scholarly journals Breeding system and pollen limitation in two supergeneralist alien plants invading Mediterranean shrublands

2009 ◽  
Vol 57 (2) ◽  
pp. 109 ◽  
Author(s):  
Ignasi Bartomeus ◽  
Montserrat Vilà
Keyword(s):  
Invasive Plants ◽  
Breeding System ◽  
Seed Set ◽  
Pollen Limitation ◽  
Native Plant ◽  
Pollination Services ◽  
Mediterranean Shrublands ◽  
Hand Pollination ◽  
Hybrid Introgression ◽  
Low Efficiency

Many widely known invasive plants are well integrated into native plant–pollinator networks. Typically, these invaders have entomophilous flowers which are visited by a diverse array of pollinators. The type of breeding system and the role that pollination services play in the reproductive success of invasive plants have, however, received little attention. We studied the breeding system and pollen limitation of two entomophilous invasive plants, Carpobrotus affine acinaciformis and Opuntia stricta, in different Mediterranean coastal localities in north-eastern Spain. Both species are, to some degree self-compatible; however, because of frequent visitation, open pollination increased the seed set in both species by at least 50%. Whereas O. stricta showed no pollen limitation, some populations of C. aff. acinaciformis had a lower seed set in open-pollinated flowers than in flowers where supplementary hand-pollination ensured out-crossing. This local pollen limitation in C. aff. acinaciformis could be due to the low efficiency of its visitors (mainly beetles) or its hybrid status. On the basis of previous studies on Carpobrotus sp. hybrid complexes, we suggest that the variability among sites in the seed set of open-pollinated flowers is caused by different degrees of hybrid introgression. Not withstanding, we found the C. aff. acinaciformis seed sets studied were higher than those reported in other regions. Further research is needed to assess the invasion potential of these hybrids in Mediterranean shrublands.

Pollination services provided by various size classes of flower visitors to Eucalyptus globulus ssp. globulus (Myrtaceae)

2004 ◽  
Vol 52 (3) ◽  
pp. 353 ◽  
Author(s):  
A. B. Hingston ◽  
B. M. Potts ◽  
P. B. McQuillan
Keyword(s):  
Seed Production ◽  
Eucalyptus Globulus ◽  
Seed Set ◽  
Pollen Limitation ◽  
Pollination Services ◽  
Flower Visitors ◽  
Large Numbers ◽  
Introduced Honeybee ◽  
Commercially Important ◽  
Almost All

Flowers of the commercially important tree Eucalyptus globulus Labill. ssp. globulus were visited by a wide variety of insects and birds within its natural distribution. Flowers were visited so frequently that most available nectar was consumed, but seed production within 5 m of the ground was consistently far less than the maximum possible, indicating the presence of large numbers of inefficient pollinators and few efficient pollinators. Pollen limitation was more severe on fully self-incompatible trees than on partially self-compatible trees, demonstrating that pollinator inefficiency resulted from infrequent outcrossing rather than inability to deposit pollen on stigmas. The flower visitors that were responsible for almost all nectar consumption from flowers within 5 m of the ground were insects that were able to permeate cages with 5-mm apertures but not cages with 1-mm apertures, the most abundant of which was the introduced honeybee Apis mellifera L. These insects contributed less than 20% of the maximum possible seed set, indicating that they were inefficient pollinators. Birds and smaller insects made lesser contributions to seed production, but consumed little nectar within 5 m of the ground. However, anthophilous birds appeared to mostly forage higher in the trees and probably consumed more nectar from, and provided more pollination services to, flowers higher in the trees.

