休眠与水稻成熟胚细胞脱分化间的关系

 本文阐明了水稻种子休眠与脱分化的关系,成熟度越低(休眠度愈高),其愈伤组织诱导率越高。在种子收获后立即在55℃高温连续处理4天,强制性打破休眠,能显著提高愈伤组织诱导率;另外,在诱导培养基中附加适量的 ABA(脱落酸)也可明显地提高水稻成熟胚的培养力。这可能与外植体内源激素含量变化有关。     

芸苔属种子生活力监测方法的研究

本文研究了芸苔属(BrassicaL,)种子的休眠特性。破眠技术及其生活力监测方法。结果表明:(1)芸苔属6个物种都存在有一定程度的休眠现象。其中以B.nigra程度最深;B.juncea、B.carinata次之;B.oleracea、B.napus、B.campestris较浅。(2)气干、200PPmGA_3、变温(4—31℃、12小时交替)相结合的破眠技术能够有效地解除休眠。对中深休眠的物种可以全部促进其发芽;而对浅休眠的物种,发芽率稳定在97.20%以上。(3)破眠四唑法与常规发芽法和四唑染色法相比,可以准确、快速、简便地提供种子生活力的无偏估计,置信水平达99%。     

变温及GA3处理对辽东槐木种子解除休眠信号物质变化影响

研究了在变温条件下赤霉素(GA3)对辽东楤木(Araliaelata)种子解除休眠过程中部分信号物质变化的影响。方法是将辽东楤木种子在200mg/kg的GA3水溶液中浸泡12h,然后在高温(18￣20℃12h)和低温(0￣4℃12h)下进行变温层积处理60d。结果表明:在层积过程中,赤霉素(GA3)和钙调素(CaM)含量分别出现两次峰值,而脱落酸(ABA)含量一直很低,并在第12d降到最低点,此外,NADK激酶和质膜Ca2 -ATPase活性酶在种子开始裂口期,分别出现先升高后降低和先降低后升高的变化。     

Environmental control of growth and flowering of Rubus idaeus L. cv. Glen Ample

Environmental control of the annual growth cycle of ‘Glen Ample’ raspberry has been studied in order to facilitate crop manipulation for out-of-season production. Plants propagated from root buds were raised in long days (LD) at 21 °C and then exposed to different temperature and daylength conditions at varying ages. Shoot growth was monitored by weekly measurements and floral initiation by regular sampling and examination of axillary bud #5. Under natural summer daylight conditions at 60°N shoot growth was nearly doubled at 21 °C compared with 15 °C, while at 9 °C one half of the plants ceased growing and formed flower buds at midsummer. Developing shoots have a juvenile phase and could not be induced to flower before the 15-leaf stage. No significant reduction in induction requirements was found in larger plants. Plants exposed to natural light conditions from 10th August, had an immediate growth suppression at 9 and 12 °C with complete cessation after 4 weeks (by September 7). This coincided with the first appearance of floral primordia. At 15 °C both growth cessation and floral initiation occurred 2 weeks later (by September 21), while at 18 °C continuous growth with no floral initiation was maintained until early November when the photoperiod had fallen below 9 h. The critical photoperiod for growth cessation and floral initiation at 15 °C was 15 h. Plants exposed to 10-h photoperiods at 9 °C for 2–4 weeks had a transient growth suppression followed by resumed growth under subsequent high temperature and LD conditions, while exposure for 5 or 6 weeks resulted in complete growth cessation and dormancy induction. The critical induction period for floral initiation was 3 weeks although no transitional changes were visible in the bud before week 4. When exposed to inductive conditions for marginal periods of 3 or 4 weeks, an increasing proportion of the plants (20% and 67%, respectively), behaved as primocane flowering cultivars with recurrent growth and terminal flowering. It is concluded that growth cessation and floral initiation in raspberry are jointly controlled by low temperature and short day conditions and coincide in time as parallel outputs from the same internal induction mechanism.     

外源酚类物质处理对百合鳞茎萌发的影响

为探讨酚类物质与百合鳞茎休眠的关系,研究了3种不同浓度下对羟基苯甲酸、阿魏酸、水杨酸和香豆素处理对鳞茎萌发的影响.结果表明:在100～500 mg/mL浓度范围内,中、低浓度的对羟基苯甲酸和水杨酸抑制了鳞茎萌发,随着浓度升高,鳞茎萌发率显著增加,顶芽在鳞茎内的萌动加快,鳞茎出苗日期提前.香豆素对百合鳞茎萌发有明显促进作用,500 mg/mL 处理鳞茎发芽率最高,200 mg/mL处理的出苗一致性最好.阿魏酸与百合鳞茎休眠没有显著相关关系.     

