Sexual reproduction of Engelmann spruce (Picea engelmannii)

1981 ◽  
Vol 59 (5) ◽  
pp. 793-810 ◽  
Author(s):  
Hardev Singh ◽  
John N. Owens
Keyword(s):  
Sexual Reproduction ◽  
Female Gametophyte ◽  
Developmental Stages ◽  
Young Female ◽  
Picea Engelmannii ◽  
Spongy Tissue ◽  
Cell Stage ◽  
Engelmann Spruce ◽  
Lower Elevation ◽  
Mother Cells

The anatomy and phenology of sexual reproduction of Picea engelmannii Parry from three sites near Prince George, B.C., has been described. The developmental stages at the higher elevation and consequently colder site lagged by 1–2 weeks compared with the lower elevation sites. Pollen mother cells underwent meiosis in mid-May and the five-celled pollen was shed from the end of June to the 1st week of July. The ovules went through the winter rest in the megaspore mother cell stage. The latter underwent meiosis in mid-May to form linear tetrads. The integument was initiated in the postdormancy stages and developed two micropylar prongs which seem characteristic of the genus. The nucellus showed a massive nucellar cap and a pollen chamber formed by the degeneration of cells. The young female gametophyte was surrounded by a spongy tissue which persisted at the chalazal end where the megaspore wall was thickest. The female gametophyte usually bore two archegonia which were fertilised in mid-July (3 weeks after pollination). The embryo developed over the next 3 months. Two main factors which contribute to ovule abortion are failure of pollination and degeneration of embryo during early development.

scholarly journals Identification and evaluation of the novel genes for transcript normalization during female gametophyte development in sugarcane

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12298
Author(s):  
Maokai Yan ◽  
Xingyue Jin ◽  
Yanhui Liu ◽  
Huihuang Chen ◽  
Tao Ye ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sexual Reproduction ◽  
Reference Genes ◽  
Female Gametophyte ◽  
Developmental Stages ◽  
Reproductive Organs ◽  
The Novel ◽  
Biofuel Feedstock ◽  
Gametophyte Development ◽  
Female Gametophyte Development

Background Sugarcane (Saccharum spontaneum L.), the major sugar and biofuel feedstock crop, is cultivated mainly by vegetative propagation worldwide due to the infertility of female reproductive organs resulting in the reduction of quality and output of sugar. Deciphering the gene expression profile during ovule development will improve our understanding of the complications underlying sexual reproduction in sugarcane. Optimal reference genes are essential for elucidating the expression pattern of a given gene by quantitative real-time PCR (qRT-PCR). Method In this study, based on transcriptome data obtained from sugarcane ovule, eighteen candidate reference genes were identified, cloned, and their expression levels were evaluated across five developmental stages ovule (AC, MMC, Meiosis, Mitosis, and Mature). Results Our results indicated that FAB2 and MOR1 were the most stably expressed genes during sugarcane female gametophyte development. Moreover, two genes, cell cycle-related genes REC8 and CDK, were selected, and their feasibility was validated. This study provides important insights into the female gametophyte development of sugarcane and reports novel reference genes for gene expression research on sugarcane sexual reproduction.

Sexual reproduction of Sitka spruce (Picea sitchensis)

1980 ◽  
Vol 58 (8) ◽  
pp. 886-901 ◽  
Author(s):  
John N. Owens ◽  
Marje Molder
Keyword(s):  
Sexual Reproduction ◽  
Female Gametophyte ◽  
Seed Set ◽  
Mature Female ◽  
Picea Sitchensis ◽  
Contributing Factors ◽  
Embryo Abortion ◽  
Male And Female ◽  
Cell Divisions ◽  
Mother Cells

The phenology of sexual reproduction of Picea sitchensis (Bong.) Carr. was similar at the three sites on Vancouver Island, British Columbia, used in the study. As indicated by cell divisions, cone buds ended dormancy in early March, 2 weeks before dormancy ended in vegetative buds. Pollen mother cells underwent meiosis in mid-March and mature, saccate, four- or five-celled pollen was formed by late April. Megaspore mother cells underwent meiosis in late March and mature female gametophytes were developed by late May. Pollination occurred in late April. A pollination drop was produced by the nucellus and exuded between the two micropylar arms and pollen was drawn down into a nucellar depression where pollen germinated in late April. Fertilization occurred in early June and early stages of embryo development occurred by late June, 9 weeks after pollination. Cotyledons were initiated in late July and seed was mature by mid-August and shed during the early fall.Development of male and female gametophytes and embryos was similar to patterns shown for other species of Picea. In this study seed set was very poor and resulted primarily from a lack of pollination. Other contributing factors were female gametophyte abortion before fertilization, embryo abortion during early development, and insect damage.

