Effects of Seed Soaking with Plant Growth Regulators(PGRs)on the Carbon Metabolism of Soybean Seedling Cotyledon

The objective of this study was to compare the carbon metabolism of soybean seedling cotyledon treated with different plant growth regulators.Sand culture experiments were conducted on the trail farm of Heilongjiang August First Land Reclamation University(46.90 N 125.00E)with soybean cultivar Kennong4 as material.The seeds were soaked with plant growth regulators Diethyl aminoethyl hexanoate(DTA-6),25(D25),50(D50) and 100 mg·L-1(D100);and Uniconazole(S-3307),0.1(S0.1),0.2(S0.2)and 0.4 mg·L-1(S0.4),with seed water soaking as comparison.Content of sugar,reducing sugar,soluble sugar and starch in soybean seedling cotyledon were determined every two days afteremergence.During the seedling period,the soluble sugar content of all treatments showed increasing-decreasing-increasing trend,and soluble sugar content of DTA-6 was lower than the S-3307 and CK 6 days after emergence.Starch content showed decreasing-and-then-increasing trend,and reach its lowest point on the 8th day after emergence,on the 12th day after emergence,the starch content of DTA-6 was lower than the S-3307 and CK.Sucrose content was showed zigzag dynamic trend,and the sucrose content of S-3307 was higher than those of DTA-6 treatment.Reducing sugar content occurred several fluctuations within the sampling time,andreduced to a minimum on the 8th days after emergence.DTA-6 generally increased reducing sugar content,while S-3307(S0.2 excepted)reduced the reducing sugar content in late sampling days.Results suggest that suitable dosage of plant growth regulator seed soaking can improve the activity of seedling cotyledon,promote carbon metabolism,and D50 and S0.2 treatments showed better regulation effects.