The effects of thermotherapy and sodium hypochlorite treatments on pepino seed germination, a crucial step in breeding programmes

We evaluated the effects of treatments with thermotherapy (80°C for 24 h) and dipping in sodium hypochlorite (NaOCl; 0.8% for 10 min) on the germination percentage, germination rate, vigour index and ToMV inactivation of seeds from three pepino (Solarium muricatum) accessions (96–5, B–2 and OV–8) and two wild relatives (S. tabanoense EC–26 and S. caripense EC–40). Thermotherapy decreased the germination percentage (especially in the wild species), germination rate in wild species but not in cultivated pepino, and vigour index in all cases. Sodium hypochlorite increased germination, except for nonthermotreated seeds of OV–8, improved the germination rate in wild species and the vigour index in all cases except for non thermotreated OV–8. Seed coats were altered by both treatments, especially by NaOCl. Thermotherapy was totally effective in the inactivation of seed-borne ToMV, while NaOCl was not. Thermotherapy combined with NaOCl allows effective seed disinfection of S. muricatum seeds without negatively affecting seed germination. For the wild species, although thermotherapy reduces germination, the higher number of seeds per fruit in these species reduces the magnitude of the problem. Even when no disinfection is necessary, treatments with NaOCl are always advisable as they improve germination.     

Inactivation of Salmonella Typhimurium,Escherichia coli O157:H7 and Listeria monocytogenes on alfalfa seeds by the combination treatment of vacuumed hydrogen peroxide vapour and vacuumed dry heat

We evaluated the combined effects of vacuumed hydrogen peroxide vapour (VHPV) and vacuum-sealed dry heat (vacuum heat, VH) to inactivate food-borne pathogens (Salmonella Typhimurium, Escherichia coli O157:H7 and Listeria monocytogenes) on alfalfa seeds. Alfalfa seeds inoculated with food-borne pathogens were sequentially treated initially with 1·0 ml of 0 or 30% VHPV for 1 min and later with dry heat (DH) or VH for 2 h, and the rate of seed germination was evaluated. The combination treatment decreased the populations of three food-borne pathogens below the limit of detection (1·0 log CFU per gram) on alfalfa seeds without decreasing germinability. The sequential treatment using VHPV and VH greatly reduced the total treatment time needed to inactivate pathogens on alfalfa seeds by more than 5 log CFU per gram. These results demonstrate that a combination of VHPV and VH has potentially employed as a new method for pasteurization of alfalfa seeds without affecting their germinability.     

Heat and smoke pre‐treatment of seeds to improve restoration of an endangered Mediterranean climate vegetation type

Invasive alien plants impact ecosystems, which often necessitates their removal. Where indigenous species recovery fails following removal alone, an active intervention involving reintroduction of seed of native species may be needed. This study investigated the potential for a combination of the fire cues of smoke and heat as a pre‐treatment of seeds in breaking dormancy and facilitating increased germination. Species were selected to represent different functional types within Cape Flats Sand Fynbos; a fire‐prone, critically endangered vegetation type in South Africa. Seeds were exposed to either a heat pulse (temperatures between 60 and 300°C for durations of between 30 s and 20 min) or dry after‐ripening (1 or 2 months at milder temperatures of 45°C or less). Thereafter, seeds were soaked in smoke solution for 18 h and subsequently placed on agar at 10/20°C for germination. Most species fell into one of two main groups: Seed germination in the first group was greatest following a lower temperature (60°C) heat pulse, an extended period of mild temperature (20/40°C or 45°C) exposure, or no pre‐treatment with heat. Seed germination in the second group was promoted after brief exposure to higher (100°C) temperatures. No germination occurred in any species following heat treatments of 150°C or higher. Species which responded better to higher temperatures were mainly those possessing physical dormancy, but seed morphology did not correlate with germination success. This study showed that heat stimulation of seeds is more widespread in fynbos plant families than previously known and will enable the development of better seed pre‐treatment protocols before large‐scale sowing as an active restoration treatment after alien plant clearing.     

