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The species of the family Malpighiaceae are mainly diversified in the Neotropical Region as a consequence of a specialized pollination system. Due to the production of floral oils as a reward to pollinators, and their interaction with Centris, Epicharis (Centridini) and Monoeca (Tapinotaspidini) oil-collecting bee species in most neotropical species, many studies were focused on this interesting mutualistic interaction. However, a few have approached the reproductive biology of these species. The aim of this study was to gather all the existing information to date on the reproductive biology, megagametophyte development and apomixis of the Malpighiaceae species and analyze it together. We found 39 studies on the reproductive biology of 66 species, of which 47% are self-compatible, 33.3% self-incompatible, 18.2% have a mixed system, showing variable behavior among populations and 1.5% agamospermic species. We also found studies/reports on apomixis for eight species (three genera), polyembryony for six species (five genera) and on the development of megagametophyte for 14 species. We showed that our knowledge about the reproductive biology of Malpighiaceae species is scarce and fragmented, obtaining data for only 70–80 species (6–7% out of the total), most of which belonged to one population and/or few analyzed individuals. Further studies about the integral reproductive biology of these species that focus on the analysis of inter-population variations of the reproductive characters should be carried out to better understand how certain reproductive traits of Malpighiaceae species might have evolved and to provide valuable information on the mechanisms of population differentiation. [ABSTRACT FROM AUTHOR]

Asteraceae have the most endemic species of any flowering plant family in oceanic archipelagos, and these insular endemics display a higher frequency of self-compatibility (SC) compared to mainland composites. However, little attention has focused on the evolution of selfing in situ in islands. The genus Tolpis (Asteraceae) in the Macaronesian archipelagos consists predominantly of self-incompatible (SI) or pseudo-self-compatible plants, with one documented occurrence of the origin of self-compatibility (SC) in the Canary Islands. This study reports SC in two small populations of T. succulenta on Graciosa Island in the Azores. Progeny from the two populations exhibit high self-seed set. Segregation in F2 hybrids between SC and SI T. succulenta indicates that one major factor is associated with breeding system, with SC recessive to SI. Molecular phylogenetic analyses show that SC T. succulenta is sister to SI T. succulenta in the Azores, suggesting that SC originated from SI T. succulenta in the Azores. Plants on Graciosa are morphologically distinct from SI populations of T. succulenta on other islands in the Azorean archipelago, with smaller capitula and lower pollen-ovule ratios, both indicative of the selfing syndrome. The factors that may have favored selfing in these populations are discussed, as are the conservation implications of SC. Finally, the issue of whether the two SC populations are cryptic species worthy of taxonomic recognition is discussed. [ABSTRACT FROM AUTHOR]

Brassica rapa and Raphanus sativus are strictly self-incompatible (SI) plants; however, x Brassicoraphanus (baemoochae) is an intergeneric hybrid synthesized following hybridization of B. rapa and R. sativus that is self-compatible (SC). Self-incompatibility in Brassicaceae is controlled by multiple alleles of the S-locus. Two S-locus genes, SRK ( S-locus receptor kinase) and SP11/SCR ( S-locus protein 11 or S-locus cysteine-rich), have been reported to date, both of which are classified into class I and II. In this study, we investigate if there is an alteration in the structure or the expression in SRK or SP11 genes behind the alteration of SI to SC in baemoochae. Class I and II SRK were identified by PCR of the genomic DNA of baemoochae using SRK-specific universal primers. Cloning and sequencing of both classes of SRK was conducted and compared with SRK genes of parental species. Comparison analysis showed no genomic alterations and both of them showed expression in the stigma. Similarly, SP11 genes also showed no genomic alterations and normally are expressed in the anther. Other SI-related genes ( MLPK, ARC1, THL) also showed normal expression in the stigma and anther. Taken together, these results revealed that no structural/gene expression change in these genes was responsible for the breakdown of SI in baemoochae. Rather, the transformation from SI parents to SC descendants could be responding to epigenetic mechanisms. [ABSTRACT FROM AUTHOR]

The breeding system of Eichhornia azurea (Pontederiaceae) has been described as being both self- and heteromorphic incompatible based on crossing experiments performed on plants grown in an experimental garden. We studied the breeding system of tristylous E. azurea population under natural conditions in the Pantanal wetlands, Brazil. Controlled pollinations were conducted using 35 individuals of each floral morph. Legitimate pollinations produced more fruits than self- and illegitimate pollinations, except for the mid-styled morph which was highly self- and heteromorphic compatible. The number of seeds per fruit was higher under legitimate pollinations than in the other treatments, but self- and illegitimate pollinations produced more fruits and seeds in the Pantanal than for individuals of E. azurea in other populations. The higher fruit and seed production resulting from legitimate pollinations corroborate previous studies, but self-compatibility of mid-styled plants was not previously reported. Overall results indicate a partially self- and heteromorphic compatible system for this species in the Pantanal. [ABSTRACT FROM AUTHOR]