Comparison of Terpene Composition in Engelmann Spruce (Picea engelmannii) Using Hydrodistillation, SPME and PLE

2004 ◽  
Vol 59 (9-10) ◽  
pp. 641-648 ◽  
Author(s):  
Marek Mardarowicz ◽  
Dorota Wianowska ◽  
Andrzej L. Dawidowicz ◽  
Ryszard Sawicki
Keyword(s):  
Essential Oils ◽  
Steam Distillation ◽  
Solid Phase ◽  
Picea Engelmannii ◽  
Enzymatic Reactions ◽  
Plant Materials ◽  
Engelmann Spruce ◽  
Pressurised Liquid Extraction ◽  
Conifer Trees ◽  
Spruce Needles

Abstract Terpenes emitted by conifer trees are generally determined by analysing plant extracts or essential oils, prepared from foliage and cones using steam distillation. The application of these procedures limits experiments to cut plant materials. Recently headspace techniques have been adopted to examine terpene emission by living plants. This paper deals with the application of solid-phase micro-extraction (SPME) for the analysis of terpenes emitted by conifers foliage of Engelmann spruce (Picea engelmannii), including its seedlings. The compositions of SPME extracts obtained for destroyed and non-destroyed old and juvenile spruce needles were compared with the compositions of essential oils and pressurised liquid extraction (PLE) extracts corresponding to the same plant materials. No substantial differences have been found in the qualitative terpene composition estimated by analysing essential oil and PLE and SPME extracts from non-destroyed old and juvenile foliage. The disintegration of spruce needles results in the formation of a significant amount of myrcene in the case of the old conifer foliage and non-terpenoic compounds in the case of juvenile conifer foliage. This phenomenon can be attributed to enzymatic reactions occurring in the destroyed plant cells.

Factors influencing understory seedling establishment of Engelmann spruce (Picea engelmannii) and subalpine fir (Abies lasiocarpa) in southeast Wyoming

1982 ◽  
Vol 60 (12) ◽  
pp. 2753-2761 ◽  
Author(s):  
Alan K. Knapp ◽  
William K. Smith
Keyword(s):  
Seedling Establishment ◽  
Rocky Mountain ◽  
Field Measurements ◽  
Incident Radiation ◽  
Picea Engelmannii ◽  
Abies Lasiocarpa ◽  
Northern Rocky Mountains ◽  
Medicine Bow Mountains ◽  
Engelmann Spruce ◽  
Surface Drying

Although seedlings of Abies lasiocarpa are generally more abundant than those of Picea engelmannii in the understory of mature spruce–fir forests throughout the central and northern Rocky Mountains, little information exists concerning environmental or plant factors that may influence the establishment of these two conifers. Field measurements in the Medicine Bow Mountains of southeast Wyoming showed that seedlings of A. lasiocarpa had greater photosynthetic rates at low understory light levels and required lower levels of incident radiation for saturation of photosynthesis compared with those of P. engelmannii. However, both conifers occurred in understory locations where total daily solar radiation was equally low (<2 MJ∙m−2∙day−1) and thus, a lack of light did not appear to be responsible for the low number of P. engelmannii seedlings in the understory. In contrast, seedlings of P. engelmannii were substantially more abundant at locations with thinner litter layers compared with those of A. lasiocarpa. Also, laboratory studies showed that the smaller seeds of P. engelmannii germinated more rapidly and at lower temperatures than seeds of A. lasiocarpa although growth of tap roots on A. lasiocarpa seedlings was greater initially ([Formula: see text] longer in 2-week-old seedlings) as well as for 10-week-old seedlings (50% longer). The deeper penetrating tap root of A. lasiocarpa seedlings may enable this conifer to establish more abundantly on thick, rapidly drying litter layers that are characteristic of mature spruce–fir forests. In contrast, establishment of P. engelmannii seedlings may be limited to microsites without a thick litter layer such as disturbed areas or decomposing wood, where surface drying may occur more gradually throughout the summer. These results are discussed in terms of the potential effects of seedling establishment on the observed patterns in climax vegetation of central and northern Rocky Mountain subalpine forests.

scholarly journals Transcription Factor Lbx1 Expression in Mouse Embryonic Stem Cell-Derived Phenotypes