The critical role of honeyeaters in the pollination of the catspaw Anigozanthos humilis (Haemodoraceae)

2019 ◽  
Vol 67 (4) ◽  
pp. 281
Author(s):  
Tayla van der Kroft ◽  
David G. Roberts ◽  
Siegfried L. Krauss
Keyword(s):  
Seed Set ◽  
Environmental Changes ◽  
Pollen Limitation ◽  
Critical Role ◽  
Outcrossing Rate ◽  
Camera Traps ◽  
Visitation Rates ◽  
Flowering Season ◽  
Hand Pollination ◽  
Study Population

The pollination biology of Anigozanthos humilis (Haemodoraceae) was studied within a Banksia woodland reserve using a combination of field techniques and genetic analysis. Motion-triggered cameras were deployed on 25 flowering plants to identify visitors to flowers, quantify visitation rates and assess visitor behaviour. Entire A. humilis plants were caged to exclude potential floral visitors with six treatments: (i) bird and honey possum exclusion, allowing access by insects; (ii) bird and insect exclusion, allowing access by honey possums; (iii) total animal exclusion; (iv) open, allowing access by birds, insects and honey possums; (v) hand-pollination with cross-pollen; and (vi) hand-pollination with self-pollen. Open pollinated seed were genotyped to assess mating system parameters including outcrossing rate. From 23424 h of surveillance with camera traps, 109 visits were recorded, 106 (97%) of which were western spinebills (Acanthorhynchus superciliosus), with three visits by brown honeyeaters (Lichmera indistincta). We recorded an average of 8 (±4) visits per plant, equivalent to one visit every eleven days over the 2016 flowering season (mean = 63 days). Mean seed set per fruit was negligible (0.2–0.3 seed per fruit) for all pollination treatments except open- and hand-pollination with cross pollen. Mean seed set per fruit for hand cross-pollinated flowers (37.1 seed per fruit) was 37 times that of open pollinated flowers (1.0 seed per fruit). Outcrossing rate estimates were not significantly different to one. Our results indicate that at least for the study population and season, A. humilis was largely dependent on western spinebills for delivery of outcross pollen and resulting seed set, but visitation rates were low and pollen limitation was severe. Given the known sensitivity of western spinebills to habitat fragmentation, our results suggest flow on effects that may negatively impact on reproduction, and means that A. humilis may be particularly vulnerable to environmental changes that impact on bird pollinators.

Preferential outcrossing in Banksia ilicifolia (Proteaceae)

2005 ◽  
Vol 53 (2) ◽  
pp. 163 ◽  
Author(s):  
Bambang Heliyanto ◽  
Erik J. Veneklaas ◽  
Hans Lambers ◽  
Siegfried L. Krauss
Keyword(s):  
Breeding System ◽  
Fungal Pathogen ◽  
Fruit Set ◽  
Pollen Limitation ◽  
Genetic Load ◽  
Open Pollination ◽  
Self Pollination ◽  
Hand Pollination ◽  
Self Compatibility ◽  
Non Local

The breeding system of Banksia ilicifolia was assessed by performing controlled hand-pollination manipulations on flowers in a natural population in Perth, Western Australia. The percentage of 2000 flowers per treatment converted to fruits and seeds was assessed across 24 recipient plants following (1) self-pollination, (2) local outcross pollination (same population), (3) non-local outcross pollination (pollen sourced from another population 30 km away), (4) unpollinated but bagged flowers and (5) unpollinated, unbagged flowers (natural pollination). The relative performance of the resulting seeds was assessed by seed weight, germination rates and, in an unplanned component of the study, resistance to a fungal pathogen. The percentage of flowers converted to fruits following self-pollination was low (0.9%), but demonstrated self-compatibility. Fruit set following cross-pollinations (3.6 and 3.3% for non-local and local crosses, respectively) was significantly greater than that following self-pollination, open-pollination (0.4%) and autogamous (0.04%) treatments. Low fruit set for open-pollinated flowers, compared with self- and outcross-pollination treatments, suggests pollen limitation. Pollen tubes were observed in 15 and 20% of upper styles of flowers hand-pollinated with self and local outcross pollen, respectively. Seed germination was dependent on the source of pollen, where fewer selfed seeds germinated (37%) than did both non-local and local outcrossed seeds (83 and 91%, respectively). Selfed seedlings showed poorer survival (33.3%) following fungal attack than both non-local and local outcrossed seeds (69.2 and 68.5%, respectively). Only 13% of selfed seeds survived to be 2-month-old seedlings, compared with 63% for non-local and 57% for local outcrossed seeds. Ultimately, for 2000 flowers hand-pollinated with self pollen, only three seedlings survived to an age of 16 weeks, compared with 37 and 45 seedlings for local-cross and non-local cross treatments on 2000 hand-pollinated flowers, respectively. These results indicate that in this population, B. ilicifolia is self-compatible, but preferentially outcrossing, with strong early acting inbreeding depression. Consequently, the breeding system of B. ilicifolia promotes the maintenance of genetic variation and a high genetic load.

