不同种子预处理方法对提高三树种幼苗耐盐性的效应

刺槐（ＲｏｂｉｎｉａｐｓｅｕｄｏａｃａｃｉａＬｉｎｎ．）、湿地松（ＰｉｎｕｓｅｌｉｏｔｉＥｎｇｅｌｍ．）和侧柏〔Ｐｌａｔｙｃｌａｄｕｓｏｒｉｅｎｔａｌｉｓ（Ｌ．）Ｆｒａｎｃｏ〕种子经０３％ＣａＣｌ２,２５０μｇ／ｇＨ３ＢＯ３和２５０μｇ／ｇ多效唑（ＭＥＴ）浸种２４ｈ,然后测定幼苗的耐盐性。结果表明,在０．３％ＮａＣｌ胁迫条件下,不同种子预处理方法对种子发芽率、平均苗高、根茎比、简易活力指数（ＳＶＩＳ）以及幼苗中Ｎａ＋与Ｋ＋的累积量、Ｎａ＋／Ｋ＋比及游离脯氨酸含量有较大影响。树种不同,处理效果也存在明显差异。湿地松以０．３％ＣａＣｌ２,侧柏以２５０μｇ／ｇＨ３ＢＯ３浸种处理效果最好,显著提高种子发芽率、平均苗高、根茎比和ＳＶＩＳ,降低幼苗Ｎａ＋吸收量和Ｎａ＋／Ｋ＋比,缓解盐胁迫逆境。３种种子预处理方法均降低刺槐种子发芽率、平均苗长和ＳＶＩＳ,但提高刺槐幼苗游离脯氨酸含量和幼苗根茎比,减少幼苗对Ｎａ＋的吸收,降低Ｎａ＋／Ｋ＋比     

中国的肉座菌科Ⅲ.：肉座菌属的菌生种

对肉座菌属的系统分类史进行了回顾,并对３个菌生种进行了报道,其中硫磺肉座菌（新拟）Ｈｙｐｏｃｒｅａ ｓｕｌｐｈｕｒｅａ（Ｓｃｈｗｅｉｎ．）Ｓａｃｃ．为中国新记录种,拟层孔肉座菌Ｈ．ｆｏｍｉｔｏｐｓｉｓ Ｐ．Ｇ．Ｌｉｕ ｅｔ Ｙ．Ｄｏｉ为新种;讨论了它们与其近缘种的区别和在本属下的统分类位置。采用了全型世代特征集要分类法（ＭＴＳＣＨ）的研究方法。     

东灵山地区脊椎动物对辽东栎坚果捕食的时空格局

在北京东灵山地区,选择３种不同森林类型,于辽东栎（Ｑｕｅｒｃｕｓ ｌｉａｏｔｕｎｇｅｎｓｉｓ Ｋｏｉｄｚ．）坚果下落高峰期和坚果自然下落后,对坚果逃逸脊椎动物捕食的存活时间进行调查。森林类型、坚果下落时期以及森林类型和坚果下落的交互作用对坚果的生存时间都有显著影响。在辽东栎坚果下落高峰期和坚果自然下落后,华北落叶松（Ｌａｒｉｘ ｐｒｉｎｃｉｐｉｓ－ｒｕｐｐｒｅｃｈｔｉｉ Ｍａｙｒ．）林和油松（Ｐｉ     

小麦异细胞质效应的研究

采用四种异细胞质“中国春”小麦即（Ｔ．ＺｈｕｋｏｖｓｋｉＧ）ｃｓ,（ＡｅＭｕｔｉｃａＭ）ｃｓ（Ａｅ．ＶａｒｉａｂｉｌｌｉｓＳ）ｃｓ（Ａｅ．ＣｒａｓｓａＤ＾２）ｃｓ与普通小麦“哈师一号”杂交,探讨异细胞质的效应。结果表明：不同细胞质对杂交当代的结实率,种子饱满度,发芽率,Ｆ１的株高,分蘖数,穗长,生育期,育性的不同的影响,特别是育性差异较大,Ｆ１的减数分裂行为：在Ｇ型,Ｍ＾ｔ型细胞质Ｆ１植株中出现少     

