Bangladesh Australia Wheat Improvement Project-CIMMYT
P.O. Box 6057, Gulshan, Dhaka-1212m, Bangladesh.
E-mail: C.MEISNER@CGNET FAX: 880-2-883516
Craig A. Meisner, Agronomist & Project
Advisor.
Bangladesh: towards food self-sufficiency.
CIMMYT has been linked with the wheat
research of Bangladesh since 1968 through its yearly training
program in Mexico and, recently, with the placement of CIMMYT
scientists in Bangladesh working bilaterally with the Wheat Research
Center since 1982.
Wheat was a minor crop until a thrust
by the Government of Bangladesh in 1975 created an environment
for rapid wheat expansion that peaked in 1981 in both production
(1.1 million tons) and area (0.5 million hectares). Yields went
from 1 t/ha in 1970 to over 2 t/ha in 1981, but have not changed
much since that time.
However, Bangladesh agriculture has
changed with the introduction of winter (boro) MV rice and shallow
tubewell irrigation. Thus, much of the wheat hectareage of 1980
was replaced by winter rice, and the wheat hectareage of 1995
is in the marginal, fallow lands of 1980. Yet, wheat follows
rice in 95 % of the cropping patterns.
A recent economic survey indicated
that wheat has a comparative financial advantage over winter rice
in those soils less conducive for rice (lighter texture) and at
slightly higher elevations where irrigation is difficult (CIMMYT-IFPRI,
1994).
Two new lines were released in 1994
by the Wheat Research Center (WRC): Protiva, maturing
at 112 DAS, with Lr10, Lr13, and Lr26 (KU
Head selection made in Thailand), and Sawghat, maturing
the same as Protiva, with Lr13 and Lr23 (IAS 58/3/
KAL/BB//ALD/4/OLN/TRM//7C/ALD CM 69201-B-1Y-3M-7Y-1M-0Y). They
offer better disease resistance, but no yield advantage, over
the widely adapted released variety of 1984, Kanchan (UP301/C306
1187-1-1P-5P-5JO-OJO).
Intensive screening is conducted for
Helminthosporium sativa leaf blotch (Bipolaris
sorokiniana or Cochliobolus sativus). High
natural infection occurs from soil inoculum throughout the country.
Reductions of 15-23
% in growers' fields have been reported in 1994.
Spike sterility in growers' fields (some fields having 90 % sterility in some years) represents another problem of growing wheat in Bangladesh. The causes have not been determined, but are believed to be complex. They involve low soil boron, foggy humid (low light) weather at booting (pollen meiosis), and water logging at
booting. Genotypic differences are
shown. Low fertility exascerbates the problem in growers' fields.
Intensive collaborative experiments are being conducted with
CSIRO, Australia, and Chaing Mai University, Thailand, on this
problem.
The Bangladesh-Australia
Wheat Improvement Project is unique in involving CIMMYT scientists
in both the development of the NARS' program and supplementing
their scientific knowledge through sustainable methods. For example,
computer usage has increased the scientists' awareness of their
lack of information, so CD ROM databases (e.g., CABI, AGRICOLA,
etc.) have been installed. E-mail capabilities are being investigated
for linking the WRC scientists to the rest of the world.
Food self-sufficiency may not be a
sustainable goal for the long term for Bangladesh (the size of
North Carolina with a population of 115 million, growing at 2
% per year, and a median age of 18). However, for the short term,
the goal is reachable and the benefits for the 85 % of the population
who are rural-based will be great. Once the rural population
can educate the next generation, the possibilities of more industrialization
and labor-intensive businesses can be realized. Then, imports
may be the only real sustainable way of providing food for this
country by the year 2030.
National Center for Wheat Research-EMBRAPA
Centro Nacional de Pesquiza de Trigo, BR 285, KM 174, Caixa Postal 569, 99001-970,
Passo Fundo, Rio Grande do Sul, Brazil.
Wheat leaf rust.
