Effects of Seed Soaking with Uniconazole and Substrate Formula on Seedling Quality of Rapeseed

[Objective] To cultivate blanket rapeseed seedlings suitable for automatic mechanical transplanting, the effects of seed soaking with uniconazole and substrate formula on seed germination and seedling quality of rapeseed were investigated using HY4 as the material. [Method] The rapeseed seeds were soaked in different concentrations（0, 5, 10, 20, 30, 40 and 50 mg/L） of uniconazole for 0, 1, 2, 4 and8 h, respectively. Subsequently, they were dried naturally. After the preliminary screening carried out in petri dishes and in a laboratory, the optimum soaking concentration and time of uniconazole were obtained. On the other hand, the rapeseed seeds were soaked in different concentrations（0, 5, 10, 15 and 20 mg/L） of uniconazole for 0, 1 and 2 h, respectively for outdoor pot experiment. At the same time, the screening of optimum substrate formula for cultivating blanket rapeseed seedlings was carried out. The field test was carried out to verify the screened optimum substrate formula. [Result] The results of petri dish experiment showed that seed soaking with uniconazole could delay seed germination, reduce seed germination rate, inhibit hypocotyl elongation and promote root growth. When the soaking concentration exceeded 30 mg/L and soaking time exceeded 2 h, the effect of seed soaking with uniconazole on seed germination was greater, and the seed soaking inhibited root growth. The results of outdoor pot experiment showed that the soaking concentrations and times all significantly reduced seedling height, slowed shoot growth and promoted root growth, which all contributed to the cultivation of blanket rapeseed seedlings suitable for automatic mechanical transplanting. In the substrate formula, the lower the proportion of soil was, the better the seedling growth was. In the substrate with lower proportion of soil, the seed germination rate, plant height,root vigor and dry matter accumulation were all increased（P〈0.05）, which was verified by the field test. When the soaking concentration was less than 10 mg/L and soaking time was less than 1 h, the uniconazole showed weaker regulation effect on seedling growth, and the rapeseed seedlings were higher. In the substrate with soil proportion less than 50%, the adequate fertility relatively weakened the regulation effect of uniconazole on seedling growth, and the rapeseed seedlings were larger. [Conclusion] When the soaking concentration ranged within 15-20 mg/L and soaking time ranged within 1-2 h and the proportion of soil in substrate was 50%,the height of cultivated rapeseed seedlings was less than 18 cm, there were 5-6leaves remained on each plant and the nursing period was shortened to 30-40 d,which were all beneficial to industrial production.

Effect of Seed Soaking with Rare Earth on the Seed Germination and Seedling Growth of Tartary Buckwheat under Different Water Conditions

[Objective] This study aimed to investigate the effect of soaked seed with rare earth on the seed germination and seedling growth of tartary buckwheat under different water conditions. [Method] A hydroponic experiment was carried out with the seeds of tartary buckwheat variety ＂Heifeng No.1＂ in the year 2012. [Result] ①In the normal irrigation, suitable concentration of rare earth increased the germination rate, vital index, germination index and sprouting index of tartary buckwheat seed; at the same time, the leaf area, stem thickness, total root length, root weight,leaf relative water content, proline content, soluble sugar content, soluble protein content, root activity, SOD activity and POD activity of seedling were significantly enhanced, while the relative conductivity and MDA content of tartary buckwheat were decreased obviously. ② Compared with water stress and normal irrigation, the indices of germination potential, germination rate, vital index, germination index, the leaf area, stem thickness, total root length, root weight, leaf relative water content,proline content, chlorophyll content, soluble sugar content, root activity, SOD and POD activity were reduced, while relative conductivity and MDA content were increased, and the extents differed in the treatment of different chemical regulators,and the varied range increased with the higher severity of soil water stress. ③ Under water stress, soaking seeds with suitable concentration（200 mg/L） of rare earth could significantly improve the SOD and POD activity, leaf area, total root length,chlorophyll content and root activity compared with CK. They could increase leaf relative water content by 8.9% and 10.8%, proline content by 7.5% and 8.2%, TTC activity by 13.8% and 16.7%, and soluble sugar content by 10.4% and 7.9% under mild and severe water stress, separately. [Conclusion] The appropriate concentration of rare earth was 200 mg/L.

