四翅滨藜种内不同变异类型初探

四翅滨藜[Atriplex canescens(Pursh)Nutt.]播种苗种内分化明显,变异大,具有较广阔的选优潜力,文中对张掖引种的四翅滨藜进行了初步的表型划分,并对初选的8个不同变异类型进行物候调查和生长量表型指标的测定,结果表明,不同变异类型间生长指标差异性极显著,四翅滨藜生长指标种内变异分化明显,存在很大的选优空间和潜力,为进一步系统地研究四翅滨藜种质资源及开展育种工作奠定基础。     

河西走廊四翅滨藜硬枝扦插试验研究

四翅滨藜(Atriplex canescens)硬枝扦插繁殖试验表明:四翅滨藜采用1年生枝插穗、浓度为0.005%的1号ABT生根粉浸泡处理5h、在塑料拱棚环境条件下管理可有效提高扦插成活率,成活率可达77.66%。2年生枝采用浓度为0.005%的1号ABT生根粉浸泡5h扦插成活后,扦插苗的苗高、地径、冠幅和新梢生长量大于1年生枝扦插苗。四翅滨藜生根类型属皮部生根型,在其生根过程中基部无愈伤组织产生,扦插后60~70d时皮部长出新根,根量较少。     

催芽、覆盖对楤木种子萌发和生长的影响

【目的】研究催芽、覆盖物对楤木种子萌发和幼苗生长的影响,为六盘山楤木播种繁育和幼苗生长选择合适的催芽方法和覆盖材料提供理论依据。【方法】以六盘山楤木种子为试验材料,采用低温沙藏+高温催芽、室温沙藏+高温催芽、低温冷冻沙藏+高温催芽和低温沙藏4种催芽方法,研究这4种催芽方法下六盘山楤木种子萌发率差异;播种后采用胡麻草、玉米秸秆、落叶松针叶或不覆盖,对比研究4种处理下六盘山楤木种子出苗率、苗高和叶片数差异。【结果】在0℃环境下沙藏150 d后转到25℃环境中继续沙藏30 d,种子萌发率最高,为84.7%,其余依次为处理室温沙藏+高温催芽、低温冷冻沙藏+高温催芽和低温沙藏,三者萌发率分别为72.7%、68.7%和50.0%。覆盖物对楤木幼苗生长的影响采用完全随机区组试验设计,玉米秸秆覆盖的六盘山楤木种子出苗率最高,为74.5%;其余依次为胡麻草、松针和对照,三者出苗率分别为45.6%、43.3%和34.4%。胡麻草覆盖苗高最高,为23.0 cm,其余依次为玉米秸秆、对照和松针,三者苗高分别为13.9、7.1和6.4 cm。胡麻草覆盖的幼苗叶片数最高,为7.7枚·株~(-1),其余依次为玉米秸秆、对照和松针,三者叶片数分别为4.9、4.3和3.7枚·株~(-1)。【结论】六盘山楤木种子萌发以0℃下沙藏150 d后继续在25℃下沙藏30 d为宜,播种后以玉米秸秆覆盖出苗率高,以胡麻草覆盖促进幼苗生长效果好。     

小尾寒羊对四翅滨藜表观消化率的影响

为研究小尾寒羊对四翅滨藜(Atriplex canescens(pursh)Nutt.)饲料养分消化率的影响,选用1年龄小尾寒羊按试验要求随机分为3组,每组3个重复,每个重复1只。分别饲喂Ⅰ组(苜蓿)、Ⅱ组(四翅滨藜)、Ⅲ组(玉米秸秆)。预试期7 d,正试期6 d。结果表明:小尾寒羊对Ⅰ组(苜蓿)的日均采食量为654.12 g,而采食率为68.75%,就采食量和采食率而言,与Ⅰ组(苜蓿)差异不显著,与Ⅲ组(玉米秸秆)差异显著(P<0.05),其高低顺序依次为Ⅰ组(苜蓿)>Ⅱ组(四翅滨藜)>Ⅲ组(玉米秸秆)。小尾寒羊对Ⅱ组(四翅滨藜)养分CP的消化率与Ⅰ组(苜蓿)差异显著(P<0.05),其它差异不显著;小尾寒羊对Ⅱ组(四翅滨藜)养分CP、EE、NFE的消化率差异极显著(P<0.01),P的消化率差异显著(P<0.05)。     