Seed longevity and fire: germination responses of an exotic perennial herb in NW Patagonian grasslands (Argentina)

Fire affects grassland composition by selectively influencing recruitment. Some exotic species can increase their abundance as a consequence of fire-stimulated seed germination, but response may depend on seed age. Rumex acetosella L. (Polygonaceae, sheep's sorrel) is a cosmopolitan herb that has invaded NW Patagonia's grasslands. This species forms persistent soil seed banks and increases after disturbances, particularly fire. We studied how fire and seed longevity influence R. acetosella germination. In 2008, we conducted laboratory experiments where we exposed different-aged seeds (up to 19 years old) to heat, smoke, charcoal, ash and control treatments. Total percentage germination and mean germination time depended on both seed age and fire treatment. Germination of younger seeds decreased with increasing temperature. There was no general pattern in germination responses of different-aged seeds to smoke, charcoal and ash. While smoke improved the germination of fresh seeds, charcoal decreased germination. Germination of untreated seeds was negatively correlated with seed age, and mean germination time increased with seed age. In most treatments, fresh seeds had lower germination than 1-5-year-old seeds, indicating an after-ripening requirement. Smoke stimulates R. acetosella germination, causing successful recruitment during post-fire conditions. Fresh seeds are particularly responsive to fire factors, possibly because they have not experienced physical degradation and are more receptive to environmental stimuli. Knowing the colonisation potential from the soil seed bank of this species during post-fire conditions will allow us to predict their impact on native communities.     

Influence of heat on seed germination of seven Mediterranean Leguminosae species

The influence of high temperatures (dry heat and hot water) on germination of seven Mediterranean Leguminosae species typical of fire-prone ecosystems in southern Spain is analyzed, in order to know the response of seeds to wildfires and the possible implications in their regeneration after this disturbance. Seeds were heated to a range of temperatures (50 °–150 °C) and exposure times (1–60 min) similar to those registered in the upper soil layers during wildfires. Germination tests were carried out in plastic Petri dishes over 60 days. In general, the degree of seed germination promotion by dry heat treatments showed a wide interspecific variation, although the final germination level was increased in all the studied species except for Scorpiurus muricatus. The thermal pretreatment of 50 °C, however, was not effective for germination in any species, and rising the temperature to 70 °C only slightly enhanced the germination in Cytisus patens. The preheatings of 90 °C (5 and 10 min), 120 °C (5 and 10 min), and 150 °C (1 min) were the most effective in promoting seed germination. Hot water (100 °C) scarification also increased the final germination level in all cases, with the exception of C. patens. The germination rates after preheating were much lower than in mechanically scarified seeds and closely resembled those of the untreated seeds, except for C. reverchonii, whose seed germination rate decreased with heat. The response of species to heat shock had no clear relationship with life trait or with the specific post-fire regeneration strategy (obligate seeder or facultative resprouter). Those species coexisting in the same habitats had different heat optimal requirements for seed germination, an strategy suggested by some authors as minimizing interspecific competition in the secondary succession started after fire.     

Heteromorphic seeds of wheat wild relatives show germination niche differentiation

• Crop wild relatives are fundamental genetic resources for crop improvement. Wheat wild relatives often produce heteromorphic seeds that differ in morphological and physiological traits. Several Aegilops and Triticum species possess, within the same spikelet, a dimorphic seed pair, with one seed being larger than the other. A comprehensive analysis is needed to understand which traits are involved in seed dimorphism and if these aspects of variation in dimorphic pairs are functionally related.
• To this end, dispersal units of Triticum urartu and five Aegilops species were X‐rayed and the different seed morphs weighed. Germination tests were carried out on seeds, both dehulled and left in their dispersal units. Controlled ageing tests were performed to detect differences in seed longevity among seed morphs, and the antioxidant profile was assessed in terms of antioxidant compounds equipment and expression of selected antioxidant genes. We used PCA to group seed morphs sharing similar patterns of germination traits, longevity estimates and antioxidant profile.
• Different seed morphs differed significantly in terms of mass, final germination, germination timing, longevity estimates and antioxidant profile in most of the tested species. Small seeds germinated slower, had lower germination when left in their dispersal units, a higher antioxidant potential and were longer‐lived than large seeds. The antioxidant gene expression varied between morphs, with different patterns across species but not clearly reflecting the phenotypic observations.
• The results highlight different trait trade‐offs in dimorphic seeds of Aegilops and T. urartu, affecting their germination phenology and longevity, thereby resulting in recruitment niche differentiation.