低温下水稻幼苗形态生理应变研究

低温下水稻幼苗形态生理应变研究李太贵王磊（中国水稻研究所，杭州３１０００６）ＳｔｕｄｙｏｆＭｏｒｐｈｏＰｈｙｓｉｏｌｏｇｉｃａｌＳｔｒａｉｎｏｆＲｉｃｅＳｅｅｄｌｉｎｇＵｎｄｅｒＬｏｗＴｅｍｐｅｒａｔｕｒｅ．ＬｉＴａｉｇｕｉ，ＷａｎｇＬｅｉ（Ｃｈｉ...     

磁场处理种子后番茄幼苗在低温胁迫下保护酶的变化

试验用场强为１０００ＧＳ、１４００ＧＳ、１８００ＧＳ的磁场处理番茄（ＬｙｃｏｐｅｒｓｉｃｏｎｅｓｃｕｌｅｎｔｕｍＭｉｌ）种子,于子叶期和真叶期进行低温胁迫,发现处理组超氧化物岐化酶（ＳＯＤ）比活性和过氧化氢酶（ＣＡＴ）活性均高于对照组。子叶期幼苗谷胱甘肽（ＧＳＨ）和可溶性蛋白含量与对照相比均有所升高。幼苗外观寒害症状也较轻。因此,可以认为磁场处理在一定程度上可提高番茄幼苗的抗寒性。     

盐浓度对3种单子叶盐生植物渗透调节剂及其在渗透调节中贡献的影响

单子叶盐生植物星星草（Ｐｕｃｃｉｎｅｌｌｉａｔｅｎｕｉｆｌｏｒａ（Ｇｒｉｓｅｂ）．Ｓｃｒｉｂｎ．ｅｔ．Ｍｅｒｒ．）碱草（Ａｎｅｕｒｏｌｅｐｉｄｉｕｍｃｈｉｎｅｓｅ（Ｔｒｉｎｓ．）Ｋｉｔａｇ）和獐茅（Ａｅｌｕｒｏｐｕｓｓｉｎｅｎｓｉｓ（Ｄｅｂｅａｕｘ）Ｔｚｖｅｌ）的种子萌发后长至３ｃｍ高,用０,５０,１００,２００和４００ｍｍｏｌ／ＬＮａＣｌ处理２周后,测定３种植物幼苗的生长,无机和有机渗透调节剂,     

光对4种木本植物叶片清除有机自由基能力的影响

生长在没光强下的４种木本植物荷对（Ｓｃｈｉｍａ ｓｕｐｅｒｂａ Ｇａｒｄｎ．ｅｔ Ｃｈａｍｐ．）、黧蒴（Ｃａｓｔａｎｏｐｓｉｓ ｆｉｓｓａ （Ｃｈａｍｐ．ｅｘ Ｂｅｎｔｈ．）Ｒｅｈｄ．ｅｔ Ｗｉｌｓ．）（乔木）和九节（Ｐｓｙｃｈｏｔｒｉａｒｕｂｒａ （Ｌｏｕｒ。．）Ｐｏｉｒ）,罗伞（Ａｒｄｉｓｉａ ｑｕｉｎｑｕｅｇｏｎａ Ｂ１．）（林下灌木）幼苗（盆栽）或幼树（自然林下）叶片的５０％乙醇提取液具     

