核桃楸种子催芽处理和育苗株距的研究

对核桃楸种子进行不同催芽处理和不同育苗株距对比试验的结果表明:变温层积催芽[室温(18～23℃,30 d)+室外冷冻(90 d)+窖藏(-2～2℃,60 d)]的处理方法,种子的发芽率和出苗率达到88.53％和86.34％,出苗整齐(25 d),苗木质量好.不同育苗株距对1年生核桃楸苗高影响差异极显著(p<0.01和p...     

北美冬青容器育苗试验研究

采用随机区组试验设计,进行北美冬青容器育苗试验。结果表明:不同水温浸种催芽对低温沙藏或低温冷藏的北美冬青种子的发芽率均产生极显著影响;低温沙藏的平均发芽率92.75%,低温冷藏的平均发芽率98.5%,低温冷藏比低温沙藏更有利于提高种子发芽率;低温沙藏或低温冷藏+不同水温处理之间差异程度不同,80℃水温对种子发芽率影响最大;变温层积催芽,种子贮藏期只需90d;生产实践中可采用低温冷藏+80℃水温浸种变温层积催芽,不仅可以缩短贮藏期,而且还可以极大地提高种子的利用周期和发芽率。     

大叶椴种子不同贮藏方式对发芽和出苗率的影响

在大叶椴种子贮藏时期进行打破休眠对发芽率和出苗率影响的试验表明:即先从大叶椴坚硬果实内取出休眠种子在浓硫酸中脱皮10 min后,再在无基质(3℃)条件下层积催芽140～168 d(直到第1粒种子开始发芽为止).结果表明:经过处理后的种子当发芽试验中昼夜温度为3～15℃(16 h+8 h)时,几周后种子的发芽率达90%;...     

低温层积时间及冷冻处理对龙芽楤木种子发芽力的影响

以龙芽楤木种子为对象,研究不同低温层积时间、冷冻处理对发芽力的影响,结果表明:龙芽楤木种子经日变温层积处理后,低温处理120 d左右时,发芽率、发芽势最高;已解除休眠的龙芽楤木种子经冷冻处理后进入二次休眠状态,经90 d左右的低温层积处理可解除休眠,与二次休眠前相比较其发芽率略有降低而发芽势则有所提高。     

紫椴种子解除休眠及催芽育苗方法的研究

采取不同浸种方法、GA_3应用和层积催芽对比试验,对紫椴种子解除休眠方法进行研究。结果表明:温水(7d)+GA_3+室内(13～18℃,30d)+室外冷冻(60d)+窖藏(-2～2℃,60d)为最佳处理组合,发芽率和出苗率为84.7%和79.5%,出苗整而齐(25d全苗);苗木质量好,1a生平均苗高和平均地径分别为0.55m和0.56cm,主根长25.5cm,侧根25条。GA_3浸种对紫椴种子解除休眠具有促进作用,层积催芽室内高温+室外冷冻+低温窖藏效果最好,高低变温效果次之,低温窖藏效果再次,而室内高温效果最差。研究表明,紫椴为综合性休眠类型,采用浸种+GA_3+合理层积催芽,能有效解除种子休眠。     

刺楸种子催芽处理试验研究

本文对刺楸种子催芽处理技术进行了试验研究。证明刺楸种子处于生理休眠,其休眠原因在于胚未完成发育。不进行催芽处理,当年不能出苗,种子在催芽过程中,必须先暖温处理,后转低温处理,使之完成生理后熟,才能解除休眠。     

盐肤木种子表型特征测定及发芽试验初报

通过对盐肤木果实、种子形态特征观测与分析,并进行种子发芽试验,结果表明:盐肤木果实与种子皆呈扁圆形,种子与果实特征未有相关性;水温、GA处理、储藏方式3个因子对盐肤木种子发芽皆有显著影响,将盐肤木种子先用初始温度80℃热水浸泡3h,之后用50mg·L^-1赤霉素溶液处理24h,最后室外变温层积90d,种子发芽率达到最高,为89.6%。     

刺楸种子打破休眠和变温催芽试验

通过对刺楸进行打破休眠和变温催芽试验,研究了刺楸种子深度休眠的机理和催芽方法,结果表明:引起深度休眠的主要原因是种胚发育不完全,尚需一定的时间和温度条件才能完成种胚的发育,种子采收后须立即用湿河沙堆藏,层积处理的天数不少于120d。     

紫椴种子层积催芽处理新法

紫椴种子属于综合因素导致的深休眠种子类型,必须进行催芽处理才能解除休眠。传统层积催芽处理发芽率不稳定,通过采取化学和物理方法结合进行层积处理,可使紫椴种子发芽率达到70%以上,苗木生长健壮,超过国家和地方标准规定的技术指标。     

赤霉素对三种白蜡种子发芽率的影响

在不同温度条件下,利用不同浓度的赤霉素对大叶白蜡、绒毛白蜡和水曲柳的种子进行药剂催芽试验,浸种时间均为48 h,分别以经过层积处理60 d的种子作为对照。结果表明,用适宜浓度的赤霉素处理后,在20℃~30℃的变温条件下,可以显著提高大叶白蜡和绒毛白蜡种子的发芽率。催芽大叶白蜡的最佳处理组合为200 mg/L,平均发芽率为71%,催芽绒毛白蜡最佳处理组合为300 mg/L(20℃~30℃),平均发芽率为73%,发芽率均接近各自的对照,催芽效果十分显著。水曲柳具有相对深的休眠特性,单纯赤霉素处理不能有效打破水曲柳种子的休眠。     

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。     

Roles of gibberellins and abscisic acid in dormancy and germination of red bayberry (Myrica rubra) seeds

