scholarly journals Doing the twist: a test of Darwin's cross-pollination hypothesis for pollinarium reconfiguration

2005 ◽  
Vol 2 (1) ◽  
pp. 65-68 ◽  
Author(s):  
Craig I Peter ◽  
Steven D Johnson
Keyword(s):  
Inbreeding Depression ◽  
Mating Success ◽  
Positive Relationship ◽  
Pollen Dispersal ◽  
Strong Support ◽  
Cross Pollination ◽  
Self Pollination ◽  
Strong Positive Relationship ◽  
Mating Opportunities

Mating success in plants depends largely on the efficiency of pollen dispersal. For hermaphrodite plants, self-pollination, either within or among flowers, can reduce mating opportunities because of pollen and ovule discounting and inbreeding depression. Self-pollination may be particularly detrimental in plants such as orchids and asclepiads that package each flower's pollen into one or more pollinia which, together with accessory structures, comprise a pollinarium. Darwin proposed that physical reconfiguration of pollinaria serves as a mechanism for reducing the likelihood of self-pollination. To be effective, the time taken for pollinarium reconfiguration would need to exceed that spent by a pollinator on a plant. We investigated pollinarium reconfiguration (including pollinarium bending, pollinium shrinking and anther cap retention) in 19 species and found a strong positive relationship between reconfiguration time and the duration of pollinator visits. Reconfiguration times were also consistently longer than pollinator visit times. These results provide strong support for Darwin's idea that this mechanism promotes cross-pollination.

scholarly journals Breeding system and inbreeding depression in the rare orchid, Platanthera praeclara, in a fragmented grassland landscape

Botany ◽  
2018 ◽  
Vol 96 (3) ◽  
pp. 151-159 ◽  
Author(s):  
Steven E. Travers ◽  
Kirk Anderson ◽  
Pati Vitt ◽  
Marion O. Harris
Keyword(s):  
Inbreeding Depression ◽  
Seed Quality ◽  
Detectable Effect ◽  
Plant Fitness ◽  
Cross Pollination ◽  
Self Pollination ◽  
Capsule Production ◽  
Hand Pollination ◽  
Platanthera Praeclara ◽  
Self Compatibility

An important consequence of self-compatibility in plants is that self-pollination can have deleterious effects on plant fitness because of inbreeding. We conducted a hand pollination experiment under field conditions to measure the magnitude of inbreeding depression associated with self-pollination in the rare western prairie fringed-orchid Platanthera praeclara Sheviak and Bowles. By comparing capsules and seeds resulting from cross versus self-pollination treatments, we determined that self-pollination reduces seed quality while having no detectable effect on capsule production or seed numbers. A smaller percentage of seeds resulting from self-pollination contained an embryo (18%) relative to seeds from cross-pollination (46%). Seeds that had an embryo were scored for the size of the embryo, small or large. A smaller proportion of seeds from self-pollination contained a large embryo (75%) relative to seeds from cross-pollination (92%). These results suggest that sexual reproduction and recruitment in this rare plant are dependent on the frequency of pollinator visitations that result in outcrossing.

scholarly journals Fitness costs of delayed pollination in a mixed-mating plant

2019 ◽  
Vol 124 (5) ◽  
pp. 869-881 ◽  
Author(s):  
Laura S Hildesheim ◽  
Øystein H Opedal ◽  
W Scott Armbruster ◽  
Christophe Pélabon
Keyword(s):  
Inbreeding Depression ◽  
Population Variation ◽  
Mixed Mating ◽  
Reproductive Assurance ◽  
Fitness Costs ◽  
Cross Pollination ◽  
Floral Longevity ◽  
Self Pollination ◽  
Evolutionary Consequences ◽  
Pollinator Declines

Abstract Background and Aims To predict the evolutionary consequences of pollinator declines, we need to understand the evolution of delayed autonomous self-pollination, which is expected to evolve as a mechanism of reproductive assurance when cross-pollination becomes unreliable. This involves estimating the costs of increased levels of selfing as well as those associated with floral senescence. Methods We studied the mechanisms and costs of delayed self-pollination in the mixed-mating vine Dalechampia scandens (Euphorbiaceae) by first assessing among-population variation in herkogamy and dichogamy, which together determine the rate and timing of autonomous self-pollination. We then tested whether floral longevity responds plastically to delayed pollination. Finally, we assessed the costs of delayed self-pollination in terms of seed number and size, explicitly separating inbreeding depression from effects of floral senescence. Key Results Herkogamy varied extensively, while variation in dichogamy was more limited. Unpollinated blossoms increased their longevity, but seed quantity and quality decreased with increasing delays in pollination, independently of inbreeding depression. Conclusions In D. scandens, earlier autonomous selfing is facilitated by reduced herkogamy rather than reduced protogyny, providing reproductive assurance while maintaining the possibility for outcrossing events. Effective early autonomous self-pollination may evolve under reduced cross-pollination reliability in response to costs associated with floral senescence.

