The Relationship Between Flowering Phenology and Seed Set in an Herbaceous Perennial Plant, Polemonium foliosissimum Gray

1984 ◽  
Vol 111 (1) ◽  
pp. 185 ◽  
Author(s):  
Michael Zimmerman ◽  
Ronald S. Gross
Agronomy ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 289 ◽  
Author(s):  
Leonardo Sulas ◽  
Giuseppe Campesi ◽  
Giovanna Piluzza ◽  
Giovanni A. Re ◽  
Paola A. Deligios ◽  
...  

Sulla (Sulla coronaria [L.] Medik), a Mediterranean short-lived legume with tolerance to drought-prone environments, requires inoculation outside its natural habitat. Its leaves are appreciated for the bromatological composition and content of bioactive compounds. However, no information is available regarding the distinct effects of inoculation and nitrogen (N) applications on leaf dry matter (DM), fixed N, and bioactive compounds. Sulla leaves were sampled from the vegetative stage to seed set in Sardinia (Italy) during 2013–2014 and leaf DM, N content, and fixed N were determined. Compared to the best performing inoculated treatments, DM yield and fixed N values of the control only represented 8% to 20% and 2% to 9%, respectively. A significant relationship between fixed N and leaf DM yield was established, reaching 30 kg fixed N t–1 at seed set. Significant variations in leaf atom% 15N excess and %Ndfa quantified decreases in leaf N fixation coupled with N application. Moreover, the petiole content of phenolic compounds markedly increased in the uninoculated control, suggesting deeper investigations on the relationship between bioactive compounds and inoculation treatments. Results highlighted substantial variation in DM, N yields, N-fixation ability, and content of bioactive compounds of sulla leaves caused by inoculation and N fertilization.


2017 ◽  
Author(s):  
Ranae Dietzel ◽  
Matt Liebman ◽  
Sotirios Archontoulis

Abstract. Plant root material makes a substantial contribution to the soil organic carbon (C) pool, but this contribution is disproportionate below 20 cm, where 30 % of root mass and 50 % of soil organic C is found. Root carbon inputs changed drastically when native perennial plant systems were shifted to cultivated annual plant systems. We used the reconstruction of a native prairie and a continuous maize field to examine both the relationship between root carbon and soil carbon and the fundamental rooting system differences between the vegetation under which the soils developed versus the vegetation under which the soils continue to change. In all treatments we found that root C : N ratios increased with depth, which may help explain why an unexpectedly large proportion of soil organic C is found below 20 cm. Measured root C : N ratios and turnover times along with modeled root turnover dynamics showed that in moving from prairie to maize, a large, structural-tissue dominated root C pool with slow turnover, concentrated at shallow depths was replaced by a small, non-structural-tissue dominated root C pool with fast turnover evenly distributed in the soil profile. These differences in rooting systems suggest that while prairie roots contribute more C to the soil than maize at shallow depths, maize may contribute more C to the soil than prairies at deeper depths.


1977 ◽  
Vol 57 (3) ◽  
pp. 873-881 ◽  
Author(s):  
R. MICHAUD ◽  
T. H. BUSBICE

Alfalfa (Medicago sativa L.) is a highly heterozygous cross-pollinating species, and most breeding efforts have been conducted on noninbred populations. The purpose of this study was to determine whether greater breeding progress could be made by selecting within partly inbred populations rather than within noninbred ones. One hundred and twenty F1 (noninbred) and 120 S1 (partly inbred) plants that were issued from crossing and selfing four alfalfa clones were evaluated for self-fertility. The most self-fertile 10% of the plants from each family were selected in each population. The selected plants within each level of inbreeding were intercrossed to produce an advanced generation in which the effectiveness of the selection was evaluated. Selection increased both self- and cross-fertility in the advanced generation. Selection was more effective at the F1 level than at the S1 level. Fertility was reduced drastically by inbreeding. The average self-fertility of the S1’s was only about 7% of the cross-fertility of their parental clones. An exponential model was proposed to describe the relationship between seed setting and the coefficient of inbreeding in the developing zygote. This model explained 95% of the variation among 11 unselected populations having differing levels of inbreeding.


