桃种子的休眠与萌发研究──种皮的调控作用

用桃品种秋香蜜去核壳种子，探索了种皮控制休眠与萌发的效应及作用机制。结果表明：①桃种子剥除种皮，休眠可被解除，出苗率与有皮种子经ＧＡｓ２００ｍｇ·ｌ￣（－１）浸种２４ｈ相近；种皮抑制萌发的效应与ＡＢＡ５ｍｇ·ｌ￣（－１）浸渍去皮种子２４ｈ相当。②桃新鲜种子内ＡＢＡ主要存在于种皮中，ＧＡ３主要存在于胚和子叶中，剥除种皮即人为地改变种子内ＧＡ＿３／ＡＢＡ值，有利于种子由休眠向萌发方向转化。③桃种皮对种子内过氧化物酶活性具强烈抑制作用；去皮种子的酶活性随ＧＡ３处理而增强，随ＡＢＡ处理而被抑制。④桃种皮无透水性障碍，种皮对种子的吸水总量虽有一定限制，但不影响种子萌芽。     

Effect of stratification temperature,stratification period and seed coat on seed germination of peach cultivar ‘Sharbati’

Freshly harvested seeds of peach cultivar ‘Sharbati’ were found to be dormant and did not germinate at all. A specific low-temperature stratification treatment was required to overcome seed dormancy. 10° C stratification was found to be the best for breaking seed dormancy. Increased seed germination was recorded when the seeds were after-ripened without seed coats as compared to the seeds after-ripened with seed coats. There was no further increase in germination when seeds without seed coats were stratified beyond 60 days at 10° C, while a significant increase was recorded up to 75 days of stratification in the case of seeds with seed coats. Unstratified seed coats, soaked in water for 72 h, leached out a water-soluble inhibitor, which could suppress the germination of stratified peach seeds without seed coats. When this leachate was bioassayed by a cress-seed germination test, it showed the presence of an inhibitor at Rf 0.7-0.9. Hence, delayed germination of seeds with seed coats may be due to the presence of an inhibitor in seed coats.     

红毛五加种子特性及发芽抑制物研究

以红毛五加为试材,观察红毛五加种子形态,测定千粒重、种皮透水性,研究果实各部分水浸物对油菜种子发芽和胚根生长抑制活性的影响。结果表明:红毛五加种子较小,种皮较薄,种皮透水性良好,对发芽率没有影响;红毛五加种子成熟度极不均匀,种胚细小,不具备萌发能力,需经过形态后熟和生理后熟才能萌发;红毛五加果实各部浸提液,对油菜种子发芽、胚根生长有显著的抑制作用,随着浸泡量的增加,对油菜种子发芽抑制活性越强,胚根长度越短;红毛五加果实各部分水浸物对油菜种子发芽抑制活性,果肉最强,种皮次之,种仁最弱。     

4种中国野生无髯鸢尾种子休眠原因的研究

玉蝉花、山鸢尾、金脉鸢尾和西南鸢尾4种中国野生无髯鸢尾种子均存在休眠。对种子进行了离体胚培养、切割胚乳、剥离种皮等处理和用Instron 5848微力材料试验机测量刺穿珠孔端结构所需要力的试验,研究表明：种皮对种子萌发具有一定的影响,珠孔端胚乳对胚生长的机械束缚是萌发的主要限制因素;4种无髯鸢尾的种子的胚乳中含有抑制种子萌发的物质,它们对种子的成苗率有显著影响。     

The Effect of Scion on Root.: II. Stem-Worked Apples.

Summary

The effects of seed coat removal and chilling on the germination of seeds of ten cultivars of ornamental peach (Prunus persica Batsch) were investigated. Seeds were rinsed in running tap water for 48 h in order to facilitate seed coat removal. Only a few non-chilled, intact seeds germinated (e.g., 6% of ‘Hito’ seeds). Seed coat removal and no chilling resulted in some seed germination in eight of the ten cultivars, ranging from 6% to 83%. Chilling intact seeds at 5°C for up to 10 weeks resulted in greater frequencies of germination (average = 85% germination) than seed coat removal before (average = 80%) or after chilling (average = 73%). There was a linear decrease in the germination percentage with an increase in abscisic acid (ABA) content for ‘Yaguchi’,‘Kanpaku’, and ‘Kikumomo’ seeds (R = –0.66; P <0.001). The most consistent decrease in total seed ABA content (average of 64%) occurred during the 48 h rinsing period. In ‘Kanpaku’, dry seeds had an intermediate ABA content (13 ng per seed); but, in the embryonic axes, this increased from 0.03 ng to 1.2 ng per seed with an increase in the duration of the chilling period. The lowest germination percentages were found in this cultivar. These results suggest that ABA synthesis in the embryonic axes during chilling may affect the varietal characteristic of seed dormancy, and that rinsing seeds for >48 h could remove sufficient ABA to allow seed germination with minimum chilling.     

