广西绞股蓝种子休眠与萌发特性研究

对广西绞股蓝种子进行了生活力测定、发芽试验、吸水率测定及离体胚萌发试验,并对广西绞股蓝种子进行酸碱处理、低温层积和干藏处理、GA₃和6-BA溶液处理,探讨不同的处理对广西绞股蓝种子萌发的影响。结果表明新鲜广西绞股蓝种子的活力高达98%,但在6个恒温和1个变温条件下,其萌发率最高仅为11.7%,说明广西绞股蓝具有明显的休眠现象。种子吸水性测定结果表明,广西绞股蓝种皮限制种子吸水,离体胚萌发实验证实广西绞股蓝种子的胚在离体条件下没有休眠现象,说明种皮障碍是导致广西绞股蓝种子休眠的主要原因。低温层积不能解除广西绞股蓝种子的休眠,而干藏则会导致种子内部失水,从而导致种子生活力降低。浓硫酸和不同浓度的NaOH溶液处理均不能打破种子的休眠,仅6-BA溶液处理对4℃层积后的种子萌发起到一定的促进作用。     

胚培养途径探索铁棒锤种子的休眠原因

目的:探索铁棒锤种子休眠的原因。方法:在MS培养基上对铁棒锤全种子、切去部分胚乳的种子、离体胚进行离体萌发试验。结果:由于胚乳的存在,即使种胚已经完成了形态后熟,胚的萌发率依然很低,部分去除胚乳或全部去除胚乳后胚的萌发率显著提高。结论:铁棒锤种胚本身不休眠,在适宜的条件下能够正常萌发,胚乳当中存在抑制其发芽的抑制物质,适量的生长激素能促进胚的萌发。     

北细辛种子贮藏过程中生活力及种胚形态后熟研究

通过对北细辛(Asarum heterotropoides Fr.Var.mandshuricum(Maxim)kitag.)种子种胚萌发能力的验证、贮藏过程中种子活力测定以及种胚形态石蜡切片观察。结果表明,离体胚在25℃恒温、3 500~4 000 lx光照条件或暗条件下培养均枯死,北细辛种子采收后种胚不具有萌发能力。种子在3 500~4 000 lx光照条件下培养,5周后开始萌发,而在暗培养条件下,5周后则不萌发。室温条件下沙藏,北细辛种子活力保持不变,活力指数为88.3%~88.7%。种胚形态解剖结构观察发现,北细辛种胚发育过程为经过球形胚、心形胚、鱼雷型胚、具有完整子叶胚等阶段,其胚轴伸长、胚根伸长直至发芽。     

太子参种子特性及种胚离体诱导培养技术研究

采用解剖学观察和无菌诱导培养技术研究太子参种子特性并离体诱导培养种胚。结果表明:太子参种子由外种皮、内种皮、外胚乳和胚构成,胚由子叶、胚芽、下胚轴和胚根组成,其中胚芽非常细小;种子具休眠特性,需要后熟过程才能自然萌发;种子的外胚乳对胚的萌发有抑制作用,剥去种皮和外胚乳的裸胚在培养基MS+6 BA 1.0 mg/L+NAA 0.2mg/L中能很快被诱导萌发生长,萌发率78.3%。说明太子参种胚通过离体诱导培养,可有效解决种子的休眠现象,这为实现太子参无病毒种苗的工厂化育苗提供新途径及技术支持。     

药用植物盘龙参种子形态、萌发及贮藏的初步研究

对盘龙参种子的形态、萌发及贮藏条件进行初步研究,结果表明,种子的长度0.167～0.218 mm、胚长0.091 8～0.115mm、胚宽0.039～0.056 mm;种子萌发时首先形成类原球茎,在其表面附有菌丝;再分化芽与根,根上具有根毛;由种子萌发到3片叶子小苗,需要约40 d;不同贮藏温度对种子萌发率影响存在差异,4℃下有利于保持新鲜种子的萌发。     

葡萄糖和ABA对小麦胚萌发过程中α-淀粉酶表达的调控

为了探讨种子的萌发特性与胚对ABA的敏感性和α-淀粉酶表达之间的关系,比较了葡萄糖和ABA 对不同生理状态的小麦离体胚萌发过程中α-淀粉酶表达的调控作用.结果表明,葡萄糖对未成熟胚、休眠成熟胚和不休眠成熟胚的萌发均有促进作用;葡萄糖能够抵消ABA对胚萌发的抑制作用,对于不休眠成熟胚,葡萄糖可以减轻ABA对胚根发生的抑制作用,但对随后的形态发生无影响.葡萄糖可以抑制小麦胚萌发过程中α-淀粉酶的表达;ABA可以抑制未成熟胚与休眠成熟胚中α-Amy-1的表达,但在不休眠成熟胚中则诱导α-Amy-1表达.因此,小麦离体胚的萌发特性、胚对ABA敏感性和α-淀粉酶的表达均与生理状态有密切关系.     

