Floral Morphology Research Articles

Reduced visitation to buzz-pollinated Cyanella hyacinthoides in the presence of other pollen sources in the hyperdiverse Cape Floristic Region.

Many plant species have floral morphologies that restrict access to floral resources, such as pollen or nectar, and only a subset of floral visitors can perform the handling behaviors required to extract restricted resources. Due to the time and energy required to extract resources from morphologically complex flowers, these plant species potentially compete for pollinators with co‐flowering plants that have more easily accessible resources. A widespread floral mechanism restricting access to pollen is the presence of tubular anthers that open through small pores or slits (poricidal anthers). Some bees have evolved the capacity to remove pollen from poricidal anthers using vibrations, giving rise to the phenomenon of buzz‐pollination. These bee vibrations that are produced for pollen extraction are presumably energetically costly, and to date, few studies have investigated whether buzz‐pollinated flowers may be at a disadvantage when competing for pollinators’ attention with plant species that present unrestricted pollen resources. Here, we studied Cyanella hyacinthoides (Tecophilaeaceae), a geophyte with poricidal anthers in the hyperdiverse Cape Floristic Region of South Africa, to assess how the composition and relative abundance of flowers with easily accessible pollen affect bee visitation to a buzz‐pollinated plant. We found that the number of pollinator species of C. hyacinthoides was not influenced by community composition. However, visitation rates to C. hyacinthoides were reduced when the relative abundances of flowers with more accessible resources were high. Visitation rates were strongly associated with petal color, showing that flower color is important in mediating these interactions. We conclude that buzz‐pollinated plants might be at a competitive disadvantage when many easily accessible pollen sources are available, particularly when competitor species share its floral signals.

Phylogenetic Relationships of the Orchid Genus Coelogyne in Peninsular Malaysia Inferred from Morphological Characteristics and Internal Transcribed Spacer (ITS) Sequence Data

The phylogenetic relationships among the Peninsular Malaysian orchid genus Coelogyne were studied by morphological characteristics and sequence data of the internal transcribed region (ITS) from the nuclear ribosomal DNA (nrDNA). Coelogyne is a large genus of about 200 species distributed in pantropical areas from the Himalayas, Sri Lanka, India, Southern China and throughout South East Asia to Papua New Guinea. The widely accepted previous classification system was exclusively based on floral morphology. There were very few molecular systematic studies of Coelogyne done in Peninsular Malaysia thus far. In this study, 59 Coelogyne samples were collected throughout Peninsular Malaysia and 57 of them were identified to the species level. To study the phylogeny of this genus, morphological characters were utilized together with molecular evidences to generate the systematic hypotheses. Cluster analysis was performed using both the vegetative and floral characters. The results showed that three sections of Peninsular Malaysian Coelogyne, namely Longifoliae, Speciosae, and Fuliginosae were sister groups which were more closely related by forming one clade by itself. Another clade consisted of four other sections, namely Flaccidae, Coelogynae, Tomentosae, and Verrucosae. Molecular phylogenies obtained by using the Neighbour-Joining method showed the close relationship between the sections Tomentosae and Verrucosae, whereas usage of the Maximum Likelihood method demonstrated that three sections, namely Longifoliae, Speciosae, and Fuliginosae, were sister groups since they formed a single clade.

Short flowers for long tongues: Functional specialization in a nocturnal pollination network of an asclepiad in long‐tongued hawkmoths

AbstractSince Darwin, very long and narrow floral tubes have been known to represent the main floral morphological feature for specialized long‐tongued hawkmoth pollination. However, specialization may be driven by other contrivances instead of floral tube morphology. Asclepiads are plants with a complex floral morphology where primary hawkmoth pollination had never been described. We detailed here the intricate pollination mechanism of the South American asclepiad Schubertia grandiflora, where functional specialization on long‐tongued hawkmoth pollinators occurs despite the short floral tube of this species. We studied two plant populations in the Brazilian Cerrado and recorded floral visitors using different approaches, such as light‐trapped hawkmoths for pollen analysis, direct field observations, and IR motion‐activated cameras. Finally, using a community‐level approach we applied an ecological network analysis to identify the realized pollinator niche of S. grandiflora among the available niches in the pollinator community. Throughout a period of 17 years, long‐tongued hawkmoths were consistently recorded as the main floral visitors and the only effective pollinators of S. grandiflora. Flowers rely on highly modified corona and gynostegium, and enlarged nectar chambers, to drive visitors and pollination mechanism. Despite its relative short‐tube, network analysis placed S. grandiflora in the module including exclusively long‐tongued hawkmoth pollinators and the most phenotypically specialized sphingophilous plants in the community. These results represent the first example of functional specialization in long‐tongued hawkmoths in an asclepiad species. However, this specialization is uncoupled from the long floral tubes historically associated with the sphingophily syndrome.Abstract in Portuguese is available with online material.