Effects of temperature and seed coat treatments on germination of sweet pea

Tests on seeds of sweet pea (Lathyrus odoratus L.) were set up to examine responses to temperature during germination and to investigate the effects of mechanical and chemical treatments on the permeability of the seed coat to water.Optimum temperatures for germination occurred at about 21 °C, and higher temperatures resulted in the production of fewer seedlings. Although temperatures below c. 15 °C also reduced the numbers of seeds which germinated, even at 2 °C more than 50 % germinated within 60 days.Treatments with concentrated sulphuric acid or the mechanical removal of part of the seed coat by filing greatly increased permeability to water and under some conditions improved germination responses. Filing, followed by exposure to excess free water, reduced germination rates, possibly as a result of loss of solutes from the seed during imbibition.     

牛鼻栓种子萌发特性研究

通过对牛鼻栓的种子进行不同浓度GA_3及不同贮藏方式的处理,进行发芽试验,总结牛鼻栓种子的一些萌发规律,得出最佳处理方式和最高萌芽率的结论。阻碍种子萌发的因素主要是坚硬的种皮,而用自然沙藏或GA_3浸泡等方式可以打破休眠。自然沙藏4个月萌芽率最高,为98%;其次为以浓度400μg/ml的GA_3浸泡48h后恒温冷藏处理3个月,萌芽率为97%。     

无籽西瓜种子萌发与磷酸戊糖途径关系的研究

为了探讨无籽西瓜种子萌发与磷酸戊糖代谢途径的关系,研究了无籽西瓜种子萌发过程中磷酸戊糖代谢途径的G-6-PDH和6-P-GDH2个关键性酶联合活性变化。结果表明:无籽西瓜种子随着萌发过程的进行,G-6-PDH和6-P-GDH联合活性在36h种子的各个部位出现高峰值,然后下降,与种子的萌发裂口时间一致,且种胚中G-6-PDH和6-P-GDH联合活性大小决定其萌动的开始,表明无籽西瓜种子萌发与磷酸戊糖代谢途径密切相关。     

瓜类蔬菜种子休眠与萌发研究进展

破除瓜类蔬菜种子休眠的技术有机械损伤种皮、植物激素处理和化学药剂处理。多数休眠的瓜类蔬菜种子在特殊条件下能够发芽。瓜类蔬菜种子休眠的原因有胚休眠、种皮的障碍、发芽抑制物质的存在和激素不平衡等几个方面。     

Physical dormancy in myrtle seed

The nature of dormancy in seeds of myrtle (Myrtus communis L.) was investigated. Scarification with cold acid or sand paper and soaking in water increased seed germination, whilst stratification, inserting the seeds in boiling water or hot acid treatment decreased the number of germinating seeds. The highest germination was obtained by treating the seeds with 100 % cold acid for 60 min or 80 % cold acid for 120 min. Hard seed coat was found to be the principal cause of poor seed germination.Scarified and non-scarified seeds were germinated for 2 weeks at 6 temperatures between 5 and 30° C, and 20° C was optimum.     

冬枣极早期幼胚培养成苗技术研究

以胚龄15 ~ 20 d的球形期后期‘冬枣’幼胚为试材,对培养基种类、种皮保留与否、接种方式、生长调节剂种类、水解乳蛋白（LH）和活性炭（AC）用量、蔗糖浓度等影响极早期幼胚培养的诸因素进行了系统研究。结果表明,采用MS + 3.0 mg ? L-1 IAA + 0.5 mg ? L-1 6- BA + 1 g ? L-1 AC + 0.8 g ? L-1 LH + 30 g ? L-1蔗糖的培养基,去除种皮后将带有胚乳的幼胚合点端接入培养基,在21 ℃下进行培养,胚萌发率和正常胚比率最高可分别达到93%和84%。萌发后的幼胚在MS + IBA 0.4 mg ? L-1的培养基中继续培养,生根率可达40%。其中,去除种皮带胚乳培养和幼胚合点端朝下接种对极早期幼胚的培养至关重要。     