东北刺人参种胚形态后熟过程中的解剖观察

通过对东北刺人参(Oplopanax elatus Nakai)种子后熟期间胚形态的解剖观察发现:东北刺人参果实成熟时种胚尚未分化完全,处于心形胚阶段,这是种子休眠的主要原因。种子在暖温处理过程中逐渐完成种胚的分化与生长,种子胚分化和发育的速度不一致,从而导致种子休眠程度不一致。     

短梗五加种子萌发影响因子研究

短梗五加[Acanthopanax sessiliflorus(Rupr.et Maxim.)Seem]种子透水性良好,休眠后萌发不受其影响。果肉、种皮和胚乳中均存在抑制物质,胚乳中提取物质对白菜种子萌发的抑制效果最明显,果肉其次,种皮最弱。果实成熟种子自然脱落时,种胚尚未发育完全,处于心形胚阶段。种子萌发需要先暖温层积以完成胚的分化与生长,然后转入低温完成生理后熟。     

新疆阿魏胚萌发研究

研究了新疆阿魏离体胚培养中,不同培养基、光照、温度、碳源、pH值及低温层积、赤霉素、6-苄氨基嘌呤处理等因素对胚萌发及生长的影响。结果表明：诱导胚萌发较理想的培养基为MS（pH值为5.5-6.0）＋1mg／L GA3＋0.1mg／L6-BA＋3％蔗糖;光照对胚的萌发势差异不明显（P=0.334）,但存在显著的温度差异（P=0.000）,其中20、25、30℃较适宜;离体胚的萌发率随种子低温层积时间的延长而有所下降,推测新疆阿魏种子产生休眠效应的部位可能在胚以外的种皮或胚乳。本研究能有效克服新疆阿魏种子抑制物或种皮本身限制,萌发率可达94％。不仅为新疆阿魏人工培育奠定了基础,也为研究种子低温层积打破休眠的机制提供了新的思路。     

箭叶淫羊藿(Epimedium sagittatum Maxim)种子后熟作用的形态解剖研究

目的:了解箭叶淫羊藿种子后熟休眠的形态结构基础,探索其种子的萌发条件。方法:在对箭叶淫羊藿种子进行常规发芽试验的基础上,采用直接测量和石蜡制片技术等方法对其外部形态和解剖结构进行了观察。结果:箭叶淫羊藿种子存在明显的休眠现象,其外部形态无异常,但其胚结构未分化,停留在球型胚阶段。后熟过程中,其胚结构逐步发育完全,形成子叶胚。结论:箭叶淫羊藿种子存在明显的休眠现象,其休眠类型为形态生理休眠(MPD)。其萌发需要一定时间的层积以完成其胚分化。     

多花黄精种子萌发过程的形态和解剖研究

为解除多花黄精种子休眠、促进种子萌发,利用Nikon-SMZ 800体式显微镜观察多花黄精种子不同萌发时期的外观形态,采用石蜡切片法将多花黄精种子特殊部位制成切片,在Olympus-BX 61光学显微镜下观察其解剖结构,探究多花黄精种子萌发过程中的形态变化及解剖特征。结果表明,1)多花黄精种子萌发过程可分为:刚采摘、未萌发、刚萌发、小球茎形成、初生根茎形成和出苗6个阶段;2)成熟的多花黄精种子,其胚未分化出明显的子叶、胚芽和胚根,随着种子的萌发而分化成成熟胚;3)多花黄精种子的萌发伴随着胚乳的降解;4)多花黄精种子同时存在生理休眠和形态休眠,具有形态生理休眠特性。     