     

棕果蝠取食对两种榕树种子萌发行为的影响

在实验室利用聚果榕（Fieus racemosa）和对叶榕（Fieus hispida）成熟的果实饲喂笼养棕果蝠（Rousettus leschenaulti）,比较了不同处理的3组种子的萌发行为：（1）棕果蝠粪便中的种子;（2）被吐出的果渣中的种子;（3）成熟果实中的种子（对照）。棕果蝠取食行为显著影响了两种榕树种子的萌发过程,3种不同处理的种子萌发过程及最终萌发率（GP）之间都存在显著的差异。聚果榕种子经过棕果蝠消化道后GP显著降低,而对叶榕种子的GP显著提高。棕果蝠粪便中的聚果榕种子萌发开始（GS）和最短萌发时间（Tmin）均比对照种子延迟了2d,但其粪便中的对叶榕种子G5比对照种子提前了1d,Tmin提前了2d;与之相似,前者种子萌发比果实中种子提前2d达到萌发总量的50％（T50）,但后者没有改变T50。不同种榕果果渣中的种子萌发行为也有重大差异：聚果榕果渣中种子的Tmin和T50均比对照种子延迟1d,GS没发生改变;而对叶榕果渣中种子的Tmin比对照种子提前了3d,GS提前1d,T50没有改变。棕果蝠取食两种榕果后在飞行过程中排泄,进而有效的散布种子;而且通过消化明显改变了种子萌发行为,使种子萌发类型更为多样,增加了种子在不同时空条件下萌发的可能性。     

Soil Seedbank in a Dipterocarp Rain Forest in Xishuangbanna,Southwest China1

Dipterocarp rain forest reaches its northern latitudinal limit in Xishuangbanna, Southwest China. We studied the soil seedbank of dipterocarp rain forest in Xishuangbanna during the dry and wet seasons. Results showed that there were large seed accumulations in both the dry (mean ± SD; 3925 ± 2533 seeds/m²) and wet seasons (5415 ± 3232 seeds/m²). One hundred and sixteen species of seed plants were identified from germination, 66 percent of which were woody species. Weed or pioneer species dominated the seedbank. The soil seedbank in Xishuangbanna had similar species composition as compared to those in tropical Asia, but higher seed storage reflects the intense disturbance and forest fragmentation in this area.     

膏桐种子不同消毒方法效果比较

比较了不同消毒方法处理后膏桐种子的霉烂率和发芽率。结果表明,与对照相比,不同浓度高锰酸钾溶液浸种30min,虽然可显著降低霉烂率,但同时也抑制了发芽率;1%硫酸铜溶液浸泡10、20和30min处理,不仅显著降低霉烂率,而且明显提高种子的发芽率,其中,1%硫酸铜溶液浸泡种子30min效果最好;而高锰酸钾不适于膏桐种子的消毒处理。     

Smoke and heat effects on soil seed bank germination for the re‐establishment of a native forest community in New South Wales

The effects of plant‐derived smoke and of heat on the emergence of seedlings from seeds were assessed. Seeds had been stored in forest topsoil used for mine site rehabilitation. The study was carried out in a dry sclerophyll, spotted gum (Corymbia maculata), forest community at the Mount Owen open‐cut coal mine in the Hunter Valley region of New South Wales. Samples of the surface 2.5 cm of topsoil were either exposed to cool smoke from eucalypt foliage for 60 min, heated to 80°C, or left untreated. Seedling emergence from the seed bank in this soil was then monitored in a glasshouse. Within the first month, smoke alone promoted a 4.3‐fold increase in the density of seedlings relative to control. There were 540 emergents per m² in the control and 2309 per m² in the smoke treated topsoil. Many annual and perennial herbs emerged but grasses responded most strongly to smoke. Germination in seven of the 20 grass species was promoted by smoke. Smoke promoted the germination of some introduced species as well as native species, and accelerated the rate at which seedlings emerged, although these differences sometimes declined with time. Heat also stimulated germination but smoke and heat stimuli appeared to be complementary in their promotion of seedling emergence from the topsoil seed bank. Each treatment increased the density of different species, enhanced the species richness of different components of the seed bank, and had different effects on the rate of emergence. The results suggest that increased seed germination in the field immediately following a moderate intensity fire may sometimes be the result of smoke stimulation and sometimes the result of heat stimulation of the soil seed bank. These findings may have important implications for minesite revegetation programs where topsoils are replaced after mining and rapid germination of seeds stored in these soils is required during short periods when conditions are favourable for germination.     

Patterns of Seed Size,Germination and Seed Viability of Tropical Tree Species in Southern India1

Seed weight, days to germination and seed viability were observed for 99 species growing in the Western Ghats of Karnataka, India. Seed size was strongly correlated with days to germination; smaller seeds germinated faster than larger seeds. Species which flowered during the rainy season had lighter seeds than species which flowered during the dry season. It was also found that seed size and viability of seeds were related to the season of fruiting. Species which fruit during the rainy season had heavier seeds and shorter viability than species which fruit during the dry season. These flowering and fruiting patterns and varying seed sizes are argued to be adaptations to the time of dispersal, time of moisture availability in the habitat and seedling survival.     

