共查询到20条相似文献，搜索用时 62 毫秒
1.
为了解高山龙胆种子萌发的适宜条件,[方法]研究了不同温度、不同光照条件和不同赤霉素浓度处理对种子萌发的影响。研究结果表明,不同温度对高山龙胆种子的发芽率影响明显,低温(5 ℃)和高温(35 ℃)严重抑制种子萌发,25 ℃是高山龙胆种子萌发的最理想温度,发芽率达到68.9%。光照条件对高山龙胆种子萌发具有显著的影响,黑暗条件不利于种子萌发。赤霉素处理对高山龙胆种子的发芽势和发芽率均有促进作用,但过高的浓度会阻碍种子萌发,以300-400 mg/L的赤霉素处理种子最为适宜,发芽率可达85%以上。 [结论]因此,高山龙胆种子发芽最适温度为25 ℃,且种子需光萌发,300-400 mg/L的赤霉素处理可以明显提高种子发芽率。 相似文献
2.
3.
以刺山柑种子为材料，研究干藏、埋藏和层积处理后不同温度、光照、赤霉素浓度对刺山柑种子萌发的影响，探讨刺山柑种子的休眠类型和萌发特性。结果表明，刺山柑种子存在非深度生理休眠，千粒重(3.931 6±0.096 2)g,种子活力为98%;最适萌发温度为15℃/2℃;埋藏和低温层积能解除种子休眠；赤霉素能显著提高种子的萌发率(p<0.05),光照不是种子萌发的必要条件；干藏对种子的萌发率无显著性影响(p<0.05)。 相似文献
4.
探讨大叶千斤拔种子发芽最佳基本条件和种子的寿命,为栽培生产提供科学依据。测定种子的吸水率;通过磨破种皮、热水处理和浓硫酸处理等找到破除种子硬实的最佳方法;考察不同温度和光照、发芽床、贮藏对种子萌发的影响。结果表明,大叶千斤拔种子吸水率为31.26%,种皮透水性差是影响种子发芽的关键因素。种子适宜萌发的温度范围为25～30℃,发芽前用磨擦种皮+80℃热水浸种4 h的方法可使种子的发芽率提高到66.67%;光照和发芽床对种子萌发无显著影响。种子在4℃低温条件下贮藏3年发芽率仍有61%,贮藏4年发芽率降至32%。综上,大叶千斤拔种子为硬实性种子,发芽前需要预处理;种子为高温萌发型、光中性种子;种子寿命在4年以上。 相似文献
5.
6.
为研究伊犁郁金香(Tulipa iliensis)种子的萌发特性,根据伊犁郁金香在自然环境中先经历夏季高温,再渡过严寒的冬季之后再萌发的特点,探讨夏季室温储藏、冬季低温贮藏的时间和二者的交互作用及赤霉素(GA3)对打破种子休眠的影响.结果表明:15/2℃是伊犁郁金香种子较为理想的萌发条件;新鲜伊犁郁金香种子在5℃条件下贮藏15d或在室温下储藏30d有助于打破种子休眠;800 mg/L的GA3对新鲜种子萌发率的影响较大.由此可见,低温是伊犁郁金香种子萌发的首要条件,种子的休眠类型为胚后熟引起的休眠,而种皮的机械阻碍作用也是引起其休眠的原因之一. 相似文献
7.
西南鸢尾种子萌发特性初步研究 总被引：4，自引：0，他引：4
以西南鸢尾种子为研究对象,从种皮透水性、不同光温条件下种子萌发率以及低温湿沙层积和赤霉素处理对打破种子休眠的效应等方面对西南鸢尾种子萌发特性进行了初步研究。结果表明,种皮透水性良好,在浸水2h后吸水量迅速增加,在48h后达到吸水高峰。4种恒温15、20、25、30℃和3种变温20／10、25／15、30／20℃条件下,发现种子萌发最适温度为30／20℃,同时有光条件下的种子萌发率明显高于无光条件,即西南鸢尾种子萌发具有需光性。种子在5℃湿沙层积1～6个月后,萌发率提高18.3％～48.9％。而不同浓度的赤霉素（50～600mg／L）处理24h后均没有提高种子萌发率,以上结果表明西南鸢尾具有非深度生理体眠特性。 相似文献
8.