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Stefanie Schmitteckert ◽  
Cornelia Ziegler ◽  
Liane Kartes ◽  
Alexandra Rolletschek
Keyword(s):  
Transcription Factor ◽  
Developmental Stages ◽  
Troponin T ◽  
Es Cells ◽  
Expression Patterns ◽  
Embryonic Stem ◽  
Mouse Embryonic Stem Cell ◽  
Cardiac Cells ◽  
Cell Stage

Transcription factor Lbx1 is known to play a role in the migration of muscle progenitor cells in limb buds and also in neuronal determination processes. In addition, involvement of Lbx1 in cardiac neural crest-related cardiogenesis was postulated. Here, we used mouse embryonic stem (ES) cells which have the capacity to develop into cells of all three primary germ layers. Duringin vitrodifferentiation, ES cells recapitulate cellular developmental processes and gene expression patterns of early embryogenesis. Transcript analysis revealed a significant upregulation ofLbx1at the progenitor cell stage. Immunofluorescence staining confirmed the expression of Lbx1 in skeletal muscle cell progenitors and GABAergic neurons. To verify the presence of Lbx1 in cardiac cells, triple immunocytochemistry of ES cell-derived cardiomyocytes and a quantification assay were performed at different developmental stages. Colabeling of Lbx1 and cardiac specific markers troponin T, α-actinin, GATA4, and Nkx2.5 suggested a potential role in early myocardial development.

scholarly journals 2 CORRELATION BETWEEN OXYGEN RESPIRATION RATES AND MORPHOLOGY, SEX, DIAMETER AND DEVELOPMENTAL STAGE OF SINGLE BOVINE IVP-EMBRYOS

2005 ◽  
Vol 17 (2) ◽  
pp. 151 ◽  
Author(s):  
A.S. Lopes ◽  
N. Ramsing ◽  
L.H. Larsen ◽  
M. Räty ◽  
J. Peippo ◽  
...  
Keyword(s):  
Developmental Stage ◽  
Respiration Rate ◽  
Developmental Stages ◽  
Glass Tube ◽  
Outer Diameter ◽  
Bovine Embryos ◽  
Embryo Viability ◽  
Concentration Gradients ◽  
Cell Stage ◽  
Respiration Rates

A simple, non-invasive, rapid and sensitive oxygen microsensor system was developed to investigate correlations between oxygen respiration rates of individual bovine embryos and their morphology, sex, diameter and developmental stage. Bovine IVP-embryos (n = 78; Holm et al. Theriogenology 52, 683–700) were analysed around the 8-cell stage (Day 3; n = 18) and at various blastocyst stages (Day 7; n = 60). Each embryo was morphologically evaluated, its outer diameter measured and was then loaded into a glass tube (i.d. 0.68 mm, length 3 mm). After 1 h, oxygen concentration gradients generated by the embryo’s respiration were measured over app. 8 min with an oxygen microelectrode (www.unisense.com). Five embryos were measured in one round together with an empty tube as control. The procedure was repeated twice for each embryo with app. 1 h interval. Individual respiration rates in nL O2/embryo/h (nL/h) were calculated from these gradients. The measurements were performed at 38.5°C under constant flow of humidified 5% CO2 in air (app. 19% O2). After this, 64 embryos (14 Day 3; 50 Day 7) were lysed for sex diagnosis by PCR. Values are given as mean ± SD. The sensitivity of the oxygen measurement system was high (controls: 0.034 ± 0.035 nL/h, n = 15) and its repeatability from 1st to 2nd measurement was 99.7 ± 9.8% (n = 71). The average embryo respiration rate was 0.39 ± 0.05 nLl/h on Day 3 (n = 18) and 1.31 ± 0.52 nLl/h on Day 7 (n = 60). For Day 7 embryos, the respiration rates varied according to their morphological quality, being 1.87 ± 0.46a (n = 18), 1.17 ± 0.32b (n = 23), 0.95 ± 0.27b,c (n = 14) and 0.72 ± 0.24c (n = 4) nL/h for quality 1, 2, 3, and 4 embryos, respectively (Proc Mixed,a,b,c: P < 0.05; values with different superscripts differ significantly). The sex ratio (male:female) was 9:5 (Day 3) and 32:18 (Day 7), and on Day 7 this ratio varied between qualities: 11:2, 12:8, 8:4, and 1:3 for quality 1, 2, 3, and 4, respectively. The average respiration rate on day 3 was the same for males and females, as it was on day 7 (1.22 ± 0.43 nL/h (females) and 1.31 ± 0.58 nL/h (males), P > 0.05). There was a correlation between embryo diameter and respiration rate (r2 = 0.65, n = 74), which was even stronger for Day 7 male embryos (r2 = 0.72, n = 32). In conclusion, a highly reliable, repeatable and sensitive system was established for measuring respiration rates in single bovine embryos, even at early developmental stages. The respiration rate was lower on day 3 compared to Day 7 embryos, and it was correlated with the morphological embryo quality on Day 7. Oxygen consumption could be a valuable supplementary indicator of embryo viability, especially in difficult evaluations (e.g. quality 2 and 3 after IVP). It remains to be demonstrated if such measurements can also reveal quality differences already at Day 3, which would be of interest in, e.g. the human field. ASL is supported by FCT, Portugal.

