scholarly journals Self fertility of pear varieties conditioned by natural self pollination (autogamy)

2000 ◽  
Vol 6 (1) ◽  
Author(s):  
J. Nyéki ◽  
M. Soltész ◽  
J. Iváncsics
Keyword(s):  
Fruit Set ◽  
Experimental Period ◽  
Gene Bank ◽  
Viable Seed ◽  
Ecological Conditions ◽  
Self Pollination ◽  
Seed Content ◽  
Viable Seeds ◽  
Number Of Seeds

Authors studied the autofertility depending on natural self pollination (autogamy) in 59 pear cultivars during 4 seasons at three locations with different ecological conditions (Helvetia, Kecskemet-Kisfai, Keszthely). The aim of the experiments was to determine the autogamous tendencies of varieties hitherto unexplored in the Hungarien gene bank, or to check data found in the literature. A total of 42616 isolated pear flowers produced 1.2% fruits with at least one viable seed in each. The 59 varieties observed did not set fruit by autogamy on either of the three sites during the four years of the study. The triploid (3n=51) varieties were entirely self-sterile. According to the highest autogamous fruit set, during the experimental period, the varieties have been assigned to four groups: (1) Entirely auto-incompatible (0% fruit set), (2) auto-incompatible (0.1 to 0.9%), slightly self fertile (1.1 to 5%) and (4) self fertile (5.1 to 10%). According to the number of viable seeds per fruit resulting from autogamy, the varieties are assigned to three groups as (1) low seed content (less than 3 seeds per fruit), medium (3.1 to 5) and (3) high (more than 5 seeds). Thus, the assessment of the number of seeds per fruit resulting from autogamy is indispensable as a proof of the absence of parthenocarpy.

Hard-seed content of alfalfa grown in Canada

1991 ◽  
Vol 71 (2) ◽  
pp. 437-444 ◽  
Author(s):  
D. T. Fairey ◽  
L. P. Lefkovitch
Keyword(s):  
British Columbia ◽  
Geographic Location ◽  
Viable Seed ◽  
Hard Seed ◽  
Peace River ◽  
Seed Content ◽  
River Region ◽  
Hard Seeds ◽  
Viable Seeds ◽  
Production Areas

The hard-seed content of alfalfa (Medicago spp.) grown in Canada in relation to genotype and geographic location of production was surveyed for the commercial growing regions in Manitoba, Saskatchewan, Alberta and British Columbia. The average hard-seed content of all pedigreed production over a 5-yr period, ranged from 22 to 37% and that in nonpedigreed production was between 14 and 30%. A database of the five widely grown cultivars revealed that the hard-seed content of alfalfa in the most northerly growing areas in the Peace River region of Alberta and British Columbia ranged from 31 to 51%, while hard seed content of alfalfa produced elsewhere varied from 22 to 38%. There was no apparent effect of latitude on the proportion of hard seeds, while there was a small increase for two of the five cultivars in production areas further west. Of particular interest was the trend in viable seed production. There was consistent evidence suggesting that the proportion of viable seeds decreased in production areas further north, but increased in production areas further west. However, the minimum viability was always in excess of 85%. There was no correlation between hard and viable seed. Key words: Medicago spp., alfalfa, lucerne, hard seeds, viable seeds

VIABLE SEED POPULATIONS IN ALBERTA PRAIRIE TOPSOILS

1969 ◽  
Vol 49 (1) ◽  
pp. 75-82 ◽  
Author(s):  
A. Johnston ◽  
S. Smoliak ◽  
P. W. Stringer
Keyword(s):  
Constant Temperature ◽  
Plant Succession ◽  
Viable Seed ◽  
Soil Temperatures ◽  
Viable Seeds ◽  
Number Of Seeds ◽  
Secondary Plant

Naturally disseminated seeds in soil obtained from native and cultivated grass stands were permitted to germinate and grow in pots at different soil temperatures or in greenhouse flats at a constant temperature. There were differences in numbers of seeds of various species germinating at various temperatures, but greatest differences were among sites. Grazing affected number of seeds of a species that germinated, with grasses decreasing and weeds increasing as intensity of grazing increased. Viable seeds ranged in number from 204 to 12,342/m2, Distribution of numbers of seeds in topsoils was skewed, with the mode at 780/m2. The presence of viable seeds of many species on or in the topsoil would, upon its disturbance, assure secondary plant succession.

scholarly journals Trade of commercial potting substrates: A largely overlooked means of the long-distance dispersal of plants

