赤霉素GA_3对不同层积催芽紫椴种子萌发的影响

为探讨解除紫椴种子休眠的方法,进行了不同温度层积催芽试验,并在此基础上进行了赤霉素GA_3处理后对紫椴种子萌发过程中贮藏物质的影响研究,结果表明:在前期高温后期低温(T20-5)的处理下种子具有较高的萌发指数,50 mg·L-1GA_3可使紫椴种子可溶性糖含量在萌发初期快速升高,以提高种子对逆境的适应能力;而150 mg·L-1GA_3对可溶性糖含量的增加具有抑制作用。GA_3处理对紫椴种子淀粉分解具有促进作用,但不同层积温度对淀粉水解酶活性有影响,为提高淀粉酶活性和可溶性蛋白含量,可适当提高GA_3浓度。

明党参种胚的分化发育与萌发

作者用整体解剖法观察了明党参种胚的分化发育形态,并对种胚分化发育的温度进行了试验。种胚分化发育的适温在10℃左右,变温可提高种子的萌发率;萌发率随着种子贮藏年限的延长而下降。试验结果认为:种子收获后凉干保存,于9～10月结合清水选种拌入湿沙处理,冬前播种可提高出苗率。

Effect of Different Treatment on Seed Germination of Echinochloa crus-galli

The effect of different treatment on seed germination of Echinochloa crusgalli was investigated in this study. The results showed that GA3, concentrated sulfuric acid, KNO3, NaOH and temperature treatments all could promote the germination of E. crus-galli seeds, but there were great differences in the promoting effect. Seed soaking with 1 000-1 500 mg/L of GA3 for 24 h and seed soaking with concentrated sulfuric acid for 15-20 min all maintained the germination rate of E. crusgalli seeds higher than 70.0%; 1.5% NaOH made the germination rate of E. crusgalli seeds up to 93.7%, but higher-concentration NaOH significantly reduced the germination rate of E. crus-galli seeds; KNO3 treatment showed certain promoting effect on germination of E. crus-galli seeds, but the effect was not ideal, i.e., the germination rate was lower than 35.5%; 20-25 ℃ temperature treatment could effectively promote the germination of E. crus-galli seeds, and the germination rate ranged from 68.2% to 75.8%.

Effect of pre-soaking and pre-chilling treatments on seed germination of Pinus roxburghii provenances from western Himalaya, India

After subjecting the seeds to GA3 and H2O2 treatments for 24 h and chilling at 2-3℃ for a period of 15 days, we conducted the seed germination tests for 21 different seed sources ofPinns roxburghii from western-central Himalaya under laboratory conditions at various temperatures viz., 20℃, 25℃ and 30℃ inside a seed germinator. The results reveal that the soaking of seeds in H2O2 （1% v/v） and GA3 （ 10 mg.L^-1） solutions manifested 82.39% and 78.19% germination, respectively whereas untreated seeds exhibited 70.79% average germination. Both GA3 and H2O2 treatments caused an appreciable shortening of the germination period by 8 days and 10 days, respectively. Moist-chilling did improve the rate and percentage of germination when germinated at 20℃ over 21 days; however total germination was not affected at temperatures 25℃ and 30℃, Although the seeds of P. roxburghii germinate well due to lack of dor- mancy, the increasing demand for large quantities of seeds of P. roxburghii for reforestation programmes make pre-sowing treatments useful in improving the rate and percentage of gemaination.

Influences of Temperature Regime on Germination of Seed of Wild Soybean(Glycine soja)

As an important plant species with high protein contents,wild soybean(Glycine soja),has drawn much attention and appeared to be useful for the genetic improvement of soybean germplasms.Since temperature is one of the numerous environmental factors affecting the germination of most plants,an experimental study was carried out to determine the effect of temperature on germination of wild soybean(G.soja)seeds.Germination test was conducted by setting up thirty-six constant and alternating temperature regimes,ranging from 5 to 40 ℃(16 h night/8 h day).Responses in germination rate to these temperature regimes were then used to construct a quadratic response surface,giving estimated germination rates with confidence intervals at P ≤ 0.05.The results showed that germination capacity was significantly greater while exposed to constant temperatures of 25 ℃,and under the alternating temperature regime the optimum temperature occurred at the 20/25,25/25,25/30 ℃ regime(16 h/8 h)with the amplitude widened from 0 to 5 ℃.Together with regional monthly climate data,these results could be used to improve and promote the cultivation of wild soybean(G.soja),making it available to develop the location-specific optimum seeding time and to apply weed-control treatments.

Evaluation the Effect of Diurnal Temperature Fluctuations on Seed Germination of Pistacia vera L.

This experiment was carried out in order to investigate the effect of diurnal temperature fluctuations on seed germination of Pistacia vera L. The seeds of Badami-e-Zarand and Sarakhs cultivars were treated with the following temperatures： T1 = 24 hr at 25℃, T2= 16 hr at 25 ℃ ＋ 8 hr at 10 ℃, T3= 12 hr at 25 ℃ ＋ 12 hr at 10℃ and T4= 8 hr at 25℃ ＋ 16 hr at 10℃. The germination percentage was increased by diurnal temperature fluctuations, however all of treatments extended MTG compared to control （T1）. Temperature affected the quality of roots, in a matter that high constant temperature resulted in dichotomous （forked） roots during seed germination of pistachio. The response of cultivars was different in this case, so that, Badami-e-Zarand had higher dichotomous root percentage. This disorder can be decreased by diurnal temperature fluctuation.

Influences of Seed Source, Pre-chilling, Light and Temperature on the Germination of South African Pelargonium sidoides

Pelargonium sidoides DC is used in herbal medicine for the treatment of various infections. The roots are being indiscriminately harvested for local and export trade and the collection rate is becoming unsustainable. Seed germination dynamics of this species was studied with the aim to reveal factors that influence its survival in the wild in order to adopt the appropriate germination conditions for use in ex-situ propagation and conservation program. Germination was affected by age of seeds, temperature and pre-chilling conditions. Temperature higher than 25 oC reduced germination by 60%. When seeds of P. sidoides were subjected to pre-chilling treatment for seven days, there was a significant drop in final germination by 29% compared to the other treatments. Although, final germination was not affected by different light treatments, continuous light significantly promoted germination velocity Seeds harvested from the plants grown in the green house performed better in germination than those collected from the field. The ecological implications of these observations on the propagation and conservation ofP. sidoides are discussed.