Characterization of a green non‐dormant sunflower (Helianthus annuus) mutant NDG

A sunflower (Helianthus annuus L.) mutant was observed in the progeny of a cross between the sunflower cultivar ‘HA 89’ and an amphiploid of a Helianthus divaricatus L. × P21 cross that exhibited loss of dormancy induction in the developing embryo. Seeds of this mutant frequently germinate on the head about 40 days after pollination. The cotyledons of this mutant remain green, whereas some other non‐dormant mutants exhibit loss of pigmentation. The objectives of this investigation were to compare levels and activities of abscisic acid (ABA), a plant hormone that induces dormancy in developing embryos, in the non‐dormant green mutant (NDG) and ‘HA 89’ from which NDG was derived. Immunoassays showed that abscisic acid was present in NDG and the levels were not significantly different from those in ‘HA 89’. Exposure of excised NDG mutant embryos to 40 μm abscisic acid failed to prevent germination, suggesting that non‐dormancy could result from impairment in ABA receptors or from a defect in other proteins participating in the subsequent signalling pathway that normally induces dormancy.     

Wheat ABA-insensitive mutants result in reduced grain dormancy

This paper describes the isolation of wheat mutants in the hard red spring Scarlet resulting in reduced sensitivity to the plant hormone abscisic acid (ABA) during seed germination. ABA induces seed dormancy during embryo maturation and inhibits the germination of mature seeds. Wheat sensitivity to ABA gradually decreases with dry after-ripening. Scarlet grain normally fails to germinate when fully dormant, shows ABA sensitive germination when partially after-ripened, and becomes ABA insensitive when after-ripened for 8?C12?months. Scarlet ABA-insensitive (ScABI) mutants were isolated based on the ability to germinate on 5???M ABA after only 3?weeks of after-ripening, a condition under which Scarlet would fail to germinate. Six independent seed-specific mutants were recovered. ScABI1, ScABI2, ScABI3 and ScABI4 are able to germinate more efficiently than Scarlet at up to 25???M ABA. The two strongest ABA insensitive lines, ScABI3 and ScABI4, both proved to be partly dominant suggesting that they result from gain-of-function mutations. The ScABI1, ScABI2, ScABI3, ScABI4, and ScABI5 mutants after-ripen more rapidly than Scarlet. Thus, ABA insensitivity is associated with decreased grain dormancy in Scarlet wheat. This suggests that ABA sensitivity is an important factor controlling grain dormancy in wheat, a trait that impacts seedling emergence and pre-harvest sprouting resistance.     

穿龙薯蓣新陈种子萌发条件优选研究

目的:研究赤霉素( GA3)、萘乙酸(NAA)和层积后温度对穿龙薯蓣新陈种子萌发条件.方法:培养皿培养法遮光培养,得出3种处理最优条件后对陈种子进行相同处理.结果:穿龙薯蓣新种子4℃低温砂层积后,25℃条件下发芽率和发芽势最高,分别为80％和53.33％,陈种子为45％和25％;而采用100 mg/L GA3直接浸泡未层积新种子24h,发芽率和发芽势可达66.65％和48.35％,陈种子为40％和25％;1 mg/L NAA浸泡12 h新种子发芽率和发芽势为58.35％和43.35％,陈种子为30％和23.35％;低温砂层积新种子发芽进程最快,其第6天开始发芽,第12天发芽完毕,快于GA3的10d和22 d,NAA的11d和24d.结论:生产上若有层积条件,建议采用4℃低温砂层积60d后在25℃下进行新种子催芽;若没有层积条件,建议直接采用100 mg/L GA3进行新种子催芽处理.     

食用蒲公英种子萌发对PEG-6000模拟干旱胁迫的响应

采用浓度分别为0％、5％、10％、15％、20％和25％的PEG-6000溶液模拟干旱条件,测定蒲公英种子在不同干旱胁迫条件下的日相对萌发率、发芽势、发芽指数、活力指数及上下胚轴长度等指标,研究了蒲公英种子萌发及幼苗生长对PEG-6000模拟干旱胁迫的响应,探讨了经20％、25％ PEG-6000浸种预处理后种子的萌发恢复能力.结果表明:5％PEG-6000胁迫下提前了萌发高峰、提高了发芽率,促进了种子的萌发;10％PEG-6000胁迫显著降低了种子发芽势,但未对其发芽率产生显著影响;高度水分胁迫(15％ PEG-6000浓度)显著抑制了蒲公英种子的萌发,并延长其萌发时间,但是,其种子萌发率仍是对照的73.35％,说明蒲公英具有很强的抗旱性.当重度胁迫时(20％、25％ PEG-6000浓度)蒲公英种子未见萌发,解除胁迫后遇充足水分,蒲公英种子即立刻快速整齐的萌发,表现为蒲公英种子对较强干旱环境的适应性,也是野生植物的生存策略之一.     

