Agriculture Reference
In-Depth Information
some extent. Most commercial tomato cultivars are moderately sensitive
to increased salinity and only limited variation exists in cultivated species.
Genetic variation for salt tolerance during seed germination in tomato has
been identified within cultivated and wild species. Yildirim and Guvenc
(2006) reported that pepper genotypes Demre, Ilica 250, 11-B-14, Bagci
Carliston, Mini Aci Sivri, Yalova Carliston, and Yaglik 28 can be useful as
sources of genes to develop pepper cultivars with improved germination
under salt stress. In Tunisia, pepper cultivar 'Beldi' significantly out-yield-
ed than other test cultivars at high salt treatments.
S. esculentum
accession
(PI174263) showed that the ability of tomato seed to germinate rapidly un-
der salt stress (Foolad & Jones 1991).tomato genotypes, LA1579, LA1606
both
S. pimpinellifolium
) and LA4133 (
S. lycopersicum
var
cerasiforme
)
from AVRDC, Taiwan have shown salt tolerance. Wild tomato species
S.
cheesmanii
,
S. peruvianum
,
S pennelii
,
S. pimpinellifolium
, and
S. hab-
rochaites are
the potential source of salt tolerance
(Cuartero et al.,
2006;
Flowers, 2004; Foolad, 2004). Attempts to transfer quantitative trait loci
(QTLs) and elucidate the genetics of salt tolerance have been conducted
using populations involving wild species. Elucidation of mechanism of
salt tolerance at different growth periods and the introgression of salinity
tolerance genes into vegetables would accelerate development of variet-
ies that are able to withstand high or variable levels of salinity compatible
with different production environments.
8.4.3 USE OF BIOTECHNOLOGY TOOLS IN STRESS
MANAGEMENT
Use of
molecular technologies has revolutionized the process of tradition-
al plant breeding. Combining new knowledge from genomic research with
traditional breeding methods enhances our ability to improve crop plants.
The use of molecular markers as a selection tool provides the potential for
increasing the efficiency of breeding programs by reducing environmental
variability, facilitating earlier selection, and reducing subsequent popu-
lation sizes for field testing. Molecular markers facilitate efficient intro-
gression of superior alleles from wild species into the breeding programs
and enable the pyramiding of genes controlling quantitative traits. Thus,
enhancing and accelerating the development of stress tolerant and higher
yielding cultivars for farmers in developing countries. Several QTLs have