scholarly journals Penyebaran Polen Berdasarkan Analisis SSR Membuktikan Penyerbukan

Buletin Palma ◽  
2016 ◽  
Vol 16 (1) ◽  
pp. 77 ◽  
Author(s):  
SITI HALIMAH LAREKENG ◽  
ISMAIL MASKROMO ◽  
AGUS PURWITO ◽  
NURHAYATI ANSHORI MATTJIK ◽  
SUDARSONO SUDARSONO
Keyword(s):  
Ssr Marker ◽  
Cocos Nucifera ◽  
Pollen Dispersal ◽  
Paternity Analysis ◽  
Font Size ◽  
Cross Pollination ◽  
Ssr Analysis ◽  
Self Pollination ◽  
Marker Loci ◽  
Cocos Nucifera L

<p><span style="font-size: medium;">ABSTRAK </span></p><p>Analisis paternitas digunakan untuk mengetahui pola penyebaran serbuk sari pada kelapa (Cocos nucifera L.) tipe Dalam Kalianda. Tujuan penelitian ini adalah untuk (1) mengevaluasi pola penyebaran serbuk sari dan menentukan kisaran  jarak penyebaran serbuk sari pada kelapa tipe Dalam Kalianda, (2) menentukan persentase penyerbukan silang  (outcrossing) dan penyerbukan sendiri (selfing) yang terjadi pada kelapa tipe Dalam Kalianda, dan (3) menentukan  frekuensi pola penyerbukan silang antara kelapa tipe Dalam normal (N) dengan kelapa Dalam Kopyor (K), KxN dan KxK yang terjadi pada populasi campuran antara kelapa tipe Dalam Kopyor dan kelapa Dalam normal Kalianda.  Populasi yang digunakan terdiri atas 60 pohon kelapa tipe Dalam dewasa, 21 pohon merupakan kelapa tipe Dalam berbuah normal (homozigot KK) dan 39 merupakan pohon kelapa tipe Dalam Kopyor (heterosigot Kk). Empat belas  pohon (5 pohon KK dan 9 pohon Kk) digunakan sebagai tetua betina. Sebanyak 49 progeni dipanen dari 15 induk  terpilih dan dikecambahkan untuk sumber DNA dalam analisis paternitas. Enam lokus marka SSR polimorfik, yaitu  CnCir_B12,  CnCir_86,  CnCir_87,  CnCir_56,  CnZ_51,  CnZ_18  dan  empat  lokus  marka  SNAP  polimorfik,  yaitu  CnSUS1#14,CnSUS1#3, CnWRKY6#3 dan CnWRKY19#1 digunakan untuk menentukan genotipe seluruh progeni, seluruh kandidat tetua jantan, dan semua tetua betina yang digunakan. Hasil penelitian menunjukkan bahwa  serbuk sari kelapa tipe Dalam Kalianda menyebar dengan jarak terjauh 63 m. Jarak penyebaran serbuk sari terbanyak pada jarak 40-50 m, dengan frekuensi sebesar 13 kejadian polinasi (27%). Dari 47 progeni yang dievaluasi, hanya satu (2%) progeni yang berasal dari penyerbukan sendiri (self pollination) dan 48 (98%) berasal dari penyerbukan silang. Dari  progeni hasil penyerbukan silang, 24 (49,0%) progeni teridentifikasi sebagai hasil persilangan antara induk dan tetua  jantan kelapa tipe Dalam kopyor heterosigot Kk, 11 (22,4%) sebagai hasil persilangan antara induk kelapa tipe Dalam  Kopyor heterosigot Kk dan normal homosigot KK, 10 (20,5%) sebagai hasil persilangan antara induk kelapa tipe Dalam normal homosigot KK dan Kopyor heterosigot Kk, serta 3 (6,1%) sebagai hasil persilangan antara induk dan tetua jantan tipe Dalam normal homosigot KK.</p><p>Kata kunci : Kelapa Dalam Kopyor, kelapa Kopyor Kalianda, tingkat penyerbukan sendiri, tingkat penyerbukan silang.</p><p> </p><p><strong>Pollen Dispersal Based on SSR Analysis Proves Kalianda to Kopyor Coconut Pollinations</strong></p><p><span style="font-size: medium;">ABSTRACT </span></p><p>Paternity analysis was applied to determine the pattern of pollen spread among Kalianda Tall coconut (Cocos nucifera L.) in Kalianda, Lampung. The objectives of this research are to (1) evaluate patterns of pollen dispersal and ranges of pollen  spread, (2) determine percentage of outcrossing or selfing rates, and (3) determine the frequency of cross pollination  among normal (N) to kopyor (K), KxN and KxK in the mix population of Kalianda Tall coconut at Kalianda, Lampung. The population used in this study was 60 palms, consisted of 21 Kalianda Tall Normal coconuts (homozygous KK) and 39 Kalianda Tall Kopyor coconuts (Heterozygous Kk). Fourteen palms out of those were selected as female parents. Progeny arrays (49 nuts) were harvested from 15 female parents and they were germinated. The DNA was isolated from  young leaf of all adult palms and germinated coconut seedlings and they were used in paternity analysis. Six  polymorphic SSR marker loci used were CnCir_B12, CnCir_86, CnCir_87, CnCir_56, CnZ_51, CnZ_18 and the four  polymorphic SNAP markers used were CnSUS1#14, CnSUS1#3, CnWRKY6#1 and CnWRKY19#3. The markers were used to genotype all the progenies, the potential male and the female parents. Results of the experiment indicated pollen of Kalianda Tall Kopyor coconut farthest disperse was 63 m. Distance of the mostpollen dispersal was between 40-50  m,with the frequency of 13 pollination events (27%). Among the evaluated progenies, only one (2%) comes from self  pollination event and 48 (98%) comes from cross pollination. Results of the progeny evaluation also indicated 24  progenies (49.0%) are results of outcrossing among Kalianda Tall kopyor heterozygous Kk parents, 11 progenies (22.4%)  are outcrossing among kopyor heterozygous Kk female and normal homozygous KK male parents, 10 progenies (20.5%) are outcrossing among normal homozygous KK female and kopyor heterozygous Kk male parents, and 3 progenies (6.1%) are outcrossing among normal homozygous KK female and male parents.</p>Keywords : Tall kopyor coconut, Kalianda Kopyor coconut, self polination, cross pollination rate.