水位梯度对湿地植物生长、繁殖和生物量分配的影响

本文考察了水位梯度对武夷慈姑（Ｓａｇｉｔａｒｉａｗｕｙｉｅｎｓｉｓ）、小慈姑（Ｓ．ｐｏｔａｍｏｇｅｔｉｆｏｌｉａ）、野荸荠（Ｅｌｅｏｃｈａｒｉｓｐｌａｎｔａｇｉｎｅｉｆｏｒｍｉｓ）和锐棱荸荠（Ｅ．ａｃｕｔａｎｇｕｌａ）植物幼苗生长、繁殖器官干重、生物量及其分配式样的影响。实验表明：植物高度、生物量及其分配对水位梯度的反应在种间有一定差异，而慈姑属植物的叶数、荸荠属植物的秆数、繁殖器官干重等对水位梯度处理的反应在种间有一定相似性。综合植物生物量和繁殖的反应特点，可以认为武夷慈姑和锐棱荸荠适宜生长在０～５ｃｍ水深处，小慈姑在２０ｃｍ水深处生长较佳，而野荸荠适宜于０～２０ｃｍ范围。结果提示：湿地植物的空间分布与其对水位反应的差异性有一定关系。     

闪电河流域6种农作物磷元素含量动态变化规律研究

本文报道了闪电河流域１５种植物磷含量特征及６种农作物含磷量的动态变化规律。结果表明：闪电河流域植物平均含磷量为１．３８±０．６２ｍｇ·ｇ￣（－１）,最高达２．２５ｍｇ·ｇ￣（－１）,最低只有０．８８ｍｇ·ｇ￣（－１）,与海河流域及锡林河流域植物磷含量基本一致。６种农作物在整个生长期间的磷含量变化规律表现为三种类型：禾本科植物小麦（Ｔｒｉｔｉｃｕｍａｅｓｔｉｖｕｍ）、莜麦（Ａｖｅｎａｎｕｄａ）和油料作物类亚麻（Ｌｉｎｕｍｕｓｉｔａｔｉｓｓｉｍｕｍ）,果实成熟期＞幼苗期＞营养期（Ｐ＜０．０５）;豆科作物豌豆（Ｐｉｓｕｍｓｅｔｉｖｕｍ）和蚕豆（Ｖｉｃｉａｆａｂａ）幼苗期＞营养期≥果实成熟期（Ｐ＜０．００１）;块茎类作物马铃薯（Ｓｏｌａｎｕｍｌｕｂｅｒｏｓｕｍ）则表现为营养期＞幼苗期＞果实成熟期（Ｐ＜０．００１）。６种农作物不同器官部位中根、茎、叶表现为幼苗期＞营养期＞果实成熟期（马铃薯除外）,而果实则为成熟后期＞果实形成期。不同器官磷含量比率的变化可反应磷在根、茎、叶、果４个器官的迁移清况,研究认为植物磷在幼苗期及营养期,通过根→茎→叶迁移,而在果实成熟期则通过根→茎叶→果途径运输。     

Burial of canopy-stored seeds in the annual psammophyte Agriophyllum squarrosum Moq. (Chenopodiaceae) and its ecological significance

Agriophyllum squarrosum Moq. is a dominant annual on sand dunes in the arid regions of central Asia. A high percentage of seeds is retained on dead plants which become covered by moving sand, but little is known about the ecological significance of burial of canopy-stored seeds. We investigated the size and dynamics of the buried canopy-stored seed bank and effects of burial on seed germination. In March (during the windy season), May (beginning of the germination season), and July (middle of the growing season), the number of seeds per square meter in sample plots in the dunes was 623, 223 and 22, respectively, with 54.6, 30.6 and 12.9% of the total seeds retained on buried plant canopies. In a controlled experiment, more seedlings emerged from released (dispersed) than from canopy-stored seeds when burial depth was the same. No viable ungerminated released seeds were found, but 45–80% of the ungerminated canopy-stored seeds were viable. In general, with an increase in applied water germination of released seeds buried at a depth of 1 or 2 cm and of canopy-stored seeds buried at 1 cm increased, but regardless of watering regime few or no released seeds at 4 cm or canopy-stored seeds at 2 or 4 cm germinated. Significantly more seedlings emerged from plants buried in a horizontal than in a vertical position. Seedlings originating from buried canopy-stored seeds on an active dune accounted for only 5.4% of the total seedlings emerging, and most of them emerged later than those from released seeds. Thus, seed release is more effectively postponed in buried than in exposed canopies, and burial of canopy-stored seeds is a mechanism that helps regulate seed germination and seedling emergence of A. squarrosum on active dunes.     

