scholarly journals Heterodichogamy, Pollen Viability, and Seed Set in a Population of Polyploidy Cyclocarya Paliurus (Batal) Iljinskaja (Juglandaceae)

Forests ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 347 ◽  
Author(s):  
Xia Mao ◽  
Xiang-Xiang Fu ◽  
Peng Huang ◽  
Xiao-Ling Chen ◽  
Yin-Quan Qu
Keyword(s):  
Seed Set ◽  
Pollen Viability ◽  
Pollen Dispersal ◽  
Natural Populations ◽  
Flowering Phenology ◽  
Cyclocarya Paliurus ◽  
Medicinal Value ◽  
Juvenile Population ◽  
Pollen Density ◽  
The Individual

Research Highlights: Cyclocarya paliurus, native to the subtropical region of China, is a monoecious species with a heterodichogamous mating system. Its flowering phenology and low seed success characteristics differ from other typical heterodichogamous Juglandaceae species. This could be caused by the existence of polyploidy in the population. Background and Objectives: C. paliurus has been attracting more attention as a result of its medicinal value. To meet the needs for leaf harvest, cultivation expansion is required, but this is limited by a shortage of seeds. This study aims to profile the flowering phenology and the efficacy of pollen dispersal as well as elucidate on the mechanism of low seed success in the population. Materials and Methods: The flowering phenology pattern of C. paliurus was observed in a juvenile plantation containing 835 individuals of 53 families from 8 provenances at the individual (protandry, PA and protogyny, PG) and population levels for 5 consecutive years (2014–2018). Slides with a culture medium of 10% sucrose and 0.01% boric acid were used to estimate pollen density and viability in the population, and seeds were collected from 20 randomly selected PA and PG individuals to assess seed success during 2017–2018. Results: Four flowering phenotypes and strongly skewed ratios of PA/PG and male/female occurred in the juvenile population. Sexual type and ratio changed significantly with the growth of the population over the years, showing an increasing monoecious group (11.1% to 57.2%) and a decreasing unisexual group (33.6% to 16.3%), as well as a tendency for the sexual ratio to move towards equilibrium (5.42:1 to 1.39:1 for PG:PA). Two flowering phases and bimodality in gender were displayed, as in other heterodichogamous species. However, the high overlap of inter-phases and within individuals was quite different from many previous reports. Owing to the low pollen viability of C. paliurus (~30%), low seed success was monitored in the plantation, as well as in the investigated natural populations. Conclusions: Female-bias (PG and F) and a skewed ratio of mating types corresponded to nutrient accumulation in the juvenile population. Heterodichogamy in C. paliurus was verified, but was shown to be different from other documented species in Juglandaceae. The latest finding of major tetraploidy in a natural population could explain the characteristics of the flowering phenology and seed set of C. paliurus and also give rise to more questions to be answered.

Observations on Natural Pollination in Commercial Plantings of Oil Palm (Elaeis Guineensis) in Malaya

1967 ◽  
Vol 3 (2) ◽  
pp. 105-116 ◽  
Author(s):  
J. J. Hardon ◽  
P. D. Turner
Keyword(s):  
Oil Palm ◽  
Elaeis Guineensis ◽  
Pollen Viability ◽  
Pollen Dispersal ◽  
Early Morning ◽  
Total Rainfall ◽  
Atmospheric Pollen ◽  
Natural Pollination ◽  
Pollen Density ◽  
Days After Anthesis

SummaryMost oil palm pollen is produced by male inflorescences 2–3 days after anthesis, and this pollen is the most viable. When protected, pollen viability on female inflorescences is good up to 6 days, after which it declines. The majority of the pollen remains below the canopy, especially at bunch level. Results of quantitative evaluation of pollen dispersal showed that atmospheric pollen density is very variable and is governed by numerous factors. There is a marked diurnal variation, with highest pollen density during the afternoon and a negligible amount during the night and early morning. Rain causes an immediate drop in concentration, but pollen densities were influenced more by the number of days on which rain was recorded than by total rainfall. A relationship exists between pollen density, the number of male inflorescences in the vicinity, and rainfall, but the effects of relative humidity, sunshine and wind are obscure. Whilst pollen density drops rapidly within a short distance from the inflorescence, there is a significant dispersal over greater distances than previously thought.