Effects of Financial Innovations on Profitability for Deposit Taking Microfinancing Institutions in Kenya

2018 ◽  
Vol 9 (6) ◽  
pp. 529-536
Author(s):  
Martin Khoya Odipo ◽  
Keyword(s):  
Financial Institutions ◽  
Positive Relationship ◽  
Financial Institution ◽  
Secondary Data ◽  
Financial Statements ◽  
Descriptive Statistics ◽  
Primary Data ◽  
Microfinance Institutions ◽  
Financial Innovations ◽  
Strong Positive Relationship

Recent studies have documented that innovations improve profitability of firms. This article documents that deposit taking micro financial institutions that have adopted financial innovations have increased their profitability. The study covered five years between 2009-2013. Both primary and secondary data were used in the study. Primary data was obtained through administration of drop and pick questionnaires to selected employees of the institutions. Secondary data was obtained from financial statements and management reports of these deposit taking microfinance institutions. Data was analyzed using descriptive statistics, return on asset and multi-liner regression model to determine the effect of each financial innovation applied on profitability on the micro-financial institution. The results showed that most deposit taking microfinance institutions adopted these financial innovations in their current operations. There was strong positive relationship between individual innovations and profitability. In line with profitability ROA also showed improvement each year after the adoption of these financial innovations.

INTERCONNECTION OF SUSTAINABLE DEVELOPMENT COMPONENTS FOR THE INDIGENOUS PEOPLES OF THE NORTH

2020 ◽  
Vol 2 (8) ◽  
pp. 101-110
Author(s):  
N. N. ILYSHEVA ◽  
◽  
E. V. KARANINA ◽  
G. P. LEDKOV ◽  
E. V. BALDESKU ◽  
...  
Keyword(s):  
Climate Change ◽  
Sustainable Development ◽  
Economic Development ◽  
Indigenous Peoples ◽  
Ecological Footprint ◽  
Positive Relationship ◽  
The North ◽  
Strong Positive Relationship ◽  
The Face ◽  
The Relationship