FIELD GERMINATION AND SEEDLING GROWTH OF CH AND CL PROGENY OF IMPATIENS CAPENSIS (BALSAMINACEAE)

The germination behavior and early growth of chasmogamous (CH) and cleistogamous (CL) progeny of Impatiens capensis were investigated in two eastern Nebraska stands. Field germination of families of buried seeds was scored in mid-April. In one stand a significantly higher proportion of CL seeds germinated than CH seeds while no significant differences were observed in the second stand. Among-family variation in germination rates was significant in both stands. The time course of field germination was similar for CL and CH seeds. A sample of the germinated CL and CH seedlings, matched in size, was planted individually in pots and grown in the greenhouse for five wk. Early growth of CL and CH seedlings was similar. In addition, CL seedlings were as variable as CH seedlings for four morphological traits. Overall, a large fitness advantage for CH progeny was not detected in the germination and early growth of Impatiens capensis seedlings.     

Effects of sand burial on purple sandgrass (Triplasis purpurea): the significance of seed heteromorphism

The effects of sand burial on seedling emergence, growth, and reproduction of the annual dune grass Triplasis purpurea (Walt.) Chapm. were examined. This species matures heteromorphic seeds on panicles enclosed by leaf sheaths along tiller nodes in a characteristic pattern: seeds at the lower nodes are heaviest, whilst those at the upper nodes are lightest. Field excavation of seedlings revealed that seedlings can emerge from seeds buried to 4 cm.In one experiment in an incubator, seeds collected from the upper and lower tiller nodes of glasshouse-grown parental plants were buried in sand at depths of 0, 3, and 6 cm. As expected, the effects of seed depth on seedling growth were due to delayed emergence for seedlings from buried seeds. However, seedlings from the larger seeds from the lower nodes of parental plants had significantly greater dry mass than those from the lighter seeds from upper nodes. Because lower node seeds are the most likely to become buried by sand in nature, the seed heteromorphism may be adaptive in the coastal environment.A second experiment involved the burial of seedlings to 0, 50, or 100% of their height. Although most seedlings did not survive complete burial (100% height), for partially buried seedlings (50% height) there was high survival and a marked stimulation of growth and eventual reproduction compared to unburied seedlings. This stimulation could be linked to increased root growth for seedlings that had been buried. The ability to respond positively to sand accumulation may represent an adaptation to the dynamic dune environment.     

DORMANCY AND GERMINATION IN SEEDS OF COMMON RAGWEED WITH REFERENCE TO BEAL'S BURIED SEED EXPERIMENT

Common ragweed (Ambrosia artemisiifolia L.) was one of 19 herbaceous weedy species used by Beal in his buried viable seed experiment started in 1879. No seeds germinated during the first 35 years of the experiment when germination tests were performed in late spring, summer or early autumn. Germination did occur in seeds buried for 40 years when seeds were exhumed and tested for germination in early spring. Data obtained in more recent research provide the probable explanation for these results. Seeds of common ragweed that do not germinate in spring enter secondary dormancy by mid to late spring and will not germinate until dormancy is broken the following late autumn and winter. Thus, during the first 35 years of the experiment seeds were dormant when tested for germination, whereas seeds buried for 40 years were nondormant. Seeds buried 50 years or longer did not germinate when tested in spring, probably because they had lost viability and/or seeds germinated during burial and seedlings died.     

