Breeding System and Tests for Pollen-Limitation in Two Species of Banksia

1990 ◽  
Vol 38 (1) ◽  
pp. 63 ◽  
Author(s):  
RL Goldingay ◽  
RJ Whelan
Keyword(s):  
Breeding System ◽  
Reproductive Output ◽  
Fruit Set ◽  
Pollen Limitation ◽  
Floral Display ◽  
Cross Pollination ◽  
Self Pollination

Three factors that potentially influence fruit set (breeding system, inadequate cross-pollination and variable floral display) were examined for two species of Banksia. Firstly, self-pollination and autogamy treatments failed to produce any fruit in B. spinulosa and produced very few fruit in B. paludosa. This suggests that cross pollen is required to produce the level of fruit set observed in the field. Secondly, when plants were given abundant cross pollen, fruit set was not altered in B. spinulosa but was in B. paludosa. Although the number of follicles per inflorescence was was not different for open- pollinated (control) and manipulated B. paludosa inflorescences, the latter produced twice the proportion of inflorescences with follicles produced by control plants and twice the total number of follicles per plant. Thirdly, larger floral display in open-pollinated B. spinulosa plants was associated with a greater production of fruit. However, larger floral display was not associated with a greater reproductive output in B. paludosa, and we suggest that recurrent pollen-limitation in this species may be responsible for this result.

scholarly journals Flower visitors of Streptocarpus teitensis: implications for conservation of a critically endangered African violet species in Kenya

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10473
Author(s):  
Mark Otieno ◽  
Neelendra Joshi ◽  
Benjamin Rutschmann
Keyword(s):  
Breeding System ◽  
Fruit Set ◽  
Safety Net ◽  
Critically Endangered ◽  
Flower Visitors ◽  
Critically Endangered Species ◽  
African Violet ◽  
Cross Pollination ◽  
Self Pollination ◽  
Published Evidence

Background The African violets are endangered plant species restricted mainly to the Eastern Arc Mountains biodiversity hotspots in Kenya and Tanzania. These plants grow well in shaded environments with high humidity. Given their restricted geographical range and published evidence of dependance on insect vectors to facilitate sexual reproduction, understanding their pollination biology is vital for their survival. Methods We conducted an empirical study using flower visitor observations, pan trapping and bagging experiments to establish the role of flower visitors in the fruit set of a locally endemic and critically endangered species of African violet in Taita Hills, Kenya, Streptocarpus teitensis. Results The study found that fruit set is increased by 47.8% in S. teitensis when flowers are visited by insects. However, it is important to note the presence of putative autogamy suggesting S. teitensis could have a mixed breeding system involving self-pollination and cross-pollination since bagged flowers produced 26.9% fruit set. Conclusions Insects appear to be essential flower visitors necessary for increased fruit set in S. teitensis. However, there is evidence of a mixed breeding system involving putative self-pollination and cross-pollination suggesting that S. teitensis is somewhat shielded from the negative effects of pollinator losses. Consequently, S. teitensis appears to be protected to a degree from the risks such as reproduction failure associated with pollinator losses by the presence of a safety net in putative self-pollination.

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.

scholarly journals Pollination biology and reproduction of Seemannia sylvatica (Kunth) Hanstein (Gesneriaceae) in the Serra da Bodoquena National Park, Mato Grosso do Sul

2011 ◽  
Vol 11 (4) ◽  
pp. 125-130 ◽  
Author(s):  
Eduardo Camargo ◽  
Licléia da Cruz Rodrigues ◽  
Andréa Cardoso Araujo
Keyword(s):  
Breeding System ◽  
Fruit Set ◽  
Riparian Forest ◽  
Floral Biology ◽  
Nectar Production ◽  
Mato Grosso ◽  
Nectar Volume ◽  
Cross Pollination ◽  
Self Pollination ◽  
Different Ages

In Brazil, the family Gesneriaceae is represented by 23 genera and approximately 200 species. Seemannia sylvatica is an herb that occurs in dense populations in the riverbeds at Serra da Bodoquena. Goals of this study were to report the floral biology (on the first five days of anthesis), as well as to determine the breeding system and the pollinators of S. sylvatica. Data collection was conducted from June 2005 to July 2006 through monthly field trips, lasting for five days. Data on floral biology, breeding system and on the floral visitors were taken from individuals located along a track 2500 m long, in riparian forest of Salobrinha river. Flowers of S. sylvatica are tubular, red, with no perceptive odor and lasted more than five days (ca. 10 - 20 days in individuals transferred to an urban garden and kept in vases). Seemania sylvatica is protandrous, and the male phase occurred between the first and the fourth days of anthesis, while the female one started in the fifth day. Mean nectar volume secreted was 4.77 ± 3.2 µl, with a significative variation among flowers of different ages. Otherwise, nectar concentration average was 9.71 ± 4.41%, and did not varied significantly in flowers of different ages. The flowers of S. sylvatica were pollinated mainly by the hummingbirds Phaethornis pretrei and Thalurania furcata, and pierced by the bee Ceratina chloris. The butterfly Parides anchises orbygnianus was considered an occasional pollinator of these flowers. Seemannia sylvatica is self-compatible, since fruit set occurred on the experiments of spontaneous self-pollination, manual self-pollination, cross-pollination and open pollination (control). The protandry, coupled with the pattern of nectar production, characterized by low volume and solute concentration, which induces the pollinators to visit different flowers in a given circuit foraging, act maximizing the likelihood of cross-pollination in S. sylvatica. Moreover, the high proportion of fruit set by autogamy is an important strategy considering that S. sylvatica is visited by few species, being pollinated mainly by P. pretrei. Therefore, in the absence of these visitors, the formation of fruits may be achieved.