The article deals with the problem of achieving sustainable development. The purpose of this study is to reveal the relationship between the components of sustainable development, taking into account the involvement of indigenous peoples in nature conservation. Climate change makes achieving sustainable development more difficult. Indigenous peoples are the first to feel the effects of climate change and play an important role in the environmental monitoring of their places of residence. The natural environment is the basis of life for indigenous peoples, and biological resources are the main source of food security. In the future, the importance of bioresources will increase, which is why economic development cannot be considered independently. It is assumed that the components of resilience are interrelated and influence each other. To identify this relationship, a model for the correlation of sustainable development components was developed. The model is based on the methods of correlation analysis and allows to determine the tightness of the relationship between economic development and its ecological footprint in the face of climate change. The correlation model was tested on the statistical materials of state reports on the environmental situation in the Khanty-Mansiysk Autonomous Okrug – Yugra. The approbation revealed a strong positive relationship between two components of sustainable development of the region: economy and ecology.

scholarly journals Cytological Observation and Transcriptome Comparative Analysis of Self-Pollination and Cross-Pollination in Dendrobium Officinale

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 432
Author(s):  
Yaling Chen ◽  
Benchang Hu ◽  
Fantao Zhang ◽  
Xiangdong Luo ◽  
Jiankun Xie
Keyword(s):  
Pollen Tubes ◽  
The Self ◽  
Dendrobium Officinale ◽  
Self Incompatibility ◽  
Related Gene ◽  
Cytological Observation ◽  
Lectin Receptor ◽  
Cross Pollination ◽  
Self Pollination ◽  
Medicinal Value

Dendrobium officinale is a rare and traditional medicinal plant with high pharmacological and nutritional value. The self-incompatibility mechanism of D. officinale reproductive isolation was formed in the long-term evolution process, but intraspecific hybridization of different germplasm resources leads to a large gap in the yield, quality, and medicinal value of D. officinale. To investigate the biological mechanism of self-incompatibility in D. officinale, cytological observation and the transcriptome analysis was carried out on the samples of self-pollination and cross-pollination in D. officinale. Results for self-pollination showed that the pollen tubes could grow in the style at 2 h, but most of pollen tubes stopped growing at 4 h, while a large number of cross-pollinated pollen tubes grew along the placental space to the base of ovary, indicating that the self-incompatibility of D. officinale may be gametophyte self-incompatibility. A total of 63.41 G basesum of D. officinale style samples from non-pollinated, self-pollination, and cross-pollination by RNA-seq were obtained, and a total of 1944, 1758, and 475 differentially expressed genes (DEGs) in the comparison of CK (non-pollinated) vs. HF (cross-pollination sample), CK vs. SF (self-pollination sample) and SF vs. HF were identified, respectively. Forty-one candidate genes related to self-incompatibility were found by function annotation of DEGs, including 6 Ca2+ signal genes, 4 armed repeat containing (ARC) related genes, 11 S-locus receptor kinase (SRK) related genes, 2 Exo70 family genes, 9 ubiquitin related genes, 1 fatty acid related gene, 6 amino acid-related genes, 1 pollen-specific leucine-rich repeat extensin-like protein (LRX) related gene and 1 lectin receptor-like kinases (RLKs) related gene, showed that self-incompatibility mechanism of D. officinale involves the interaction of multiple genes and pathways. The results can provide a basis for the study of the self-incompatibility mechanism of D. officinale, and provide ideas for the preservation and utilization of high-quality resources of D. officinale.

Are leaders with postgraduate degrees perceived to be more transformational? A quasi-experimental field study

2019 ◽  
Vol 40 (2) ◽  
pp. 259-273 ◽  
Author(s):  
Morris Mendelson ◽  
Jasmine Alam ◽  
Chris Cunningham ◽  
Adam Totton ◽  
Carrie Smith
Keyword(s):  
Transformational Leadership ◽  
Field Study ◽  
Positive Relationship ◽  
Master's Degree ◽  
Leadership Qualities ◽  
Content Type ◽  
Experimental Field ◽  
Strong Positive Relationship ◽  
Quasi Experimental ◽  
Master’S Degree

PurposeTransformational leadership has been shown to have a positive impact on a host of employee level and organizational performance indicators. However, little research has sought to understand some of the antecedents of this style of leadership. The purpose of this paper is to examine the link between having a post-secondary education and perceptions of transformational leadership.Design/methodology/approachData were collected from two surveys issued in a mid-sized energy company located on the eastern seaboard of North America. One-way ANOVA comparing employees’ perceptions of transformational leadership exhibited by their supervisors that either did or did not have a post-graduate degree demonstrated a strong, positive relationship between the attainment of a Master’s degree and perceived levels of transformational leadership qualities.FindingsThe findings of this quasi-experimental field study demonstrated a strong, positive relationship between the attainment of a Master’s degree and perceived levels of transformational leadership qualities.Originality/valueThis study is the first of its kind to demonstrate that more educated managers are generally perceived to be more transformational in their leadership style.