Emergence and performance of volunteer oilseed rape (Brassica napus) in different crops

Volunteer oilseed rape (OSR, Brassica napus L.) causes various agronomic problems in crop rotations and can contribute to gene dispersal by pollen and by seed admixture. A 4-year field experiment (2008–2011) was set up in south-west Germany to investigate the performance of volunteers derived from two OSR cultivars with different levels of seed dormancy. Volunteers of a high-dormancy (HD) and a low-dormancy (LD) OSR cultivar were deliberately generated by spreading 10,000 seeds m⁻² on a field in August 2008 and 2009. Four different crops were grown on that area in the first year following the seed rain: winter wheat (Triticum aestivum L.), winter turnip rape (Brassica rapa L.), spring barley (Hordeum vulgare L.) and field pea (Pisum sativum L.). In the second year, maize (Zea mays L.) was sown uniformly across all plots. Numbers of OSR seedlings emerging in early autumn shortly after seed rain were not connected with the size of the soil seed bank in early spring of the following year. The seeds of the HD-cultivar formed a much greater soil seed bank (up to 14% of the initially spread seed number) compared with the LD-cultivar (up to 1.3%) in the soil layer of 0 to 30 cm in early spring 2009 and 2010). Across all crops, considerably more volunteers of the HD-cultivar than of the LD-cultivar were present at several survey dates in the first year following seed rain. The highest number of volunteers originated from the HD-cultivar with up to 11 volunteers m⁻² in winter turnip rape compared with a maximum of 0.48 plants m⁻² in the other crops. Cultivar-specific differences in volunteer density were observed as well in maize two years after OSR seed rain. Flowering and seed setting volunteers were only present in 2010 and the flowering time was crucially overlapping with that of sown winter OSR. The reproductive ability (seeds produced m⁻²) of the LD-volunteers was five times lower in winter turnip rape than of the HD-volunteer; a similar trend was observed for the OSR volunteers in the other host crops.Strategies to definitely reduce unwanted effects of OSR volunteers, such as gene flow, should include the use of LD-cultivars with a low potential to form a soil seed bank, particularly if selective herbicides are not available, for instance in broad-leaved crops, or if the volunteers are herbicide-tolerant.     

寄生植物种子休眠与萌发的研究进展

寄生植物种子的休眠与萌发的研究对寄生植物种子萌发过程中物理信号的寻找和寄生过程中化学信号的识别起着很重要的作用。对环境信号、激素水平和化学信号物质刺激寄生植物种子打破休眠,从而促进萌发方面进行了综述,并提出了有待进一步研究的问题。     

马铃薯的休眠特性及其生理调控研究

试验马铃薯品种、自交实生薯、杂交实生薯的休眠特性。室温保存品种的强度和幅度分别为42~70d和35~42d;自交实生薯分别为56~77d和42~49d,杂交实生薯分别为56~91d和49~63d。赤霉素处理能使休眠期较室温保存期强度缩短25.0%~62.5%,幅度缩短34.7%~71.4%,但使芽的生长变弱。变温处理能有效缩短休眠期较长的品种和家系的休眠时间,对缩短休眠期短的品种和家系的休眠时间效果不明显,但能使休眠幅度较室温下缩短28.6%~50.0%,使芽生长得较粗壮。赤霉素处理和变温处理均不能改变３种类型试验材料之间休眠幅度的差异。CIPC抑芽剂处理块茎,能够有效地抑制芽的生长。     

东北铁线莲种胚后熟过程中内源激素动态变化

用植物激素的酶联免疫吸附测定法（ELISA）测定不同时期东北铁线莲种子内源激素IAA、ABA、GA、ZR的动态变化。结果表明：低温层积初期东北铁线莲种子ABA的含量呈较明显的下降趋势;进入生理后熟期以后,GA、ZR的含量持续升高,抑制萌发物质减少及促萌物质的增加与积累,最终导致东北铁线莲种胚休眠的解除。     

影响烟草种子萌发的理化因素研究

[目的]研究理化因素对烟草种子萌发的影响,提高烟草种子萌发率。[方法]采用摇床振荡水培养、MS培养基培养、赤霉素(GA3)浸种后MS培养基培养几种方法,分别处理烟草种子和浸种回干烟草种子,研究水分、温度、光照及激素等因素对烟草种子萌发的影响。[结果]摇床振荡水培养能促进种子萌发,MS培养基培养比较利于烟草幼苗的生长;浓度0.1~0.9 mg/L的GA3浸种10 min能打破种子休眠,而附加浓度1~7 mg/L GA3培养基培养能促进烟草植株茎的生长,其中浓度为0.7 mg/L GA3浸种和培养基附加7 mg/L GA3培养的效果最好。经过浸种回干的种子在每个对比试验中均比未处理的种子提早萌发。[结论]浸种回干和适当浓度的激素处理能有效打破烟草种子的休眠,提高萌发率。