ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Pollen performance  (3)
  • Cucurbita texana  (2)
  • Key words Hyperlipoproteinemia  (2)
  • Springer  (7)
  • Geological Society of America (GSA)
  • 2000-2004  (1)
  • 1995-1999  (5)
  • 1990-1994  (1)
Collection
Keywords
Publisher
  • Springer  (7)
  • Geological Society of America (GSA)
Years
  • 2000-2004  (1)
  • 1995-1999  (5)
  • 1990-1994  (1)
Year
  • 1
    Electronic Resource
    Electronic Resource
    Effects of pollination intensity on the vigor of the sporophytic and gametophytic generation of Cucurbita texana (1997)
    Springer
    Sexual plant reproduction 10 (1997), S. 236-240 
    Details
    ISSN: 1432-2145
    Keywords: Key words Cucurbita texana ; Pollen ; Pollen performance ; Pollen competition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  We examined the effects of pollen competition (pollen load size) on sporophytic vigor and gametophytic performance in Cucurbita texana, a wild gourd, while controlling for alternative interpretations of the data. Under field conditions we compared the vigor of progeny produced from large and small pollen loads and examined the in vitro performance of the pollen produced by the progeny. We found that the progeny from large pollen loads germinated faster and had a greater reproductive output (male flowers and fruits) than progeny produced from small pollen loads. In addition, we found that the pollen produced on plants derived from large pollen loads grew faster in vitro than the pollen produced on plants derived from small pollen loads. These findings indicate that pollen competition affects the performance of the resulting sporophytic generation and the microgametophytes they produce.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050092
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Variation in sporophytic and gametophytic vigor in wild and cultivated varieties of Cucurbita pepo and their F1 and F2 generations (1998)
    Springer
    Sexual plant reproduction 11 (1998), S. 265-271 
    Details
    ISSN: 1432-2145
    Keywords: Key words Cucurbita ; Pollen tube growth ; Pollen performance ; Hybridization ; Variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  This study examines sporophytic and gametophytic vigor in wild and cultivated varieties of Cucurbita pepo L. and their hybrids in order to determine whether hybrid vigor extends to the microgametophyte generation. It also examines the variation in sporophytic and gametophytic vigor to discern the non-genetic influences of pollen provisioning by the sporophyte on pollen performance from the genetic influences of the microgametophyte’s own genotype on pollen performance. A cultivated and a wild C. pepo and their F1 and the F2 generations were grown under field conditions and flower and fruit production were monitored over one summer. We found that the four types of plants differed significantly in the number of male and female flowers and the number of fruits they produced. The F1 plants produced significantly more male flowers and marginally more female flowers and fruits than the parental lines. To estimate gametophytic vigor pollen was germinated in vitro and pollen tube length measured after 30 min. We found that pollen tubes from the F1 plants had significantly greater growth than tubes from the parental lines or the F2 generation, indicating that hybrid vigor extends to the microgametophytic generation. By partitioning the variance of pollen tube growth into ’within’ and ’among’ plant components of variation, we were able to show that the genotype of the microgametophyte influences pollen performance in vitro, but that expression of hybrid vigor in the microgametophyte is likely to be due to an environmental effect related to provisioning of the pollen grains during development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050152
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Effects of genotype on pollen performance in Cucurbita pepo (1991)
    Springer
    Sexual plant reproduction 4 (1991), S. 208-214 
    Details
    ISSN: 1432-2145
