. Costamilan, Márcio Só e Silva, and Pedro L. Scheeren.

Embrapa Trigo has developed activities for the identification of resistance sources and genetic improvement of wheat, with emphasis on leaf rust and powdery mildew. Durable resistance (DR) contributes to a reduction in production costs and for environmental protection, by decreasing the use of chemicals, creating more stable grain yields, and minimizing crop failure by diseases. Besides DR, we strive to incorporate desirable traits for agronomic and industrial-quality characteristics.

Diseases are a great obstacle to wheat production in Brazil, and new cultivars frequently have their commercial cultivation life span shortened by breakdown in resistance. Partial resistance (PR) is an alternative option to the specific resistance for races and may be more durable, although it does not confer immunity. The association between DR and slow rusting with PR and adult-plant resistance has been identified for wheat leaf rust in Brazil (Del Duca et al. 1994). PR is characterized by a reduced rate of development of the disease, despite of the occurrence of susceptible infection. Parameters for its identification are a smaller infection frequency, a longer latent period, a lower rate of production of spores/lesion, and/or a shorter infection period. This resistance type would be controlled by genes of additive action (Parlevliet 1978).

Our emphasis on rusts and powdery mildew is because in biotrophic organisms, new pathogenic races overcome the resistance genes (Parlevliet 1981). In previous DR-breeding strategies, populations were obtained by intercrossing among different sources. The hypothesis was that this resistance, controlled many times by genes of addictive action, could be accumulated by intercrossing susceptible cultivars with low infection and selecting derived populations and progenies for transgressive levels of resistance. Progress has been obtained in lines with resistance to a specific disease, but the possibility of its commercial release has been hindered by inherent faults in other important agronomic characteristics.

Our main activities in this research have been to select sources of DR for leaf rust and powdery mildew in different nurseries and select for a more favorable plant type (lower height, better straw, and early cycle) in segregant populations and derived progenies sown in low density, under conditions of artificial inoculation. Grain selection is made after field selection and considering plumpness of grains and lack of disease symptoms. Selection for resistance to powdery mildew, in fields with natural infection and artificial inoculation of leaf rust, has allowed reasonable levels of infection in order to evaluate collections and select plants. Although there is a potential risk for stem rust, we have not been selecting for resistance because of its absence in the field in the last few years and the availability of specific populations with resistance. High levels of leaf rust and powdery mildew have allowed us to distinguish genotypes with low to moderate reactions in crosses, germ plasm, and progenies when compared with highly susceptible check cultivars such as Morocco and OR 1. Considering the difficulties in promoting lines with adequate disease resistance and other important properties for wheat improvement, new populations are being generated with the aim of associating DR for leaf rust and powdery mildew resistance and desirable agronomic type, for reaction to diseases caused by necrotrophic organisms, for preharvest sprouting, and for industrial quality. As a means to accelerate the selection of new lines, summer generations are being advanced in central Brazil, and the production of DH lines through gynogenesis are obtained from plants selected in the initial generations.

References.

• Del Duca LJA, Barcellos AL, and Sartori JF. 1994. Melhoramento de germoplasma de trigo para resistencia durável às doenças. In: Reunião Nacional de Pesquisa de Trigo, 17, 1994. Resumos, EMBRAPA-CNPT, Passo Fundo, RS. p. 139 (in Portuguese).
• Parlevliet JE. 1978. Further evidence of polygenic inheritance of partial resistance in barley to leaf rust, Puccinia hordei. Euphytica 27:369-79.
• Parlevliet JE. 1981. Race non-specific disease resistance. In: Strategies for the control of cereal diseases (Jenkyn JF and Plumb RT eds). Blackwell Scientific, Oxford, UK. pp. 47-54.

Testing early planted wheat in Paraná, 2000-2001. [p. 35-36]

L.J.A. Del Duca, O. Rodrigues, G.R. Cunha, R.S. Fontaneli, J. Almeida, N. Antoniazzi, R. Molin, F. Franco, and S.R. Dotto.