scholarly journals Does vegetation impact on the population dynamics and male function in Anemone sylvestris L. (Ranunculaceae)? A case study in three natural populations of xerothermic grasslands

2015 ◽  
Vol 84 (2) ◽  
pp. 197-205 ◽  
Author(s):  
Bożena Denisow ◽  
Małgorzata Wrzesień
Keyword(s):  
Seed Set ◽  
Pollen Viability ◽  
Natural Populations ◽  
Anthropogenic Pressure ◽  
Male Function ◽  
Se Poland ◽  
Successful Recovery ◽  
Increased Risk ◽  
Brachypodium Pinnatum ◽  
Vegetation Impact

In Poland, like in other parts of Central Europe, dry grasslands significantly contribute to the biodiversity of both fauna and flora. Anthropogenic pressure impair many species of xerothermic habitats, and several populations face an increased risk of extinction. The goal of the study was to define factors that may affect the size of wild populations of <em>Anemone sylvestris</em> L., a protected species in Poland, with both a short- and long-term perspective, and to examine the influence of vegetation changes on the density, the abundance of flowering and male function (pollen production, pollen viability), as well as seed set. In situ observations were performed in 2005–2006 and 2011–2012 in three populations located on the Lublin Upland, SE Poland. The reduction in population density and <em>A. sylvestris</em> blooming was exacerbated by the expansion of the shrubs, but not by <em>Brachypodium pinnatum</em>. Male characteristics of <em>A. sylvestris</em>, i.e. pollen amount per multi-staminate flowers or pollen viability appeared to decrease under pressure of shrub competition. Populations with limitation of male function had impaired degree of seed set. Various consequences for the functioning of populations within a metapopulation system can be expected due to substantial qualitative and quantitative disorders in pollen traits. It is crucial that successful recovery programs for <em>A. sylvestris</em> primary should aim to conserve and manage the habitat.

Study on floral traits and seed setting in parental lines of hybrid rice during early ahu and kharif seasons

2018 ◽  
Vol 78 (3) ◽  
Author(s):  
Aradhana Phukan ◽  
P. K. Barua ◽  
D. Sarma ◽  
S. D. Deka
Keyword(s):  
Seed Set ◽  
Flag Leaf ◽  
Pollen Dispersal ◽  
Pollen Sterility ◽  
Leaf Length ◽  
Floral Traits ◽  
Opening Angle ◽  
Leaf Angle ◽  
Seed Setting ◽  
Parental Lines

Two CMS lines, IR 58025A and IR 68888A along with their maintainers and two fertility restorers, LuitR and IR 36R, were evaluated for flower and plant characters during early ahu (February-June) and kharif (July-November) seasons. IR 58025A showed longer stigmata and styles, and higher spikelet Length/Breadth (L/B) ratio while IR 68888A showed broader stigmata and wider glume opening angle in both the seasons. IR 68888A also exhibited higher pollen sterility during early ahu. IR 36R was characterized with broad anthers. LuitR showed longer and broader anthers with more pollen than others. Plant height, flag leaf length, flag leaf width and area were higher in IR 36R. Panicle exsertion was complete in pollen parents whereas it was 78-80% in CMS lines. The widest flag leaf angle was found in IR 58025B during early Ahu and in IR 36R during kharif. Kharif season was more favourable for growth of the plants with higher seed set percentage while floral traits of the CMS lines were better expressed in early Ahu. Manipulation of the seeding sequence of the parental lines in early Ahu is warranted for better seed set provided the seed crop escapes heavy premonsoon showers during reproductive stage. IR 68888A/LuitR was a good combination for pollen dispersal and seed setting.

scholarly journals Flowering Phenology Adjustment and Flower Longevity in a South American Alpine Species