The assessment of in vitro characters and their influence on the success rates of doubled haploid production in barley

Summary A assessment of in vitro characters: embryo size, differentiation stage and germination time of haploid embryos, was carried out with a view to developing a selection procedure to increase the efficiency of doubled haploid (DH) production using the Hordeum bulbosum system. The differentiation stage of haploid embryos at the time of excision was found to be the most promising character for selection. In the two spring crosses examined 55% of excised embryos were undifferentiated and 45% were differentiated, with overall success rates, in terms of the percentage of DHs produced, of 7.91% and 25.16%, respectively. 17% of excised embryos produced callus. These embryos performed poorly in terms of regeneration and subsequent growth. It is suggested that only differentiated non-callusing embryos are maintained in order to maximize the efficiency of DH production. It is also shown that the overall success rate depends not only on initial stages such as seed setting but also on genotypic differences in response to colchicine treatment at later stages.     

盐引发对不同水分条件下油菜种子发芽成苗的影响

试验用两个油菜(Brassica napus L.)品种"双72"和"浙油758"研究了Ca(NO3)2溶液引发对油菜种子在不同水分条件下发芽和幼苗生长的影响,探讨通过引发来提高大田直播油菜的活力.结果表明,经过引发处理后,两个油菜品种在30%的水分条件下无法发芽;在20%和25%的水分条件下种子的发芽指数显著提高,平均发芽天数显著缩短,幼苗POD活性显著提高,而幼苗的根长、苗高、苗干重、叶绿素含量和CAT活性与对照相比没有显著差异.引发后的"浙油758"种子在20%和25%水分条件下,发芽势和发芽率显著提高,而"双72"种子的发芽势在20%水分时显著高于对照.试验表明盐引发提高了油菜种子在水分逆境下的活力,提高了幼苗的抗逆性.     

光照和盐分对醉马草种子萌发的影响

研究了光照、水分和盐分对醉马草种子萌发的影响.结果表明,醉马草种子萌发对光照不敏感,在黑暗和光照下的发芽率及幼苗长度没有显著性差异.NaCl和等渗透势的PEG对种子的萌发均产生抑制作用,降低了发芽率,且PEG的抑制程度大于等渗NaCl,说明渗透胁迫是影响醉马草种子萌发的主要因素.醉马草种子能在0～398 mmol/L的NaC1浓度下萌发,较低盐浓度有利于根长的生长.     

Response of Wheat Grain to ABA and Imbibition at Low Temperature

During after-ripening of wheat grains, embryo responsiveness to abscisic acid (ABA) decreases in parallel with the loss of grain dormancy. Dormant grains of Triticum aestivum L. line ‘Kitakei-1354’ that had lost almost half their dormancy due to chilling still respond to ABA like fully dormant grains. Imbibition a: low temperature appears to break the dormancy without change of embryo responsiveness to ABA. Gibberellin (GA) and ABA-regulated α-amylase synthesis of the embryos. This is amplified when the grains are imbibed at low temperature. Imbibition at low temperature appears to condition cells and tissues of the embryo for germination and α-amylase synthesis.     

不同处理方法对巨柏种子萌发的影响

以巨柏种子为研究对象,对其在不同处理条件下的发芽率和发芽势进行了比较分析.结果表明:温度对巨柏种子发芽具有一定的促进作用,40℃水温浸种是最佳的处理,水温过高反而抑制其萌发.发芽温度为12.5～17.5℃时巨柏种子的发芽率和发芽势最高,随着温度的再降低或增高发芽率和发芽势反而下降.浓度为300 mg/L GA浸种后,巨柏种子的发芽率和发芽势最高.随着PEG模拟干旱胁迫程度的加剧,巨柏种子的发芽率受到影响,发芽势受到严重抑制.低浓度的PEG对巨柏种子萌发具有一定的促进作用,而高浓度则有抑制作用.光照可以提高巨柏种子的发芽率和发芽势.