2021 ◽  
Author(s):  
Judit Sonkoly ◽  
Attila Takács ◽  
Attila Molnár V. ◽  
Péter Török
Keyword(s):  
Plant Species ◽  
Large Scale ◽  
Long Distance Dispersal ◽  
Viable Seed ◽  
Long Distance ◽  
Ecological Processes ◽  
Number Of Species ◽  
Seed Content ◽  
Wide Range ◽  
Viable Seeds

AbstractAlthough long-distance dispersal (LDD) events are considered to be rare and highly stochastic, they are disproportionately important and drive several large-scale ecological processes. The realisation of the disproportionate importance of LDD has led to an upsurge in studies of this phenomenon; yet, we still have a very limited understanding of its frequency, extent and consequences. Humanity intentionally spreads a high number of species, but a less obvious issue is that it is associated with the accidental dispersal of other plant species. Although the global trade of potted plants and horticultural substrates is capable of dispersing large quantities of propagules, this issue has hardly been studied from an ecological point of view. We used the seedling emergence method to assess the viable seed content of different types of commercial potting substrates to answer the following questions: (i) In what richness and density do substrates contain viable seeds? (ii) Does the composition of substrates influence their viable seed content? and (iii) Are there common characteristics of the species dispersed this way? We detected altogether 438 seedlings of 66 taxa and found that 1 litre of potting substrate contains an average of 13.27 seeds of 6.24 species, so an average 20-litre bag of substrate contains 265 viable seeds. There was a high variability in the seed content of the substrates, as substrates containing cattle manure contained a substantially higher number of species and seeds than substrates without manure. Based on this, this pathway of LDD is an interplay between endozoochory by grazing livestock and accidental human-vectored dispersal, implying that the diet preference of grazing animals largely determines the ability of a plant species to be dispersed this way. According to our results, potting substrates can disperse large quantities of seeds of a wide range of plant species, moreover, these dispersal events occur on very long distances in almost all cases. We conclude that this kind of human-vectored LDD may have complex effects on plant populations and communities; however, as this dispersal pathway is largely understudied and has hardly been considered as a type of LDD, its consequences are still largely unknown and further studies of the issue are of great importance.

scholarly journals The Study of Pollination and Fruit Set and Determination Suitable Pollinizers for Two Iranian Commercial Apple Cultivars Golab Kohanz and Shafiabadi

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 797D-797
Author(s):  
Alireza Talaie* ◽  
Ahmad Ershadi ◽  
Ali Vezvaei
Keyword(s):  
Fruit Quality ◽  
Fruit Set ◽  
Dry Weight ◽  
Fruit Weight ◽  
Soluble Solids ◽  
Open Pollination ◽  
Self Pollination ◽  
Seed Content ◽  
Pollen Sources ◽  
Apple Cultivars

In order to study pollination and fruit set and determine the best pollinizers for two Iranian apple cultivars, Golab Kohanz and Shafiabadi, experiments were conducted during two years. Different pollen sources including pollen of cultivars Golab Isfahan, Golab Kohanz, Mashhad Nouri, Shafiabadi and also open pollination were used. Pollen sources had significant effects on fruit set, fruit weight, diameter, shape, dry weight, total soluble solids (TSS), sugar and seed contents in cv. Golab Kohanz. Trees pollinated by pollen of Shafiabadi had highest fruit set, fruit weight, diameter, shape, dry weight, TSS., sugar, and seed content. Pollen sources significantly affected fruit set, fruit weight, diameter, shape, and seed content in cv. Shafiabadi. The highest fruit set, fruit weight, diameter, and seed content was resulted from flowers pollinated by Golab Kohanz. Golab Kohanz and Shafiabadi had 3.3% and 0.5% fruit set from self pollination, respectively, and seemed to be completely incompatible. Fruit resulted from self pollination were generally small and of low quality. Regardless to fruits obtained from pollination, different pollen sources had small effects on fruit quality. The results indicated that cvs. Shafiabadi and Mashad Nouri are the best pollinizers for Golab Kohanz and Golab Kohanz was superior pollinizers for Shafiabadi.

scholarly journals Effect of intensity of bee visitation and the foraging behaviour of honeybees on the fruit set and yield of apple (Malus domestica Borkh.)