Floral traits, pollination ecology and breeding system of three Clematis species (Ranunculaceae) in Yunnan province, southwestern China

2010 ◽  
Vol 58 (2) ◽  
pp. 115 ◽  
Author(s):  
Nan Jiang ◽  
Wen-Bin Yu ◽  
Hong-Zhe Li ◽  
Kai-Yun Guan
Keyword(s):  
Inbreeding Depression ◽  
Breeding System ◽  
Pollen Limitation ◽  
Mating Strategies ◽  
Breeding Systems ◽  
Floral Traits ◽  
Pollination Syndrome ◽  
Self Pollination ◽  
Hand Pollination ◽  
Integrative Study

Flowers of Clematis display showy corollas and diversified shapes. This diversity motivates study of adaptive evolution of flower–pollinator interactions and the functional association between floral traits and plant mating strategies. An integrative study was undertaken, which focused on pollination and reproductive biology of three species representing all three floral types of Clematis. Floral traits were measured, and pollinator assemblages were observed in the field. Bagging, hand-pollination and removal treatments were used to examine breeding systems. The inbreeding depression and pollen limitation were estimated by fruit-set and seed production obtained from pollination treatments. Their floral traits are distinctly different, but are highly associated with pollination syndrome and breeding system. Among them, Clematis akebioides and C. rehderiana may be facultative autogamy (the former was delayed selfing, and the later competing selfing), and C. chrysocoma may be nearly obligate outcrossing. These conclusions are reflected in their stamen-pistil ratios. The levels of inbreeding depression are negatively associated with autonomous self-pollination. Evolution of self-pollination in C. akebioides and C. rehderiana, and pollen limitation in reproduction of the three Clematis species are discussed. This present study, integrating with previous results, will help us to comprehensively recognise and understand the pollination system and reproductive characteristics of Clematis.

The effect of invasive Lythrum salicaria pollen deposition on seed set in the native species Decodon verticillatus

Botany ◽  
2011 ◽  
Vol 89 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Elizabeth M. Da Silva ◽  
Risa D. Sargent
Keyword(s):  
Native Species ◽  
Invasive Plant ◽  
Seed Set ◽  
Lythrum Salicaria ◽  
Pollen Deposition ◽  
Native Plant ◽  
Plant Populations ◽  
Hand Pollination ◽  
Whole Plants ◽  
The Impact

Relatively little attention has been paid to pollinator-mediated interactions among invasive and native plants in spite of the fact that pollen transfer between species in invaded communities has been shown to occur. In this study, we investigated the impact of pollen deposition from the invasive plant species Lythrum salicaria on seed set in a native species that is a member of the same family, Decodon verticillatus. Whole plants were subjected to hand pollination by conspecific (D. verticillatus only) or mixed (a 1:1 mixture of D. verticillatus and L. salicaria) pollen to determine if the addition of a mixed pollen load interferes with the ability of D. verticillatus pollen to set seed. We found the mixed pollen treatment reduced D. verticillatus seed set by 33.3% relative to the conspecific pollen treatment. Our study demonstrates that invasive plants have the potential to negatively impact the reproductive success of a native species through pollinator-mediated interactions. We discuss the potential implications of our findings to the evolution and persistence of native plant populations in invaded communities.

