Organizing co mmittee

 
 

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Poster presentation 
202 
RESISTANCE OF NODULAR BACTERIA OF LOCAL 
SOYBEAN VARIETIES TO SALT STRESS 
 
M.I. Egamberdiyeva, Z.S. Shakirov 
 
Institute of the Microbiology of AS RUz, Tashkent, 100128, 7
B
 A. Kadyri str. 
[phone] 
 
Soil salinity is considered to be a scourge for plant growth and crop productivity 
worldwide. Approximately 1125 million hectares of land throughout the world is 
affected by high levels of salt due to intensive agriculture and desertification processes. 
Increasing salinity tolerance for the world’s two major crops, wheat and soybean, is an 
important goal, as the world’s population is increasing more rapidly than the area of 
agricultural land. Seed germination and seedling growth of soybean, as with other crops, 
has been found to be negatively affected by salinity stress. As a consequence, plant 
tolerance to salt, mainly to the sodium cation (Na+), is a desirable trait to be selected for 
in cultivated crop plants. To overcome salinity stress, tolerant varieties can be 
developed through agronomy and breeding or advanced molecular techniques, but these 
are time-consuming and highly expensive. In this regard, one of the alternative 
approaches to achieve normal plant growth under salt stress is the efficient utilization of 
soybean nodule bacteria. 
The study salinity resistance of bacterial isolates from different soybean varieties was 
determined 
in vitro
. For this, a nutrient medium was prepared with a 2% agar pea 
extract containing a different quantity of NaCl: 200, 400, 800, 1000, 1200, 1400, 1600, 
1800, and 2000 mM. These nutrient media were poured into Petri dishes and incubated 
at 28°C for 24 hours. After that, local strains of bacteria О4-4, Н18-2, Уз5-1, Б16-1, 
Д24-1, М5-1, П12-4, С7-2, Г8-2, Ту8-2, Х12-1 and T30-1 were seeded on prepared 
nutrient media and incubated at 28°C for 4 days. The growth of bacteria has been 
recorded. 
A day after the cultivation of young bacteria on media with different salinities, the 
growth of all bacteria was observed at a salinity of 200–800 mM NaCl. Weak growth of 
all bacteria was observed at 1200-1400 mM NaCl on the 2nd day of cultivation under 
salinity conditions. Culture M5-1 stopped growing at 1400-2000 mM NaCl salinity on 
the 3rd day of cultivation. The remaining bacteria were observed to grow to a certain 
extent. In particular, normal growth of Н18-2, Б16-1, Д24-1, П12-4, Х12-1 and Т30-2 
cultures was found. Although cultures О4-1, С7-2, G8-2, and Ту8-2 cultures at 2000 
mM NaCl salinity growth was observed. 
Based on the obtained results, it can be concluded that the nodule bacteria isolated 
from local soybean varieties are resistant to high salinity levels, and in the cultivation of 
local soybean varieties treated with these nodule bacteria in medium salinity soils, the 
plant is susceptible to salinity. It helps to increase the resistance and allows to get a high 
yield.