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 461
Author(s):  
Mary T. K. Arroyo ◽  
Ítalo Tamburrino ◽  
Patricio Pliscoff ◽  
Valeria Robles ◽  
Maria Colldecarrera ◽  
...  
Keyword(s):  
Natural Populations ◽  
Flowering Phenology ◽  
Snow Accumulation ◽  
Growth Potential ◽  
Controlled Study ◽  
Temperature Threshold ◽  
Flower Longevity ◽  
Passive Warming ◽  
Alpine Species ◽  
Flowering Onset

Delayed flowering due to later snowmelt and colder temperatures at higher elevations in the alpine are expected to lead to flowering phenological adjustment to prevent decoupling of peak flowering from the warmest time of the year, thereby favoring pollination. However, even if flowering is brought forward in the season at higher elevations, an elevational temperature gap is likely to remain between the high- and low-elevation populations of a species at the time these reach peak flowering on account of the atmospheric reduction in temperature with increasing elevation. The negative effect of this temperature gap on pollination could be compensated by plastically-prolonged flower life spans at higher elevations, increasing the probability of pollination. In a tightly temperature-controlled study, the flowering phenology adjustment and flower longevity compensation hypotheses were investigated in an alpine species in the Andes of central Chile. The snow free period varied from 7 to 8.2 months over 810 m elevation. Temperatures were suitable for growth on 82–98% of the snow free days. Flowering onset was temporally displaced at the rate of 4.6 d per 100 m increase in elevation and flowering was more synchronous at higher elevations. Flowering phenology was adjusted over elevation. The latter was manifest in thermal sums tending to decrease with elevation for population flowering onset, 50% flowering, and peak flowering when the lower thermal limit for growth (TBASE) was held constant over elevation. For TBASE graded over elevation so as to reflect the growing season temperature decline, thermal sums did not vary with elevation, opening the door to a possible elevational decline in the thermal temperature threshold for growth. Potential flower longevity was reduced by passive warming and was more prolonged in natural populations when temperatures were lower, indicating a plastic trait. Pollination rates, as evaluated with the Relative Pollination Rate index (RPR), when weighted for differences in floral abundance over the flowering season, declined with elevation as did fruit set. Contrary to expectation, the life-spans of flowers at higher elevations were not more prolonged and failed to compensate for the elevational decrease in pollination rates. Although strong evidence for phenological adjustment was forthcoming, flower longevity compensation did not occur over Oxalis squamata’s elevational range. Thus, flower longevity compensation is not applicable in all alpine species. Comparison with work conducted several decades ago on the same species in the same area provides valuable clues regarding the effects of climate change on flowering phenology and fitness in the central Chilean alpine where temperatures have been increasing and winter snow accumulation has been declining.

Spikelet fertility and heat shock transcription factor (Hsf) gene responses to heat stress in tolerant and susceptible rice (Oryza sativa L.) genotypes

2019 ◽  
Vol 157 (04) ◽  
pp. 283-299 ◽  
Author(s):  
C. Malumpong ◽  
S. Cheabu ◽  
C. Mongkolsiriwatana ◽  
W. Detpittayanan ◽  
A. Vanavichit
Keyword(s):  
Heat Stress ◽  
Pollen Germination ◽  
Seed Set ◽  
Oryza Sativa L ◽  
Flag Leaf ◽  
Pollen Viability ◽  
Spikelet Fertility ◽  
Anther Dehiscence ◽  
Spikelet Sterility ◽  
Plant Parts

AbstractThe reproductive stage of rice is the most sensitive to heat stress, which can lead to spikelet sterility. Thus, heat-tolerant and heat-susceptible genotypes were used to investigate their differences in terms of phenotypic responses and expression changes of Hsf genes at the pre-flowering stage under heat stress. Results clearly showed that panicles had the highest temperature compared with other plant parts under both natural and heated conditions. However, the temperatures of tolerant and susceptible genotypes were not significantly different. In terms of spikelet fertility, the tolerant lines M9962 and M7988 had high seed set because their anther dehiscence, pollen viability and pollen germination were only slightly affected. In contrast, the susceptible line Sinlek showed severe effects at all steps of fertilization, and the pollen viability of M7766 was slightly affected under heat stress but was more affected in terms of anther dehiscence and pollen germination. Both susceptible lines showed dramatically decreased seed set. In addition, the expression of six HsfA genes in the flag leaves and spikelets at the R2 stage of plants under heat stress showed different responses. Notably, expression of the HsfA2a gene was predominantly upregulated in the flag leaf and spikelets under heat stress in M9962. Therefore, it can be concluded that heat stress has severe effects on the stamen, and that different genotypes have different susceptibilities to heat stress.