四翅滨藜硬枝扦插育苗技术

<正>四翅滨藜[Atriplex canescens(Pursh)Nutt]是美国科洛拉多州立大学农业试验站等单位经过25 a的努力,选育出的改良品种,具有耐干旱、贫瘠、抗盐碱等多种优良特性,被广泛用于牧场改良和水土保持。目前我国已有不少地区引进了该品种,我站从2000年进行了引种栽培试验研究,获得了成功。但是,由于种子资源不足,影响了大面积推广。     

7种梾木苗期育苗试验初报

对7种梾木属植物的种实性状、休眠解除、1年生幼苗生长动态及适应性进行了试验研究。6种外来梾木属植物种实经360 d的低温沙藏处理后基本解除休眠,发芽率82%~93%,毛梾种实含油量高,低温沙藏催芽处理89 d后的种实发芽率为45%。低温处理后的种实每年2月中下旬开始萌动,3月中下旬陆续出土,发芽持续时间15~20 d,为出土萌发。1年生苗平均高生长量以欧洲红瑞木最大(94.13 cm),其次是粗叶梾木(93.75 cm);圆锥梾木、毛梾、熊果梾木和斜叶梾木1年生苗高生长量中等,当年高生长量分别为80.62,78.42,77.81 cm和77.63 cm;多花梾木1年生苗平均高生长量最小(41.30 cm),初期生长速度较慢。熊果梾木、斜叶梾木、圆锥梾木、粗叶梾木、欧洲红瑞木、毛梾6树种的高生长曲线十分接近,S型曲线非常明显,属于前期生长型;多花梾木的年高生长非常小,S型曲线变化不十分明显。7种植物表现出较强的抗逆性,适于在我国南方引种育苗和扩大栽培。     

不同预处理对2种山龙眼科种子出苗率的影响

采用播种前对种子进行不同浸种处理和低温恒温层积处理的方法,研究不同预处理对美极山龙眼(Protea eximia)、大叶山龙眼(Protea magnifica)出苗率的影响。结果表明,播种前对美极山龙眼种子采用4 g.L-1的烟丝水浸种24 h效果最好,能够提高种子的发芽率、发芽势和发芽指数;大叶山龙眼种子以低温恒温层积处理效果最佳,10 d后就有种子开始萌发,45 d后种子萌发率能达到92%,极显著高于对照。     

光皮梾木种子催芽技术研究

采用不同的催芽方法对光皮梾木的种子进行处理,试验结果表明:光皮梾木的种子在低温沙藏120d发芽率较高,达63.4%,低温沙藏90d以后对促进种子的发芽作用显著。在湖北光皮梾种子低温沙藏催芽方法较其它催芽方法好。     

白三叶种子催芽技术与育苗基质的研究

以白三叶(Trifoliu mrepens)种子为试验材料,研究水浸时间、育苗基质类型、不同浓度赤霉素与硝酸钾浸种处理对白三叶种子发芽的影响。结果表明,水浸24h可极显著提高种子发芽指数、萌发活力指数、发芽势和发芽率,与未浸种的相比发芽率可提高10%-13%;基质类型对种子的发芽指数和萌发活力指数影响均达到显著水平,种子较适合的催芽浓度与育苗基质组合为50mg·L-2赤霉素、0.2%硝酸钾、园土∶沙∶泥炭土=2∶1∶1,平均发芽率达31.67%,平均萌发活力指数达42.212。     

东北地区刺楸种子解除休眠及催芽育苗的研究

通过不同试验材料、GA3应用和变温层积催芽对比试验,对刺楸种子解除休眠进行研究的结果表明:鲜种+GA3+(15℃,30 d;冷冻,90 d;-4~0℃,90 d)处理方法发芽率达到90.2%,出苗率达到81.5%;气干种温水(72 h)+GA3+(13~18℃,90 d;0~4℃,90 d)处理方法发芽率达到76.3%,出苗率达到66.4%。采用鲜种进行变温催芽处理对刺楸种子发芽率、出苗率和1年生苗木质量提高具有显著作用(p<0.01和p<0.05)。研究表明,刺楸种子属于形态-生理休眠类型,采用鲜种+GA3+变温层积催芽的综合处理方法能有效解除刺楸种子休眠。     