2005 ◽  
Vol 11 (1) ◽  
Author(s):  
K. Finta ◽  
P. Benedek
Keyword(s):  
Fruit Set ◽  
Extreme Values ◽  
Point Of View ◽  
Statistical Point ◽  
Seed Content ◽  
Pollinating Insects ◽  
Apple Cultivars ◽  
Viable Seeds ◽  
Flower Visiting ◽  
Effective Intensity

Based on the results of our experiments, both the relative and the effective intensity of bee visitation were rather different depending on the cultivars as well as the time of the day. While it varied between relatively extreme values (40-80%) in the morning for the varieties examined, there were much smaller differences between the intensity of bee visitation at the afternoon, because the relative bee visitation attained 70-90% at each cultivar. These results showed that the differences arising from intensity of bee visitation of different cultivars should be taken into consideration more carefully in the morning in orchard planning and in estimating the number of honeybee colonies required. The results showed that the greatest percentage of fruit set and the highest number of viable seeds per fruit were measured on branches of those cultivars that were most frequently visited by pure pollen gatherer bees as well as by bees collecting both nectar and pollen (mixed behaviour). The effect of pure pollen gatherers and of bees with mixed behaviour was highly significant from the statistical point of view on the fruit set and the number of viable seeds per fruit. Those bees that were sucking nectar only from apple flowers did not proved to be effective pollinators at all. Relationship between their number and the fruit set as well as the number of viable seed per fruit were not significant because the coefficient of correlation was close to nil. The ratio of side worker nectar gatherers was negatively correlated with the fruit set and the seed content of fruits of apple cultivars examined at both of our experimental sites, at Mosonmagyaróvár and Feketeerdő as well. The presence of side worker nectar gatherers resulted in higher decrease of fruit set and seed content of fruits at Feketeerd6 than at Mosonmagyaróvár, especially in the morning. The effect of flower visiting intensity by other pollinating insects was found to be fairly variable according to the time of the day. In the morning they had no effect on the fruit set as well as on the seed content of fruits either at Mosonmagyaróvár or at Feketeerdo. However, at the afternoon, when their intensity was greater, the correlation was a bit stronger.

The viable seed content of some forest soil in coastal British Columbia

1970 ◽  
Vol 48 (7) ◽  
pp. 1383-1385 ◽  
Author(s):  
M. C. Kellman
Keyword(s):  
British Columbia ◽  
Forest Soil ◽  
Surface Soil ◽  
Coniferous Forest ◽  
Alnus Rubra ◽  
Viable Seed ◽  
Seed Content ◽  
Viable Seeds ◽  
Coastal British Columbia

The upper 10 cm of surface soil and litter beneath a coniferous forest in coastal British Columbia was found to contain over 1000 viable seeds per square meter. Alnus rubra Bong. made up 68.9% of all viable seed, although 18 other species, mainly weedy and secondary types, were recorded.

scholarly journals Measurement of inbreeding depression in Rhododendron kaempferi: seed production, germination, juvenile survival, and growth

Botany ◽  
2021 ◽  
Author(s):  
Keigo Takahashi ◽  
Takao Itino
Keyword(s):  
Inbreeding Depression ◽  
Germination Rate ◽  
Self Pollination ◽  
Hand Pollination ◽  
Survival And Growth ◽  
Selection For ◽  
Bombus Ardens ◽  
Viable Seeds ◽  
Very High ◽  
Number Of Seeds

To understand the reproductive ecology of a plant species with both selfing and outcrossing reproductive systems, it is important to know how selfed individuals contribute to the maintenance of a population. Further, examination of the magnitude of inbreeding depression after pollination is essential for accurate measurement of reproductive success. In this study, we investigated the characteristics of viable seeds and seedlings of Rhododendron kaempferi in a region where the bumblebee pollinator Bombus ardens are abundant. In a hand-pollination experiment, the fruit set from self-pollination was 32%, significantly lower than that from outcross-pollination (81%). The number of seeds per fruit from self-pollination was one sixth the number from outcross-pollination. However, the number of seeds per fruit was negatively correlated with the weight per seed. In addition, the germination rate was low when the seed weight was light. Although selfed seeds could germinate, 89% of the seedlings died within a year. The inbreeding depression coefficient 1 year after sowing was very high (0.89). These results indicate that R. kaempferi shows extremely strong selection for outcrossing but maintains a slight selfing potential in a natural population in central Japan.

scholarly journals Pollinator Contribution to the Production of Cowpea in the Amazon

HortScience ◽  
1998 ◽  
Vol 33 (7) ◽  
pp. 1157-1159 ◽  
Author(s):  
Carlos G. Vaz ◽  
Domingos de Oliveira ◽  
Orlando S. Ohashi
Keyword(s):  
Experimental Design ◽  
Vigna Unguiculata ◽  
Fruit Set ◽  
Open Pollination ◽  
Cross Pollination ◽  
Self Pollination ◽  
Complementary Role ◽  
Pollinating Insects ◽  
The Mean ◽  
Number Of Seeds