Quality of Irrigated Water with Nanometer Pottery Tray Treatment and Its Effects on Seed Soaking

To study the impacts of nanometer pottery trays （NPTs） on different rice varieties, three rice varieties, Zhongzheyou 1, Jinzao 47 and Xiushui 09, were treated with four NPTs （NPT-A, NPT-B, NPT-C and NPT-D） with different energies, respectively. The results showed that when the same rice variety was treated with different NPTs or different rice varieties were treated with the same NPT, the impacts on seed germination rate, seedling growth, plant height, panicle length and weight, the number of filled grains, seed-setting rate and 1000-grain weight varied between different rice variety-NPT interaction groups. In general, high energy NPT-C and NPT-D treatments obviously enhanced the functions of most examined rice characters. For example, NPT-C and NPT-D treatments improved the germination rate of all the three rice varieties, and promoted the root growth of seedlings, and increased seedling fresh weight, single panicle weight, filled grain number per panicle, seed-setting rate and 1000-grain weight. On the contrary, low energy NPT-A treatment restrained the seed germination rate in Jinzao 47 and Zhongzheyou 1, and decreased the seedling fresh weight in Zhongzheyou 1. NPT-B treatment restrained the seedling growth in Jinzao 47 but increased the panicle length of Zhongzheyou 1. NPT-A and NPT-C treatments obviously decreased the 1000-grain weight in Xiushui 09. Therefore, when treating crop seeds or plants using nanomaterials or nanotechnologies, different types of crops/varieties should select the nanomaterials or nanotechnologies with suitable energies to reduce the negative effects.

Effect of seed soaked with urea solution on the cold tolerance of rice seedlings

In the Yangtze river aera,the first crop of indi-ca rice is sown in late Mar to early Apr andtransplanted in early May.Usually,seedlingsperish when abnormal low temperature of 6-10℃ lasted for 3 d or longer.The effect ofsocking seed with urea solution on increasingthe cold tolerance at the seedling stage was

A comparison of the toxicity of landfill leachate exposure at the seed soaking and germination stages on Zea mays L.(maize)

To compare the toxicity of landfill leachate exposure at the early stages of seed soaking and germination on maize,a field experiment was conducted to evaluate the physiological aspects of growth,yield and potential clastogenicity of root-tip cells. The maizes were treated with leachate at levels of 2%,10%,20%,30% or 50%（V/V）. First,the change of physiological indexes,including chlorophyll（Chl）,Malondialdehyde（MDA）and Reactive oxygen species（ROS）levels,combined with yield all showed that soaking with leachate,but not germination,generated a greater ecological risk on maize. After a soaking treatment of maize with 50% leachate,the Chl,MDA and ROS levels during a vigorous growth period were 47.3%,149.8% and 309.7%,respectively,of the control,whereas the yield decreased to 68.6% of the control. In addition,our results demonstrated that the leachate at lower levels could promote growth. This is mainly embodied in that the yield of maize treated with 10%leachate at the soaking stage increased to 116.0% of the control. Moreover,the cytological analysis experiment also demonstrated that the ecological risk of leachate still exists in both cases. Furthermore,the gray relational analysis showed that the ear row number and tassel branch number were the major factors affecting the yield of maize treated with 50%leachate at the stages of soaking and germination,respectively. In general,these results are helpful in understanding the phytotoxicity of leachate,which provides additional reference data for risk assessment and management of leachate.

Effects of Acetylacetone Solution Soaking on Agrobacterium - transformed Maize Seed Buds

[Objectives]The effect of acetosyringone seed soaking on the transformation of maize seed buds was analyzed,so as to improve the genetic transformation efficiency of maize and to provide technical support for transgenic breeding of maize.[Methods]The seeds of the"Zheng 58"maize inbred line were used as experimental materials.When the seeds were germinated,AS was added to the water at concentrations of 70,140,210,and 280μmol/L,respectively,and the seeds germinated without the addition of AS served as the CK.The Agrobacterium-mediated method was used to transform bud growth points of maize seeds,and green fluorescent protein detection was performed on the young shoots transformed with EGFP(enhanced green fluorescent protein)gene.The effect of soaking seeds with acetosyringone solution on the transformation of maize bud growth points by Agrobacterium was studied according to the detection results.[Results]Soaking seeds in acetosyringone solutions for germination had the effect of inhibiting the germination of maize seeds and inhibiting sprout elongation,and the higher the concentration of acetosyringone,the stronger the inhibition.When the concentration of acetosyringone solution was 280μmol/L,the germination rate of seeds was only 36.2%of the CK,while soaking seeds with 70-140μmol/L acetosyringone solution for germination could not only ensure a higher germination rate of maize seeds,but also significantly increased the transformation efficiency of maize bud growth points.When the seeds were soaked with 70μmol/L acetosyringone solution for germination,the positive rate of transformed maize buds was the highest,reaching 32.1%.[Conclusions]When maize bud growth points were used as the receptor of Agrobacterium transformation,soaking seeds with 70-140μmol/L acetosyringone for germination basically did not affect the germination of seeds,and was beneficial to the activation of Agrobacterium,thereby promoting the transformation.