银杏种子后熟生理与内源激素变化的研究

研究银杏种子后熟期间的生理变化以及内源激素对种子休眠与萌发过程的调控作用.结果表明:银杏种胚分化不完全、发育不充分是种子休眠的主要原因,银杏种子的后熟过程实质上是种胚不断分化生长的过程.在此过程中,物质代谢、酶活性的变化均有利于种胚发育和种子发芽,种子内部经历了一系列生理生化变化去调整内源激素平衡、完成种胚发育.研究发现,内源激素在银杏种子休眠与萌发过程中起着重要的作用:GA1 3是银杏种胚后熟的关键物质;ZRs对银杏种子生长起重要的促进作用;GA1 3/ABA及ZRs/ABA相对比例的变化对种子发育、胚的后熟及种子萌发均有重要的影响.     

药用植物母猪果种子发芽试验

药用植物母猪果种子外果皮较厚,进行种子繁殖时,剥去外果皮可以提高种子的发芽率.用赤霉素(GA3)和生根粉(ABT2)处理去外果皮的种子,可以迅速减少母猪果种子内含的抑制物质,打破种子休眠,使种子萌发.     

林木种子休眠研究评述

种子休眠,是指在充分满足各种发芽条件时,有生命力的种子一时不能发芽或发芽困难的自然现象。处于休眠的种子,种皮坚硬、含水量低,细胞内养分处于难溶态,代谢活动较低。一般将种子休眠划分为三个类型:即强迫休眠、生理休眠和综合休眠。种子生理休眠的机理包括:种果皮的抑制;植物激素的作用;种子的二次休眠;综合因素造成的休眠;分子变化等方面。     

Mechanical but not physical dormancy is a cause of poor germination in teak (Tectona grandis L.f.)

Poor seed germination is a significant problem for propagation of teak and it particularly hampers the deployment of genetically improved material into plantations. Seed dormancy is the putative cause for delayed and sporadic germination of teak seed but specific dormancy mechanisms have not been proven. In this paper we investigate whether physical or mechanical dormancy could affect teak germination. Physical dormancy was disproved when we observed water in every examined locule of fruit which had been immersed for 12–24 h (n = 1,700 fruits from six diverse sources). Mechanical dormancy was found to affect teak seed germination by means of valve structures which must open for the radicle to emerge. All 1,450 germinating seeds in 16 samples emerged from the endocarp via the detachment of a valve. Germination over 16 days was compared between extracted seeds (ex situ) and seeds within their endocarp (in situ) to determine the effect of mechanical dormancy on germination. Significantly greater germination of the ex situ seeds (62 ± 2% SE; n = 486) than of the in situ seeds (32 ± 2% SE; n = 564) indicated that mechanical dormancy is an important factor in the poor germination of teak.     

八棱海棠种子解除休眠方法的研究

对八棱海棠种子分别进行赤霉素溶液浸泡处理、低温裸层积、低温层积以及赤霉素与低温层积结合等处理,而后进行发芽试验,统计分析发芽率、发芽势和发芽指数等指标.结果表明:赤霉素溶液浸泡不能完全打破种子休眠;低温层积是解除种子休眠的有效方法,层积80 d后,即可解除种子休眠;赤霉素溶液浸泡后,再低温层积可显著缩短层积时间.     

The role of cold storage and seed source in the germination of three Mediterranean shrub species with contrasting dormancy types

Context

The use of native species in ecological restoration is highly recommended but, in practice, it is often impaired by knowledge gaps in the germination ecology of suitable species.

Aims

This study aimed to assess the role of storage conditions and seed source on the germination of three Mediterranean shrub species with contrasting types of dormancy.

Methods

Ripe fruits were harvested at two or three distant locations in mainland Portugal. Seeds were subjected to three treatments consisting in different storage conditions: cold storage at low and high moisture conditions, plus a control. Five replicates of up to 30 seeds were placed under constant temperature conditions and germination was monitored weekly during 14 weeks.

Results

The effect of cold storage at high moisture on germination differed between the three species and seed source played a significant role in the germination of all three species. In the case of the species with dormancy, the observed differences in germination could reflect changes in the species’ dormancy degree or sensitivity to dormancy breaking factors across their geographical range. In the case of Pistacia lentiscus (no dormancy), the results suggested a possible adaptation of the northern seed source to high moisture conditions.

