Pollen and pollination experiments. IV. ?Mentor pollen? and ?pioneer pollen? techniques regarding incompatibility and incongruity in apple and pear

Euphytica ◽  
1981 ◽  
Vol 30 (2) ◽  
pp. 363-369 ◽  
Author(s):  
T. Visser



1990 ◽  
Vol 38 (2) ◽  
pp. 217 ◽  
Author(s):  
AJ Willis ◽  
JE Ash

The breeding systems of Stylidiurn grarninifolium and S. producturn (= S. grarninifoliurn var. caulescens) were studied by observing the phenology of individual flowers and inflorescences, and relating the data to a series of pollination experiments within and between the species. Inter-specific pollinations yielded similar levels of seed-set to crosses within the species indicating a close relationship between the taxa. Self-pollination of either species is uncommon; however, when it occurs, the majority of selfed ovules are aborted post-zygotically, probably by a system of recessive lethals, as there is no indication of an incompatibility system. It is concluded that the breeding systems of S. grarninifoliurn and S. productum, two of the few eastern Australian species, are similar to those of many Stylidiurn species from the south-west, casting doubt upon hypotheses that the breeding system has led to high rates of speciation in the south-west.



2009 ◽  
Vol 25 (1) ◽  
pp. 85-92 ◽  
Author(s):  
Sara Bumrungsri ◽  
Ekapong Sripaoraya ◽  
Thanongsak Chongsiri ◽  
Kitichate Sridith ◽  
Paul A. Racey

Abstract:The floral biology and pollination ecology of durian, Durio zibethinus, were determined in eight semi-wild trees in mixed-fruit orchards in southern Thailand during April-May 2003 and 2005. Flowers open fully at 16h00–16h30 and most androecia drop around 01h00. Anthers dehisce at 19h30–20h00 when the stigmata are already receptive. In a series of pollination experiments, fruit was set in all treatments within 10 d. The greatest pollination success occurred after hand-crossed (76.6%), open (54.4%) and emasculation pollination (53.3%). Consistently, hand-crossed (12.2%), emasculation (8.7%) and open pollination (5.1%) yielded a substantial fruit set 2 mo after the pollination experiments. Very low pollination success in facilitated autogamy suggests that most durian trees are highly self incompatible. No mature fruit was found after insect pollination and automatic autogamy. Fruit bats, especially Eonycteris spelaea, are the major pollinators of this durian although the giant honey bee (Apis dorsata) was the most frequent visitor to the flowers. Bats visited durian flowers at the rate of 26.1 (SD = 20.7) visits per inflorescence per night. Since this semi-wild durian depends on fruit bats as its pollinator, protecting fruit bat populations and their roosts is vital for the production of the durian fruit crop.







1998 ◽  
Vol 38 (5) ◽  
pp. 523 ◽  
Author(s):  
P. M. Magdalita ◽  
R. A. Drew ◽  
I. D. Godwin ◽  
S. W. Adkins

Summary. A protocol for interspecific hybridisation between Carica papaya and C. cauliflora is necessary for gene introgression between these 2 incompatible species. Carica papaya × C. cauliflora hybrids were successfully created using a new, efficient hybridisation protocol. This protocol includes the use of highly viable pollen of C. cauliflora produced during summer, autumn and/or spring, the use of an isolation time ranging from 90 to 120 days post-pollination of hybrid embryos, and the use of the most compatible C. papaya cultivar 2001 for crossing with C. cauliflora. Two types of interspecific hybrid embryos, namely single and multiple, were isolated in all resulting fruit. The application of gibberellic acid (0.6 or 0.8 mol/L) or 2,4- dichlorophenoxyacetic acid (1.5 or 2.0 mol/L) to freshly cross-pollinated flowers and pollination by mentor pollen did not promote either the rate of successful crosses or the production of hybrid embryos. Using this efficient protocol, hybridisation between C. papaya and C. cauliflora conducted in 3 locations in south-east Queensland produced 338 crosses which generated 43 736 seed. From these seed, 2100 hybrid embryos were recovered resulting in the production of 485 morphologically normal interspecific hybrid plants. Studies reported elsewhere show that these hybrids are resistant to papaya ringspot virus type P.



Nature ◽  
1968 ◽  
Vol 219 (5155) ◽  
pp. 746-747 ◽  
Author(s):  
REINHARD F. STETTLER


2010 ◽  
Vol 58 (2) ◽  
pp. 124 ◽  
Author(s):  
Melanie Schneemilch ◽  
Emma Steggles

Controlled pollination experiments were conducted on Acrotriche serrulata R.Br. (Ericaceae) to determine the mating system for this species. Pollen viability and stigma receptivity were investigated to ensure effective timing and sourcing of material for maximum fertilisation. Stigmas were found to be receptive in mature buds, with receptivity maintained while nectar remained within the corolla tube. Germination testing showed that pollen from within mature buds was viable. The mating system of A. serrulata was found to be predominantly outcrossing, with 49.8% of cross-pollinated flowers developing to fruit, compared with 8.7% of self-pollinated flowers. Seed viability did not differ significantly between fruits produced by cross-pollination and those produced by self-pollination, although this may be attributable to low sample sizes available for self-pollinated fruits. These results in combination with morphological features of the flower suggest that a pollinator is required for this species.



1984 ◽  
Vol 62 (6) ◽  
pp. 1298-1303 ◽  
Author(s):  
Joel S. Shore ◽  
Spencer C. H. Barrett

Controlled pollination experiments were performed on the self-incompatible distylous herb Turnera ulmifolia L. to investigate the effects of pollination intensity and large amounts of incompatible pollen on seed set. In the first experiment, known numbers of compatible pollen grains ranging from 1 to 100 were applied to stigmas of the floral morphs. In both morphs, increasing amounts of pollen generally resulted in increased levels of seed set, although considerable variance was observed at all pollination intensities. Approximately two to seven pollen grains are required to produce a single seed and more than 95 grains are required to achieve maximum seed set in T. ulmifolia. Regression analysis of the seed set data failed to detect a difference in the response of the floral morphs to pollination intensity. In the second experiment, known proportions of compatible and incompatible pollen were applied to stigmas at various time intervals. Most treatments involving mixtures of compatible and incompatible pollen had no significant effect on seed set when compared with the controls. Clogging was only observed in the long-styled morph when one anther of compatible pollen was applied to stigmas 1.5 and 3.0 h after pollination with five anthers of incompatible pollen. The clogging of stigmas by incompatible pollen seems unlikely to have played a major role in the evolution and maintenance of distyly in Turnera ulmifolia.



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