Identifying glyphosate-tolerant maize by soaking seeds in glyphosate solution

The identification of glyphosate-tolerant maize genotypes by field spraying with glyphosate is time-consuming, costly and requires treatment of a large area. We report a potentially better technique of seed-soaking to identify glyphosate-tolerant maize genotypes. The effects of soaking maize seeds in glyphosate solution under controlled conditions were studied on seed germination rate, seedling morphological indices, seedling growth and leaf chlorophyll content. These responses were compared among a glyphosate-tolerant transgenic maize cultivar CC-2, glyphosate-susceptible inbred line Zheng 58（the recurrent parent of CC-2） and hybrid cultivar Zhengdan 1002. The results showed that the germination rate, seedling morphological indices and leaf chlorophyll content of glyphosate-tolerant CC-2 seeds did not change significantly among five different concentrations of glyphosate treatment（0 to 2%）. In contrast, germination rates, seedling morphological indices and leaf chlorophyll contents of Zheng 58 and Zhengdan 1002 seeds were significantly negatively affected by exposure to increasing concentrations of glyphosate. The glyphosate-tolerant inbred line CC-2 displayed a strong tolerance to glyphosate after soaking in 0.1 to 2.0% glyphosate solutions, while both the inbred line Zheng 58 and hybrid Zhengdan 1002 were susceptible to glyphosate. The accuracy of the glyphosate-soaking method for screening glyphosate-tolerant maize was confirmed using a field spraying trial.

Reducing toxic effect of seed-soaked Cu fertilizer on germination of wheat

A laboratory incubation experiment (20℃) was conducted to find if the detrimental effects of seed-soaked Cu on wheat seedlings can be minimized by reducing time duration of seed in contact with Cu EDTA fertilizer solution. The 24 treatments in a 6 x 4 factorial arrangement included 6 rates/amounts of Cu (0, 15, 30, 60, 120 and 240 g Cu 100 kg-1 seed) and 4 seed-soaking time durations (0, 4, 8 and 16 h). The germination of wheat seed was 100% in the zero-Cu control treatments, irrespective of the duration of seed soaking time. However, seed germination decreased with increasing amount of fertilizer Cu in the seed-soaking solution, and the magnitude of reduction in seed germination due to Cu toxicity increased with increasing duration of seed-soaking time in the Cu fertilizer solution. For the seed-soaked treatments, the detrimental effect of Cu on germination was greatest with 16 h soaking, where only 13% - 18% of the seeds germinated with Cu applied at 15 to 30 g Cu 100 kg-1 seed. For the 4 and 8 h seed soaking treatments, germination of wheat seed ranged from 73% to 83% with 15 g Cu 100 kg-1 seed treatment and 42% to 62% with 30 g Cu 100 kg-1 seed. The findings suggest that the detrimental effect of Cu on germination of wheat seed soaked in Cu EDTA solution can be decreased by reducing duration of soaking time from 16 h to 4 or 8 h, but this needs further investigation using soil under growth chamber and/or field conditions in order to make valid recommendations for use of this new technology on a commercial scale.

Effect of trace elements on growth of Pinus tabulaeformis seedling

The stimulative effect of trace elements on seed germination and seedling growth of Pinus tabulaeformis was tested. The experiments were carried out on seed soak and topdressing with different trace elements and varied concentrations at the nursery of Gardens Research Institute, Harbin, in 2000-2001. The experimental results showed that soaking seed with 1% and 0.2% concentrations of Mn element produced best result for seed germination, and the germination rate was increased by 9%~19% for the seeds treated with 1% concentration and 12%~14% for the seeds treated with 0.2% concentration compared with the control group. The seeds treated with boron element had lowest germination rate. For trace element topdressing, Mn and Mo elements presented good result for seedling growth and the treatment with low concentration was even better. The height or chlorophyll content of the seedlings with spray of low-concentration Mn and Mo element was much higher than that of untreated ones. In the contrast to the treating method of seed soak, topdressing (application of spraying on foliage) had evident effect on seedling growth.