To identify wheat lines adapted to early sowing, with greater soil cover, increased grain-yield potential, and
greater chances of escaping frost because of a longer emergence and flowering period, 37 lines developed by Embrapa and Coodetec were tested in four locations in the state of Paraná, Brazil, by Embrapa-Soja and Coamo in Campo Mourão, Coodetec in Cascavel, and Fundação ABC in Ponta Grossa and Fundação Agrária in Guarapuava in 2000. In 2001, 26 wheat lines from Embrapa Trigo were tested at Fundação ABC (Castro) and Fundação Agrária (Guarapuava). The trials included Trigo BR 23, Trigo BR 35, CEP 24-Industrial, and Ocepar 21 as early check cultivars. Severe frosts occurred in the state of Paraná in 2000 producing greater damage in the typically early, check wheat cultivars. Such results confirmed the potential advantage of a breeding strategy aimed at obtaining late­early ecoideotypes. High humidity in 2001 in the late winter and spring resulted in a high incidence of head diseases, especially scab, limiting the yield potential of the early planting. Outstanding cultivars in the anticipated-planting trials are shown in Table 2.
.

Table 2. Outstanding cultivars in anticipated-planting trials in Paraná, Brazil, in 2000-01.

Cultivar	Cross	Ponta Grossa (kg/ha)	Guarapuava (kg/ha)
1. 2000 Grain-yield Trial (without fungicide).
PF 973961	PF 84511/Coker 80.33//CTY/BR 34	3,360	3,749
PF 980416	Coker 80.33/PF 869120//BR 18	3,067	3,782
PF 980441	PF 89261/PF 87373//CEP 24	3,264	3,302
PF 970308	Balkan/PF 79777	3,338	3,121
PF 970346	PEL 73101/BR 5//PF 79777/OASIS	3,221	3,228
PF 980407	PF 89261/BR 32/3/CTY/PF 87107//EMB 16	3,151	2,986
PF 950136	PF 8569/Coker 762	3,022	2,947
PF 980405	CTY/PF 87107//EMBRAPA 16	3,333	2,454
PF 960263	Coker 762*2/CNT 8	2,061	3,644
IPF 55204	Florida 301/Coker 762	2,834	2,759
PF 970332	Coker 762/PAT 7392	2,005	3,413
PF 960262	Coker 762*2/CNT 8	1,826	3,487
CEP 24 (best check)	BR 3/CEP 7887//CEP 7775/CEP 11	1,424	1,904
2. 2000 Double-purpose Trial (with fungicide).
IPF 55204	Florida 301/Coker 762	3,035	3,840
IPF 64758	Saluda/Coker 762//Coker 80-28/FL 301	3,018	3,210
PF 950136	PF 8569/Coker 762	3,044	3,574
PF 960262	Coker 762*2/CNT 8	3,707	1,924
PF 960263	Coker 762*2/CNT 8	3,317	1,599
PF 970346	PEL 73101/BR 5//PF 79777/Oasis	3,495	3,402
PF 970347	HLN/CNT 7//AMI/CNT 7	3,264	2,953
PF 970349	Coker 762*2/CNT 8	3,668	2,522
PF 980416	Coker 80.33/PF 869120//BR 18	4,048	3,480
CEP 24 (best check)	BR 3/CEP 7887//CEP 7775/CEP 11	2,364	1,307
3. 2001 Grain-yield Trial.		Castro (kg/ha)	Guarapuava (kg/ha)
PF 990446	PF 87107/PF 87451/4/VPM83.11.48/2*BR 14//PF 869120/3/CEP 24	5,978	2,403
PF 990452	Coker 762/PF 905//CTY/BR 34	5,319	3,181
PF 990522	IPF 55204/EMB 16/3/F25950/F30505//PF 88603	4,705	4,063
PF 980417	Coker 762 /PF 89263//EMB 16/3/Coker 762/PF 87373	4,704	1,612
PF 973960	HLN/Coker 80.33//CTY/PF 869120	4,498	3,679
PF 980408	Coker 762/PF 89263//EMB 16/3/Coker 762/PF 87373	4,188	1,397
PF 990498	IPF 55204/PF 88522//CTY/CEP 24	4,096	3,510
PF 990575	Coker 80.33/PF 85202//Coker 762/PF 87107	4,011	2,762
PF 980376	EMB 16/IPF 55204//CEP 24/Coker 762	4,010	2,066
BR 23 (best check)	CC/ALD SIB/3/IAS 54-20/COP//CNT 8	4,244	2,868
4. 2001 Double-purpose Trial.
BRS 176	HLN/CNT 7//AMIGO/CNT 7	4,989	4,531
BRS 177	PF 83899/PF 813//F27141	4,607	5,066
PF 950136	FLORIDA 301/COKER 762	4,854	4,346
PF 960243	CENTURY/BR 35	4,649	5,241
PF 960262	COKER 762*2/CNT 8	4,948	4,702
PF 960263	COKER 762*2/CNT 8	4,765	4,606
PF 970349	COKER 762*2/CNT 8	4,388	3,902
PF 973961	PF 84511/COKER 80.33//CTY/BR 34	4,220	4,466
PF 980405	CTY/PF 87107//EMBRAPA 16	4,547	3,813
PF 980416	COKER 80.33/PF 869120//BR 18	5,769	4,184
PF 980441	PF 89261/PF 87373//CEP 24	4,652	4,369
BR 23 (best check)	CC/ALD SIB/3/IAS 54-20/COP//CNT 8	5,043	4,544