Restoring the Victorian Western (Basalt) Plains grassland. 1. Laboratory trials of viability and germination, and the implications for direct seeding

Summary   The Victorian Western (Basalt) Plains grassland is one of Australia's most threatened plant communities. Practitioners using seed for its restoration need to know whether seed can be sown fresh or whether it requires an after-ripening period. This study assessed the viability and germination of freshly harvested wild seed from 64 grassland species indigenous to the Basalt Plains of western Victoria. The seed was collected as part of a broader experiment that examined the potential of direct-sown complex seed mixes for the restoration of grassland communities. The germination of fresh seed at 25°C varied widely between species. Comparisons with tetrazolium viability tests for each species indicated varying levels of dormancy within the species pool. Germination separated into three broad responses at day 28. One-third of the species failed to germinate, one-third germinated at 1% to 50% and the remaining species germinated between 51% and 100%. Therefore, if the aim of a sowing was the rapid and synchronous establishment of most of the sown species, the use of fresh seed in restoration could be problematic. After 3 months of dry storage, eight species were re-tested for germination. Each of the selected species had shown high viability but low initial germination. Only two species significantly increased their total germination at 25°C. The annual species, Triptilodiscus pygmaeus , increased its total germination from 6% as fresh seed to 99% after dry storage. Testing the viability and germination capacity of freshly harvested seed from a large and diverse sample of native grassland species demonstrated that many of the species were unlikely to germinate rapidly or synchronously when sown in complex seed mixes soon after harvest. This finding has implications for the scheduling and management of restoration projects that rely on the use of such seed.     

Seed banking of terrestrial orchids: evaluation of seed quality in Anacamptis following 4‐year dry storage

• Good‐quality dry seeds of some orchids have the potential to survive for decades under conventional seed bank conditions, but further research is needed to fill existing gaps in knowledge regarding seed behaviour under long‐term dry storage. The objectives of this study were to evaluate germination ability on two asymbiotic culture media with different nitrogen source; to assess seed desiccation tolerance needed for the storage at sub‐zero temperatures; and to study the effects of dry storage at low temperature.
• Asymbiotic seed germination tests of four Anacamptis species were carried out to evaluate the effects of different culture media, dehydration and dry storage on germination ability. Viability of 4‐year‐stored seeds was assessed by means of the tetrazolium test.
• Generalised linear model (GLM) analysis detected significant effects (P < 0.01) of the species, medium and storage time on total germination, while dehydration did not significantly affect it. Except for A. palustris, germination percentage was minimum after 1‐month storage and increased with longer storage periods. Tetrazolium viability tests detected high percentages of viable seed (>90%) following 4‐year storage in three out of four species.
• Seeds of the four Anacamptis species proved to be desiccation tolerant and have orthodox storage behaviour. The consequence of these findings is of interest to practical conservation approaches for orchids in seed‐banking. The results highlight the importance of multiple assessments of seed quality, both viability and germination, to understand seed storage behaviour.

     

红皮糙果茶种子生活力测定与发芽试验

选取饱满有光泽的红皮糙果茶Camellia crapnelliana种子,进行种子贮存生活力测定、种子发芽试验及种皮解剖结构观察等研究,就种子繁殖探讨其濒危原因。结果表明,有利于保持种子生活力的贮存方式为：4 ℃贮存>常温贮存>－10 ℃贮存;种子发芽试验中,采用不同浓度赤霉素(GA₃)、吲哚丁酸(IBA)和不同温度温水处理,种子发芽率均不高,最高为40%;不同因素对种子发芽的影响不同,种子发芽最佳处理为800 mg·L^-1GA₃浸泡6 h;种皮解剖结构观察到红皮糙果茶种皮坚硬,由栓化壁和骨状石细胞组成,内、外部石细胞垂直交错排列,这可能是造成种子萌发困难的机械阻碍原因。     

Effect of seed passage through vertebrate frugivores'' guts on germination: a review

The capacity of seeds to germinate after ingestion by frugivores is important for the population dynamics of some plant species and significant for the evolution of plant-frugivore interactions. In this paper the effects of different vertebrates on seed germination of nearly 200 plant species are reviewed, searching for patterns that predict the circumstances in which germination of seeds is enhanced, inhibited, or unaffected by the passage through the digestive tract of a seed disperser. It was found that seed dispersers commonly have an effect on the germinability of seeds, or on the rate of germination, or both, in about 50% of the plants they consume, although the diversity of animal species tested so far is still rather low (42 bird species, 28 non-flying mammals, 10–15 bats, 12 reptiles, 2 fishes). Enhancement of germination occurred about twice as often as inhibition.