The Spermatozoon of Actinia Equina L. Var. Mesembryanthemum

1980 ◽  
Vol 60 (1) ◽  
pp. 193-204 ◽  
Author(s):  
A. U. Larkman ◽  
M. A. Carter
Keyword(s):  
Fine Structure ◽  
Sexual Reproduction ◽  
Recent Work ◽  
Developmental Stages ◽  
Early Stage ◽  
Genetic Material ◽  
Sea Anemones ◽  
Free Living ◽  
Pass Through ◽  
Parent Female

Actinia equina var. mesembryanthemum, the beadlet anemone (Stephenson, 1935), is a very common and widely distributed littoral anthozoan, whose sexual reproduction shows several interesting characteristics. Adult sea anemones of both sexes brood planulae and more advanced developmental stages within the gastrovascular cavity, although earlier embryonic stages are rarely found brooded in this way. Chia & Rostron (1970) suggest that embryos are expelled from the parent female anemone at an early stage and pass through a free-living phase before re-entering anemones of either sex for brooding. However, recent work (Cain, 1974) suggests that juvenile anemones are genetically related to the adult anemones in which they are brooded, and also the distribution of genetic material during sexual reproduction appears to be abnormal (Carter & Thorp, 1979). In an attempt to achieve a better understanding of the unusual sexual reproduction of this species, an ultrastructural investigation of gametogenesis was undertaken. This paper describes the fine structure of the spermatozoon within the testis.

180 IDENTIFICATION AND QUANTIFICATION OF DIFFERENTIALLY REPRESENTED TRANSCRIPTS IN PREIMPLANTATION BOVINE EMBRYOS

2008 ◽  
Vol 20 (1) ◽  
pp. 169 ◽  
Author(s):  
C. E. McHughes ◽  
G. K. Springer ◽  
L. D. Spate ◽  
R. Li ◽  
R. J. Woods ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Nuclear Transfer ◽  
Developmental Stages ◽  
Reproductive Technologies ◽  
Blastocyst Stage ◽  
Preimplantation Embryos ◽  
Cell Stage ◽  
Production Techniques

Identification of transcripts that are present at key development stages of preimplantation embryos is critical for a better understanding of early embryogenesis. To that end, this project had two goals. The first was to characterize the relative abundance of multiple transcripts during several developmental stages, including metaphase II-stage oocytes (MPII), and 2-cell-stage (2-cell), precompact morula (PCM), and in vitro-produced blastocyst-stage (IVTBL) embryos. The second was to characterize differences in the relative abundance of transcripts present in in vivo- (IVVBL), in vitro-, and nuclear transfer-produced (NTBL) blastocysts. It was our hypothesis that the identification of differentially represented transcripts from these stages would reveal not only developmentally important genes, but also genes that might be aberrantly expressed due to embryo production techniques. Individual clusters from a large bovine EST project (http://genome.rnet.missouri.edu/Bovine/), which focused on female reproductive tissues and embryos, were compared using Fisher's exact test weighted by number of transcripts per tissue by gene (SAS PROC FREQ; SAS Institute, Inc., Cary, NC, USA). Of the 3144 transcripts that were present during embryogenesis, 125 were found to be differentially represented (P < 0.01) in at least one pairwise comparison (Table 1). Some transcripts found to increase in representation from the MPII to the 2-cell stage include protein kinases, PRKACA and CKS1, as well as the metabolism-related gene, PTTG1. These same transcripts were also found to decrease in representation from the 2-cell to the PCM stage. RPL15 (translation) and FTH1 (immune function) were both more highly represented in the PCM than in the 2-cell stage. From PCM to IVTBL, we saw an increase in RPS11, another translation-related transcript. When comparing blastocyst-stage embryos from different production techniques, several transcripts involved in energy production (e.g., COX7B and COX8A) were found to be more highly represented in the NTBL than in the IVTBL. COX8A was also more highly represented in the IVVBL than in the IVTBL. By investigating these differentially represented transcripts, we will be able to better understand the developmental implications of embryo manipulation. We may also be able to better develop reproductive technologies that lead to in vitro- and nuclear transfer-derived embryos which more closely follow a normal program of development. Table 1. Differentially represented transcripts between developmental stages