Brazilian wheat production in 1999-2000 and 2000-2001. [p. 35, 37]

Leo J.A. Del Duca and Eliana M. Guarienti.

Brazilian wheat production has changed from near self-sufficiency (6.1 million ton) in 1987 to a drastic reduction of nearly 1.5 million tons in 1995. However, consumption has increased to about 10 million tons, and Brazil now imports most of the domestically consumed wheat.

Since 1997, Brazilian wheat imports have been growing because of increased demand and stabilized production. During the 1999-2000 season, an increase of 9.7 % relative to the previous period was due to greater consumption by the ration industries and an increase in demand for flour, especially for baking and cookies. In 2000, speculation in the wheat market occurred because of crop failures world wide. Importing 75 % of the annual demand was reflected in price elevation and an increase in foreign exchange. That imports may surpass 8 million tons is a great possibility, at a suspected cost of 1 billion dollars (nupla@conab.gov.br;;paulo.coutinho@conab.gov.br). For the 2000-01 wheat season, 7.6 million tons were imported for a consumption of 10.2 million tons (rubem.alves@conab.gov.br; einge@conab.gov.br). The numbers presented in the Table 3 express the largest harvest of the last 5 years, a result of adequate climatic conditions, technological progress of the national wheat crop, and remunerating prices in the market.

For the 2000-01 wheat season, 7.6 million tons were imported for a consumption of 10.2 million tons (rubem.alves@conab.gov.br; einge@conab.gov.br). The numbers presented in the Table 3 express the largest harvest of the last 5 years, a result of adequate climatic conditions, technological progress of the national wheat crop, and remunerating prices in the market. production of five cultivars (50 %) from a total of 48 wheat cultivars. Considering the size of the cropping area in Brazil in 2000-01 (1.59 million hectares) and the great ecological diversity, a greater cultivar diversity is desirable. The Brazilian wheat crop depends greatly on the climatic conditions, which can cause crop failure every 3 or 4 years (FNP Consultoria & Trade Ltda, Agrianual 2002). Thus, genotype diversification can help to reduce risk. The states of Paraná and Rio Grande do Sul are responsible for most of Brazilian wheat production. This production is widespread over a large number of growing conditions, such as rainfed or irrigated fields, presence or absence of soil aluminum toxicity, and high or low soil fertility. The most important wheat cultivars of each state are given in Table 5, along with information about their pedigree and industrial-quality classification. In 1999-2000, BRS 49 was the most widely grown Brazilian wheat cultivar, having the greatest production area in the three southern states (Rio Grande do Sul, Santa Catarina, and Paraná).

Main Brazilian wheat cultivars sown in the 1999-2000 season. [p. 35, 38]

Leo J.A. Del Duca and Eliana M. Guarienti.