In spite of the morphological and physiological differences in their digestive tracts, the different animal groups tested have similar effects on seed germination, although non-flying mammals tend to influence germination slightly more often than the other groups. Data on fishes are still too scarce for any generalization. Seed retention time in the dispersers' digestive tract is one factor affecting germination, and helps to explain the variation in seed responses observed among plant species, and even within a species. However other factors are also important; for example, the type of food ingested along with the fruits may affect germination through its influence on chemical or mechanical abrasion of the seed coat. Seed traits such as coat structure or thickness may themselves be responsible for some of the variation in seed retention times. Seeds of different sizes, which usually have different transit times through frugivores, and seeds of either fleshy or dry fruits, show often similar germination response to gut passage.

Seeds of different plants species differ strongly in their germination response after ingestion, even by the same frugivore species. Congeneric plants often show little consistency in their response. Even within a species variation is found which can be related to factors such as the environmental conditions under which germination takes place, seed morphology, seed age, and the season when the seeds are produced.

The effect of gut passage on germination differs between tropical and temperate zones. Seed germination of both shrubs and trees (data on herbaceous species are still scarce) in the temperate zone is more frequently enhanced than in the tropics. This result supports the hypothesis that enhanced germination may be more advantageous in unpredictable or less constant environments. Significant differences in frugivore-mediated germination are also found among different life forms. In both tropical and temperate zones, trees appear to be consistently more affected than shrubs or herbs. This might be due to an overall higher thickness of the seed coats, or to a higher frequency of seed-coat dormancy in tree species.

The influence of frugivory upon the population dynamics of a species has to be evaluated relative to other factors that influence germination and seedling recruitment at a particular site. Whether seed ingestion by dispersers is really advantageous to a plant (as has commonly been assumed) can only be assessed if we also determine the fate of the ingested seeds under natural conditions, and compare it to the fate of seeds that have not been ingested.     

不同发育时期小麦种子活力的变化及其对环境温度的响应

以济麦22和山农23号为试验材料,利用标准发芽试验法对不同年份小麦种子发育过程中的种子活力变化进行研究,分析环境温度对不同发育时期小麦种子活力变化的影响,为早期小麦种子的利用及高活力种子的生产提供参考依据.结果表明: 伴随着小麦种子发育,鲜种子在花后26 d左右出现发芽能力,之后其发芽率整体呈上升趋势;干种子发芽势、发芽率和发芽指数在花后5～8 d迅速升高,之后保持相对稳定,活力指数主要受到幼苗单株干质量的影响而持续升高,一般在完熟前4～6 d达到最大值;不同发育时期小麦干种子的田间种植及其后代种子的活力测定表明,济麦22花后17 d以后的干种子田间出苗较好,并可成穗结实,其后代种子的发芽率和活力指数在不同样品间无显著差异.环境温度对不同发育时期小麦种子活力变化的影响显著,小麦花后日平均温度均值、日最高气温均值以及日最低气温均值均高,且花后日温差均值大的年份,种子发育时间短、百粒重及种子活力达到最大值的时间较早;反之,发育时间较长、百粒重及种子活力达到最大值的时间较晚,但完熟期积温高,种子活力较高.     

No effect of transgene and strong wild parent effects on seed dormancy in crop–wild hybrids of rice: implications for transgene persistence in wild populations