    Keywords: Cucurbita pepo ; Pollen competition ; Geno-type ; Non-random fertilization ; Pollen performance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This study examines the assumption of the pollen competition hypothesis that genetic differences among microgametophytes lead to differences in pollen performance and result in non-random fertilization. In addition, we examined the assumption that pollen performance is genetically correlated with sporophyte vigor due to an overlap in gene expression between the two stages of the life cycle. The results from a pollen mixture experiment in which two cultivars of common zucchini were used show that the ability to sire seeds is nonrandom with respect to the cultivar of the pollen donor plant. The proportion of the progeny sired by the two cultivars is not independent of the region of the fruit where the seeds are produced. The progeny sired by the yellow cultivar outperformed the progeny sired by the green cultivar in a greenhouse study. In addition, the progeny sired by the yellow cultivar from the stylar region of the fruit germinated faster and had more leaf area than the progeny sired by the same cultivar from the peduncular end of the fruit. Thus, the most vigorous progeny are obtained from the stylar region of the fruit where the ovules are fertilized by the most vigorous microgametophytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00190007
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Effects of pollen selection on progeny vigor in a Cucurbita pepo × C. texana hybrid (1996)
    Springer
    Theoretical and applied genetics 92 (1996), S. 885-890 
    Details
    ISSN: 1432-2242
    Keywords: Key words  Microgametophyte selection ; Pollen selection ; Pollen competition ; Cucurbita texana ; Cucurbita pepo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract   We examined the effects of pollen selection for rapid pollen-tube growth on progeny vigor. First, we crossed a wild gourd (Cucurbita texana) to a cultivated zucchini (Cucurbita pepo cv `Black Beauty') to produce an F1 and then an F2 generation. Half of the F1 seeds were produced by depositing small loads of C. texana pollen onto the stigmas of C. pepo. These small pollen loads were insufficient to produce a full complement of seeds and, consequently, both the fast- and the slow-growing pollen tubes were permitted to achieve fertilization. An F2 generation was then produced by depositing small loads of F1 pollen onto stigmas of F1 plants. The F2 seeds resulting from two generations of small pollen loads are termed 'the non-selected line' because there was little or no selection for pollen-tube growth rate on these plants. The other half of the F1 and F2 seeds were produced by depositing large pollen loads (〉10000 pollen grains) onto stigmas and then allowing only the first 1% or so of the pollen tubes that entered the ovary to fertilize the ovules. We did this by excising the styles at the ovary at 12–15 h after pollination. The resulting F2 seeds are termed `the selected line' because they were produced by two generations of selection for only the fastest growing pollen tubes. Small pollen loads from the F2 plants, both the selected and the non-selected lines, were then deposited onto stigmas of different C. pepo flowers, and the vigor of the resulting seeds was compared under greenhouse and field conditions. The results showed that the seeds fertilized by pollen from the selected line had greater vegetative vigor as seedlings and greater flower and fruit production as mature plants than the seeds fertilized by pollen from the non-selected line. This study demonstrates that selection for fast pollen-tube growth (selection on the microgametophyte) leads to a correlated increase in sporophyte (progeny) vigor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220050207
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Effects of pollen selection on progeny vigor in a Cucurbita pepo x C. texana hybrid (1996)
    Springer
    Theoretical and applied genetics 92 (1996), S. 885-890 
    Details
    ISSN: 1432-2242
    Keywords: Microgametophyte selection ; Pollen selection ; Pollen competition ; Cucurbita texana ; Cucurbita pepo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We examined the effects of pollen selection for rapid pollen-tube growth on progeny vigor. First, we crossed a wild gourd (Cucurbita texana) to a cultivated zucchini (Cucurbita pepo cv ‘Black Beauty’) to produce an F1 and then an F2 generation. Half of the F1 seeds were produced by depositing small loads of C. texana pollen onto the stigmas of C. pepo. These small pollen loads were insufficient to produce a full complement of seeds and, consequently, both the fast- and the slow-growing pollen tubes were permitted to achieve fertilization. An F2 generation was then produced by depositing small loads of F1 pollen onto stigmas of F1 plants. The F2 seeds resulting from two generations of small pollen loads are termed the non-selected line because there was little or no selection for pollen-tube growth rate on these plants. The other half of the F1 and F2 seeds were produced by depositing large pollen loads (〉10 000 pollen grains) onto stigmas and then allowing only the first 1% or so of the pollen tubes that entered the ovary to fertilize the ovules. We did this by excising the styles at the ovary at 12–15 h after pollination. The resulting F2 seeds are