Considering the Brazilian 1999-2000 wheat crop, only 23 cultivars made up more than 1 % of the total seed available (Table 4). Information about the pedigree and industrial quality of the cultivars is provided. Considering the industrial quality of these 23 cultivars, only five are classified as soft wheats (CEP 27-Missões, FUNDACEP 30, FUNDACEP 32, Trigo BR 23, and FEPAGRO 15). The remaining genotypes, except IAPAR 17-Caeté (very strong gluten), are considered of good bread-making quality. In all Brazilian states, there was a high concentration of the seed production of five cultivars (50 %) from a total of 48 wheat cultivars. Considering the size of the cropping area in Brazil in 2000-01 (1.59 million hectares) and the great ecological diversity, a greater cultivar diversity is desirable. The Brazilian wheat crop depends greatly on the climatic conditions, which can cause crop failure every 3 or 4 years (FNP Consultoria & Trade Ltda, Agrianual 2002). Thus, genotype diversification can help to reduce risk. The states of Paraná and Rio Grande do Sul are responsible for most of Brazilian wheat production. This production is widespread over a large number of growing conditions, such as rainfed or irrigated fields, presence or absence of soil aluminum toxicity, and high or low soil fertility. The most important wheat cultivars of each state are given in Table 5, along with information about their pedigree and industrial-quality classification. In 1999-2000, BRS 49 was the most widely grown Brazilian wheat cultivar, having the greatest production area in the three southern states (Rio Grande do Sul, Santa Catarina, and Paraná).

Table 5. Seed availability of the most adopted wheat cultivars in the Brazilian producing states in 1999-2000. Brazilian states are RS = Rio Grande do Sul; SC = Santa Catarina; PR = Paraná; SP = São Paulo; MS = Mato Grosso do Sul; MG = Minas Gerais; GO = Goiás; DF = Distrito Federal. Seed availability is tons available for the 1998-99 season. --- incomplete or not available for the 1999-2000 season. Source of seed-availability data are MAPA/Embrapa/ABRASEM and Embrapa-SNT.

State	Cultivar name	Cross	Quality	Availability	%
RS	BRS49	BR 35/PF 83619//PF 858/PF 8550	bread	15,297.67	18.49
	CEP27-Missões	CEP 8057/Butuí//CEP 8324	soft	13,983.43	16.90
	FUNDACEP 29	BR 23/CEP 8423//BUC SIB	bread	9,214.19	11.14
SC	BRS 49	BR 35/PF 83619//PF 858/PF 8550	bread	1,612.30	34.18
	OR 1	EMBRAPA 27/Bagula SIB	bread	726.00	15.39
	CEP27-Missões	CEP 8057/Butuí//CEP 8324	soft	486.20	10.31
PR	OR 1	EMBRAPA 27/Bagula SIB	bread	22,525.55	18.30
	IAPAR 53	SULINO/IA 7929	bread	21,951.80	17.83
	IAPAR 78	VEE SIB/BOW SIB	bread	16,387.55	13.31
SP	IAC 350­Goiapa	2109-36/SERI	bread	374.42	---
	IAC 24­Tucuruí	IAS 51/IRN 597-70	strong	230.84	---
	IAC 289­Marruá	KVZ/BUHO SIB//KLY/BB, VEE 5, SERI 82	bread	225.00	---
MS	BR 18­Terena	D6301/NAI60//W/RM/3/CIA*2/CHR=ALD45SEL	bread	397.79	89.39
	BR 40­Tuiúca	ANA 75/HUAC SIB	strong	47.20	10.61
MG	Embrapa 22	VEE SIB/3/KLTO SIB/PAT 19//MO/JUP	bread	64.10	---
GO/DF	Embrapa 42	LAP 689/MS 7936	strong	72.00	---

Protein and isozyme analyses in Ae. tauschii. [p. 37]

Sandra Patussi Brammer, Daniela Silva Boscardin, and Caren Regina Cavichioli Lamb.

The species Ae. tauschii, donor of the genome D of T. aestivum, was evaluated in 2001 using HMW-glutenin and esterase analyses to detect genetic variability in different accessions to compile information that may be useful in wheat-improvement programs. The HMW-glutenins were extracted from 60 seeds, with three replications of each of the 20 accessions analyzed. The presence of 5+10 and 2+12 subunits differentiated the germ plasm lines. For the esterases, 100 plants were analyzed with five replications of the 20 accessions. Wide qualitative and quantitative variability was identified in the esterases. Currently, we also are developing molecular analyses through using microsatellites.