SOME EXPERIMENTS AND FIELD OBSERVATIONS ON THE GERMINATION OF WILD OAT (AVENA FATUA AND A. LUDOVICIANA) SEEDS IN SOIL AND THE EMERGENCE OF SEEDLINGS

The distinguishing characters of Avena fatua and A. ludoviciana are described.
Pot experiments and field observations showed that most seeds of A. fatua germinated in spring and a few in autumn; hardly any germinated in summer or winter. Seeds of A. ludoviciana germinated in winter only. The greatest depth of sowing from which seedlings of either species reached the surface was 9 in., but seedlings from this depth were weak and yellow when they first appeared. A. ludoviciana gave more and sturdier seedlings than A. fatua from 6 and 9 in. There was no evidence of induced dormancy in seeds of A. fatua buried at depths down to 20 in. Germination of this species was hastened by monthly cultivation of the soil. The maximum survival of A. fatua was 3 years in pots and slightly longer in the field; seeds of A. ludoviciana in pots survived only 2 years. The two or three seeds of each spikelet of A. ludoviciana germinated in turn, starting with the largest, but the interval between germination of successive seeds varied.
Seedlings from freshly sown seeds of both species were more vigorous than seedlings from seeds which had been buried for a year or more. Germination and subsequent growth of both species took place in soil of pH 4.5 to 7.0 approx.     

The Influence of Light and Potassium Nitrate on the Dormancy and Germination of Avena fatua L. (wild oat) Seed Stored Buried Under Natural Conditions

The influence of light and potassium nitrate on the dormancyand germination of Avena fatua L. seed stored buried under naturalconditions was studied over a 13 month period. Natural emergenceof seedlings from buried seed in relation to rainfall and temperatureregimes and fluctuation was also monitored. The present findingsshow that potassium nitrate is stimulatory to germination onlyin the light and, further, that seeds from two positions inthe spikelet respond differently. Key words: Dormancy, Light, Nitrate     

Seed germination and seedling emergence of three annuals growing on desert sand dunes in China

BACKGROUND AND AIMS: Information on the initial growth characteristics of annuals found in Chinese deserts is very limited. The aim of this study was to investigate seed germination and interactive effects of irrigation and seed burial depth in sand on seedling emergence and seedling survival in three annuals (Agriophyllum squarrosum, Bassia dasyphylla and Aristida adscensionis) commonly growing on sand dunes in these regions. METHODS: Effects of temperature, light and polyethylene glycol-6000 on seed germination were examined by irrigating seeds sown on filter paper in Petri dishes. Seedling emergence was examined for seeds sown on the surface of, or at different depths (5, 10, 20, 30, 40 and 50 mm) in, sand-filled pots, which were irrigated under different regimes. For seeds buried at a depth of 50 mm, seed viability was examined after irrigation of the pots. KEY RESULTS: Seeds of three species germinated at most temperatures recorded between spring and autumn in their native habitats. No seed dormancy was found in any species. For all three species, seedling emergence was most favoured when seeds were buried at a depth of 10 mm. When seeds sown on the sand surface were irrigated, seed germination was considerably suppressed due to water deficiency, but many seeds remained viable. For A. squarrosum and B. dasyphylla, many seeds that were deeply buried and irrigated remained ungerminated but viable, while for A. adscensionis deeply buried seeds germinated, but the seedlings did not emerge due to unfavourable seedling growth in deep sand. CONCLUSIONS: Precipitation is the most crucial factor in determining the seasonal emergence of seedlings of the three tested species in the field. The vertical distribution of seeds in sand determines the proportion of seeds that germinate after precipitation and acts to maintain seed banks over multiple years.     

Natural priming as an important metabolic event in the life history of Wigandia urens (Hydrophyllaceae) seeds