Breeding system of Tristerix corymbosus (Loranthaceae), a winter-flowering mistletoe from the southern Andes

2005 ◽  
Vol 53 (4) ◽  
pp. 357 ◽  
Author(s):  
Marcelo A. Aizen
Keyword(s):  
Reproductive Success ◽  
Breeding System ◽  
Seed Set ◽  
Breeding Systems ◽  
Southern Andes ◽  
Flower Pollination ◽  
Hand Pollination ◽  
Pollinator Service ◽  
Sephanoides Sephaniodes ◽  
Tristerix Corymbosus

Harsh climates should select for breeding systems that uncouple reproductive success from unpredictable pollinator service, such as autonomous, within-flower pollination and autogamous seed set. I assessed the breeding system and overall pollinator dependence of Tristerix corymbosus (L.) Kuijt, a mistletoe that blooms during the snowy winters of the southern Andes and whose flowers are visited by the hummingbird Sephanoides sephaniodes. The nectar produced by T. corymbosus represents the main food for overwintering populations of S. sephanioides, one of the principal pollinators in the temperate forest of southern South America. Hand-pollination experiments showed that this plant is fully self-compatible, with only a slight advantage of cross- over self-pollen during either germination or early tube growth. Despite self-compatibility, T. corymbosus exhibited a limited capacity for autonomous, within-flower pollination and high dependence on its hummingbird pollinator for full seed set. Thus, dwindling hummingbird populations should compromise reproductive success in this potential keystone plant species.

Effect of flowering phenology and habitat on pollen limitation in Erica multiflora

1999 ◽  
Vol 77 (5) ◽  
pp. 734-743 ◽  
Author(s):  
Marc Santandreu ◽  
Francisco Lloret
Keyword(s):  
Flowering Time ◽  
Breeding System ◽  
Fruit Set ◽  
Pollen Limitation ◽  
Pine Forest ◽  
Flowering Period ◽  
Erica Multiflora ◽  
Western Mediterranean Basin ◽  
Hand Pollination ◽  
Insect Visitors

Pollination can be a major factor influencing reproductive success in plants. Pollination may be influenced by variability in pollen production and vector activity associated with environmental heterogeneity in time and space. These factors were addressed experimentally using hand pollinations of Erica multiflora L., a shrub occurring in the western Mediterranean Basin that exhibits a long flowering period. Variation in pollen limitation was considered three times (early, peak, and late) over the flowering season and between two habitats (shrubland and pine forest). The breeding system and the pollination vectors were also studied by hand pollination and exclusion experiments. Xenogamy and natural pollination (control) treatments produced more seed and fruit set than geitonogamy and autogamy treatments. Insect visitors were less abundant at the end of the flowering period and in the pine forest habitat. Pollen limitation was not different between habitats, but it changed over the flowering period. Fruit set was pollen limited at the early flowering time, when less flowers were available. Both seed and fruit set were pollen limited at the late flowering time, when both flower density and insect visitors were lower. Seed and fruit set were not pollen limited at the peak of the flowering period, but their low values suggest resource limitation associated with a large number of developing fruits.Key words: breeding system, fruit set, hand pollination, insect pollinator, phenology, seed production.

