Effect of flowering phenology,date of cone collection,cone-storage treatment and seed pretreatment on yield and germination of seeds from a Douglas-Fir seed orchard

The effects of reproductive phenology, date of cone harvest, cone storage and seed pretreatment on yield and germination of seeds from a Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] seed orchard were studied. Flowering phenology (early, intermediate or late) had no discernible effect on seed maturation. Higher germination and yields of filled seeds were obtained from cones collected in mid-August, approximately 2 weeks prior to cone opening, than from cones collected just as they began to open. Seeds extracted immediately following harvest germinated better than those from cones stored for 2 months. Seeds from all treatments were dormant and responded to prechilling by exhibiting increased germination rates. The implications of these findings for cone-crop management are discussed.     

马尾松种子园种实害虫、害鼠的研究

经观察马尾松种子园种实害虫和害鼠的种类有２１种，严重危害的有机松瘿纹，马尾松窃蠹，芽梢斑螟，松实小卷蛾、油松球果小卷蛾、微红梢斑螟和社鼠。根据马尾松生殖发育规律，观察了 主要种实害虫、害鼠的 危害顺序及其程度。     

Effect of desiccation on viability and biochemical changes in Knema attenuata seeds

We studied effect of desiccation on Knema attenuata seeds in the laboratory conditions(28 ± 2℃) for 8 days.We also monitored biochemical changes during germination by following standard procedures.Seeds lost their viability in 8 days by decreasing to 18% of moisture content from its original value of 31%.The total sugar,protein and lipid contents decreased during seed ageing.An increase was noticed in the protease activity during desiccation.The phenolic content in seed exudates was increased during ageing.The result confirms the degradation of stored biomolecules in seeds during ageing.Desiccation sensitivity and biochemical changes during dehydration confirm its recalcitrant nature.     

The relationship between seed weight, germination and biochemical reserves of maritime pine (Pinus pinaster Ait.) in Morocco

Seed germination and biochemical reserves of maritime pine (Pinus pinaster Ait.) were studied with the aim of providing germination information for reforestation and conservation programs. Ten natural populations were used to assess variation in seed weight, germination characteristics and biochemical reserves and to examine the relationship between these characteristics. The analysis of variance showed highly significant population effects for seed weight, germination characteristics and protein content in both seeds and the female gametophyte. The mobilization of protein content in female gametophyte during seed germination differed more among populations than sugar content, suggesting that protein content was more sensitive to environment effects than sugar content. A strong positive correlation between germination capacity and the protein content in both seeds and female gametophyte indicated that the best populations in term of germination capacity may also be the richest in protein content. Seeds that were heavier and had a lower speed of protein content mobilization in the female gametophyte appeared to be better adapted to drought conditions. The results also suggested that as much as possible of the potentially valuable genetic variation among populations of this species should be preserved for reforestation and conservation purposes.     

Applying the IDS method to remove seeds infested with the seed chalcid,Megastigmus spermotrophus Wachtl,in Douglas-fir,Pseudotsuga menziesii (Mirb.) Franco

Douglas-fir seedlots were treated with the Incubation Drying Separation (IDS) method to test whether seeds infested with the seed chalcid, Megastigmus spermotrophus Wachtl, could be separated from non-infested seeds. Seeds were soaked in distilled water for 24 h, drained, placed in plastic bags and incubated at 15 °C for 3 days. The seeds were dried for either 0.5, 1, or 2 h at 25 °C, and then separated into floaters and sinkers in a water column. An average of 97% of the infested seed floated. The drying period did not affect the separation of infested seeds but significantly fewer sound seeds floated in the seedlots dried for 0.5 h than those dried for 1 h. Germination capacity of IDS-treated seeds did not differ from that of untreated seeds but the germination rate was significantly faster for IDS-treated seeds when all lots were stratified.     

Mycoflora associated with slash-pine seeds from cones collected at seed orchards and cone-processing facilities in the south-eastern USA1

A diverse mycoflora was associated with slash-pine seeds from cones obtained at seed orchards and cone-processing facilities in the southeastern USA. Potentially pathogenic fungi, including Lasiodiplodia tbeobromae, Sphaeropsis sapinea, and Fusarium spp., were isolated from seeds of cones obtained at all locations. Fusarium proliferatum and F. semitectum were the Fusarium spp. most often associated with seeds; F. subglutinans was rarely isolated. Many other species of fungi were associated with seeds from all locations. Incidence of fungus-damaged seeds ranged from 2 to 11% among collection sites. Disease incidence was found to increase during cone storage. Types of fungi and the incidence of fungus-damaged seeds were similar for damaged/discoloured cones and apparently healthy cones. The potential for slash-pine seeds to become colonized by pathogenic fungi, such as S. sapinea and the various Fusarium spp., could have important implications for the establishment of these fungi in forest-tree nurseries, as well as their introduction into foreign countries.     

