酸雨对油菜种子发芽的影响

选用p H值为4.0、3.5、3.0、2.5、2.0与5.0进行模拟酸雨条件,探究油菜种子发芽情况。结果表明,在p H值2.0~2.5时,油菜发芽情况为0,而在p H值为3.0时,与CK相比,具有显著的差异性;当p H值≧3.0时,油菜种子的活力指数、发芽指标、发芽势、及发芽率与p H值呈正相关系。     

模拟酸雨对蕹菜种子发芽的影响

对蕹菜（Ipomoea aquatic Forsk.）种子进行了pH1．0、2．0、3．0、4．0、5．0和pH1．4下分别接触2、4、6、8、10d的模拟酸雨实验室内试验，结果如下：种子发芽率、绝对发芽率在模拟酸雨pH值小于2．0时急剧下降；活力指数在模拟酸雨pH值3．0时就开始有明显下降；在pH4条件下，种子发芽率、绝对发芽率均随接触模拟酸雨时间的增加而下降；发芽种子中异状芽种子所占百分率随接触模拟酸雨时间增加而上升。     

水稻种子萌发对酸雨胁迫的响应

大量研究表明[1,2,9],一定pH酸雨能够抑制花生、水稻、小麦及油菜种子的萌发,且酸雨胁迫下,水稻(Oryza sativa)种子的发芽率、发芽势、活力指数、发芽指数及异状发芽率等萌发指标皆随酸雨胁迫强度与胁迫时间的改变而变化,但引发上述萌发指标变化的内在原因尚不明晰。为此研究了水稻种子萌发生理生化反应对酸雨胁迫的响应,为诠释酸雨胁迫影响水稻种子萌发的深层原因提供依据。1试验材料与方法模拟酸雨(含离子构成,以下简称酸雨)配制时先配制pH 1·0酸雨母液,其中硫酸根和硝酸根体积比为4·7∶1。用蒸馏水将母液调制成pH 2·5、3·0、3·5、…     

镧对酸雨胁迫下高粱种子萌发及POD活性和MDA含量的影响

本文以高粱"熊杂9号"为对象,采用模拟酸雨伤害的常规种子实验方法,研究稀土镧对酸雨胁迫下高梁种子萌发及过氧化物酶(POD)活性和丙二醛(MDA)含量的影响.结果显示,12 mg·L-1La(Ⅲ)浸种后,可明显缓解酸雨对高梁种子萌发的抑制作用,高粱种子发芽率、发芽势、发芽指数和活力指数较未处理组升高,而异状发芽率降低,pH 2.5时变化幅度最明显.pH 2.0时由于酸雨使种子内部结构严重破坏,La(Ⅲ)的加入已无法缓解酸雨引发的伤害.La(Ⅲ)处理组MDA含量和POD活性均低于未处理组.上述结果表明,La(Ⅲ)可通过调节POD活性减轻酸雨胁迫引发的膜脂过氧化,缓解酸雨对种子萌发的抑制作用.     

镧对西葫芦种子酸雨胁迫的缓解效应

研究了镧对酸雨胁迫下西葫芦种子萌发状况及活性氧代谢的影响。结果显示,经12mg/L LaCl3浸种后,可明显缓解酸雨对西葫芦种子萌发的抑制作用,pH3.5时效应最显著,种子的发芽率、发芽势、发芽指数和活力指数显著升高,并接近于对照;pH3.0时也有明显改善,但达不到对照水平;在pH2.5时,发芽状况没有明显改变,仍只有少数种子能萌发。同时,镧处理能显著减少强酸雨对抗氧化酶的破坏,缓和MDA的积累。上述结果表明,镧浸种可通过调节抗氧化酶活性,缓解酸雨对种子萌发的抑制作用;但活性氧代谢的改进必须达到其阈值,否则就没有生长促进效应。因此,这类指标的数值不能直接用于抗逆性评价。     

模拟酸雨对裸大麦种子萌发和幼苗生长的影响

在室温下用不同pH值(2.5、3.5、4.5、5.6)的模拟酸雨溶液对裸大麦(阿青4#)种子进行胁迫处理,用水培法研究酸雨对种子萌发的影响。对各试验组的发芽率、发芽势、种子活力指数、根长抑制指数、芽长抑制指数及平均幼苗的芽干重进行测定。试验结果表明:与对照相比,不同pH值都对萌发率、发芽势、活力指数、平均苗干重、根长和芽长的影响不一样;pH 4.5的酸雨对萌发率、发芽势、活力指数的影响较小,还有一定的促进作用,pH 2.5的酸雨抑制作用均十分突出。     