scholarly journals A Circular Chloroplast Genome of Fagus sylvatica Reveals High Conservation between Two Individuals from Germany and One Individual from Poland and an Alternate Direction of the Small Single-Copy Region

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 180
Author(s):  
Bagdevi Mishra ◽  
Bartosz Ulaszewski ◽  
Sebastian Ploch ◽  
Jaroslaw Burczyk ◽  
Marco Thines
Keyword(s):  
Chloroplast Genome ◽  
Fagus Sylvatica ◽  
Pollen Dispersal ◽  
European Beech ◽  
Single Copy ◽  
Migration History ◽  
Chloroplast Genomes ◽  
Long Read ◽  
The Individual ◽  
Small Single Copy

Chloroplasts are difficult to assemble because of the presence of large inverted repeats. At the same time, correct assemblies are important, as chloroplast loci are frequently used for biogeography and population genetics studies. In an attempt to elucidate the orientation of the single-copy regions and to find suitable loci for chloroplast single nucleotide polymorphism (SNP)-based studies, circular chloroplast sequences for the ultra-centenary reference individual of European Beech (Fagus sylvatica), Bhaga, and an additional Polish individual (named Jamy) was obtained based on hybrid assemblies. The chloroplast genome of Bhaga was 158,458 bp, and that of Jamy was 158,462 bp long. Using long-read mapping on the configuration inferred in this study and the one suggested in a previous study, we found an inverted orientation of the small single-copy region. The chloroplast genome of Bhaga and of the individual from Poland both have only two mismatches as well as three and two indels as compared to the previously published genome, respectively. The low divergence suggests low seed dispersal but high pollen dispersal. However, once chloroplast genomes become available from Pleistocene refugia, where a high degree of variation has been reported, they might prove useful for tracing the migration history of Fagus sylvatica in the Holocene.

Spatial genetic substructure within natural populations of jack pine (Pinus banksiana)

1991 ◽  
Vol 69 (3) ◽  
pp. 547-551 ◽  
Author(s):  
Chang Yi Xie ◽  
Peggy Knowles
Keyword(s):  
Spatial Autocorrelation ◽  
Pinus Banksiana ◽  
Pollen Dispersal ◽  
Natural Populations ◽  
Jack Pine ◽  
Spatial Autocorrelation Analysis ◽  
Autocorrelation Analysis ◽  
Long Distance ◽  
Genetic Substructure ◽  
Good Agreement

Spatial autocorrelation analysis was used to investigate the geographic distribution of allozyme genotypes within three natural populations of jack pine (Pinus banksiana Lamb.). Results indicate that genetic substructuring within these populations is very weak and the extent differs among populations. These results are in good agreement with those inferred from mating-system studies. Factors such as the species' predominantly outbreeding system, high mortality of selfs and inbreds prior to reproduction, long-distance pollen dispersal, and the absence of strong microhabitat selection may be responsible for the observed weak genetic substructuring. Key words: jack pine, Pinus banksiana, genetic substructure, allozyme, spatial autocorrelation analysis.

Optimization of chromosome doubling treatment for efficient in vivo doubled haploid production in maize

2021 ◽  
pp. 1-10
Author(s):  
Sourbh Kumar ◽  
Uttam Chandel ◽  
Satish Kumar Guleria
Keyword(s):  
Doubled Haploid ◽  
Seed Set ◽  
Chromosome Doubling ◽  
Pollen Viability ◽  
Haploid Inducer ◽  
Haploid Production ◽  
Maize Genotypes ◽  
Different Doses