A.L. Barcellos and M.C. Medeiros.
Wheat leaf rust virulence surveys are
conducted annually throughout the Brazilian wheat regions. The
predominant races in the period 1990-1993
were LLG, MCR, TBJ, and LCG, respectively, following the North
American nomenclature. They are characterized by virulence on
Lr9 (LLG), Lr26 (MCR and LCG), and Lr2a (TBJ).
LCG has been distributed widely in Brazil and is found also in
Argentina, Bolivia, Chile, Paraguay, and Uruguay. Most of the
races, identified from collections of these countries in the Southern
Cone of South America during the period 1988-1993,
occur also in Brazil. However, a few virulence/avirulence phenotypes
differed: SCH collected in Paraguay and NCH, SBJ, and DBB from
Chile. Isolates of the race DBB were obtained from Triticum
turgidum collections. A race not previously identified
was detected in Brazil from 1994 collections. Designated MFT,
this race is virulent on the gene combinations Lr23 + Lr24
and Lr24 + Lr26, which had been conditioning resistance
in Brazil against all the known races.
Presently, the genes Lrl9 or
Lr32 condition resistance to all known Brazilian phenotypes
of Puccinia recondita. The following gene combinations
are effective: Lr2a (Lr2c) + Lr3 + Lrl4b
+ Lr24, 16 combinations of two genes, or 36 combinations
of three genes. The two- and three-gene combinations involve
Lr2a, 2c, 3, 3ka, 9, 10,
16, 20, 21, 24, 26 and Lrl,
2a, 2c, 3, 3ka, 10, 14a,
14b, 16, 20, 21, 23, 24,
26, respectively.
An unknown gene for adult plant resistance. A.L. Barcellos, under the supervision of Drs. A. Roelfs and M.I.B. de M. Fernandes, recently submitted a Ph.D. dissertation to the Federal University of Rio Grande do Sul, Brazil. The data indicate that the durable resistance of the Brazilian cultivar Toropi is conditioned by one (or two) recessive gene(s) for
adult plant resistance distinct from
the already described Lr genes. The resistance was expressed
by one and two genes under field and greenhouse conditions, respectively.
Publication.
Barcellos AL. 1994. Genetica
da resistincia
de planta adulta -
ferrugem da folha na cultivar brasileira de trigo Toropi (Triticum
aestivum L. em. Thell). Porto Alegre: UFRGS. Tese Doutorado.
163 pp.
L.J.A. Del Duca, C.N.A. Sousa, E.P. Gomes, E.M. Guarienti, J.C.S. Moreira, and P.L. Scheeren.
EMBRAPA 16
was obtained at the National Wheat Research Center (EMBRAPA, Centro
Nacional de Pesquisa de Trigo) from the cross `HULHA
NEGRA/CNT 7//AMIGO/CNT 7',
made at Passo Fundo, Rio Grande do Sul, in 1980. The F1
generation was produced in Mexico in 1980-81.
The population was chosen for an experiment to compare breeding
methodologies. It was selected by the pedigree method, being
bulked as a line (PF 86238) in 1986 at the F7 generation
as a secondary outcome of the experiment.
EMBRAPA 16 was released for Rio Grande
do Sul in 1992, Santa Catarina in 1993, and Parana (regions C,
E, and F) in 1995.
EMBRAPA 16 has an early cycle; mid
to tall height; awned spikes; and long, red, semihard grains.
It is resistant to the aluminum toxicity of the soil, shattering,
stem rust, and soilborne mosaic virus. It has shown good resistance
to powdery mildew under field conditions (low levels of infection).
It is moderately susceptible to glume blotch and is resistant
to all races of leaf rust, except to races B 29 and B 30, and
to the new highly virulent race, B 40, at the seedling stage.
However, it has demonstrated good performance at the adult plant
stage in field conditions under high infections of leaf rust.
It may show lodging problems under
good soil fertility conditions and a tendency for sprouting with
delayed rains.