Natural priming promotes fast and synchronic seed germination and enhances the establishment of seedlings from Wigandia urens seeds. In this study, seeds of this species were buried in the field in three different sites, and each site was divided into three different microsites (natural priming). They were then exhumed and air-dried at the beginning of the rainy season. The control and exhumed W. urens seeds were tested for differences in germination, and in the protein patterns derived from heat-stable and phospho-protein enriched fractions, sucrose concentrations, amylase isoenzyme patterns, as well as catalase activity and H₂O₂ levels. All the exhumed seeds germinated faster and more synchronically than the control seeds. Nevertheless, the germinative pattern showed a microsite effect related to the microenvironmental conditions. Most exhumed samples kept the germinative advantages acquired from the soil during natural priming for 2 years but seeds from the most heterogeneous site (a forest gap) did not. Natural priming also promoted mobilization of 7-S globulin-like proteins, solubilization of the 11-S globulin-like proteins as well as sucrose consumption before radicle protrusion. Although there were no changes in starch concentration during the germination of either the control or buried seeds, a different isoenzyme amylase pattern was observed. Catalase activity decreased and hydrogen peroxide levels were lower in exhumed seeds during germination. The changes in the protein and sucrose patterns were related to advances in the germinative process acquired during burial. Metabolic advantages were maintained systematically in all seed samples along the 2 years. The ecological significance of natural priming is discussed.     

THE NINETY-YEAR PERIOD FOR DR. BEAL'S SEED VIABILITY EXPERIMENT

In 1879 Dr. W. J. Beal selected seeds of 23 different species of locally common plants, mixed 50 seeds of each species with moist sand in unstoppered one-pint bottles, and buried the bottles in a sandy knoll to be unearthed and the viability of the seeds tested periodically. The year 1970 marked the ninetieth year the seed had been buried, and the thirteenth bottle was recovered to test for seed viability. Of the three species which had germinated in the 1960 test (curly dock, Rumex crispus; evening primrose, Oenothera biennis; and moth mullein, Verbascum blattaria), only V. blattaria had viable seed with 20% germination. No other species germinated. All ten seedlings of V. blattaria were grown to maturity, and seeds were then harvested to study the possible deviations from normality and the requirements for seed germination. All seedlings emerging from the first progeny seed appeared normal. The most prominent requirement for germination was light, and this is a possible explanation of why the seeds had remained viable but dormant for so long a period. One-third of the freshly harvested seed germinated in darkness and, furthermore, redrying of dark-moistened seed in the absence of light induced additional germination. Germination of dark-moistened seed was not completely restored when the still moist seeds were subsequently exposed to light. However, when dark-moistened seeds were dried and then remoistened in the light, germination was about 95 %. About 5 % of the seed did not germinate under the conditions used. We find that 5 % of the population of V. blattaria seeds are dormant for unknown reasons, that 30 % will germinate if supplied only with moisture, and that 65 % are inhibited and require light and moisture simultaneously for germination. Supplying this 65 % of the population with moisture in darkness results in the development of a second type of inhibition which is no longer light reversible. It appears that the simultaneous requirement for light and moisture is an important factor in permitting V. blattaria seeds to remain dormant during prolonged burial.     

果肉和埋土深度对新疆野杏种子萌发与幼苗生长的影响

为探明新疆野杏（Armeniaca vulgaris）种子萌发与幼苗生长对果肉和埋土深度的响应,以期为新疆野杏的天然更新与实生苗培育提供理论参考。通过2种果皮结构（有果肉和无果肉）的种子在不同埋土深度（地表至18.0 cm的14个梯度）对新疆野杏种子萌发和幼苗生长进行研究,旨在揭示果皮结构和埋土深度对新疆野杏种子萌发与成苗能力的影响。结果表明：果肉和埋土深度显著影响野杏种子的萌发、幼苗生长与质量（P<0.05）。埋土深度<3.0 cm不利于成苗,埋土深度>6.0 cm时,萌发能力与幼苗生长量随埋土深度的增加而降低,3.0～6.0cm为适宜埋土深度。无果肉种子萌发优于有果肉种子,萌发率、萌发指数、成苗率、活力指数分别增长了37.18%、3.88%、37.18%、26.59%,幼苗高、基径、叶片数量、根冠比、幼苗质量指数分别增长了36.99%、7.48%、68.69%、20.61%、14.29%,其萌发能力与幼苗生长量显著高于有果肉种子（P<0.05）。有无果肉种子的萌发和幼苗生长指标与埋土深度呈显著负相关（P<0.05）。研究结果表明,无果肉处理对新疆野杏种...