Seed-coat anatomy and proanthocyanidins contribute to the dormancy of Rubus seed

Rubus seed has a deep double dormancy that restricts germination due to seed coat structure and chemical composition. Improved germination of diverse Rubus species required for breeding improved blackberry and raspberry cultivars is partly dependent on the seed coat structure. This study evaluated the seed coat structure of three species with thin (R. hoffmeisterianus Kunth & C. D. Bouché), medium (R. occidentalis L.) and thick (R. caesius L.) seed coats. The three species exhibited distinctive seed-coat cell composition. The very thin testa (0.086 mm) of R. hoffmeisterianus had little exotesta (surface) reticulation; with the meso- and endotesta composed of sclereids of homogenous shape and size. R. occidentalis had a thick testa (0.175 mm) and a highly reticulate exotesta; the meso- and endotesta were composed of several diverse types of sclereids. R. caesius had the thickest seed coat (0.185 mm) but only moderate exotesta reticulation; the meso- and endotesta were composed of large, irregular, loosely arranged sclereids. R. occidentalis, a medium size seed, was the most heavily lignified with seed-coat thickness similar to R. caesius, the largest seed. Proanthocyanidins (PAs) from dry seed of six Rubus species were extracted and quantified by high performance liquid chromatography. R. hoffmeisterianus, a thin only slightly hard seed, had half the PA (0.45 μg/seed) of R. occidentalis with a thick, extremely-hard seed coat and diverse sclereids (1.07 μg/seed). PA content and sclereid composition both appear contribute to seed coat hardness and resulting seed dormancy. The effectiveness of sulfuric acid for Rubus seed scarification is likely due to degradation of PAs in the testa.     

Histological and protein changes during early stages of seed germination in the orchid,Dendrobium crumenatum

Summary

During germination of seed of the tropical epiphytic orchid, Dendrobium crumenatum, cell division at the chalazal end of the globular embryo occurred after one week of culture on Vacin and Went medium. The larger cells at the middle and basal regions of the embryo continued to enlarge with distinct nuclei and chromatin, indicative possibly of endoduplication. Shoot apex organization at the chalazal end occurred after four weeks of culture. Mobilization of stored reserves was seen as a reduction in the granular nature of the cytoplasm after two weeks in culture. Utilization of protein reserves occurred within 6 d of germination. Subsequently, do novo synthesis and accumulation of cvs proteins increased steadily and reached an equilibrium between 18 and 24 d. Changes in profiles of specific proteins indicated development-specific protein accumulation. Two proteins of Mr 14 and 33 kDa were highly abundant in dry seeds but were degraded within 6 d of germination indicating their possible nutritive role in embryo development. Several other proteins showed steady increases during 24 d from germination.     

莲瓣兰原生地萌发胚培养真菌污染控制的优选

以莲瓣兰杂交种子原生地共生萌发突破种皮的胚为试验材料,采用正交试验设计研究次氯酸钠浓度、灭菌时间、灭菌次数及超声波处理时间对莲瓣兰胚培养过程中真菌污染控制及胚培养情况的影响。结果表明:莲瓣兰胚培养过程中以次氯酸钠浓度∶灭菌时间∶灭菌次数∶超声波处理时间(4%∶15 min∶1次∶6 min)的配比胚被真菌污染的污染率最低为16.0%,但是胚成活率较低仅为14.3%,不宜作为莲瓣兰胚培养的灭菌条件;经过正交试验设计优选出莲瓣兰胚培养过程中胚成活率作用大小为次氯酸钠浓度超声波处理时间灭菌时间灭菌次数,以次氯酸钠浓度∶灭菌时间∶灭菌次数∶超声波处理时间(1%∶20 min∶2次∶3 min)的配比胚成活率高达93.3%,同时胚被真菌污染率仅为19.00%,可以作为莲瓣兰(Cymbidium torliseplum)杂交种子原生地共生萌发突破种皮的胚培养灭菌条件,在此条件下胚能够从培养基中吸收营养物质,经过培养胚生长发育成根状茎。     

裸仁南瓜种皮发育研究进展

裸仁南瓜是南瓜中的一种自然突变类型,其种皮在发育过程中因缺乏木质素和纤维素逐渐退化成一层薄膜。裸仁南瓜营养丰富,方便食用和加工,是优异的种质资源,国内外市场需求旺盛,其种皮形成机制复杂,对其深入研究有助于解决生产难题和促进裸仁南瓜籽产业发展。笔者综述了近年来国内外裸仁南瓜种皮发育相关基础研究取得的最新进展与成果,包含南瓜籽主要营养成分研究、南瓜种皮分类、种皮形态学研究、相关酶分析、育种研究、种皮颜色研究、基因定位研究等。分析了目前裸仁南瓜种皮发育相关基础研究中存在的问题以及今后研究的重点和难点,以期为裸仁南瓜育种及种皮发育的深入研究提供理论和实践依据。     