Conclusions

The observed differences between species agreed well with their dormancy types, and the seed source-related differences could be adaptive features, as they seemed related with local climate conditions.     

濒危树种羊角槭种子基本生物学特征

采用种皮透水性测定、生活力测定、种皮和种胚甲醇提取液测定等方法,对羊角槭基本生物学特征进行了研究。结果表明:羊角槭种子呈压扁状卵圆形,由外种皮、内种皮、种胚和子叶组成,无胚乳;种子千粒质量50.88g,其中种皮占完整种子质量的79.55%以上;种子中空籽和败育种子比例达63.81%,反映出较高的种子败育率;饱满的种子中有生活力者占56.67%;种皮具有一定的透水性,种皮和种胚甲醇提取液对白菜籽发芽有抑制作用,说明羊角槭种子自身含有发芽抑制物可能是导致种子深休眠的主因。     

Optimal and synchronized germination of Robinia pseudoacacia,Acacia dealbata and other woody Fabaceae using a handheld rotary tool:concomitant reduction of physical and physiological seed dormancy

The Fabaceae(legume family) is one of the largest families of plants with a worldwide distribution and a major role in agriculture and in agroforestry.A hard seed coat impermeable to water is a typical feature of several species.Physical dormancy delays and reduces germination so that mechanical,physical and chemical scarification methods have been classically used to break seed dormancy of many species.We evaluate the effectiveness of a methodology to scarify seeds of several woody Fabaceae of ecological and economical importance,including Robinia pseudoacacia and Acacia dealbata and the shrubs Cytisus scoparius,C.multiflorus and Ulex europaeus.We describe the optimized use of a handheld rotary tool(HRT),and compare its effectiveness with other scarification methods reported to break dormancy such as boiling or dry heating.Total germination and/or speed of germination were enhanced after the application of the HRT,with germination percentages significantly higher than those achieved by other methods of scarification.Based on a thorough literature review,a mode of action for the HRT is suggested which could operate by breaking the physical and physiological dormancy of treated seeds through thecombined action of coat abrasion and moderate temperatures.Considering these results,we recommend the application of this rapid,effective,low-cost and highly reproducible HRT method to break seed dormancy and enhance germination of these species and others with similar dormancy constraints.     

4种槭树种子的休眠原因及催芽方法试验

乡土树种鸡爪槭、色木槭、元宝枫和美国红枫等4个树种的种子都具有显著的休眠特性。采用人工介入手段进行休眠原因和催芽技术试验研究,结果表明:这4种槭树种子的种皮含有的化学物质和机械性阻碍导致了槭树种子的休眠;采用层积处理和GA3赤霉素浸种,能明显缩短种子的休眠期;彻底解除供试种子的休眠方法就是延长浸种沙藏层积的时间。措施,对保证育苗生产,提高出苗率和出苗整齐度有一定的研究价值。文章从层积处理和赤霉素处理入手,研究不同条件下催芽处理的效果,以此解释休眠的原因。     

Pre-sowing treatment for breaking dormancy in Acer velutinum Boiss. seed lots

Acer velutinum Boiss is a valuable tree species native to Iran, and its seeds possess physiological dormancy that hampers seedling production in the nursery for large-scale reforestation efforts. The aim of this study was to determine the optimal dormancy breaking treatments for A. velutinum seeds. We conducted a factorial experiment involving six seed lots collected along an elevation gradient from 300 to 1800 m at 300 m interval and four cold-moist stratification periods (0, 4, 8 and 16 weeks) at 4℃ and 70% relative humidity. The result shows that the germination of cold-moist stratified seeds was significantly (p < 0.0001) higher than the control for all seed lots. The highest germination capacity was recorded after 16 weeks of cold-moist stratification for all seed lots (68% 88% depending on the seed lot) except those collected from mid altitude sites (600 and 900 m) that germinated equally well (≥ 75%) after 4and 8-week of clod-moist stratification compared to the other seed lots. The mean germination time was significantly shorter (12 to 19 days, depending on the seed lot) for seeds stratified for 16 weeks than for untreated seeds. It can be concluded that: (1) cold-moist stratification for 16 weeks is the best pre-sowing treatment for breaking dormancy in A. velutinum seeds; and (2) seeds should be collected from mid altitude sites (600 and 900 m) to get more than 80% germination within 15 days, and these seed lots even required shorter cold-moist stratification period(eight weeks) than other seed lots.