Soil seed banks act as a gene pool for local plant species and, as such, can buffer local populations, especially those experiencing challenging environmental conditions. Seed dormancy has important implications to dynamics of soil seed banks. Therefore, estimating the seed dormancy of transgenic crop–wild hybrids could shed light on the persistence of transgenes in wild‐plant soil seed banks. Individuals from eight populations of wild rice Oryza rufipogon were crossed with those of three insect‐resistant transgenic rice lines. Selfed (F2–F4) and backcrossed populations (BC1, BC1F2 and BC1F3) were then made from the hybrids. Seed germination was tested under three treatments: (a) normal; (b) overwintering in soil; and (c) one‐week heat‐shocking. The effects of transgene, wild parent and hybrid generation on hybrid seed germination were examined. No significant effect of insect‐resistant transgenes (Bt and CpTI) was detected on the seed dormancy of crop–wild hybrids, while a significant wild parent effect was found. The seeds of advanced generation hybrids have higher germination percentages and lower dormancy than do those of F1 and BC1 generations. The study showed that the dormancy of hybrid seeds was determined mainly by their genetic backgrounds. All hybrid seeds have higher germination percentages and lower dormancy (and, consequently, a poorer overwintering ability), compared with wild seeds, and reduce dormancy would contribute to a fitness disadvantage, compared with wild types. Therefore, such seeds might form part of naturally occurring soil seed banks, through which crop genes would persist in wild populations.     

Seed traits and germination behaviour of four Sardinian populations of Helichrysum microphyllum subsp. tyrrhenicum (Asteraceae) along an altitudinal gradient

• Helichrysum microphyllum subsp. tyrrhenicum (Asteraceae) is an endemic taxon of Sardinia and Corsica, where it grows at different altitudes. The objective of this study was to investigate the seed traits and germination behaviour of four Sardinian populations of this taxon located at different altitudes.
• Seed traits were evaluated, and germination tests were carried out by incubating seeds at a range of constant (5–30 °C) and alternating (25/10 °C) temperatures. The dry after‐ripening (DAR) pre‐treatment was also applied by storing seed in dry conditions for 3 months at 25 °C. Seed traits and germination behaviour data were statistically analysed to identify if there was a correlation with altitude.
• Differences in seed size, area and mass among populations were recorded, however, no relationship was found with altitude. High germination percentages were obtained in all populations, both in untreated and DAR seeds, and were positively affected by alternating temperatures. The final germination percentage and time required to reach 50% final germination (T₅₀) showed no relationship with altitude.
• The differences in seed traits and germination detected among the studied populations of H. microphyllum subsp. tyrrhenicum were not correlated with altitude. This study provides new and important knowledge for this taxon. H. microphyllum subsp. tyrrhenicum is characterised by high germination percentages and low T₅₀ values and does not seem to require any dormancy‐breaking treatment. This species represents a high‐potential native plant species that should be considered within environmental management plans.

     

不同种子预处理对10种沙拐枣植物萌发的影响

为了确定沙拐枣植物种子的萌发特性及最优播前预处理方法,在实验室条件下,对10种沙拐枣植物的种子进行了磨砺、硫酸和热水浸泡、冷藏、种子浸出液处理,然后进行发芽实验研究。萌发实验的结果表明,10种沙拐枣植物对于不同的种子预处理,均表现出相似的萌发反应。磨砺、硫酸浸泡和冷藏处理对种子萌发有明显地促进作用。与对照相比,种子浸出液处理对种子的发芽率、发芽速度均具有明显地抑制作用,并能增强种子的休眠。冷藏处理具有打破有活力的种子休眠、促进种子萌发的作用,但它与热水浸泡处理一样,对有活力种子表现出一定的致死作用。沙拐枣植物的萌发模式在不同种子预处理问均表现出明显的差异性。机械磨擦和硫酸处理能够促进种子的萌发率及发芽势。泡果沙拐枣(Callingonum junceum)在本项实验中表现出很强的萌发能力。     

Effects of smoke, heat, darkness and cold stratification on seed germination of 40 species in a cool temperate zone in northern Japan

The effects of smoke, heat, darkness and cold stratification on seed germination were examined for 40 species with various life history attributes. These species establish in early successional stages on a volcano and are distributed in cool temperate zones of northern Japan. Smoke decreased seed germination in 11 species and increased it in one species, Leucothoe grayana . Germination of Polygonum longisetum was enhanced by a combination of smoke and cold, and that of Aralia elata by smoke and heat. Heat increased germination for three species and decreased it for one. Cold stratification broke dormancy in seeds of 11 species. Continuous darkness decreased germination of 22 species and did not increase germination for any species, showing that approximately half of the species require light for maximum germination. Although most species are sun plants that establish in early stages of succession and/or in disturbed areas, smoke and heat do not enhance germination of these species after disturbance, even when the disturbance is fire. Germination of slender and/or large seeds tends to be decreased more by smoke, probably because of their larger surface area. Light is more important than smoke and heat for detection of disturbance and for seed germination in this region. However, despite the low fire frequency in the region, germination of a few species was increased by fire-derived stimuli.