Pollen limitation and xenia effects in a cultivated mass-flowering tree, Macadamia integrifolia (Proteaceae)

2021 ◽  
Author(s):  
Stephen J Trueman ◽  
Wiebke Kämper ◽  
Joel Nichols ◽  
Steven M Ogbourne ◽  
David Hawkes ◽  
...  
Keyword(s):  
Food Production ◽  
Fruit Set ◽  
Pollen Limitation ◽  
Pollination Services ◽  
Mass Flowering ◽  
Shell Mass ◽  
Cross Pollination ◽  
Macadamia Integrifolia ◽  
Kernel Yield ◽  
Flowering Tree

Abstract Background and Aims Pollen limitation is most prevalent among bee-pollinated plants, self-incompatible plants, and tropical plants. However, we have very little understanding of the extent to which pollen limitation affects fruit set in mass-flowering trees despite tree crops accounting for at least 600 million tons of the 9,200 million tons of annual global food production. Methods We determined the extent of pollen limitation in a bee-pollinated, partially self-incompatible, subtropical tree by hand cross-pollinating the majority of flowers on mass-flowering macadamia (Macadamia integrifolia) trees that produce about 200,000–400,000 flowers. We measured tree yield and kernel quality and estimated final fruit set. We genotyped individual kernels by MassARRAY to determine levels of outcrossing in orchards and assess paternity effects on nut quality. Key Results Macadamia trees were pollen limited. Supplementary cross-pollination increased nut-in-shell yield, kernel yield and fruit set by as much as 97%, 109% and 92%, respectively. The extent of pollen limitation depended upon the proximity of experimental trees to trees of another cultivar because macadamia trees were highly outcrossing. Between 84% and 100% of fruit arose from cross-pollination, even at 200 m (25 rows) from orchard blocks of another cultivar. Large variations in nut-in-shell mass, kernel mass, kernel recovery and kernel oil concentration were related to differences in fruit paternity, including between self-pollinated and cross-pollinated fruit, thus demonstrating pollen-parent effects on fruit quality, i.e. xenia. Conclusions This study is the first to demonstrate pollen limitation in a mass-flowering tree. Improved pollination led to increased kernel yield of 0.31–0.59 tons per hectare, which equates currently to higher farm-gate income of approximately US3,720–US7,080 per hectare. The heavy reliance of macadamia flowers on cross-pollination and the strong xenia effects on kernel mass demonstrate the high value that pollination services can provide to food production.

scholarly journals Time of flowering and fertilisation of quince varieties

1999 ◽  
Vol 5 (1-2) ◽  
Author(s):  
T. Szabó ◽  
J. Nyéki ◽  
M. Soltész ◽  
Z. Szabó ◽  
T. Tóth
Keyword(s):  
Fruit Set ◽  
Fruit Size ◽  
Late Flowering ◽  
Cross Pollination ◽  
Self Pollination ◽  
The Individual ◽  
Contradictory Data

Literature dealing with flowering and fertilisation of quince is scarce. Most controversial and scanty are informations on observations of self- and cross-pollination. According to our observations, differences in blooming time are few (2-3) days only, thus flowering of most varieties is synchronous. The varieties observed are grouped as early, intermediate and late flowering ones. Self fertility of the individual varieties, however, was not assessed unequivocally, therefore it is recommended, by safety reasons, to consider quince actually as a whole to be auto-incompatible. Artificial self-pollination (or rather geitonogamy) as well as cross pollination with other varieties increased substantially fruit set if compared with the results of natural self-pollination (autogamy). According to the fruit set of their open pollinated flowers, varieties have been classified according to fertility as low (below 10 %), medium (between 10 and 20 %) and high (more than 20 %). Cross fertility of varieties is highly variable depending on combination and on season. Contradictory data are probably due to the sensitivity of quince to conditions of search. Better fruit set was coincident with higher number of stout seeds per fruit. Well developed seeds are definitely a prerequisite of larger fruit size.  