不同处理方法对百脉根种子发芽的影响

通过试验探讨了不同温度、pH和湿度处理对百脉根种子萌发的影响。结果表明:不同温度、pH和湿度处理对百脉根种子的萌发均有显著影响。百脉根种子在24 ℃左右时发芽率和发芽指数最高,分别为64%和24.0;pH为6时其发芽率和发芽指数最高,分别为64%和24.7;当湿度为40%时,百脉根种子发芽率和发芽指数最高,分别为72% 和25.0。     

模拟酸雨对小麦种子萌发和幼苗生长的影响

以中性溶液（pH=7.0）为对照,研究了pH值为1.0,2.0,3.0,4.0,5.0和6.0模拟酸雨对小麦种子萌发和幼苗生长的影响。结果表明,小麦种子萌发和幼苗生长各指标随着pH值的降低而降低,弱酸（pH5.0～6.0）条件下小麦种子能够正常萌发和生长,种子萌发和幼苗生长各指标与对照没有显著差异（P > 0.05）;在pH低于5.0时,小麦种子萌发和幼苗生长严重受阻,种子萌发和幼苗生长各指标均显著低于对照（P < 0.05）;pH为1.0时,小麦种子则完全失去活性;不同pH值模拟酸雨胁迫对小麦幼苗生理指标影响较大,叶绿素含量、类胡萝卜素含量、保护酶（SOD,POD,CAT）和非保护酶（PPO,PAL）活性随酸性的增强呈降低趋势,而相对电导率和丙二醛（MDA）含量呈上升趋势。综合分析认为,小麦幼苗生长比种子萌发对模拟酸雨的响应更为敏感。     

纳米TiO2对油菜种子发芽与幼苗生长的影响

通过纸床培养,研究在不同浸种时间下,不同浓度的10nmTiO2悬浮液对油菜种子发芽及幼苗生长的影响。结果表明：浸泡时间为2h的各指标表现最显著,最适合作为纳米TiO2对油菜种子发芽和幼苗生长影响的浸种时间。浸种2h纳米TiO2的发芽势、发芽率、发芽指数抑制率与纳米TiO2浓度呈显著正相关,与浓度的对数作线性回归得出,IC20分别为1907、619．0、1039mg·L-1;总长、芽长、根长、总重、芽重、根重的激活率与纳米TiO2的浓度呈显著正相关,通过线性回归方程得出总长、芽长、根长、总重、根重的EC20分别为99．77、404．5、55．46、6918、2187mg·L-1。对各指标影响的敏感性大小为：发芽率〉发芽指数〉发芽势,根长〉芽长。因此,油菜发芽率与根长可以作为评价纳米TiO2生态毒性效应的较敏感指标。     

模拟酸雨对盆栽马尾松叶片光合特性的影响

采用LI-6400XT便携式光合测定仪,对缙云山马尾松在不同强度酸雨(pH 5.6,pH 5.0,pH 4.0,pH3.5,pH 3.0,pH 2.5和pH 2.0)下的光合特性进行测定。结果表明:pH 3.5～5.6的酸雨处理条件下,净光合速率、蒸腾速率和气孔导度受酸雨影响不明显,从pH 3.0或pH 2.5开始出现明显的降低趋势,且pH2.0出现不同于前几种处理的日变化趋势;从水分利用效率分析,酸雨胁迫对其影响不明显;pH 4.0～5.6的酸雨处理条件下,最大净光合速率、光饱和点和光补偿点变化不明显,从pH 3.5开始出现显著降低的趋势,且在pH 2.0时受酸雨影响已经非常明显,无法模拟出最大净光合速率、光饱和点和光补偿点;总体分析,酸雨对马尾松叶片光合特性的影响临界范围为pH 3.5～4.0,酸雨对马尾松幼苗致命的影响临界范围为pH 2.0～2.5。     

黔中废弃煤矿区酸性排水污染特征及对作物种苗生长的影响

通过对贵阳市花溪区麦坪乡废弃煤矿区酸性排水进行样品收集与分析,探讨煤矿酸性排水的污染特征及对作物种苗生长的影响。研究结果表明,在煤矿附近50～350m距离内溪沟水pH变化达2.35～6.3,污染物主要以SO24-、Fe、Mn为主;矸石堆洼地蓄积水完全抑制两种植物的萌发;距井口50m溪沟水和距井口30m农田水处理油菜都表现为种子发芽后发霉死亡;距井口100m处溪沟水和距井口30m农田水处理油菜和水稻的种子发芽率、幼苗鲜重和干重、发芽指数和简化活力指数与对照（蒸馏水处理）之间均存在极显著差异（P〈0.01）。煤矿酸性排水胁迫下,水稻各项指标变幅低于油菜,说明物种耐性强度为水稻〉油菜。     

