Under alternating photoperiod (14?h light,10?h dark,12?μmol m -2 s -1 ),final germination percentage of seeds was 87.5%,100%,100%,100%,98%,89% and 100%,respectively,at 15℃,20℃,25℃,30℃,35℃,40℃ and 30℃/20℃,and mean germination time of seeds was 34.7? d,16.3? d,5.6?
The results revealed that with Cu~(2+)、Zn~(2+)、Cd~(2+) concentrations reaching 100 mg/L,both the seed germination rates and young-seedling heights of P.pratensis declined to some extent and their decrements increased as the concentrations increased.
结果表明,当Cu2+、Zn2+、Cd2+的浓度达100 m g/L时,早熟禾的种子萌发率、幼苗株高均有所下降,并随着胁迫浓度的增加,下降幅度增大;
5. The physiological changes of 20% PEG-6000 treated depilated flower seeds was measured, the results showed that the treatment increased activity of superoxide dismutase (SOD) and catalase (CAT), decreased MDA content and electrical conductivity, enhanced anti-oxidation and seed germinating rate.
nobile has been accomplished by means of bothseed culture and embryo culture. Higher germinating rate and survival rate wereobtained when the hormone-free MS(1/2 ME, major element)medium was used as basicmedium in the condition of 5.6~5.8 of pH value, 1000~2000lx of lumination,12h/dof light duration, and 25±2℃ of temperature.
All five populations have an opposite pyramid age structure, few coning plants, few seed production, and low level of seed germination rate or sterility.
A principal-component analysis revealed that the species were distributed along two statistically independent axes, the first primarily represented the germination rate and the second represented the time of germination process.
Microspore pretreatment with cytochalasin B and colchicine followed by the treatment with serotonin, dopamine, or peroxides decreased the germination rate.
Conversely, storing them at a low temperature increased their germination rate by 15-20%.
Water content of seeds gradually increased, while the final germination percentage, germination rate of seeds and fresh weight of seedlings produced decreased with increasing accelerated ageing time.
Results showed notably increased germination percentage, root length, vitality index and fresh weight.
With decreasing water potential caused by increasing concentrations of NaCl, germination percentage, fresh weight of seedlings and protein amount markedly decreased, whereas proline amount slightly increased.
Germination percentage and amounts of proline and protein increased as germination temperature elevated to 25°C from 15°C, and decreased above 25°C; fresh weight of seedlings increased to 30°C from 15°C, and decreased above 30°C.
Few or no changes on germination percentage and vigor index were found in Indian rice seeds even after their moisture content fell to 3.5%, indicating that Indian rice exhibited a strong desiccation tolerance.
On the contrary, Japonica rice seed germination percentage rapidly decreased, after their moisture content fell to 4.5%.
The germination rates of cryopreserved and control (nonfrozen) seeds did not differ and remained as high as 100%.
The toxic effects of Cd(NO3)2, Pb(NO3)2, Ni(NO3)2, and Sr(NO3)2 were estimated from the germination rates of maize (Zea mays L.) caryopses following two-day incubation with these salts.
Germination rates of seeds after their exposure to liquid nitrogen were species-depended and could be either higher or lower than in the unfrozen control.
GmSGR was overexpressed in Arabidopsis and the germination rates of the transgenic seeds were significantly higher than that of the wild type seeds under higher concentrations of ABA and glucose respectively.
However, the germination rates of the transgenic seeds were lower than that of control under salt stress.