Studies On Seeds Characteristic Sophora Alopecuroides And Thermopsis Lanceolata

Seeds of Sophora alopecuroides and Thermopsis lanceolata collected from desert edge were chose to be materials. Their physical, hard seed and germination characteristics were researched in laboratory:1,The results showed that sharp, color, appearance and flavor had significant difference. Purity, robust degree, length, width, thickness, bulk density and TGW of Sophora alopecuroides seeds were higher than Thermopsis lanceolata seeds significantly. Two types of seeds had lower water content and higher proportion of hard seed, and their density didn't have significant difference. Hard-seededness and non hard seed were all existed together in fresh and pure bean seeds from effect of seed imbibitions and germinations, so two types of seeds must be treated along for dormancy-breaking and germination research. The best hard seed release methods for Sophora alopecuroides and Thermopsis lanceolata were treating seeds using 90%(v/v) sulfuric acid for 70min and 120min respectively. Sophora alopecuroides and Thermopsis lanceolata seeds had higher materials convert efficiency and reached to 77.94% and 77.28% respectively. Sophora alopecuroides seeds didn't germinate until 21h and lowest water requirement was 151.08%, that data of Thermopsis lanceolata were 21h and 151.71%, and they needed more water to germination. Sophora alopecuroides seeds had a fast germination speed and needed 40h to reach maximal germination value, and Thermopsis lanceolata needed 56h to reach that value.2,Under 25℃, the imbibed seeds of Sophora alopecuroides and Thermopsis lanceolate were taken out as a sample every 24h. The non-imbibing seeds after 10d were regarded as hard seed (H). Imbibing seeds and hard seeds which were imbibed for 24 h after treated with sulfat were all subjected to germination test and several vigor tests. The results indicated that the numbers of the seeds newly imbibed in one day were gradually decreased along with time. The hard seeds of Sophora alopecuroides had a relative slow rate of imbibition, which was decreased below 1% after10 d, while the imbibition rate of Thermopsis lanceolate was at the same level after 3 d, another decrease happened after a sudden increase in 9 to 10th day. The germination rate, germination index, vigor index, the activities of dehydrogenase, respiration rate and SOD of hard seeds were significantly higher than those of non-hard seeds in both species, while the relative conductivity, the contents of soluble sugar and malondialdehyde of hard seeds were lower than those of non-hard seeds, which showed that the vigor of hard seeds were higher than that of imbibing seeds, and the vigor of imbibing seeds were increased gradually with the initial imbibing time postponed.3,The research showed that the preference temperature was 25℃when there was sustained illumination, sustained dark and the illumination time was 16 hours and the dark time was 8hours. The preference change temperature was 25℃/16℃when there was the illumination time was 16 hours and the dark time was 8hours. The sophora alopecuroides of seed germination and seeding growth aren't sensitive for the right.The prefercnce soil water content was 8-13% for the sprouting of sophora alopecuroides seeds.Germinates the time in the sophora alopecuroides seeds, To the NaCl highest tolerance density is 1.2%.4,The results showed that 25℃was the most fitting temperature in sustained illumination, sustained dark and illumination for 16 hours and dark for 8 hours. The day temperature of 25℃and night temperature of 15℃was the most suitable in the alternation of day for 16～18 hours and night. Thermopsis lanceolate seeds germination and seeding growth were not sensitive for illumination. The most proper soil water content and sowing depth was 7～12% and 0.5～2cm respectively for the germination of Thermopsis lanceolate seeds. Experiments of sowing depths indicated that Thermopsis lanceolate seedling belonged to the epigeal germination type.5,Broken hard seeds of Sophora alopecuroides and Thermopsis lanceolata were chosen as material. Impact of drought conditions simulated with PEG (6000) in different concentration(5%-30%) upon imbibition, germination, seedling growth, matter distribution, rewatering recovery rate and saturated water content of two types of hard seed. The results showed that seeds imbibition had slow-fast-slow pattern under drought stress. With the increment of drought stress, two types of seeds' absorbing water speed and accumulated absorbing water rate declined significantly, and times of seeds-begin-germinate delayed, germination rate, germination index and vigor index declined significantly. Lowest osmotic potential threshold of Sophora alopecuroides and Thermopsis lanceolata seeds germination were 25%(PEG6000) and 20%(PEG6000) respectively. Quadratic equation fitted by the germination rate of Sophora alopecuroides seeds and 48h accumulated absorbing water rate was y=-2.8905x2+5.4238x+96.48(R2=0.972),and that of Thermopsis lanceolata was y=-4.6667x2+19.67+79.286 (R2=0.8829). With the increment of drought stress, Sophora alopecuroides and Thermopsis lanceolata seedling height, root length, adventitious root amount and fresh weight were inhibited, and seedling root dry weight and root/shoot ratio increased firstly, and then decreased. Germination of Sophora alopecuroides and Thermopsis lanceolata seeds simulated with 20～30% PEG after rewatering increased with increment of drought stress. That revealed response characteristic of two types bean seed germination and disclosed ecological and biological sense.