Because of its good plant-health performance,
it has not been responsive to treatments with fungicides when
compared with the check cultivar, BR 23.
It was the wheat cultivar with the
highest grain yield in the state of Rio Grande do Sul in each
year over the 1990-93
period, yielding 24 %, 20 %, 9 %, and 22 %, in 1990, 1991, 1992,
and 1993, respectively, over BR 23, the most widely grown Brazilian
wheat cultivar.
EMBRAPA 16 is classified as superior,
in baking characteristics, which are, at present, important demands
of the Brazilian market for bread, pastas, and crackers.
L.J.A. Del Duca and I. Sandini.
Although the Brazilian wheat region
F is not a part of the most important cultivated area of the Parana
state, it shows a potential that can be explored better with specifically
adapted germplasms. Such ecological conditions can be represented
by the region of Guarapuava (latitude 25 30'S
-
longitude 51 30'W
and an elevation of 1,160 m). Because of the altitude, the climate
is temperate with the possibility of frosts from May to October.
This circumstance can make promising the use of later-flowering
wheats in order to escape the risk of frost damage.
Therefore, an experiment was conducted
at the Experiment Station of Cooperativa Agraria Mista Entre Rios
Ltda. (sowing = June 26, 1993), with the following outstanding
grain yield cultivars/lines: IPF 41004, IPF 55204, PF 87158,
IPF 60669, PF 87451, PF 87452, IPF 37379, PF 86247, PF 89131,
PF 89422, and CEP 14, which yielded 7,263; 6,276; 5,348; 5,299;
5,168; 5,165; 5,029; 4,938; 4,796; 4,795; and 4,714 kg/ha, respectively.
These represent 157 % to 102 % relative to the best check (EMBRAPA
16 = 4,634 kg/ha). The grain yields of the others checks ranged
from 58 % (BR 23) to 79 % (BR 35) in relation to EMBRAPA 16.
These results obtained under Guarapuava
conditions are very promising, especially when considering that
the trial did not receive to any fungicide treatment.
Clipping effects on agronomic characters, plant health, and baking quality of winter cereals.
L.J.A. Del Duca, R.S. Fontaneli, and E.M. Guarienti.
Winter cereals for double-purpose utilization
(forage and grain) can contribute to the sustainability of the
agricultural and livestock systems. The effects of clipping (without
clipping; one clipping -
July 16, 1993; and two clippings -
August 13, 1993) with approximately 30 cm of plant height and
5-7
cm of stubble, to simulate cattle grazing, were evaluated in the
following cereals: 6 wheats (4 later flowering and 2 early checks),
2 common oats, 1 Avena strigosa, 1 barley, 1 triticale,
and 1 rye. General results included:
a). Bushel weight (BW) and kernel weight (KW) were reduced at significant levels with the clippings;
BW - without clipping (WC) = 67.4 kg/hl; one clipping (1C) = 66.0 kg/hl; and two clippings (2C) =
56.3 kg/hl; and KW -
WC = 29.8 g; 1C = 26.9 g; and 2C = 17.9 g.
b). The cycle (emergence - flowering period) was delayed with the clippings: 108 days (WC); 115 days (1C);
and 135 days (2C).
c). The average plant height was reduced
with the clippings: 93 cm (WC); 75 cm (1C); and 52 cm (2C).
Higher lodging indexes were obtained
in the oat UPF 15 (18.3), in the rye BR 1 (30.0), in the wheat
EMBRAPA 16 (36.7), and in Avena strigosa (80.0).
As a consequence of the clippings, these indexes were reduced
to low values (from 0 to 3).
Structural changes in the plants with
the clippings apparently induced lower mildew infection in oats
UPF 15, lower leaf rust infection in wheat PF 86247, and an increase
in the disease complex of spikes in wheat.
Preliminary results showed no influence
of the clippings on the values from the alveograph method (W =
deformation energy of the dough) in the six wheats evaluated for
baking quality.