Pollination ecology of the dioecious tree Commiphora guillauminii in Madagascar

2004 ◽  
Vol 20 (3) ◽  
pp. 307-316 ◽  
Author(s):  
Nina Farwig ◽  
Emile F. Randrianirina ◽  
Friederike A. Voigt ◽  
Manfred Kraemer ◽  
Katrin Böhning-Gaese
Keyword(s):  
Plant Species ◽  
Fruit Set ◽  
Pollen Limitation ◽  
Bird Species ◽  
Pollination Ecology ◽  
Floral Display ◽  
Flower Visitation ◽  
Visitation Rates ◽  
Male Flowers ◽  
Female Flowers

In dioecious plant species differences in morphology and resources between female and male flowers can have consequences for flower visitation rates. Female flowers sometimes lack pollen and can be less attractive to pollinators than male flowers. We studied the pollination ecology of the dioecious tree Commiphora guillauminii in a dry deciduous forest in western Madagascar. We recorded floral display, visiting insect species and visitation rates for female and male trees. The results showed that female trees produce significantly larger but fewer flowers per inflorescence than male ones. Number of flowers per tree did not differ between the sexes. During 270 observation-hours we observed 17 insect and two bird species visiting the flowers. Mean visitation rates of male flowers were 6.1 times higher than those of female flowers (1.07 vs. 0.18 visitors per flower h−1). Visitation rates to female and male trees showed similar daily and seasonal patterns. Fruit set (2.9%) was low, which could have been caused by pollinator or pollen limitation. This study suggests that dioecy may pose a risk for fruit set and, potentially, reproductive success for plant species with depauperate pollinator faunas on islands such as Madagascar.

scholarly journals Preliminary evaluation of pollen quality, fertility relations and fruit set of selected sour cherry cultivars in polish conditions

2012 ◽  
Vol 61 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Ewa Szpadzik ◽  
Ewa Jadczuk-Tobjasz ◽  
Barbara Łotocka
Keyword(s):  
Fruit Set ◽  
Sour Cherry ◽  
Preliminary Evaluation ◽  
Open Pollination ◽  
Pollen Quality ◽  
Cross Pollination ◽  
Self Pollination

Preliminary experiments were carried out in spring 2006. The percentage of fruit set of 'Schattenmorelle IR-2', 'Koral', 'Debreceni Bötermö', 'újfefértói Fürtos' and 'Karneol' was higher after open pollination compared with self-pollination. The cultivar Vowi had an inconsiderably higher percentage of fruit set after self-pollination compared with open pollination. The percentage of fruit set in 'Debreceni Bötermö' and 'újfehértói Fürtos' was about 25 % higher after pollination by 'Schattenmorelle IR-2' and 'Koral' compared with the percentage of fruit set after cross - pollination of both cultivars with each other. In general, they did not appear to be good pollinators with each other. The highest quality of pollen was observed for the following cultivars: 'Schattenmorelle IR-2', 'Koral' and Vowi and the lowest result was obtained in 'újfehértói Fürtos'. The highest yield was given by the following cultivars: Vowi, Schattenmorelle IR-2 and Koral.

scholarly journals Poor fruit set due to lack of pollinators in Aristolochia manshuriensis (Aristolochiaceae)

2021 ◽  
Vol 154 (1) ◽  
pp. 39-48
Author(s):  
Olga V. Nakonechnaya ◽  
Olga G. Koren ◽  
Vasilii S. Sidorenko ◽  
Sergey A. Shabalin ◽  
Tatyana O. Markova ◽  
...  
Keyword(s):  
Fruit Set ◽  
Pollen Limitation ◽  
Floral Morphology ◽  
Pollen Grains ◽  
Ex Situ ◽  
Colour Pattern ◽  
The Poor ◽  
Self Pollination ◽  
Hand Pollination ◽  
Aristolochia Manshuriensis