9.
在实验室条件下,对南蛇藤(Celastrus orbiculatus Thunb)种子的形态特征、千粒重、生活力、吸水速率及萌发特征进行了初步研究。结果表明:南蛇藤种子平均大小为0.413 cm×0.220 cm×0.194 cm(长×宽×厚),千粒重约8.269 g;自然条件下产出有活力种子比例为69%左右;种皮具有较好的透水性,但因其较厚、硬的外种皮束缚了种胚的生长,影响其透气性,从而引起种子休眠;破种皮与3 mmol/L的赤霉素同时处理种子可使种子的发芽率达到29.33%,而完整种子同时用赤霉素处理、完整种子不用赤霉素处理、破种皮但不用赤霉素处理3种条件下,均不萌发。种皮机械障碍和胚的生理后熟均是引起南蛇藤种子休眠的原因。 相似文献
10.
为探查药用植物假马鞭(Stachytarpheta jamaicensis)种子破除休眠的贮藏方法以及萌发的最佳温度条件,将假马鞭种子分别进行30 天的室温干燥贮藏、15℃湿润贮藏、4℃低温层积和0℃冰冻贮藏后,测定其萌发率;种子在6 个温度梯度(15、20、25、30、35、40℃)、12 h 光照/12 h 黑暗条件下培养,观测其萌发率和萌发进程。结果表明：假马鞭种子具有较高活性(92%),初始萌发率为10%~49.3%;经过室温干燥贮藏、15℃、4℃湿润贮藏的种子,在变温(25℃/15℃)培养下其萌发率分别达到55.3%、70%和56.7%,经0℃冰冻贮藏后萌发率降低至9.3%;假马鞭种子对6 种培养温度显示出不同的响应,在30℃和35℃培养下,萌发开始时间较早（1~7 天）,累积萌发率不足20%;在20℃和25℃培养下,萌发开始时间较晚（7~11天）,累积萌发率分别达到72.7%和56%。假马鞭种子具有中度生理休眠,经过室内干燥贮藏、15℃湿润贮藏和4℃层积可以破除种子部分休眠,获得较高萌发率,种子达到最高萌发率(70%)的最佳贮藏条件是15℃湿润贮藏、变温培养(25℃/15℃);未经贮藏处理的种子达到最高萌发率(72.7%)的培养温度是20℃。 相似文献
11.
Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts 总被引：7，自引：0，他引：7
Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed. 相似文献
12.
C. J. Spurr D. A. Fulton P. H. Brown R. J. Clark 《Journal of Agronomy and Crop Science》2002,188(4):275-280
Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality. 相似文献
13.
G. H. Kroon 《Euphytica》1994,76(1-2):125-125
Summary
K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes. 相似文献
14.
Jens Jensen 《Euphytica》1979,28(1):47-56
Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans. 相似文献
15.
Hongyan WEI Jian ZHOU Jinguang LU Jingzheng SONG Qiongxi YU Zhihong JIANG 《Medicinal Plant》2019,(6):27-29
[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol... 相似文献
16.
Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed. 相似文献
17.
Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes. 相似文献
18.
W. Erskine M. Tufail A. Russell M. C. Tyagi M. M. Rahman M. C. Saxena 《Euphytica》1993,73(1-2):127-135
Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed. 相似文献
19.
D. A. Bond G. J. Jellis G. G. Rowland J. Le Guen L. D. Robertson S. A. Khalil L. Li-Juan 《Euphytica》1993,73(1-2):151-166
Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses. 相似文献
20.
Chunli TANG Fengxian ZHAO Hongxia CHEN Jiabao MA Jiangcun WEI Meiyan QIU Zhen XIE 《Medicinal Plant》2019,(6):60-65
[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination... 相似文献