Environmental Engineering Reference
In-Depth Information
above all, BB52 not only absorbed much less Na
+
and Cl
-
and accumulated them in roots
to restrict their transportation to the above-ground parts, but also assimilated more K
+
.
Therefore, BB52 was able to maintain a higher K
+
/Na
+
ratio, especially in leaves that is
very important for salt tolerance. In conclusion, ZH13 and BB52
exhibited a certain
tolerance through many kinds of physiological regulations such as photosynthetic
modulation, osmotic adjustment and ion homeostasis, but BB52 seemed to have a higher
salt tolerance.
Keywords:
Wild soybean, salt stress, growth, photosynthesis, ion homeostasis
1.
I
NTRODUCTION
Soil salinization has become a global ecology and resource problem which poses a great
threat on agricultural development around the world. Up to now, more than 800 million
hectares of lands have been affected by salinity in the world [1]. The saline lands (especially
for agricultural lands) are still expanding with the development of industrialization and
urbanization [2, 3]. Soil salinity can inhibit plant growth and decrease crop yields, especially
in arid, semiarid and coastal regions [4]. It is well known that the halophytes can survive in
saline lands, and some special physiological mechanisms may help them to adapt to this
adverse
environment.
Therefore,
screening
valuable
halophytes
and
exploring
the
physiological mechanisms of stress tolerance is utmost importance.
Soybean (
Glycine max
L.) is one of the main crops and is widely cultivated in the world.
As an important source of food, soybean has high-protein content and useful nutraceuticals,
thus the need for soybean throughout the world is increasing [5,6] However, cultivated
soybean is identified as a salt-sensitive species [7]. Its growth is severely suppressed and
yield decreases dramatically under salt stress [8]. As more and more agricultural lands are
affected by soil salinity, soybean production is being threatened. Thus, it is very important to
breed salt-tolerant soybean cultivars [9]. Wild soybean (
Glycine soja
) which is the progenitor
of cultivated soybean(
Glycine max
L.) and is widely distributed in the Far East of Russia, the
Korea peninsula, Japan and China, not only possess more genetic diversity and better seed
quality [10, 11] but also has higher environmental stress resistance (such as drought tolerance,
saline-alkali tolerance, leanness tolerance) [5]
.
What is more, both of them have no misogamy
and can produce fertile offspring upon crossing since they have the same genome. Thus, it is
possible to improve salt tolerance and seed quality of cultivated soybean by conventional or
genetic engineering breeding.
In this study, we compared the effects of salt stress on the growth, photosynthesis, proline
content and ion accumulation between cultivated and wild soybean. It can not only help us
understand the difference of salt-tolerance mechanisms between them but also provide a
reference for breeding salt-tolerant soybean cultivars.