Background and aims – Interactions of insects with trap flowers of Aristolochia manshuriensis, a relic woody liana with fragmented natural populations from south-eastern Russia, were studied. Pollination experiments were conducted to identify the causes of the poor fruit set in this plant.Material and methods – The study was carried out at two ex situ sites within the natural range of A. manshuriensis in the suburban zone of the city of Vladivostok (Russia). The floral morphology was examined to verify how it may affect the process of pollination in this species. To test for a probability of self-pollination, randomly selected flowers at the female phase of anthesis (day 1 of limb opening) were hand-pollinated with pollen from the same plant. The daily insect visitation was studied. The pollen limitation coefficient and the number of visitors to the flowers were determined. To identify insects that lay eggs on the flowers, the insects were reared from eggs collected from fallen flowers. Both caught and reared insects were identified.Key results – The floral morphology and the colour pattern of A. manshuriensis are adapted to temporarily trap insects of a certain size. The hand-pollination experiment showed that flowers of this plant are capable of self-pollination by geitonogamy and require a pollinator for successful pollination. The positive value (2.64) for the pollen limitation coefficient indicates a higher fruit set after hand-pollination compared to the control without pollination. The number of visitors to the flowers was low (0.17 visitors per flower per day). Insects from three orders were observed on the flowers: Diptera (up to 90.9%), Coleoptera (8.3%), and Hymenoptera (0.8%). Four species of flies (Scaptomyza pallida, Drosophila transversa (Drosophilidae), Botanophila fugax, and Botanophila sp. 1 (Anthomyiidae)) are capable of transferring up to 2500–4000 pollen grains on their bodies and can be considered as pollinators of A. manshuriensis. Data of the rearing experiment indicate that flies of the families Drosophilidae (S. pallida, D. transversa), Chloropidae (Elachiptera tuberculifera, E. sibirica, and Conioscinella divitis), and Anthomyiidae (B. fugax, B. sp. 1) use A. manshuriensis flowers to lay eggs. Beetles were also collected from the flowers, but they were probably not involved in pollination, because no pollen grains were observed on them during our study.Conclusions – Pollinators of A. manshuriensis include mainly Diptera that lay eggs on the flowers. The poor fruit set (2%) in A. manshuriensis is associated with pollen limitation due to the lack of pollinators, as the number of visitors to flowers was extremely low. This may be due to the fact that the flowers of this species are highly specialized on insects of a certain size for pollination.

scholarly journals Reproductive Success after Self-pollination and Cross-pollination of Olive Cultivars in Croatia

HortScience ◽  
2011 ◽  
Vol 46 (2) ◽  
pp. 186-191 ◽  
Author(s):  
Gabriela Vuletin Selak ◽  
Slavko Perica ◽  
Smiljana Goreta Ban ◽  
Mira Radunic ◽  
Milan Poljak
Keyword(s):  
Reproductive Behavior ◽  
Fruit Set ◽  
Positive Response ◽  
Flowering Period ◽  
Self Incompatibility ◽  
Cross Pollination ◽  
Self Pollination ◽  
Cross Compatibility ◽  
Olive Cultivars ◽  
Simultaneous Flowering

Olive orchard productivity largely depends on the choice of planted cultivars and their pollination needs. Orchard designs in Croatia are changing because a number of valuable foreign olive cultivars, mostly Italian, have been introduced in this region in the last 30 years. The compatibility relationships of introduced cultivars with autochthonous cultivars are unknown. With the objective of studying reproductive behavior of the most important Croatian cultivars (Drobnica, Lastovka, Levantinka, and Oblica) and their cross-pollination to recently introduced Italian cultivars Leccino and Pendolino, initial and final fruit set in self-pollination versus cross-pollination and free pollination were compared during three flowering seasons. Experiments were conducted in three different orchards (Kastela, Mravince, and Brac) to identify the effect of the environment on reproductive behavior of olive cultivars. The differences of fruit set in five olive cultivars after tested pollination treatments appeared at the time of initial fruit set. Increased final fruit set under cross-pollinations was observed when compared with self-pollination for all olive cultivars in all experimental orchards. In the Mravince orchard, a positive response to cross-pollination was consistent, and fruit set increased under cross-pollination in all cultivars and years with the exception of ‘Levantinka’ in which no significant differences were noticed between self-pollination treatment and cross-pollination treatments in 2005. Variable self-fertility behavior from season to season was found for tested cultivars. A self-incompatibility index (ISI) higher than 0.1 was recorded for ‘Levantinka’ in all experimental years and, therefore, classified it as a partially self-incompatible cultivar. Self-incompatibility response was observed for ‘Lastovka’. The positive response to cross-pollination over self-pollination only in some experimental years classified ‘Drobnica’, ‘Leccino’, and ‘Oblica’ as partially self-incompatible. Results obtained from this study indicated that pollination efficiency is strictly combination-specific. The Italian cultivar, Leccino, was a successful pollen acceptor and pollenizer of most Croatian cultivars. Reciprocal high success in cross-pollination was recorded for ‘Levantinka’ and ‘Oblica’. In the Mravince orchard, ‘Lastovka’, ‘Leccino’, and ‘Oblica’ were efficient pollenizers of ‘Levantinka’ where the simultaneous flowering period was in accordance with their cross-compatibility. ‘Levantinka’ was a good pollenizer for ‘Lastovka’ in the Mravince orchard, and both cultivars entered into the flowering period earlier than other studied cultivars, which was not the case in the other two orchards. The variations in flowering timing among orchards were a consequence of differences in environmental conditions. According to the high fruit sets recorded in ‘Oblica’ after pollination with ‘Leccino’ or ‘Levantinka’, an increase in tree productivity of the acceptor cultivar is expected in the presence of selected pollenizers in all olive-growing regions.

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