The relationships between the number of seeds in the cones of Abies alba Mill. and their damage by spermatophagous insects

A study was conducted on the relationships between the total number of seeds in cones of Abies alba Mill. and the number of seeds that were viable, infertile, infested with the larvae of Megastigmus suspectus Borr. or damaged by Resseliella piceae Seitn. The seeds were obtained from cones collected in southern Poland in the Gorce National Park in both partial and strict reserves during 1996–1998. A total of 54,958 seeds extracted from 217 cones were used in the study. The data obtained were subjected to statistical analysis. Spearman rank correlation coefficient was computed. A correlation was found between the total number of seeds and each of the groups mentioned above except seeds infested with M. suspectus. An appropriate test was also used to compare the proportions of each of the groups. It was found that the proportions differ from year to year, and for the different sites, except the proportion of viable seeds. No correlation was found between the numbers of seeds infested with M. suspectus and the number of seeds damaged by R. piceae.     

Cono- and seminiphagous insects of Abies alba Mill. in the Gorce National Park in Poland during 1996 – 1998

A study was conducted on the insects infesting seeds and cones of Abies alba Mill. in the Gorce National Park, in southern Poland during 1996?–?1998. A total of 856 cones were collected from 66 trees growing at 11 sites located in partially or strictly protected forest reserves. Of this sample, 217 cones with 54,958 seeds were dissected. This study yielded 5,816 specimens of insects, namely: seminiphagous Resseliella piceae Seitn., Megastigmus suspectus Borr. as well as conophagous Earomyia impossibile Morge, Barbara herrichiana Obr. and Dioryctria abietella (Den. et Schiff.). The most abundant species was R. piceae with 4,186 individuals. The index of cone infestation was calculated. It showed great variability between forest reserves and study-years. The numbers of insect individuals, numbers of viable and infertile seeds, and seeds damaged by M. suspectus and R. piceae, in both strict and partial reserves in the consecutive years were compared statistically. The test of significant differences between two frequencies at 0.05 level was used in statistical analysis. In both strict and partial reserves, statistically significant differences were found between studied variables.     

Seed storage behavior of <Emphasis Type="Italic">Knema attenuata</Emphasis>, an endemic species of Western Ghats,India

We performed desiccation and storage trials to better under- stand storage behavior of Knema attenuata seeds. Mature seeds with moisture content (MC) of 31% exhibited 73% germination. During the period of desiccation (open lab condition) seeds with MC 23% showed 40% germination. After further drying to MC 21% germination was reduced to 16%. Complete loss in viability resulted when seed moisture was reduced to 18%. The seeds stored at -10°C, 0°C, 10°C and 28±2°C (open lab condition) lost their viability within 10 days. Seeds stored in sealed polythene bags and moist sand retained viability for more days than did seeds stored under all other storage conditions. Sensitivity of seeds to lower temperature and desiccation suggest that the storage be- havior of K. attenuata seeds is recalcitrant. Seeds stored in moist condi- tions can, at best, be stored for a period of two months.     

Promotion of seed production in Douglas-fir grafts by girdling + gibberellin A4/7 stem injection,and effect of retreatment

Twelve- to 17-year-old Douglas-fir grafts, which in 1985 received no treatment, stem girdles only (G), or girdles plus stem injection of gibberellin A_4/7 (G + GA) at vegetative bud burst, were in 1987 retreated with G + GA or left untreated. Tree were untreated in 1986 and cone production the following year was very sparse. G + GA treatment in 1987 increased the 1988 production of seed cones from 465 to 1600 per tree, with a comparable increase in frequency of grafts producing a heavy crop of pollen cones. However, induction treatments applied in 1985 adversely affected seed- and pollen-cone production in 1988, independent of treatment in 1987. Cone size, total and filled seed per cone, and seed germination were little affected by treatment either year. Treatment with G + GA in 1987 only maximized the production of filled seeds (48 100/tree), although G + GA in both 1985 and 1987 (31 200/tree) was still highly effective relative to no treatment in either year (14 700/tree). The G + GA treatment adversely affected tree condition more severely than previously (or since) experienced, probably as a consequence of grafts also being subjected to prolonged late-summer droughts during each of the treatment years.     