春小麦航天育种效果的研究

将小麦纯系种子用硼酸溶液和水浸泡后进行航天诱变处理。研究表明 ,航天处理对种子发芽、出苗和生长有明显的促进作用 ,第 2代农艺性状具有广泛变异 ,而且正向变异较多 ,为后代选择提供了更多机遇。选出了 5个高产、抗病、优质的小麦新品系 ,其中 97- 5 1 99已进入生产试验     

A two-year experience on 15N-urea fertilization of a corn field amended with fly ash

Soybean seedlings (Glycine max) were exposed to simulated acid rain containing sulfate ion only or a mixture of sulfate, nitrate and chloride anions, using a continuous rain generating system in a side opened glasshouse. Plants were subjected to acid rain treatment twice a week, for a 1 or 3 hr period at a rate of 2.2 or 5.0 mm hr^?1, respectively. Dry seed yield in plants treated with simulated acid rain at pH 2.0, in the three of 4 experiments conducted over a 3 yr period, was significantly less than that at pH 3.0 or higher. Simulated acid rain treatment at pH 3.0 or higher did not significantly affect yield compared to pH 5.6; however, plants exposed to simulated acid rain at pH 4.0 tended to yield more than those treated with pH 5.6 rain. Based on the current 3 years of research in which results from 4 experiments were combined, rain acidity at current levels in Japan would not directly affect seed production of selected cultivars of soybean.     

介质阻挡放电低温等离子体处理对小麦种子活力及幼苗生理的影响

为揭示低温等离子体处理对小麦种子活力及幼苗生理特性的影响，该研究以济麦22、百农307为处理对象，对其进行不同时长（0、6、9、12、15 s）的介质阻挡放电（dielectric barrier discharge，DBD）低温等离子体处理，分析其对小麦种子萌发、幼苗生长、种皮形态结构、幼苗代谢生理及抗氧化性指标的影响。结果表明：以氩气为气源的DBD低温等离子体处理明显提高了小麦种子发芽率及其幼苗根苗长、鲜干重、活力指数；各处理时长条件下小麦种子吸水率均有所增加，当处理时间为9 s时，两种小麦种子的吸水率增幅最大，分别显著增加了6.4%（济麦22）、5.9%（百农307）（P<0.05）；小麦种子接触角随处理时间的延长而逐渐减小，表明其润湿性能逐渐提高；处理9 s时小麦的种皮结构组织轮廓模糊，呈现明显裂纹；处理后小麦种子的新生幼苗中光合色素含量、可溶性蛋白含量均得到不同程度的增加；处理后小麦种子的新生幼苗抗氧化能力有所提高，当处理时间为9 s时，两种小麦幼苗中的丙二醛含量降幅最大，分别显著降低了15.6%（济麦22）、18.0%（百农307）（P<0.05）。因此，DBD低温等离子体有效改善了小麦种子活力及其幼苗生理特性，可作为潜在的种子强化方法用于提高作物生产中的种子质量及促进后续小麦生长。     

Influence of seed nitrogen content and biofertilizer priming on wheat germination in salinity stress conditions

In order to study the effects of seed nitrogen content and biofertilizer priming on germination indices of wheat seeds under salinity stress, a factorial experiment based on a completely randomized design with four replications was conducted in 2009. Experimental factors consisted of: (1) the application of different nitrogen fertilizer rates (0, 55, 110 and 165 kg ha^?1 N) on parent plants; (2) priming of achieved seeds by biofertilizers (Nitragin, Biophosphorus and distilled water); and (3) different levels of salinity produced by NaCl (0, ?0.4, ?0.8 and ?1.2 MPa). Germination percentage, germination rate, mean germination time, germination index, radicle and plumule length, radicle and plumule dry weight and radicle number per seedling were measured. Nitrogen application increased seed nitrogen content in parent plants. All germination indices decreased with increasing in salinity levels. Biofertilizer priming, especially Nitragin, had a positive effect on germination percentage, radicle number and radicle and plumule length in most salinity levels. The highest values for germination factors were related to achieved seeds from parent plants that were treated with 110 kg ha^?1 N. Overall, application of middle levels of N fertilizer (55 and 110 kg ha^?1 N) on parent plants combined with seed priming with Nitragin biofertilizer improved the germination indices of wheat under salinity stress.     

