| dc.description | Salinity is a major abiotic constraint on crop production and food security and adversely
impacts the socio-economic fabric of many developing countries. In Bangladesh, over 30%
of the net cultivable area lies in the coastal zone of the Bay of Bengal of which
approximately 53% is affected by varying degrees of salinity. The salt affected area in the
coastal zone of the country was about 0.83 million hectaresin 1966-76, which expanded to
3.1 million hectaresover the last three decades (Haque, 2006). In addition, more area in that
zone is expected to become saline in the future due to increase in sea water level as a
consequence of the greenhouse effect. The area in close proximity to the sea is vulnerable to
salinity especially, those with tidal water flowing over the areas. The problem becomes
acute when tidal water goes away and soil becomes dry. Moreover, cyclones, like those
which occurred in Bangladesh in 1991, 2007 (Sidr) and 2009 (Aila) pushed the saline water
front further inland and into the groundwater. A study showed that the salt-affected areas in
the coastal region of Bangladesh increased sharply by 26.71% to 950,780 hectares in 2009
from 750,350 hectares in 1973 (Ali, 2011). Agricultural land use in salt affected areas is
very poor, which is roughly 50% of the country’s average yield (Petersen and Shireen,
2010). Most of the high yielding salt sensitive crop might become unsuitable for cultivation
in the existing cropping pattern. Serious attempt should therefore be undertaken to search
for tolerant crops or genotypes of a crop to keep agriculture in the salt affected area
economically viable. | en_US |
| dc.description.abstract | Two experiments (Germination test & seedling growth, and pot experiment for yield) were carried out at
laboratory and shade house, Department of Agronomy, Hajee Mohammad Danesh Science and
Technology University (HSTU), Dinajpur during Nobember 2013 to March 2014. For germination and
seedling growth 22 wheat genotypes were tested in three salinity levels (0, 100 and 200 mM) for 10 days
in sand culture in small plastic pot. Speed of germination as expressed by germination percentage (GP),
rate of germination (GR), germination co-efficient (GC) and germination vigor index (GVI) of all wheat
genotypes were delayed and germination percentage was reduced due to salinization compared to
control. The lower reduction of GP, GR, GC and VI due to salinity was observed in BARI Gom 25,
BARI Gom 27, Shatabdi, Sonora, and Akbar whereas higher reduction was recorded in BARI Gom 26,
Duram, Triticale, Sufi and Kheri. Shoot and root lengths, fresh and dry weights were found to be affected
due to salinization and shoot was more affected than root. Under saline conditions, longer shoot and root
length was recorded in BARI Gom 25, BARI Gom 27, Akbar, and Shatabdi, i.e. less reduction of shoot
and root lengths was observed, on the other hand, BARI Gom 26, Duram, Prodip and Triticale produced
shorter shoot and root length. In this study, genotypes BARI Gom 25, BARI Gom 27, Shatabdi, Sonora
and Aghrani showed better performance in terms shoot and root growth (fresh and dry weights) and
proved to be tolerant genotypes to salinity. On the other hand, Duram, BARI Gom 26, Triticale, Kheri
and Prodip were affected seriously in terms of fresh and dry weights by the saline environment. BARI
Gom 25, BARI Gom 27, Shatabdi, Sonora and Aghrani showed more salt tolerance index (STI) based on
shoot dry weight while BARI Gom 26, Triticale, Durum, Sufi, Prodip and Kalyanson demonstrated lower
STI value under saline conditions. Results on germination and seedling growth indicate that BARI Gom
25 and BARI Gom 27 performed well but BARI Gom 26 and Durum were affected more than other
genotypes under salinity stress. After screening from experiment-1, BARI Gom 25 appeared as the most
salt tolerant and BARI Gom 26 as the most salt sensitive genotype. Therefore, the yield performance of
these two genotypes BARI Gom 25 and BARI Gom 26 was evaluated in three saline conditions (0, 75
and 150 mM NaCl). With the increase in salinity level, days to first heading and maturity were reduced
and BARI Gom 25 showed lesser reduction than BARI Gom 26 at 150 mM NaCl. BARI Gom 26 was
affected more in its plant height, tiller production, spike length, spike plant’, spikelet spike”, grain dry
weight spike", 100 grain weight, and finally grain yield plant under saline condition than BARI Gom 25.
Considering the results of both experiments, it can be concluded that the BARI Gom 25 could be treated
as the most salt tolerant and BARI Gom 26 as the most salt sensitive genotypes. | en_US |