Effects of Salt Stress on Seed Germination and Seedling Growth in Raphanus sativus L.

[Objective] This study aimed to investigate the effects of salt stress on seed germination and seedling growth in radish（Raphanus sativus L.）.[Method] First,effects of soaking seeds with clear water and different concentrations of saline solution were compared; then,different concentrations of salt solution （0.2％-1.0％） was used to treat radish during the whole germination period.[Result] soaking seeds with clear water can improve the germination indicators of radish seeds exposed to high salt stress; low salt concentration（0.2％,0.4％） had little effect on the growth indicators of radish seedlings,and 0.2％ salt concentration can even promote the growth of radish seedlings,however,the high salinity had a bad inhibition on seedling growth,the higher the salt concentration,the stronger the inhibition.[Conclusion] According to the comprehensive comparison,the order of the six varieties in salt-tolerance was as follows：Xinxiayuanbai＞W1029,Xiayuanbai ＞ Nanyangbailizhi,Chunyidianhong＞ Sijihong 3.

生根粉浸种对木薯生长与产量的影响

为探索木薯的抗逆增产技术,设置5个生根粉浸种浓度(0、10.0、20.0、40.0、60.0 mg·L^(-1))、2个浸种时间(6、12 h)、以不浸种处理为对照(CK),研究其对木薯农艺性状、薯块产量与品质的影响。结果表明:与不浸种比较,20.0、60.0 mg·L^(-1)浸种6 h和20.0~60.0 mg·L^(-1)浸种12 h显著增粗茎径,20.0 mg·L^(-1)浸种6 h显著提高薯长和薯径,0、10.0、60.0 mg·L^(-1)浸种12 h显著增长薯长,0、40.0、60.0 mg·L^(-1)浸种6 h及40.0、60.0 mg·L^(-1)浸种12 h显著增粗薯径,20.0 mg·L^(-1)浸种6 h鲜薯产量显著增加42.3%、淀粉产量显著提高49.9%、收获指数显著提高10.5%。综上,推荐20.0 mg·L^(-1)生根粉溶液浸泡木薯种茎6 h的增产技术。

壳寡糖浸种对低温下江西铅山红芽芋脱毒试管芋萌发及生理代谢的影响

江西铅山红芽芋脱毒试管芋一般在1月至2月上旬晴天播种,“倒春寒”等低温胁迫会导致早播的江西铅山红芽芋脱毒试管芋生长缓慢,出苗周期变长,严重时会造成烂种死亡,出苗率降低,影响其产量。为提高播种期江西铅山红芽芋脱毒试管芋抗寒性,该研究利用植物组织培养和植物生理学的方法测定了壳寡糖浸种后低温下江西铅山红芽芋脱毒试管芋的萌发及其相关生理指标。结果表明:200~250 mg/L壳寡糖浸种可显著促进低温下江西铅山红芽芋脱毒试管芋的萌发。与低温对照相比,当浸种浓度为200 mg/L时,在内源激素方面,有利于低温下江西铅山红芽芋脱毒试管芋萌发过程中赤霉素、玉米素核苷、多胺和茉莉酸的积累,而不利于生长素和脱落酸的积累;在抗氧化方面,提高了超氧化物歧化酶、过氧化物酶、过氧化氢酶的活性,降低了丙二醛和过氧化氢的含量;在渗透调节方面,有利于可溶性糖、可溶性蛋白、脯氨酸的积累;在代谢关键酶方面,可提高脂肪酶、蛋白酶和α-淀粉酶活性以及三磷酸腺苷含量。因此,200 mg/L壳寡糖可以调控低温下江西铅山红芽芋脱毒试管芋内源植物激素和渗透调节物质含量、抗氧化酶和代谢关键酶活性,促进其在低温下的萌发。