Intact seeds from freshly harvested fruits of Myrica rubra (Sieb et Zucc.) were dormant and required 8 weeks of warm stratification followed by 12 weeks of cold stratification for germination. Exogenous application of gibberellic acid (GA(3)) to intact fresh seeds was effective in breaking dormancy, with > 70% of seeds germinating when treated with 5.2 mM GA(3) and incubated at a day/night temperature of 30/20 degrees C for 20 weeks. Removing the hard endocarp or endocarp plus seed coat of fresh seeds promoted germination, and addition of GA(3) to the embryo accelerated germination. The gibberellins GA(1) and GA(4) were more effective than GA(3) in promoting germination of seeds with the endocarp removed. Endogenous contents of GA(1), GA(3), GA(4), GA(7) and GA(20) were quantified by gas chromatography-mass spectrometry-selected ion monitoring in the endocarps, seed coats and embryos of fresh seeds treated with 5.2 mM GA(3). The content of GA(3) decreased in the endocarp during incubation, whereas GA(1) contents increased in the endocarp and seed coat. A high GA(1) content was detected in the endocarps and embryos of newly germinated seeds. We speculate that GA(3) was converted to GA(1) during incubation and that GA(1) is involved in seed germination. Endogenous abscisic acid (ABA) contents were measured in fresh seeds and in warm and cold stratified seeds. The ABA content in fresh seeds was distributed in the order endocarp > seed coat > embryo, with the content in the endocarp being about 132-fold higher than in the seed coat and embryo. Total ABA content of seeds subjected to warm or cold stratification, or both, was 8.7- to 14.0-fold lower than that of fresh seeds. Low contents of endogenous GA(1), GA(3), GA(7) and GA(20), but elevated contents of GA(4), were found in the seed coats and endocarps of warm plus cold stratified seeds and in the seed coats and embryos of newly germinated seeds. These observations, coupled with the finding that GA stimulated germination of dormant Myrica seeds, provide evidence that endogenous ABA inhibited release of dormancy and that endogenous gibberellins, especially GA(4) or GA(1), or both, are involved in germination.     

不同条件下紫珠种子萌发特征研究

通过设定L9(34)3因素3水平正交试验,探究了萌发温度条件、光照条件和激素(GA3)条件.结果表明:在紫珠发芽率、发芽指数、发芽势和活性指数指标方面,温度是其影响的最主要因子,光照次之,GA3的影响相对最低,综合分析结果显示,紫珠发芽率、发芽指数、发芽势和活性指数指标最优的萌发条件组合为A3 B3 C2,即1000L...     

不同处理方式对黑莓‘Kiowa’种子发芽的影响

研究了7种不同化学药剂结合不同时间的低温层积处理后黑莓‘Kiowa’品种种子的萌发特性,探索打破种子休眠的有效方法。结果表明,对种皮具有软化或腐蚀作用的NaClO、浓H2SO4和H2O2对黑莓种子发芽具有明显的促进效应,而GA3、PEG6000、KNO3、NaOH促进效果不明显,表明种皮障碍是影响其萌发的主要因素,而且以20%NaClO的处理发芽率最高。低温层积时间越长越好,以90～120天为宜。以NaClO处理并低温沙藏90天的种子发芽试验表明,不同浓度NaClO处理的种子发芽率在萌发过程中均呈现先急剧增加再缓慢增加直至恒定的趋势,其中以培养20天时达到高峰期。     

日本厚朴种子催芽试验

日本厚朴种子具有休眠习性,常规层积方法催芽时间长且播后发芽率不整齐。研究了昼夜变温、阶段变温以及不同浓度GA处理结合低温层积的方法对日本厚朴种子催芽的效果,实验结果表明:GA处理结合低温层积的方法催芽效果最佳,且随GA浓度升高,催芽效果稍呈上升趋势;昼夜变温处理效果次之,阶段变处理效果最差。     

Breaking seed dormancy in Cupressus atlantica Gaussen, an endemic and threatened coniferous tree in Morocco

Cupressus atlantica Gaussen (Cupressaceae) is an endemic and endangered coniferous tree geographically restricted to the N’Fis valley in South-Western Morocco. Like many forest species, C. atlantica exhibits dormancy which delays and reduces germination. To improveseed germination, different pre-treatments were conducted on C.atlantica seeds after storage for different periods (one, two and five years) including: scarification with sandy paper; soaking seeds in hot distilled water at 60℃and 80℃for 15 min and soaking seeds for 48 h in agibberellic acid (GA3) at 1,000 and 2,000 mg·L-1. Results showed that scarification with sandy paper increased the germination rate of Atlas cypress by up to 67%, indicating that the species possess essentially anexogenous dormancy (physical dormancy) due to the hard seed coat(hardseededness). Exogenous application of gibberellic acid (GA3) at1,000 mg·L-1 was also effective in breaking seed dormancy and germination induction. These two treatments induced faster speed germination expressed by low number of days to first germination (8 10days) and low values of mean germination times (MGT). However,germination rate, under any treatment, is greatly dependent on the year of seed collection. Seeds collected in year 2004 gave the highest value,suggesting that even after five years of storage, the germination capacity of C. atlantica seeds could remain high. This observation is very interesting in the exsitu conservation of such endemic and endangered species where the production of seeds is irregular over the years.     

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.     

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.     

黄檗种子不同沙藏层积时间和播种密度研究

以黄檗种子和1 a生播种苗为材料,研究不同沙藏层积时间对发芽率与出苗率和不同播种密度对苗高与地径生长的影响,结果表明:当沙藏层积时间达到150 d时,种子发芽率和出苗率均最高,分别为80.85%和64.09%;当播种密度为90株·m~(-2)时,单位面积Ⅰ级苗产量最高,达到96.15%。