Agriculture Reference
In-Depth Information
Fig. 5.2.
Mean yield of F
2:4
families evaluated in family yield trials (upland rice).
discoloration), and long slender grains, which are soft and nonsticky
when cooked.
The latest release of Embrapa
is upland rice breeding program is BRS
Esmeralda, derived from a cross between BRS Primavera and sources
of blast resistance and drought tolerance. In a study of a combined
indexof grainyield, stability, and adaptability of elite lines over 27years
of
'
field trials (Colombari Filho et al. 2013), BRS Esmeralda ranked
eighth among 264 elite lines, above all other cultivars with adequate
grain quality. The inbred line AB 062008 presented even better per-
formance over a wide range of environments, and is in the pipeline for
release, pending
final quality tests.
The genetic background of Brazilian upland cultivars is predomi-
nantly
tropical japonica
(Borba et al. 2009), although considerable
introgression of
indica
germplasm occurred over time, especially due
to contributions from CIAT and CIRAD. Those introgressions were ess-
ential to change the plant type from traditional landraces to a modern
plant type. This change made possible upland rice cultivation in more
favorable conditions, with higher inputs.
Brazilian cultivars may be adaptable to other tropical areas with high
rainfall (
1000m). Host plant resistance
to biotic stresses other than what is common in Brazil, however, is
unknown. For this reason, the introduction of Brazilian cultivars in other
countries would require careful
>
1200mm) and low altitude (
<
field testing, especially in target pest and
disease hot spots.