种子包衣再浸种双重措施对水稻恶苗病的防治效果

为了缓解黑龙江省局部地区水稻恶苗病病害的加重态势,探寻种子包衣+浸种双重处理应用于水稻恶苗病防治的可行性,选用5%精甲·咯·嘧菌FS、62.5 g·L^(-1)精甲·咯菌腈FSC种子包衣,然后用氰烯菌酯浸种,进行田间小区探索试验。结果表明,5%精甲·咯·嘧菌FS、62.5 g·L^(-1)精甲·咯菌腈FSC种子包衣+25%氰烯菌酯SC浸种的双重处理对水稻出苗及生长安全,可以显著增强秧苗素质,对水稻恶苗病的平均防治效果达98.47%~100.00%,显著高于单一种子包衣或单一浸种处理。说明种子包衣再浸种双重处理是提高水稻恶苗病防效的有效措施,生产上,优先推荐5%精甲·咯·嘧菌FS 1000 mL·(100 kg)^(-1)种子包衣+25%氰烯菌酯SC 2000倍液浸种,其次推荐62.5 g·L^(-1)精甲·咯菌腈FSC 400 mL·(100 kg)^(-1)种子包衣+25%氰烯菌酯SC 2000倍液浸种,5%精甲·咯·嘧菌FS 750 mL·(100 kg)^(-1)种子包衣+25%氰烯菌酯SC 2000倍液浸种,感病品种或带菌种子建议提高施用剂量。

十二烷基苯磺酸钠(SDBS)在水溶肥料中的应用探索

为了探索十二烷基苯磺酸钠(SDBS)在水溶肥料中的应用,通过对表面张力或润湿面积的测试研究了SDBS对水溶肥料稀释液润湿性能的影响,采用浸种试验考查了SDBS对微量元素水溶肥料种子萌发效果的促进作用。结果表明:在中量元素和大量元素水溶肥料稀释液中添加0.20 g·L^(-1)左右的SDBS能较好地降低肥液表面张力;在微量元素水溶肥料稀释液中添加0.15 g·L^(-1)左右的SDBS能较好地提高肥液润湿性能和浸种效果。

干旱胁迫下两种芽胞杆菌对玉米幼苗促生作用研究

供试玉米品种为‘先玉335’(XY335),供试菌株为NECC11322(Bacillus subtilis)枯草芽胞杆菌、NECC11324(B.megaterium)巨大芽胞杆菌。试验设4组处理:Con(无菌水浸种,干旱胁迫),C1(无菌水浸种,正常供水),C2(NECC11322菌液浸种,干旱胁迫),C3(NECC11324菌液浸种,干旱胁迫),测定了浸种后盆栽玉米幼苗的生长状况、抗性生理指标及植株的N、P、K含量。结果表明:在干旱胁迫下接种NECC11322、NECC11324后,玉米幼苗叶片及根系SOD、POD、CAT、APX活性较Con均不同程度升高,其中接种NECC11322根系POD活性增长最为显著,较Con增长67.78%;植株叶片及根系可溶性蛋白含量、可溶性糖含量较Con均呈上升趋势,其中接种NECC11322叶片可溶性糖含量增长最为显著,较Con增长152.10%;与Con相比,植株叶片及根系全氮、全磷、全钾养分含量均有所提升,接种NECC11322后叶片全氮含量升高最为显著,较Con增长88.47%;干旱胁迫下接种两种芽胞杆菌后,植株叶片及根系丙二醛含量较Con均显著降低,接种NECC11322后根系降幅最为显著,较Con降低51.03%。综上可知,干旱胁迫下接种两种芽胞杆菌均可降低干旱胁迫对玉米幼苗生长的抑制,其中NECC11322菌株更具有抗旱性。通过提高保护酶活性、可溶性蛋白、可溶性糖含量、叶绿素含量以及植株养分含量提高玉米幼苗抗旱性,促进玉米幼苗生长。

二氢卟吩铁浸种对水稻生长与增产效应研究

为探明0.02%二氢卟吩铁可溶粉剂浸种后对水稻生长、产量的影响及使用剂量。以‘南粳9108’为供试水稻品种,将水稻种子在不同浓度0.02%二氢卟吩铁SP浸种处理,以0.0016%28-表高芸苔素内酯AS和0.136%赤·吲乙·芸苔SP为对照药剂,清水浸种为空白。分别在水稻苗期、分蘖期和成熟期调查其生长状况,并在收获期测定产量。结果表明:0.02%二氢卟吩铁浸种不影响水稻发芽,但浓度升高会降低水稻出苗率;0.02%二氢卟吩铁浸种可提高水稻秧苗鲜重、根数及水稻分蘖率;0.02%二氢卟吩铁稀释15000~10000倍浸种能增加水稻穗长、实粒数,提高水稻产量。因此,采用0.02%二氢卟吩铁15000~10000倍液浸种,可促进水稻生长,提高水稻产量,水稻生产中可扩大示范应用。

