الفهرس 
Effect of Some Abiotic Stresses on Seed Quality of Soybean
AbstractOnly 14 pages are availabe for public view
 |  | from | 167 |  |  |
| | | from | 167 | | |
Abstract
Four field experiments were conducted at the Agriculture Experiments and Research
Station at Giza, Faculty of agriculture, Cairo University, Egypt during 2018, 2019 and
2020 seasons. The objective of this work are: study the effect of water stress, air
temperature during seed formation as well as field weathering stress after physiological
maturity on seed constituents, physical and physiological seed traits as well as seedling
establishment in the field of Soybean variety Giza 111. According to the obtained
results from water stress study exposing irrigated soybean crop to water stress during
seed formation up to harvest maturity reduced the normal seeds of the total yield by
20%and increased t h e defective seeds,greenseeds andseedswithcrackedseedcoat
percentage. This was in parallel with reduction in germination percentage, normal
seedling, seedling length, seedling dry weight and seedling vigor index. Also, when
water stress started at R5 stage (seed formation) or earlier at R3 stage (pod formation)
caused significant reduction in oil and protein content, but carbohydrate and fiber
contents were increased. Also saturated fatty acids (palmitic & stearic) of the
extracted oil did not gr e at l ychanged, while oleic (18:1) increased by 4.76 percent
point, while linoleic (18:2) decreased by 4.51 percent points and linolenic (18:3)
decreased by 2.11 percent points when the parental plants exposed to water stress at R3
stage up to harvest maturity compared to non-stressed plants. According to field
weathering study, harvesting at 7 days after physiological maturity produced greatest
normal seeds but delaying harvesting after that increased defective seed%, EC value
and decreased seed weight. Highest seed germination % and normal seedling%,
longest and heaviest seedling were recorded from the seed harvested at PM which
showed highest oil and protein content and highest values of seedling vigor index.
According to heat stress study little temperature increase (1.0 C°
) of the air around the
soybean plants during seed formation reduced seed oil content by 1.0- 1.5 %and
increased protein content by 0.5-1.0%, with small change in other components. In
context, the oleic fatty acid tended to increase and lenolenic acid tended to decrease
under the condition of high air temperature