Career Plateau and Turnover Intention in Chinese Employees: Career Anchor as Moderator

2015 ◽  
Vol 43 (5) ◽  
pp. 757-766 ◽  
Author(s):  
Yueran Wen ◽  
Liu Liu
Keyword(s):  
Turnover Intention ◽  
Positive Relationship ◽  
Management Practices ◽  
Career Anchor ◽  
Career Plateau ◽  
Strong Positive Relationship ◽  
High Level ◽  
The Relationship ◽  
Moderating Role

Based on a survey of 147 Chinese employees, we examined the relationship between perceived career plateau and turnover intention, and the moderating role of career anchor in challenge in this process. We hypothesized that perceived career plateau would be positively related to turnover intention, and that this relationship would be stronger in employees with a higher level of career anchor in challenge than in those with a lower level. The results showed that perceived career plateau had a strong positive relationship with turnover intention, especially in employees with a high level of career anchor in challenge. These findings have implications for research in career development and turnover intention, as well as in management practices.

Hubungan Budaya Pengamanan dan Kinerja Bandar Udara dengan Kepuasan Penumpang Angkutan Udara di Bandar Udara Internasional Soekarno - Hatta

WARTA ARDHIA ◽  
2013 ◽  
Vol 39 (2) ◽  
pp. 128-145
Author(s):  
Siti Masrifah
Keyword(s):  
Significant Relationship ◽  
Positive Relationship ◽  
Service Performance ◽  
Air Transport ◽  
Cultural Relations ◽  
Security Culture ◽  
International Airport ◽  
Passenger Satisfaction ◽  
Strong Positive Relationship ◽  
And Performance

This study examined the association of security culture (X1) and the performance of airport services (X2) with air transport passenger satisfaction (Y), either individually or jointly.This study with a sample of 100 respondents passenger air transport, the distribution of questionnaires to terminal 2F domestic at Soekarno Hatta International Airport Cengkareng.Calculation results show a positive and significant relationship shown in securing cultural relations (X1) to the satisfaction of passenger air transport (Y). Airport service performance (X2) to the satisfaction of passenger air transport (Y). The relation security culture and performance of airport service to the satisfaction of the air transport of passengers together.The final results of this study have a strong positive relationship between security culture in air transport passenger satisfaction. Strong positive relationship between performance of airport services in air transport passenger satisfaction. And a strong positive relationship between culture security and performance of airport services to the satisfaction of the air transport of passengers together.Penelitian ini untuk mengetahui hubungan budaya pengamanan (X1) dan kinerja pelayanan bandar udara (X2) dengan kepuasan penumpang angkutan udara (Y), baik secara sendiri-sendiri maupun secara bersama-sama. Penelitian ini dengan jumlah sampel sebanyak 100 responden penumpang angkutan udara, dengan melakukan sebaran kuesioner di terminal 2F domestik Bandar Udara International Soekarno Hatta Cengkareng. Hasil perhitungan menunjukkan hubungan yang positif dan signifikan pada budaya pengamanan (X1) dengan kepuasan penumpang angkutan, hubungan positif dan signifikan antara kinerja pelayanan bandar udara (X2) dengan kepuasan penumpang angkutan udara (Y), serta menghasilkan hubungan positif dan signifikan antara budaya pengamanan (X1) dan kinerja pelayanan Bandar udara (X2) dengan kepuasan penumpang angkutan udara (Y) secara bersama-sama. Hasil akhir penelitian ini mempunyai hubungan positif dan kuat antara budaya pengamanan dengan kepuasan penumpang angkutan udara. Hubungan positif dan kuat antara kinerja pelayanan Bandar udara dengan kepuasan penumpang angkutan udara. Hubungan positif dan kuat antara budaya pengamanan dan kinerja pelayanan Bandar udara dengan kepuasan penumpang angkutan udara secara bersama-sama. Implikasi bagi penyelenggara bandar udara dalam tercapainya kepuasan penumpang angkutan udara dengan memberikan rasa aman, lancar, tertib, dan selamat dalam suatu penerbangan, serta jasa pelayanan bandar udara dengan kebersihan terminal dan ketersediaan fasilitas yang cukup dan baik.

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