外源物质浸种对迟播油菜越冬期抗寒性及产量的影响

确保迟播油菜产量是压减长江流域双季稻区冬闲田的关键,提高越冬期抗寒性、促进冬前干物质积累是增加迟播油菜产量的有效途径。播前外源物质浸种是提高越冬期抗寒性,促进冬前快速生长的有效措施。试验选用早熟品种华油杂137,设置清水(CK),0.01 mmol L-1、0.05 mmol L^(-1)、0.10 mmol L^(-1)的甜菜碱(T1-1、T1-2、T1-3),0.1 mmol L^(-1)、0.5 mmol L^(-1)、1.0 mmol L^(-1)的脯氨酸(T2-1、T2-2、T2-3),0.03%、0.15%、0.30%的过氧化氢(T3-1、T3-2、T3-3),0.001 mmol L^(-1)、0.01 mmol L^(-1)、0.05 mmol L^(-1)的苹果酸(T4-1、T4-2、T4-3),25 mg L^(-1)、100 mg L^(-1)、300 mg L^(-1)的氧化纳米锌(T5-1、T5-2、T5-3),0.5 mmol L^(-1)、1.0 mmol L^(-1)的多胺(T6-1、T6-2)浸种处理后,于2021—2023年开展田间试验,研究不同外源物质及浓度浸种对迟播油菜越冬期抗寒性及产量的影响。结果表明,不同外源物质和不同浓度浸种处理影响迟播油菜出苗率,部分处理如T3-3、T4-2、T5-3与CK相比显著提高,提高幅度分别达到19.2%、15.3%、17.3%。部分外源物质浸种也显著提高了迟播油菜抗寒性,其机制一方面是提高抗氧化系统中过氧化物酶、过氧化氢酶活性和谷胱甘肽含量,减少活性氧、过氧化氢及丙二醛含量,另一方面是增加可溶性糖、脯氨酸、苹果酸、多胺、甘露醇等渗透调节物质含量,提高膜联冷应答蛋白激酶含量从而提高抗寒性。叶片抗寒性的增加有利于越冬期叶片生物量的积累,有效分枝数增加,单株角果数增加,从而促进产量的提高。另外,对筛选出的9个正向指标和3个负向抗寒性指标进行综合评价,结果表明,2年平均产量排序和抗寒性综合评价值排序结果基本一致,产量较高、抗寒性较强的浸种处理为T5-3、T5-2、T2-3、T1-2。该研究可为长江流域迟播油菜冬前壮苗培育、提高越冬期抗寒性提供理论与技术支撑,为迟播油菜抗逆稳产、促进冬闲田开发利用提供依据。

外源物浸种对苗期遭遇冷害棉花生长发育、产量及品质的影响

以‘中棉113’为试验品种,施用海藻糖、褪黑素和抗坏血酸对棉花进行浸种预处理,在棉花出苗期间遭受低温冷害后,比较3种外源物处理的棉花成苗情况、主要农艺性状、生物量积累、产量及其构成因素及纤维品质性状间的差异。结果表明:与CK处理相比,外源物处理的棉花成苗率显著提高1.3%~6.1%;株高、茎粗和果枝台数分别显著提高8.1%~9.2%、10.1%~14.6%和13.7%~22.2%;生物量显著增加1.6%~20.9%,生物量在库(蕾、花、铃)的分配比例提高3.3%~16.4%;籽棉产量显著提高11.7%~18.4%;棉花纤维品质表现较好,棉花纤维上半部平均长度和断裂比强度均达到29 mm以上和29 cN·tex^(-1)以上,马克隆值为B级。综上所述,外源物浸种处理可以显著提高受灾棉花的成苗率,促进棉花植株的生长发育和生物量的积累与分配,提高产量,其中,100μmol·L^(-1)褪黑素浸种的效果优于其余2种外源物浸种。