termed ‘the selected line’ because they were produced by two generations of selection for only the fastest growing pollen tubes. Small pollen loads from the F2plants, both the selected and the non-selected lines, were then deposited onto stigmas of different C. pepo flowers, and the vigor of the resulting seeds was compared under greenhouse and field conditions. The results showed that the seeds fertilized by pollen from the selected line had greater vegetative vigor as seedlings and greater flower and fruit production as mature plants than the seeds fertilized by pollen from the non-selected line. This study demonstrates that selection for fast pollen-tube growth (selection on the microgametophyte) leads to a correlated increase in sporophyte (progeny) vigor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221902
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    A novel LDLR mutation, H190Y, in a Utah kindred with familial Hypercholesterolemia (1999)
    Springer
    Journal of human genetics 44 (1999), S. 364-367 
    Details
    ISSN: 1435-232X
    Keywords: Key words Hyperlipoproteinemia ; Lipoproteins ; LDL receptor ; Familial hypercholesterolemia ; Genetic diagnosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Heterozygous familial hypercholesterolemia (FH) is a serious disorder causing twice normal low-density lipoprotein (LDL) cholesterol levels early in childhood and very early coronary disease in both men and women. Treatment with multiple medications together with diet can normalize cholesterol levels in many persons with FH and prevent or delay the development of coronary atherosclerosis. Previously published blood cholesterol criteria greatly under-diagnosed new cases of FH among members of known families with FH and over-diagnosed FH among participants of general population screening. Thus, there is a need for accurate and genetically validated criteria for the early diagnosis of heterozygous FH. In the course of investigations of coronary artery disease in Utah, we identified a family whose proband showed elevated plasma levels of LDL cholesterol. To carry out molecular genetic diagnosis of the disease, we screened DNA samples for mutations in all 18 exons and the exon-intron boundaries of the LDL receptor gene (LDLR). Novel point mutations were identified in the proband: a C-to-T transversion at nucleotide position 631, causing substitution of tyrosine for histidine at codon 190 in exon 4 of the LDLR gene. The mutant allele-specific amplification method was used to examine 12 members of the family recruited for the diagnosis. This method helped to unequivocally diagnose 7 individuals as heterozygous for this particular LDLR mutation, while excluding the remaining 5 individuals from carrier status with FH.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100380050179
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Co-segregation of elevated LDL with a novel mutation (D92K) of the LDL receptor in a kindred with multiple lipoprotein abnormalities (2000)
    Springer
    Journal of human genetics 45 (2000), S. 154-158 
    Details
    ISSN: 1435-232X
    Keywords: Key words Hyperlipoproteinemia ; Lipoproteins ; LDL receptor ; Familial combined hyperlipidemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Factors predisposing to the phenotypic features of familial combined hyperlipidemia have not been clearly defined. In the course of investigating familial coronary artery disease in Utah, we identified a three-generation family in which multiple members were affected with type IIa hyperlipoproteinemia (HLP IIa), type IIb hyperlipoproteinemia (HLP IIb), or type IV hyperlipoproteinemia (HLP IV). Because several family members had relatively severe low-density lipoprotein (LDL) cholesterol elevation, in order to dissect the possible contribution to the plasma lipoprotein abnormalities in this pedigree, we identified a novel point mutation in the low-density lipoprotein receptor (LDLR) gene, a G-to-A transition at nucleotide position 337 in exon 4. This change substituted lysine for glutamic acid at codon 92 (D92K) of the LDL receptor. By means of mutant allele-specific amplification we determined that the mutation co-segregated with elevated cholesterol and LDL cholesterol in the plasma of family members with HLP IIa and HLP IIb, but not with the elevated plasma triglycerides seen in HLP IIb and HLP IV patients. Thus, in families with apparent familial combined hyperlipidemia, a defective LDLR allele and other genetic or environmental factors that elevate plasma triglycerides may account for the multiple lipid phenotypes observed in this kindred.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100380050202
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...