146 Quercetin supplementation during boar semen thawing and incubation improves the in vitro production of pig embryos

2019 ◽  
Vol 31 (1) ◽  
pp. 198
Author(s):  
E. Hicks ◽  
E. Winn ◽  
B. Whitaker
Keyword(s):  
Oxidative Stress ◽  
Embryonic Development ◽  
Developmental Stages ◽  
Membrane Damage ◽  
In Vitro Production ◽  
Cell Stage ◽  
Stage Of Development ◽  
Boar Semen ◽  
Morphological Deformities

Elevated levels of reactive oxygen species in the in vitro environment cause oxidative stress, which leads to membrane damage, decreased fertility, and morphological deformities of spermatozoa. Antioxidants, such as quercetin (a polyphenol flavonoid), are often supplemented to reduce the effects of oxidative stress on spermatozoa. Supplementing frozen-thawed boar semen with quercetin improves sperm forward progressive motility, viability and lipid peroxidation up to 10h after thawing. However, the effects of fertilizing with quercetin-supplemented sperm are unknown. Therefore, the objective of this study was to determine the effects of supplementing quercetin (0.25, 0.50, 0.75mM) during the thawing and incubation of frozen-thawed boar semen on oocyte fertilization characteristics (n=400) and subsequent embryonic development (n=1340) at 48 and 144h for cleavage and blastocyst formation, respectively. Oocytes from aspired aspirated mature follicles (3-6mm diameter) were obtained from a local abattoir and matured in medium 199 for 40 to 44h at 38.5°C in an atmosphere of 5% CO2. Fertilization was performed using pooled frozen-thawed semen from 3 different boars, and co-incubation of the sperm (2×105 sperm mL−1) and oocytes (30 oocytes/well) lasted for 6 to 8h at 38.5°C in an atmosphere of 5% CO2. Data were analysed using ANOVA with the main effects including treatment, well and replicate. Chi-squared analysis was used to determine percentages of embryos reaching the different developmental stages for each treatment. There were no differences in penetration rates and male pronuclear formation between treatment groups; however, supplementation of 0.25 (18.18±10.63%), 0.50 (20.93±9.89%) and 0.75mM (18.07±12.02%) quercetin significantly decreased (P&lt;0.05) polyspermic penetration rates compared with no supplementation (40.00±11.34%). Embryos produced from frozen-thawed boar sperm supplemented with 0.25 and 0.50mM quercetin had a significantly higher percentage (P&lt;0.05) of embryos reaching the 2-cell stage of development by 48h after IVF (75.00±7.89%, 68.75±2.23%, respectively) compared with 0.75mM quercetin supplementation (64.62±3.88%) and no supplementation (62.97±4.11%). Supplementation of 0.25 (44.12±6.23%), 0.50 (43.75±7.02%) and 0.75mM (43.08±2.98%) quercetin to the sperm significantly increased (P&lt;0.05) the percentage of embryos reaching the blastocyst stage of development by 144h after IVF compared with no supplementation (28.27±8.07%). These results indicate that supplementing frozen-thawed boar semen with quercetin decreases the incidence of polyspermic penetration and improves early embryonic development in pigs.

Effects of Storage, Planting Date, and Shelter on Engelmann Spruce Containerized Seedlings in the Central Rockies

1991 ◽  
Vol 6 (2) ◽  
pp. 36-38 ◽  
Author(s):  
Scott D. Roberts ◽  
James N. Long
Keyword(s):  
Planting Date ◽  
Picea Engelmannii ◽  
Planting Dates ◽  
Engelmann Spruce ◽  
Containerized Seedlings ◽  
Storage Methods ◽  
Survival Of Seedlings

Abstract Containerized Engelmann spruce (Picea engelmannii) seedlings were treated with different nursery storage methods, planting dates, and amounts of overstory shelter after planting. Third-year survival of seedlings stored in refrigeration did not differ from that of seedlings maintained in a lathhouse prior to planting. Survival of seedlings planted in mid-June was about 70% compared to 48% for seedlings planted in late July. Survival was only 52% within strip shelterwood units and more than 72% in the more protected environment of uniform shelterwood units. Seedlings within strip shelterwood units were slightly taller after 3 years than those under a uniform shelterwood. West. J. Appl. For. 6(2):36-38.

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