The relationship between polyploidy and breeding system is of critical importance for understanding evolution and improving the taxonomy of large Rosaceous genera. Reviewing the data available for the family and for tribe Pyreae (formerly subfamily Maloideae) in particular, it appears that hybridization, pseudogamous gametophytic apomixis, polyploidy, and self-compatibility are closely linked. Studies of the evolutionary significance of any one or two of these factors need to consider the others as well. Taxonomic decisions likewise need to be informed by knowledge of how these factors affect patterns of phenetic and genetic variation. [ABSTRACT FROM AUTHOR]

We examined the reproductive biology of Melocactus curvispinus Pfeiffer (Cereeae, Cactoideae) in xeric areas of northern Venezuela. Floral traits correspond to a classic hummingbird-pollination syndrome; however, pollination is shared between hummingbirds, Leucippus fallax (Bourcier 1843), and anthophorid bees, Ceratina sp. Reproduction occurs during most of the year. Anthesis and nectar secretion occur between noon and sunset. Average daily nectar production per flower was 163.1 μl, nectar sugar concentration between 29.1 and 30.2% (w/w). Hummingbirds promoted inter-plant pollen movement and were relatively more reliable floral visitors than anthophorid bees, but these insects had a higher frequency of floral visits (28.75/day) than hummingbirds (4.96/day). M. curvispinus is self-compatible and autogamous. By combining extended reproductive activity, frequent animal-mediated pollination, and selfing capabilities, this cactus possesses a mating strategy that guarantees reproduction under variable environmental conditions. We argue that based on its reproductive biology, M. curvispinus should be considered an example of evolutionary transition towards selfing within tribe Cereeae. [ABSTRACT FROM AUTHOR]

Heterostyly rarely occurs in families with strongly zygomorphic flowers. For this reason Darwin (1877) doubted whether heterostyly would occur in the Lamiaceae and recent reviews have not reported the floral polymorphism in this family. Here we describe distyly in a rare species of Salvia restricted to bluffs and seaward canyons on Santa Rosa Island (Santa Barbara Co., California) and northwestern Baja California (Mexico). Salvia brandegeei is morphologically distylous with populations composed of equal frequencies of long-and short-styled morphs differing reciprocally in stigma and anther position. Controlled hand pollinations demonstrated no significant differences in the seed set of self, intramorph or intermorph pollinations. Unlike most heterostylous species investigated, S. brandegeei does not possess diallelic incompatibility or ancillary polymorphisms of pollen and stigmas. We propose that the evolution of distyly in S. brandegeei may have been associated with an ecological shift to a new environment in which protandry failed to prevent increased levels of geitonogamy. Heterostyly was then selected because it increased the proficiency of cross-pollination. The origin of distyly in self-compatible S. brandegeei is consistent with Lloyd and Webb's theoretical model for the evolution of distyly. [ABSTRACT FROM AUTHOR]

The reproductive biology of W. berteroi, W. fernandeziana, and a putative hybrid between W. fernandeziana and W. grahamiae, endemic to Robinson Crusoe Island (Juan Fernández archipelago, Chile) was studied. Flowers are hermaphroditic, protandrous, offer nectar, and exhibit secondary pollen presentation involving pollen collecting hairs on the style. These features imply allogamy and biotic pollination. However, male and female phases overlap and no effective pollinators were observed. Experimental data indicate these taxa are self-compatible and facultatively autogamous, a conclusion also suggested by the pollen/ovule ratios. Selfing is accomplished when the stigmatic lobes reflex and touch the style, except for W. berteroi where they do not reflex completely. Autogamy is accomplished in the latter when pollen grains deposited on the inner surface of the corolla throat by the “pollen brush” are gathered by stigmatic lobes when shaken by wind. The degree of autogamy, and perhaps self-compatibility, seems to be inconstant, as implied by the variable natural seed set (overall range 21–188 seeds per fruit). A mixed mating system — primarily outcrossing/entomophilous, but also autogamous — must have been present in the continental ancestors of these taxa. Autogamy promoting self-fertilization is important now — on an island with scarce pollinators — and in the past — when the first founders arrived. [ABSTRACT FROM AUTHOR]