Cowpea, Vigna unguiculata (L.) Walp., is a very important legume in the diet of the population of the Amazon. Although it is autogamous, this species has a cross-pollination rate of ≈10%. Over several years, the mean productivity of cowpea has declined. We suggest that this is linked to a decrease in or an absence of pollinating insects in the fields. The objective of this study is to ascertain the pollinator contribution to cowpea production, as well as to determine the pollination type of the `BR3-Tracuateua' cultivar. In an experimental design, four treatments were compared: no pollination, with flowers in cages to prevent insect visits; open-pollination, with flowers exposed to all visiting insects; self-pollination, with flowers pollinated with their own pollen; and cross-pollination, with emasculated flowers being pollinated manually with pollen from another plant. We observed higher fruit set in the presence of pollinators (83%) than in their absence (77%, caged flowers). However, cross-pollination reduced both the number of seeds per pod and fruit set relative to self-pollination. This result suggests that pollinators have a complementary role in the yield of cowpea, by creating a mixed pollination system where self-pollination dominates.

scholarly journals A comparative study on the reproductive success of two rewarding Habenaria species (Orchidaceae) occurring in roadside verge habitats

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Wenliu Zhang ◽  
Jiangyun Gao
Keyword(s):  
Reproductive Success ◽  
Fruit Set ◽  
Plant Density ◽  
Flowering Plant ◽  
Floral Display ◽  
Pollinator Behaviour ◽  
Factors Affecting ◽  
Nectar Sugar ◽  
Viable Seeds ◽  
Viable Embryo

Abstract Background Most orchid species have been shown to be severely pollination limited, and the factors affecting reproductive success have been widely studied. However, the factors determining the reproductive success vary from species to species. Habenaria species typically produce nectar but exhibit variable fruit set and reproductive success among species. Here, we investigated the influence of the flowering plant density, inflorescence size, breeding system, and pollinator behaviour on the reproductive success of two rewarding Habenaria species. Results Our observations indicated that Habenaria limprichtii and H. petelotii co-occur in roadside verge habitats and present overlapping flowering periods. Both species were pollination limited, although H. limprichtii produced more fruits than H. petelotii under natural conditions during the 3-year investigation. H. petelotii individuals formed distinct patches along roadsides, while nearly all H. limprichtii individuals clustered together. The bigger floral display and higher nectar sugar concentration in H. limprichtii resulted in increased attraction and visits from pollinators. Three species of effective moths pollinated for H. limprichtii, while Thinopteryx delectans (Geometridae) was the exclusive pollinator of H. petelotii. The percentage of viable seeds was significantly lower for hand geitonogamy than for hand cross-pollination in both species. However, H. limprichtii may often be geitonogamously pollinated based on the behaviours of the pollinators and viable embryo assessment. Conclusions In anthropogenic interference habitats, the behaviours and abundance of pollinators influence the fruit set of the two studied species. The different pollinator assemblages in H. limprichtii can alleviate pollinator specificity and ensure reproductive success, whereas the more viable embryos of natural fruit seeds in H. petelotii suggested reducing geitonogamy by pollinators in the field. Our results indicate that a quantity-quality trade-off must occur between species with different breeding strategies so that they can fully exploit the existing given resources.

The importance of recruitment patterns versus reproductive output in the persistence of a short-range endemic shrub in a highly fragmented landscape of south-western Australia

2012 ◽  
Vol 60 (7) ◽  
pp. 643 ◽  
Author(s):  
Neil Gibson ◽  
Colin Yates ◽  
Margaret Byrne ◽  
Margaret Langley ◽  
Rujiporn Thavornkanlapachai
Keyword(s):  
Short Range ◽  
Reproductive Output ◽  
Fruit Set ◽  
Seedling Recruitment ◽  
Fragment Size ◽  
Fragmented Landscape ◽  
Recruitment Failure ◽  
Degree Of Isolation ◽  
Number Of Seeds ◽  
Significant Mortality

Calothamnus quadrifidus subsp. teretifolius A.S.George & N.Gibson is a short-range endemic shrub whose habitat has been greatly reduced by clearing for agriculture. Reproductive output was high in all populations sampled, although there were large differences among populations in fruit set, the number of seeds per fruit and seed germination. These traits showed no relationship to population size, degree of isolation, or fragment size, which contrasts strongly with the patterns found in a widespread congener. Demographic studies in remnants with an intact understorey showed stable adult populations with continuous seedling recruitment. In contrast, there was consistent widespread failure of seedling and juvenile recruitment in degraded roadside remnants that also showed significant mortality of reproductive adults. In these degraded remnants, recruitment failure appears to be the primary cause of species decline.

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