Reproductive biology and breeding system in Casuarina equisetifolia (Casuarinaceae) – implication for genetic improvement

2016 ◽  
Vol 64 (2) ◽  
pp. 120 ◽  
Author(s):  
Y. Zhang ◽  
C.L. Zhong ◽  
Q. Han ◽  
Q.B. Jiang ◽  
Y. Chen ◽  
...  
Keyword(s):  
Reproductive Biology ◽  
Breeding System ◽  
Genetic Improvement ◽  
Fruit Set ◽  
Seed Set ◽  
Pollen Limitation ◽  
Casuarina Equisetifolia ◽  
Open Pollination ◽  
Floral Longevity ◽  
Improvement Programs

Understanding the reproductive biology of plant species is essential for successful domestication and genetic improvement programs. Casuarina equisetifolia L. is an important plantation species in China and India but information on reproductive biology is limited. To address this issue, grafted ramets of C. equisetifolia were used to study floral biology, breeding system and progeny performance. The female floral longevity of C. equisetifolia reached 28.4 days under non-pollination conditions, which was significantly longer than that of supplementary pollination (5.5 days) and open pollination (12.2 days), implying successful pollination would accelerate senescence of female flowers. Higher fruit set (88.8%) and seed set (35.7%) under supplementary pollination were obtained, compared with 75.9% and 21.7%, respectively, under open pollination, although there were no fruit set and seed set under non-pollination conditions. Pollen limitation was evident based on pollen limitation index (0.39) in seedling plantations of C. equisetifolia. Selfed seedlings had low height and diameter growth in both nursery and field trials and markedly lower survival in field trial, indicating inbreeding depression. Microsatellite-based estimates of selfing rate of open pollinated, monoecious individuals was 42%, suggesting that monoecious C. equisetifolia individuals are self-compatible, and that the breeding system should be classified as facultative xenogamy.

scholarly journals Occurrence and Prevention of Delayed Autonomous Selfing in Salvia umbratica (Lamiaceae)

2021 ◽  
Vol 12 ◽  
Author(s):  
Han-Wen Xiao ◽  
Yan-Bo Huang ◽  
Yu-Hang Chang ◽  
Yun Chen ◽  
Richard J. Abbott ◽  
...  
Keyword(s):  
Fruit Set ◽  
Seed Set ◽  
Pollen Limitation ◽  
Pollen Grains ◽  
Flower Longevity ◽  
Plant Resources ◽  
Floral Longevity ◽  
Hand Pollination ◽  
Pollen Vector ◽  
Highly Correlated

Delayed autonomous selfing (DAS) provides reproductive assurance under conditions of pollinator and/or pollen-limitation. Few plant species have been investigated to determine if DAS is terminated when a flower is sufficiently pollinated by a pollen vector, thereby saving plant resources for other purposes. We examined this possibility in bumblebee-pollinated Salvia umbratica. We first showed that DAS resulting in high fruit set (100%) and seed set (>80%) per flower occurred in the absence of insect pollinators by means of style recurvature and was completed in 94% of flowers 72 h after they opened. In contrast, in flowers pollinated immediately after opening, DAS was prevented by corollas dropping away before styles recurve toward the upper thecae. We next showed that hand-pollination of flowers immediately after they opened resulted in high fruit set (100%) and seed set (>80%) when 5–10 pollen grains or more were deposited on their stigmas, whereas fruit set and seed set were reduced to 45.00 and 22.50%, respectively, when pollen loads were reduced to 1–3 pollen grains. Finally, we showed that on average single pollinator visits deposited 26 pollen grains on stigmas of flowers that had just opened, which is more than enough to ensure high fruit and seed set. Our results indicate that flower longevity is highly correlated with the pollinator environment and female fitness of S. umbratica, with extended flower longevity allowing DAS to occur being advantageous when pollinators are absent, while reduced floral longevity and prevention of DAS being favored when flowers are pollinated by pollinators. Thus, flower longevity in S. umbratica varies so as to optimize reproductive output and resource efforts, and is dependent on the availability and effectiveness of pollinators to pollinate flowers.

Hand-Pollination ofCardamine californicaImproves Seed Set

2006 ◽  
Vol 7 (3) ◽  
pp. 248-252 ◽  
Author(s):  
Kazuki Ariyoshi ◽  
Emily Magnaghi ◽  
Mark Frey
Keyword(s):  
Seed Set ◽  
Hand Pollination
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