刺玫果的种源选择

刺玫果又称山刺玫,落叶灌木。分布于我国东北、内蒙及华北等省区。刺玫果用途广、价值大,易采收加工,是一种很有开发前途的野生经济植物。通过对吉林省9个主要种源地刺玫果种子性状的研究,发现安图县亮兵乡地区的种子最饱满,含水率适中,易于贮芷,种皮厚度亦居中,发芽时所受机械阻力小。因此,安图县亮兵乡可作为吉林省刺玫果大面积种植的最佳人工生产种源基地。     

Fleshy fruits eating birds and their role in the seed dispersal of plants in Maoer Mountain, NE China

There are 16 species of fleshy-fruit cating birds in Autumn in Maoer Mt. NE China. According to their feeding strategies. we can divide them into 3 groups: 1. Pulp-cating birds, they get nutrition from pulp. so. their seeds are defecated completely. These birds have a great effect on seed dispersal. 2. Seed-cating birds, they obtain nutrition from the seed but pulp. Seeds are digested totally. They don’t disperse seeds at all. 3. Whole-fruit-eating birds, both seed and pulp are digested when passing through gut. They don’t have any effect on seed dispersal either. Supported by NSFC 39370137 (Responsible Editor: Sun Yueqi)     

Effects of fire on germination of Pterocarpus angolensis

Pterocarpus angolensis (Fabaceae) is a leguminous tree species of the miombo region of sub-Saharan Africa that is highly prized for its wood value. We use both experimental exposure to fire, as well as classification of field burned seeds, to predict germination rates in seeds from both husked and unhusked fruits. We find that seed germination and seed persistence in unhusked fruits are maximized by moderate exposure to fire. Germinating seeds had heavier fruit and seeds than those that did not. Finally, seeds without husks persisted in the soil yet continued to germinate even after 18 months in wet soil, indicating potentially long soil longevity. Using these results, we support an intermediate fire exposure model wherein repeated moderate exposure to fire enhances the capability of seeds to emerge from fruits. Seeds from unburned and unhusked fruits were never observed to germinate and had poorer soil longevity than those exposed to moderate fire. Similarly, extreme exposure to fire resulted in poor seed germination rates, often as a consequence of direct fire mortality of seeds. We suggest that early burning resulting in cool fires may augment germination and recruitment in wild populations.     

对球果损失造成油松良种减产的分析

调查了油松种子园、母树林良种减产的原因，主要是由于球果在生长发育过程中的大量损失；而虫害、雌花授粉不良、因缺少水肥造成的落花落果是油松球果损失的主要原因。同时提出了减少球果损失的几点技术措施。     

Morphological and anatomical differences in Aleppo pine seeds from serotinous and non-serotinous cones

Mediterranean communities have been historically conditioned by fire and have therefore developed adaptive traits. Serotiny is a strategy that increases fire resilience by storing seeds in the canopy, protecting them from heat and delaying their dispersion. Aleppo pine is an important serotinous tree species in the low altitude, near-coastal Mediterranean Basin. Differences in serotinous and non-serotinous cones have been detected previously but in order to resolve a gap in the knowledge on seed adaptation to fire, we focused this study on two fire-prone habitats in southern Italy. Several cones were sampled and opened in an oven at two different temperatures in order to group seeds according to provenance and cone type (serotinous or non-serotinous). The sampled seeds were weighed and their coats were removed. Seed size, embryo diameter and nutritive tissue thickness were recorded. We found that seeds with greater weight and size came from the more humid site and from non-serotinous cones. Also, we observed wax and cutine cells formed a thicker seed coat in seeds from the more humid site using a scanning electron microscope. The scanning electron microscopy/energy dispersive X-ray spectroscopy showed higher Si and Ca concentrations in the covers of serotinous seeds. Seeds from different provenance and cone types have anatomic and morphological differences that confer different properties against heating. This knowledge can improve post-fire management and promote restoration tools.     

Germination of <Emphasis Type="Italic">Juniperus procera</Emphasis> seeds in response to stratification and smoke treatments,and detection of insect-damaged seeds with VIS + NIR spectroscopy

Seeds of Juniperus procera collected from five provenances across its geographic range in Ethiopia were subjected to cold-moist stratification at 5°C or 10°C for 6–12 weeks. The effect of aqueous smoke solution in overcoming the light requirement for germination, and the potential of visible (VIS) and near infrared reflectance (NIR) spectroscopy for sorting sound and insect-damaged seeds were also investigated. Highly significant differences in germination were detected among provenances (P < 0.0001) and stratification periods (P < 0.0001), but not between temperature regimes (P=0.111). Seeds from the south and southeast distribution ranges had higher percentage germination after 6 weeks of stratification than seeds collected from north, northwest and central ranges of distribution. The smoke treatment did not affect germination regardless of whether the seeds were exposed to light. Exposure to light increased germination capacity three fold. Sound and damaged seeds were distinguished with 90% accuracy using VIS + NIR spectroscopy. It can be concluded that dormancy in juniper seeds varies with provenances, and cold stratification for 6 weeks alleviates dormancy in some seed lots. Tentatively, smoke treatment seems ineffective in overcoming photo-dormancy in juniper seeds. VIS + NIR spectroscopy has demonstrated a great potential for sorting damaged seeds, thereby upgrading seed lot purity.     