Abstract An investigation to optimize the protocol for application of colchicine for enhancing the doubled haploid production in maize was done. 106 maize genotypes were used as maternal parents, whereas, pollen source involved tropically adopted haploid inducer (TAIL P1 and TAIL hybrid). After the elimination of chromosomes of inducer lines, haploid seeds were obtained from the crosses. Haploid seedlings were treated with three different doses, such as 0.04, 0.06 and 0.08 per cent of colchicines for different durations (8, 12 and 15 hours). The response of various colchicine concentrations applied for different time durations revealed significant differences at P ≤ 0.05 for various parameters viz., per cent plants survivability, stalk colour, the fertility of tassel, silk present/absent, pollen viability, seed set and per cent doubled haploid formation. In maize, colchicine doses of 0.04 per cent for 12 hours and 0.06 per cent for 8 hours, respectively were established as optimum for enhanced doubled haploid production. But among these two, 0.04 per cent for 12 hours was observed to be best dose for doubled haploid production in maize.

Effect of potato spindle tuber viroid on sexual reproduction and viroid transmission in true potato seed

1986 ◽  
Vol 64 (2) ◽  
pp. 336-340 ◽  
Author(s):  
M. E. Grasmick ◽  
S. A. Slack
Keyword(s):  
Fruit Development ◽  
Seed Weight ◽  
Seed Set ◽  
Transmission Rate ◽  
Pollen Viability ◽  
Polyacrylamide Gel Electrophoresis ◽  
Potato Spindle Tuber Viroid ◽  
Potato Seed ◽  
True Potato Seed ◽  
Viroid Infection

The effect of potato spindle tuber viroid infection on pollen viability, fruit-set, botanical seed set, seed weight, and seed germination in potatoes was determined. Pollen collected from the infected cultivar 'Monona' was less viable than pollen collected from healthy plants. Pollen collected from infected plants reduced seed set significantly but did not reduce fruit development or seed set in all cultivars tested. For some cultivars, infected maternal plants increased the frequency of fruit development and seed weight compared with healthy controls. True potato seed from viroid-infected 'Katahdin' × 'Superior' crosses germinated at a higher rate than did seed from comparable uninfected parents. Progeny from viroid-infected parents that exhibited potato spindle tuber viroidlike symptoms did not always test positive for potato spindle tuber viroid by bioassay or polyacrylamide gel electrophoresis tests. Efficiency of potato spindle tuber viroid detection by bioassay was highest for seedlings 2 weeks after imbibition. Potato spindle tuber viroid was detected in 100% of the progeny tested after true potato seed was stored at 4 °C for 12 years. Tests on selfed true potato seed from the viroid-infected cultivar 'Monona' demonstrated a transmission rate of 100% after subinoculation of initial bioassay plants.

scholarly journals Individual growth of Heleobia piscium in natural populations (Gastropoda: Cochliopidae) from the multiple use natural Reserve Isla Martin Garcia, Buenos Aires, Argentina

2008 ◽  
Vol 68 (3) ◽  
pp. 617-621 ◽  
Author(s):  
SM. Martin
Keyword(s):  
Buenos Aires ◽  
Natural Populations ◽  
Dynamic Structure ◽  
Reproductive Period ◽  
Individual Growth ◽  
Growth Equation ◽  
Multiple Use ◽  
Natural Reserve ◽  
Drainage Channels ◽  
The Individual

The present work analyses the individual growth of Heleobia piscium in natural conditions in coastal drainage channels of the Multiple Use Natural Reserve Isla Martín García, Buenos Aires, Argentina. Isla Martín García is located in the Upper Río de la Plata, to the south of the mouth of the Uruguay river (34° 11' 25" S and 58° 15' 38" W). Monthly collections were made from July 2005 to July 2006 in the eastern part of the island (Arena Beach). The population of H. piscium showed a complex and dynamic structure of sizes during a long period of the annual cycle. Two cohorts could be detected. The Bertalanffy growth equation was: Lt = 6 (1-e -1.85 (t+0.38)) and Lt = 3.9 (1-e -0.19 (t+4.84)) for cohorts 1 and 2, respectively. The pattern of population growth displayed a staggered model, where the greatest growth is observed during the summer. The reproductive period occurred during six months, from the beginning of summer to middle of fall. Based on only one reproductive effort, this pattern is not similar to that of other cogeneric species already studied.

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