Tropentag 2010, September 14 - 16, Zurich, Germany "World Food System - A Contribution from Europe"

Effect of Water Deficit Stress during Seed Maturity on Germination Parameters of Three Soybean (Glycine max L.) Cultivars

¹Tarbiat Modares University, Agronomy, Iran
²Takestan Azad University, Iran

Abstract

In order to study the effect of water stress during soybean seeds maturity on their germination parameters, a field and phytothron investigation was conducted at Seed and Plant Improvement Institute (SPII) and Tarbiat Modares University in 2008 and 2009, respectively. Treatments were arranged in a factorial experiment on the basis of randomised complete blocks with four replications. Factors consisted of: three soybean cultivars (DPX, BP and 032) and water deficit stress on mother plants including irrigation after 50, 100 and 150 mm evaporation from an evaporation pan class A, representing the control, a mild stress and a severe stress, respectively. All germination tests were carried out in a phytothron (model STC1300) with 16/8 h (day/night) and by 30/20°C. Several traits including 1000 seed weight, rotten seeds, normal and abnormal seedlings, mean time to germination, coefficient of velocity of germination, mean daily germination and the final germination percentage were measured during the field and laboratory investigations.
Results indicated that increased water deficit stress on mother plants significantly decreased 1000 seed weight, number of normal seedlings, mean daily germination and the final germination percentage. All cultivars produced more number of rotten seeds due to water deficit stress during seed maturity. Mean comparison of control and sever stress treatment showed that final seed germination percentage decreased as much as 7, 15 and 28 % in BP, DPX and 032 cultivars respectively. Therefore 032 cultivar had the lowest germination percentage (59.33 %) which reflects the negative effect of severe water deficit stress in maturity period. So this cultivar has been more susceptible to stress than others.
Furthermore it has minimum rate of normal seedlings number as much as 42 and 20 percent for mild and severe stress condition and the lowest mean daily germination (7.41 seed d^-1) at sever stress treatment. Altogether it could be stated that low mean daily germination influenced by water deficit stress on mother plant significantly decreased the uniformity of germination.

Keywords: Germination, seed quality, soybean, water deficit stress

Contact Address: Majid Aghaalikhani, Tarbiat Modares University, Agronomy, Jalal-Ale Ahmad, Nasr Bridge, 1411713116 Tehran, Iran, e-mail: maghaalikhanimodares.ac.ir