La(Ⅲ)对酸雨胁迫下水稻萌发种子能量代谢的影响

为探索稀土元素镧La(Ⅲ)对酸雨(AR)胁迫下水稻萌发种子能量代谢的影响,试验采用蒸馏水和La(Ⅲ)浸泡水稻种子,用pH2.5的模拟酸雨处理种子,观测试验条件下水稻萌发种子的呼吸速率、过氧化氢酶(CAT)活性、线粒体蛋白、ATP含量及能荷(EC)。结果表明,随着酸雨胁迫时间的延长,La+AR组和AR组各项指标变化趋势基本一致,水稻种子呼吸速率先下降后上升,在AR胁迫第4天,呼吸速度达到最大,随后又下降。CAT活性和线粒体蛋白含量均呈逐渐上升趋势最后趋于平稳,ATP含量及EC水平先急剧上升,第5天达到最高值后有所下降。La+AR组各项指标均高于AR组,表明La(Ⅲ)浸种可缓解AR胁迫下上述各指标降幅,增强水稻种子对酸雨的抵抗能力,缓解酸雨对种子萌发的伤害。     

磁化等离子体处理大豆种子的生物学效应

利用不同剂量的磁化等离子体处理晋豆20种子,分析被处理种子发芽率、幼苗生长、呼吸与能量的代谢以及同功酶谱的变化,为探讨磁化等离子体对种子的作用机理提供依据。结果表明,经不同剂量磁化等离子体处理后,种子的发芽率和幼苗的根长、干重没有显著变化;2.0～3.0A处理组苗高、鲜重比对照分别增加17.8%～26.9%和12.70%～17.08%;2.0A处理侧根数比对照显著增加,增幅为11.8%。当处理剂量为2.5A时,根系活力提高60.9%,叶片和根系的呼吸速率分别提高43.68%和38.92%,ATP含量分别提高37.79%和47.68%。磁化等离子体处理大豆种子后幼苗同工酶谱没有特异性条带的产生,但POD和酯酶同工酶的活性得到了普遍提高,其中2.5A处理后POD活性最高。综合分析指标表明2.5A的磁化等离子体处理对刺激种子活力、促进种子发芽和幼苗生长效果最佳。     

~(60)Coγ射线辐射小麦种子贮藏效应的研究

用 2 5 0、30 0、35 0和 40 0Gy 4种不同剂量的60 Coγ射线照射鄂恩 4号小麦干种子 ,测定了照射后及时播种和贮藏 1 5 0d播种对小麦的发芽势、发芽率、幼苗高、幼苗根数和根长的影响。结果表明 :被照射的小麦种子 ,贮藏 1 5 0d后 ,较及时播种的小麦种子其发芽和生长得到了一定程度的恢复 ,即贮藏减轻了辐射损伤 ,但辐射效应仍然存在。     

Effects of seedbed properties on crop emergence: 1. Temporal effects of temperature and sowing depth in seedbeds with favourable properties

Abstract

Rapid and uniform crop establishment is a prerequisite for efficient crop production and minimal environmental impact. Experiments were carried out in shallow plastic boxes placed directly on the ground in the field for studies of the effects of seedbed properties on emergence of various crops. This paper presents an analysis of the time required for germination and emergence under near-optimal seedbed conditions. The crops studied were barley, oats, wheat, pea, rape seed, white mustard, sugar beet, red clover and timothy. The time required for germination generally increased with size of the seeds, presumably because larger seeds needed more water to initiate germination. This applied both when comparing different crops and different seed sizes of the same crop. However, considerable differences occurred between seed lots of the same crop and there were greater differences between seed lots of the same crop than between the three small grain crops studied. Growth rate of the seedlings generally increased with seed size, presumably because of increased energy content in the seed. Consequently, the most rapid emergence was obtained from small seeds at shallow sowing and from large seeds at deep sowing. The crops studied had a minimum temperature for germination and seedling growth close to 0 °C. Under optimal seedbed conditions, thermal time required for 50% germination of barley was typically about 65 °C days over this base temperature and for seedling growth about 6 °C days cm^?1. From 4 cm sowing depth, about 80 °C days were required for emergence but with considerable variations between seed lots. For rape seed or white mustard about 40 °C days were required for germination and about 8 °C days cm^?1 for the seedling growth.