Breeding systems and mating systems of plants in a previously studied secondary deciduous forest were reanalysed in the context of new data. In this analysis, we increased the number of plant species (up to approximately 25% of the plant species in the community), included other life forms (23 annual and perennial species, plus habitat disturbance categories), and considered information about pollinator specificity. The frequencies of species with different sexual systems in a sample of 51 species were 82% hermaphrodite, 14% monoecious, and 4% dioecious. The frequencies of breeding systems in the sample of 49 hermaphroditic and monoecious species were 53% self-incompatible and 47% self-compatible. Self-compatible species included seven partially self-compatible, three self-compatible non-autogamous, and 13 self-compatible autogamous species. None of the species evaluated proved to be agamospermous. Fifty-five percent of the species tested were obligate outbreeders. The proportion of self-incompatible species was higher among trees and shrubs than among annual herbs. The proportion of self-compatible species for perennial herbs and lianas was not different. The association between annual herbs and autogamy was not strong: seven of 13 species were autogamous, five were partially self-compatible, and one was self-incompatible. The main characteristics or factors associated with breeding system were life cycle and successional stage. Short-lived species were mostly self-compatible, and xenogamy tended to be associated with forest and forest-border. In contrast, pollination specificity and life form were not consistently related to breeding system (self-compatibility or self-incompatibility) and mating system (xenogamy or autogamy). [ABSTRACT FROM AUTHOR]

Nuphar ( Nymphaeaceae) comprises a small holarctic group of aquatic perennials whose flowers are pollinated by flies, bees, and beetles. We studied pollination in different populations of the two European species N. lutea and N. pumila in Norway and in Germany. Flowers are self-compatible and protogynous, preventing automatic selfing, and insect pollination is required for seed production. Sympatric populations were studied in Vest-Agder county in Norway to determine whether N. lutea and N. pumila have the same or different pollinators. Allopatric populations of N. lutea in Germany and Norway were then compared to determine whether their pollinator spectra differ as would be expected in an open flower with seemingly easily accessible pollen and nectar. Results of the present as well as previous studies of the pollination of N. lutea and N. pumila show that both species are mainly pollinated by flies, including apparent Nuphar specialists, such as the scatophagid Hydromyza livens and the ephydrids Hydrellia and Notiphila, the last also a long-known pollinator of N. advena in Florida. Pollinator overlap between sympatric heterospecific populations was small, while allopatric conspecific populations had similar visitor and pollinator spectra. We found no evidence of pollination by Donacia beetles as reported from some North American populations of Nuphar. [ABSTRACT FROM AUTHOR]

The reproductive biology of some Scrophularia species in the Iberian Peninsula and Balearic Islands has been studied. Levels of fruit-set in bagged and unbagged inflorescences, the production of seeds/capsule, the effectiveness of seed-set following cross-pollination in the genus and the pollen/ovule ratios have been analyzed. [ABSTRACT FROM AUTHOR]

Pollination mechanisms within the genus Campanula were studied. Tests were undertaken to examine whether in vitro culture of pollen grains can serve as a useful tool for understanding the self- and cross-pollination mechanisms among species. Characteristics of pollen germination were interpreted in relation to mating system and floral biology. Four annual species ( Campanula kremeri, C. dichotoma, C. afra, C. lusitanica), and two perennial species ( C. rotundifolia and C. persicifolia) were investigated. In the annual species pollen germinability is controlled by (1) the age of pollen and/or (2) in what position pollen is deposited around the style. Correlations were found between pollen germinability and mating system in three of the four annual species. No correlations were found either between germinability and age of pollen or position on the style in the perennial species. Pollen germinability reached its maximum in the middle of the male phase in all species, except for C. dichotoma, which had a decreasing germinability throughout anthesis. The germinability was lowest at the time of stigma receptivity for all species except for C. persicifolia, where the stigma did not develop as long as pollen remained on the style. The pollen collecting hairs and pollen removal have been found to play an important role controlling the stigma development, thus affecting self-pollination. This was especially pronounced in C. persicifolia. Further studies will be undertaken to elucidate factors influencing pollination within the genus Campanula. [ABSTRACT FROM AUTHOR]

Senecio vulgaris L. (2n = 40) is suggested to be of autotetraploid origin from S. vernalis Waldst. & Kit. (2n = 20). This conclusion is based on results obtained from experimental hybridisations and cytological observations, and the consideration of morphological affinities, patterns of geographical distribution and hybrid formation under natural conditions. The morphological differences between the two species are related to a difference in the breeding system. Whilst S. vernalis is self-incompatible, S. vulgaris is self-compatible and strongly self-pollinating. Equally, other self-pollinating taxa traditionally associated with S. vulgaris are shown to have evolved independently from outbreeding relatives. Within a narrow frame of relationship, annual weeds have evolved in different cytotaxonomic circumstances. [ABSTRACT FROM AUTHOR]