Variable dormancy in seed of Pinus contorta

Seeds of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) collected southwest of Grande Praire, Alberta at three different times and altitudes between August 20, 1984 and August 15, 1985 showed variable responses to stratification. The responses were related to seed ripeness, as judged through evaluations of cone moisture contents, and with the length of time that the cones had remained on the trees. Unripe seeds started to lose germination in the third year after pollination when on the tree. Mature seeds which lost germination by late fall 1984 regained it by the next fall, while most unripe seeds did not. Immature seeds increased their need for stratification over time while mature seeds did not. Seeds should be left on the tree until the end of the third year to insure maximum viability because they do not reach maturity until then.     

Changes in the biochemical composition and enzyme activity during dormancy release of Cyclocarya paliurus seeds

Cyclocarya paliurus is only propagated from seeds which have pronounced dormancy. Overcoming seed dormancy is an important component of efficient and cost-effective seedling production of Cyclocarya paliurus. Changes in biochemical composi-tion and enzyme activity were investigated during dormancy release. The activities of all the studied enzymes in the stratified seeds increased significantly, compared to those in the control samples. Of the enzymes examined, the activities of protease increased the most (413.8%), followed by peroxidase (278.7%), lipase (161.0%), glucose-6-phosphate dehydrognase (149.1%) and amylase (60.6%) after 8 months of stratification. Crude fat and protein constituted the bulk of the storage reserves in mature seeds of C. pali-urus. Compared with the seeds before stratification, about 45% of the starch, 46% of the protein and 11% of the crude fat were de-pleted during dormancy release of C. paliurus seeds, while the soluble sugar content was enhanced by 101.5% in the germinating seeds. Correlation analysis showed, during dormancy release of C. paliurus seeds, a close positive relationship between POD and G6PDH activity as well as soluble sugar content and amylase activity, while there was a significant negative relationship between storage substances and their related enzyme activities.     

Fleshy Fruits Eating Birds and Their Role in the Seed Dispersal of Plants in of Plants in Maoer Mountain,NE China

lntroducti0nMan}'pIantshavFt1eshytYLlitsinALItumnil1teInperatezone.Thesefruit3providefoodtbrmanytYugivorouSbirds.BirdsgetnutritiontYomthetYuits,anddispersetheseedsofthesepIantsatthesametime.Manyre-searchesonthistopicaretinishedinMediterraneanScrubIandsand…     

Variability in permeability and integrity of cell membrane and depletion of food reserves in neem （Azadirachta indica） seeds from trees of different age classes

We quantified cell membrane permeability(electrical conductivityEC,water soluble sugar-WSS,and amino acids-AA)and integrity(phospholipids,α-tocopherol and lipid peroxidation)along with food reserve deterioration(total proteins,total sugar,and total starch)of neem seeds collected from various mother tree age classes and stored for 65days in airtight plastic containers at ambient room temperature(35±5°C).Results show that the activities were higher in fresh seeds(EC267.56-2950.01μS/g,WSS 19.96-19.48 mg/g and AA 5.40-5.35 mg/g)and declined with increasing duration of storage period(EC153.37-195.17μS/g,WSS 3.13-4.17 mg/g and AA 4.29-4.49 mg/g after35 days and EC 144.02-161.56μS/g,WSS 2.06-2.40 mg/g and AA3.98-4.27 mg/g after 65 days of storage).Phospholipids andα-tocopherol were higher in fresh seed(0.073-0.093 OD at 710 nm and0.080-0.105 OD,respectively)and declined as storage duration increased(0.033-0.042 OD at 710 nm and 00.0010-0.0020 OD,respectively).Dead seeds showed reduced amounts of phospholipids and minimum activity ofα-tocopherol(antioxidants).The level of MDA was lower in fresh seeds(0.0066-0.0087 OD at 600-535 nm)and increased as storage duration increased(0.0248-0.0268 OD after 65 days of storage).The higher amount of MDA indicated that seeds died due to rancidity of the oil inside the seed.Neem seed cake was assessed for deterioration of food reserves(total proteins,total sugar,and total starch),concentrations of which were higher in fresh seed and declined as storage duration increased.Germination was higher in fresh seeds and after 65days,no germination was received perhaps due to deterioration of biochemicals in seeds.Patterns of seed deterioration were similar across all seed lots.