脱落酸与种皮对杜梨种子休眠与萌发的影响

以当年新采收杜梨种子和自然贮藏1 a种子为试验材料,研究了种皮和不同浓度的脱落酸(ABA)对诱导杜梨种子休眠与萌发的影响.结果表明:杜梨种皮和脱落酸均能够抑制杜梨种子的萌发,种皮的抑制萌发效应显著大于ABA的作用,杜梨种子去除种皮后,休眠性可被部分解除.脱落酸对杜梨种子抑制萌发的效应在去皮和不去皮种子中表现明显差异,5 mg/L ABA浓度对未去皮种子产生明显抑制效应,20 mg/L ABA浓度对去皮种子产生明显抑制效应,说明未去皮种子对ABA的敏感性大于去皮种子.种皮与ABA的双重抑制效应,使种子对ABA浓度水平差异的敏感性增强.不同激素组合试验说明了GA3、6-BA和ABA在杜梨种子休眠与萌发中的作用.     

东北铁线莲种子萌发特性的研究

由于受种子生理休眠作用的影响及硬而厚的种皮所产生的抑制作用,使东北铁线莲种子发芽慢、发芽率较低。现研究了东北铁线莲种子的形态学、种子活力等特性及不同温度、不同低温层积天数、不同化学试剂处理对其种子发芽率、发芽势、发芽指数的影响。结果表明:25℃低温层积140～160d,95%浓硫酸浸泡20s处理效果最好,可以提高东北铁线莲种子的发芽率。     

The germination of watercress (Rorippa nasturtium- aquaticum) seeds. II. The relationship between seed colour and germination

Freshly-harvested seeds of green watercress were pale yellow, rapidly turning to pale brown under ambient laboratory conditions. Older seeds ranged from pale to very dark brown, the darker seeds losing more electrolyte than the pale ones when immersed in water. Dark seeds germinated more readily than pale ones when the seeds were freshly harvested, but with old seeds germination was generally greater with paler seeds than darker ones. The results suggested that darkening of the seed coat was associated initially with a loss in dormancy and ultimately a loss in viability. Darkening of the seeds was enhanced by moisture. It could be induced by high humidity storage at 40°C, a treatment which resulted in increased electrolyte leakage from the seeds, or by holding individual seeds dormant at 35°C, although only the former treatment reduced germination. The results suggest that the ability of the seeds to germinate and the colour of the seed coat are not directly linked but that both are influenced by RH and temperature during storage.     

核果类果树种子休眠的机制及其解除方法研究进展

核果类植物是温带地区重要的果树资源,兼具良好的经济价值、生态价值及园林观赏价值。休眠是核果类果树种子为应对不良外界环境而产生的适应性进化,有利于保障种群的延续,但不利于苗木的规模化繁育。为了优化核果类植物繁育技术,提高苗木繁育效率,对核果类植物种子休眠与萌发机制的研究现状进行综述。本研究重点分析国内外相关研究进展,分别从果肉、内果皮、种皮、种胚4个方面对核果类果树种子休眠机制及休眠打破方法进行总结归纳,并基于综述结果对其研究前景进行展望,以期在阐明核果类果树种子休眠与萌发机制的基础上,为解决生产过程中种子休眠问题提供思路与方法,并为乡土植物资源保护、引种栽培提供科学依据。     

Methods to break seed dormancy in Cyclocarya paliurus (Batal)Iljinskaja

Cyclocarya paliurus is native to China and is the sole species in its genus. However, the seeds remain deeply dormant for 2 years in their natural environment. We tested different pretreatments of chemical scarification and exogenous application of gibberellic acid (GA₃) for efficacy in breaking dormancy and speeding germination. In contrast to scarified seeds, non-scarified seed did not germinate, indicating that C. paliurus seeds have hard, impermeable seed coat dormancy. Exogenous application of GA₃ significantly enhanced germination of scarified seeds. Compared with seeds stratified in sand with water, the germination of seeds stratified in sand moistened with 400 ppm GA₃ for 60 days was significantly increased and germination rate was over 90% after 120 days. Analysis of variance indicated that both GA₃ concentration and stratification medium had significant effects on seed germination and final germination percentage. Germination was higher for longer stratification periods, but no significant difference in germination was observed after 90 days. These results suggested that C. paliurus seeds exhibit both exogenous and endogenous dormancy. A combination of chemical scarification and exogenous application of GA₃ alleviated seed dormancy in a relatively short period of time.