The Influence Of Rehygdration-dehydration And PEG Osmotic Conditioning On Chinese Pine Seed Vigor

In this experiment, high vigor (germination: 80%) and medium vigor (germination: 60%) Chinese pine seeds were respectively treated with rehygdration-dehydration and osmotic conditioning with PEG. Thereinto. Six different treatments of rehygdration-dehydration respectively at 10℃,15℃,20℃was designed randomly and PEG osmotic conditioning was designed with L16(45) positive-cross experiment (including mol.wt, concentration and time). The results showed that most treatments improved the seed germination percentage, germination rate and the activity of protective enzyme, and reduced its relative electrical conductivity and the content of MDA. Among all treatments, the double-circulation and rehygdration-dehydration at 20℃should be the best methods for improving seed vigor. To high vigor seeds, the germination index of double-circulation and rehygdration-dehydration at 20℃was respectively 1.61 and 1.58 times of the CK, the germination quotiety was 1.34 and 1.36 times, vigor index was 1.80 and 1.91 times, the activity of SOD,CAT,POD, were respectively 3.05 and 3.60times, 1.72 and 1.32 times, 1.30 and 1.30 times of the CK, relative electrical conductivity was 0.71 and 0.70 times of the CK , and the content of MDA was respectively reduced by 26.3% and 34.9%. To medium vigor seed, the germination index of double-circulation and rehygdration-dehydration at 20℃was respectively 2.59 and 2.36 times of the CK, the germination quotiety was 1.85 and 1.81 times, vigor index was 3.93 and 4.60 times, the activity of SOD,CAT,POD, were respectively 2.99 and 2.49 times, 1.96 and 2.05 times, 1.58 and 1.50 times of the CK, relative electrical conductivity was 0.73 and 0.75 times of the CK ,the content of MDA was respectively reduced by 34% and 37%. Among the sixteen treatments of PEG, most of them improved the seed vigor at different degree. Totally, the effect of the A1B1C3 (That is: molut: 1000, concentration: 10% and time: five days ) was the best. The analysis indicated that the three factors all had distinct effect on the indexes related with seed vigor (the sequence is mol.wt>concentration>time). Based on the results, we can conclude that the A3B2C2 (molut: 1000, concentration: 20%, three days, treatment) was the best condition combination. Compared to high vigor seeds, the effect of the two treatments on medium vigor seeds was more obvious.