Some pollinators are more equal than others: Factors influencing pollen loads and seed set capacity of two actively and passively pollinating fig wasps

2014 ◽  
Vol 57 ◽  
pp. 73-79 ◽  
Author(s):  
Finn Kjellberg ◽  
Nazia Suleman ◽  
Shazia Raja ◽  
Abelouahad Tayou ◽  
Martine Hossaert-McKey ◽  
...  
Keyword(s):  
Seed Set ◽  
Fig Wasps ◽  
Pollen Loads ◽  
Factors Influencing

Factors Influencing Realized Sex Ratios in Fig Wasps: Double Oviposition and Larval Mortalities

2011 ◽  
Vol 25 (3) ◽  
pp. 254-263 ◽  
Author(s):  
Salah Ghana ◽  
Nazia Suleman ◽  
Stephen G. Compton
Keyword(s):  
Sex Ratios ◽  
Fig Wasps ◽  
Factors Influencing

Pollination and reproductive success in the gynodioecious endemic Thymus loscosii (Lamiaceae)

2005 ◽  
Vol 83 (2) ◽  
pp. 183-193 ◽  
Author(s):  
Maria Renée Orellana ◽  
Anna Maria Rovira ◽  
Cèsar Blanché ◽  
Maria Bosch
Keyword(s):  
Reproductive Success ◽  
Seed Quality ◽  
Seed Set ◽  
Pollen Deposition ◽  
Pollinator Visitation ◽  
Heterospecific Pollen ◽  
Pollen Loads ◽  
Visual Attraction ◽  
Insect Exclusion ◽  
Two Populations

Sexual dimorphism can have implications in the reproductive biology of gynodioecious species, affecting sex fitness. We explored the effects of flower sex on pollination visitation rates and pollinator efficiency in terms of stigmatic pollen loads, as well as on quantitative and qualitative aspects of reproductive success in two populations of Thymus loscosii Willk. (Lamiaceae) endemic to the northeastern Iberian Peninsula. We also assessed the dependence of T. loscosii on insect pollination in both hermaphrodite and female plants by performing an insect exclusion test. Apis mellifera and different species of Bombylidae were the most frequent pollinators (68% of approaches to studied plots and 93% of total visited flowers). Hermaphrodite plants received more visits than female ones, possibly as a response to visual attraction, since flowers of the former are larger. Conspecific pollen deposition was higher on stigmas of hermaphrodite flowers than on those of females; in contrast, female stigmas received more heterospecific pollen loads, notably higher in one population. Despite these differences, seed set from open-pollinated flowers was similar in both sexes and in both populations, and relatively low (around 0.5–1 nutlet per fruiting calyx, on average). Thymus loscosii is self-compatible as it was able to produce seeds by spontaneous selfing, but at very low rates, indicating that it is insect-dependent for pollination. In addition, bagged female flowers also set seeds formed by apomitic mechanisms. In general, seeds from females were slightly heavier and began to germinate earlier and at higher rates than those from hermaphrodites, even those formed by apomixis. These results suggest that female plants enjoy a resource allocation advantage that allows increased seed quality and contributes to the maintenance of gynodioecy.Key words: gynodioecy, pollinator visitation, pollen loads, seed set, sex fitness, Thymus loscosii.

Disassortative pollination in the distylous plant Jepsonia heterandra

1974 ◽  
Vol 52 (11) ◽  
pp. 2401-2406 ◽  
Author(s):  
Fred R. Ganders
Keyword(s):  
Seed Set ◽  
Adaptive Significance ◽  
Pollen Loads ◽  
Self Pollination

Stigmatic pollen loads were analyzed from naturally pollinated intact and emasculated pin- and thrum-form flowers of Jepsonia heterandra. Observed pollen loads on stigmas of emasculated flowers were compared with expected loads based on random pollination. Observed pollen loads indicated that 13.2% disassortative pollination occurred in the pin form and 43.5% disassortative pollination in the thrum form. Pollen loads from intact flowers indicated that much more self pollination and geitonogamy takes place in the pin form than in the thrum form. In this species, distyly effectively promotes phenotypic disassortative pollination.It is suggested that the adaptive significance of distyly m a diallelic self-incompatible species is that the resultant disassortative pollination increases seed set in the population.

COMPARISON OF THE CROSSABILITY OF RYE (SECALE CEREALE) AND HORDEUM BULBOSUM ONTO WHEAT (TRITICUM AESTIVUM)

1981 ◽  
Vol 23 (1) ◽  
pp. 81-88 ◽  
Author(s):  
D. E. Falk ◽  
K. J. Kasha
Keyword(s):  
Triticum Aestivum ◽  
Secale Cereale ◽  
Seed Set ◽  
Genetic System ◽  
Triticum Aestivum L ◽  
Hordeum Bulbosum ◽  
Factors Influencing ◽  
Main System ◽  
Wheat Lines ◽  
System Operating

Fifty-six wheat (Triticum aestivum L.) lines representing a wide diversity of germplasm were screened for crossability with rye. Seed set values ranged from 0.0% to 95.4% of the florets pollinated. Twenty-eight of these wheat lines representing the range of crossability with rye were then pollinated with tetraploid Hardeum bulbosum L. Seed set ranged from 0.0% to 32.2%. Those wheats giving seed set with H. bulbosum generally had medium to high crossability with rye. A high correlation (r = 0.75) was obtained for crossability of rye and H. bulbosum on wheat, indicating that the main genetic system (Kr1 and Kr2) governing crossability with rye is also the main system operating in crosses with H. bulbosum. Evidence for additional factors influencing crossability and for differences between rye and H. bulbosum is provided. Hybrids between wheats having different crossability levels exhibited intermediate crossability levels with rye but very low crossability with H. bulbosum. Hordeum bulbosum genotypes differ in their ability to effect seed set.

Outcrossing Distance Effects in Delphinium Nelsonii: Pollen Loads, Pollen Tubes, and Seed Set

Ecology ◽  
1991 ◽  
Vol 72 (1) ◽  
pp. 171-179 ◽  
Author(s):  
Nickolas M. Waser ◽  
Mary V. Price
Keyword(s):  
Seed Set ◽  
Pollen Tubes ◽  
Pollen Loads ◽  
Distance Effects

scholarly journals Hybridization and Factors Influencing Seed Set in Oat

2021 ◽  
Author(s):  
Harshavardan J. Hilli ◽  
Rahul Kapoor ◽  
Amandeep .
Keyword(s):  
Seed Set ◽  
Floral Structure ◽  
Damage Rate ◽  
Factors Influencing ◽  
Oat Cultivars ◽  
Hybrid Development ◽  
Neglected Crop

Background: Oat is mostly neglected crop for hybrid development due to its floral structure which results in high damage rate during hybridisation. Due to the cumbersome in acquiring a sufficient number of hybrids and subsequent backcrosses are difficult that lead to lack of much inheritance studies in Oats. Methods: The procedure for crossing used was almost identical to that used by oat breeders which was conducted for 2 years viz., 2019-20 and 2020-21 at Forage Station, Punjab Agriculrural University, Ludhiana. Result: The experiment was conducted to know the seed set percent in oat cultivars. Since the oat flower is fragile compared other cereals and it is easily harmed during the emasculation and pollination process. The seed set percent observed was only 12 and 10 percent in the year 2019-20 and 2020-21, respectively.

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