纳米级Fe_(3)O_(4)分散液浸种对NaCl胁迫下番茄种子萌发及幼苗保护酶系统的影响

为揭示纳米级Fe_(3)O_(4)(Fe_(3)O_(4)NPs)调控作物耐盐的效应和机理,采用共沉淀法成功合成10 nm粒径的Fe_(3)O_(4)NPs,并通过了表征分析和鉴定;进一步研究其0、1、10、50、100、200、300、400 mg·L^(-1)分散液浸种处理对NaCl胁迫下番茄种子萌发、幼苗生长及其抗氧化的影响。结果表明:盐胁迫下1 mg·L^(-1) Fe_(3)O_(4)NPs浸种明显降低番茄种子发芽、幼苗胚根和下胚轴生长,随着浸种浓度上升,其发芽逐步得到改善;100 mmol·L^(-1)NaCl胁迫下,200 mg·L^(-1)Fe_(3)O_(4)NPs浸种的种子发芽势和下胚轴长达到峰值,显著高于仅盐处理的对照。100 mmol·L^(-1) NaCl胁迫明显降低番茄种子成苗率、幼苗鲜物质量和含水量,1 mg·L^(-1)Fe_(3)O_(4)NPs浸种,导致其进一步降低,随着Fe_(3)O_(4)NPs浸种浓度上升,其数值逐渐上升,200 mg·L^(-1)Fe_(3)O_(4)NPs浸种的幼苗鲜物质量和含水量达到峰值,显著高于仅盐处理的对照。盐胁迫下,1 mg·L^(-1)Fe_(3)O_(4)NPs浸种的幼苗超氧化物歧化酶(SOD)和过氧化物酶(POD)活性显著上升,而过氧化氢酶(CAT)活性下降,随着Fe_(3)O_(4)NPs浸种浓度上升,SOD和POD酶活逐渐下降再逐渐回升,CAT酶活逐渐上升再回落,100~200 mg·L^(-1) Fe_(3)O_(4)NPs浸种的幼苗SOD和POD酶活、丙二醛(MDA)、脯氨酸(Pro)含量、超氧阴离子自由基(2O×-)和过氧化氢(H2O_(2))含量均最低,而其CAT酶活最高。相关性分析表明,幼苗鲜物质量、成苗率与SOD和POD活性以及MDA和活性氧含量均呈极显著负相关。综上所述,在盐胁迫下Fe_(3)O_(4)NPs浸种处理的番茄种子萌发和成苗依赖于Fe_(3)O_(4)NPs不同浓度的调控特征,即1 mg·L^(-1) Fe_(3)O_(4)NPs浸种处理展示了进一步抑制的典型特征,其氧化胁迫加剧;而200 mg·L^(-1) Fe_(3)O_(4)NPs浸种处理表现为促进萌发、成苗和壮苗的显著作用,与其抗氧化得到明显改善直接相关。

不同药剂浸种对秃杉低温贮藏种子萌发的影响

为探索提高低温贮藏种子活力、促进种子萌发的适宜方法,以4℃条件下贮藏365 d的秃杉种子为材料,研究了不同质量浓度的6-BA、GA_(3)、NAA、Ca(NO_(3))2、NH_(4)NO_(3)和KNO_(3)浸种处理对种子发芽与幼苗生长的影响。结果表明:6种药剂对低温贮藏种子发芽和幼苗生长均有不同程度的促进作用,同种药剂不同质量浓度间亦存在差异。与清水浸种空白对照(control check,CK)相比,NAA、KNO_(3)浸种的平均发芽率、发芽势、发芽指数和活力指数均有显著提高。发芽率以12 mg/L NAA最高,达到35.56%,约为CK的2.7倍;发芽势、发芽指数、活力指数均以4 mg/L NAA最高,分别达到14.44%、1.94、2.70,约为CK的13.0、3.5、4.0倍。NAA、KNO_(3)、NH_(4)NO_(3)浸种的平均苗高显著高于CK,以12 mg/L NAA最高,达到1.48 cm,约为CK的1.2倍。NAA、KNO_(3)、Ca(NO_(3))_(2)浸种的平均根长显著高于CK,以12 mg/L NAA最高,达到0.98 cm,约为CK的1.6倍。NAA、KNO_(3)浸种有利于秃杉低温贮藏种子的萌发与幼苗生长,以12 mg/L NAA浸种为最优。该研究结果将为经过低温贮藏的秃杉种子的播种育苗提供参考。