1982 ◽  
Vol 60 (2) ◽  
pp. 210-219 ◽  
Author(s):  
Robert I. Bertin

The Ruby-throated Hummingbird (or rubythroat, Archilochus colubris) and several of its major food plants were examined to assess the importance of rubythroat versus insect pollination, the overlap of geographical ranges, and the synchrony between migration and flowering times. Seed set of Impatiens biflora was increased 8–17% by rubythroat and insect visitation over the level achieved by insects alone. The rubythroat's range is not contiguous with that of any of 22 putative food plants examined, but is nearly coincident with the range of certain forest types, perhaps reflecting the importance of sap for food. A new method was developed to estimate peak flowering times of plants from herbarium data. Based on these data and field observations, only one rubythroat food plant (Impatiens biflora) had peak flowering times close to peak rubythroat migration times throughout their shared range. Rubythroats and their North American food plants are facultative mutualists, with the plants apparently having been evolutionarily more labile.


2006 ◽  
Vol 33 (1) ◽  
pp. 1 ◽  
Author(s):  
Catherine M. Cox ◽  
Stephen M. Swain

In Arabidopsis, as in the majority of flowering plants, developing seeds promote fruit growth. One method to investigate this interaction is to use plants with reduced seed set and determine the effect on fruit growth. Plants homozygous for a transgene designed to ectopically express a gene encoding a gibberellin-deactivating enzyme exhibit reduced pollen tube elongation, suggesting that the plant hormone gibberellin is required for this process. Reduced pollen tube growth causes reduced seed set and decreased silique (fruit) size, and this genotype is used to explore the relationship between seed set and fruit elongation. A detailed analysis of seed set in the transgenic line reveals that reduced pollen tube growth decreases the probability of each ovule being fertilised. This effect becomes progressively more severe as the distance between the stigma and the ovule increases, revealing the complex biology underlying seed fertilisation. In terms of seed-promoted fruit growth, major localised and minor non-localised components that contribute to final silique length can be identified. This result demonstrates that despite the relatively small size of the fruit and associated structures, Arabidopsis can be used as a model to investigate fundamental questions in fruit physiology.


2019 ◽  
Vol 2 ◽  
Author(s):  
Elina Yankova-Tsvetkova ◽  
Stoyan Stoyanov ◽  
Antonina Vitkova ◽  
Ivanka Semerdjieva

Helichrysum arenarium (L.) Moench is herbaceous perennial plant belonging to Asteraceae family. The plant is well known in phytotherapy for its potential in the treatment of gallbladder disease and is classified as endangered in a number of European countries. In Bulgaria it is a protected species according to the Biodiversity Act (Annex 4) and is in the List of Species of Medicinal Plants under special regimen of conservation and use. The data on the distribution of H. arenarium in the Bulgarian flora have not been updated for more than 20 years. The aim of this study is to determine the current distribution of H. arenarium in Bulgaria on the basis of reviewing the available herbarium specimens in the Bulgarian herbariums, literature data, and personal collections. As a result, the locations of the species on the territory of the country were described and mapped. In Bulgaria H. arenarium is represented with only a few populations located in a limited area in the northeastern part of the country, in a narrow strip between the towns of Shumen and Varna.


2020 ◽  
Author(s):  
Sylvan Kaufman

Abstract Zingiber capitatum is a herbaceous, perennial plant that spreads by rhizomes and possibly also by seed. It is native to India and is probably also native to Bangladesh and Nepal. It has medicinal properties and is likely to have been introduced to countries outside its native range for horticultural use. It is cultivated in Brazil and is also present in China and Vietnam. It is described as an invasive, transformer species in Cuba, but this is thought to be a misidentification. It is not listed as a weed or invasive species in any other country and information on its possible impact on habitats or biodiversity outside of its native range is lacking.


2020 ◽  
pp. 75-83
Author(s):  
Milica Aćimović ◽  
Jovana Stanković-Jeremić ◽  
Mirjana Cvetković

Nepeta nuda L. (syn. N. pannonica L.) is a herbaceous perennial plant that is the most widespread species of the genus Nepeta, the largest genera in Lamiaceae family. N. nuda is divided into four subspecies according to morphological differences which occur within large geographical range of distribution: subsp. nuda, subsp. albiflora, subsp. lydiae, and subsp. glandulifera. In this review, previous reports on N. nuda concerning its botanical description and systematics, phytochemistry, use in traditional medicine, pharmacology, and posibilities for other applications were summarized. All of these data indicate N. nuda as a highly promising species for application in food and pharmaceutical industries, as well as in agriculture for the development of natural pesticides.


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