SlMBP22 overexpression in tomato affects flower morphology and fruit development

MADS-domain transcription factors have been identified as key regulators involved in proper flower and fruit development in angiosperms. As members of the MADS-box subfamily, Bsister (Bs) genes have been observed to play an important role during the evolution of the reproductive organs in seed plants. However, their effects on reproductive development in fruit crops, such as tomato (Solanum lycopersicum), remain unclear. Here, we found that SlMBP22 overexpression (SlMBP22-OE) resulted in considerable alterations in floral morphology and affected the expression levels of several floral homeotic genes. Further analysis by yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays demonstrated that SlMBP22 forms dimers with class A protein MACROCALYX (MC) and SEPALLATA (SEP) floral homeotic proteins TM5 and TM29, respectively. In addition, pollen viability and cross-fertilization assays suggested that the defect in female reproductive development was responsible for the infertility phenotype observed in the strong overexpression transgenic plants. Transgenic fruits with mild overexpression exhibited reduced size as a result of reduced cell expansion, rather than impaired cell division. Additionally, SlMBP22 overexpression in tomato not only affected proanthocyanidin (PA) accumulation but also altered seed dormancy. Taken together, these findings may provide new insights into the knowledge of Bs MADS-box genes in flower and fruit development in tomato.

The symmetry spectrum in a hybridising, tropical group of rhododendrons.

Summary Many diverse plant clades possess bilaterally symmetrical flowers and specialised pollination syndromes, suggesting that these traits may promote diversification. We examined the evolution of diverse floral morphologies in a species‐rich tropical radiation of Rhododendron.We used restriction‐site associated DNA sequencing on 114 taxa from Rhododendron sect. Schistanthe to reconstruct phylogenetic relationships and examine hybridisation. We then captured and quantified floral variation using geometric morphometric analyses, which we interpreted in a phylogenetic context.We uncovered phylogenetic conflict and uncertainty caused by introgression within and between clades. Morphometric analyses revealed flower symmetry to be a morphological continuum without clear transitions between radial and bilateral symmetry. Tropical Rhododendron species that began diversifying into New Guinea c. 6 million years ago expanded into novel floral morphological space.Our results showed that the evolution of tropical Rhododendron is characterised by recent speciation, recurrent hybridisation and the origin of floral novelty. Floral variation evolved via changes to multiple components of the corolla that are only recognised in geometric morphometrics with both front and side views of flowers.

Evolution of the Anther Gland in Early-Branching Papilionoids (ADA Clade, Papilionoideae, Leguminosae).

Papilionoideae is the most diverse subfamily of Leguminosae, especially in terms of floral morphology. The ADA clade shows some exciting floral features among papilionoids, such as anther glands. However, the evolution of the anther glands in such early-branching papilionoids remains unknown. Thus, we compared the occurrence, distribution, morphology, and evolutionary history of the anther glands in species of the ADA clade. Floral buds and/or flowers in 50 species were collected from herbarium specimens and investigated using scanning electron and light microscopy and reconstruction of ancestral character states. The anther apex has a secretory cavity, secretory duct, and phenolic idioblast. The lumen shape of the cavity and duct is closely related to the shape of the anther apex. The oval lumen is located between two thecae, the spherical lumen in the prominent anther apex and the elongated lumen in anthers with a long apex. The occurrence of cavities/ducts in the anther in only two phylogenetically closely related subclades is a unifying character -state. The floral architecture is not correlated with cavity/ducts in the anther but is possibly related to the type of pollinator. Future research needs to combine floral morphology and pollination systems to understand the evolution of floral designs and their diversification.

Colocasia spongifolia sp. nov. (Araceae) in southern China and central Vietnam

Colocasia spongifolia sp. nov. (Araceae) is a large herb in forest edges on mountain slopes in southern China and central Vietnam. The plant is remarkable for its distinct vegetative morphology, while floral morphology places it as a close wild relative of C. esculenta (taro), among other closely-related species. The name given here reflects a thick, rubbery, spongy leaf blade unlike the blades in other Colocasia species known to us. The blade has exceptionally large spongy mesophyll cavities that are visible to the naked eye. Vegetative reproduction appears to be limited to direct (though shy) sprouting of lateral buds to form new erect stems, without production of side-tubers or stolons. In contrast to other Colocasia species, dense spreading colonies (clumps or patches) were not seen.

Eriocaulon benedictum and E. naviculum (Eriocaulaceae): Two New Species from the Brazilian Cerrado

Abstract— Two new species of Eriocaulon (Eriocaulaceae) from the Brazilian Cerrado are described and illustrated. Eriocaulon benedictum, found in the Tocantins River Basin and Plate River Basin has a vegetative morphology similar to Eriocaulon aquatile and E. modestum due to the submerged life form with submerged leaves and long scapes surpassing the water column, but differs from both by the presence of a submerged stem with spiral leaves (vs. a rhizome with rosulate leaves), obtrullate floral bracts (vs. oblong floral bracts in E. aquatile or obovate in E. modestum), and band shaped projections on the seeds (vs. post shaped projections on E. modestum or projections absent in E. aquatile). Eriocaulon naviculum, found in the Araguaia River Basin, an emergent species, has a floral morphology similar to E. altogibbosum and E. gibbosum due to the presence of gibbous sepals in the pistillate flowers, but differs from both by the grey trichomes on the leaf sheath (vs. translucent trichomes in the latter species), slightly sinuous scapes (vs. straight scapes in the latter species), membranous, gibbous swelling in the sepals of the pistillate flowers (vs. incrassate gibbous swelling in the latter species), and seeds without projections with a rough lumen (vs. seeds without projections with a smooth lumen in E. gibbosum or seeds with band-like projections in E. altogibbosum). Detailed descriptions, including anatomical and seed data, illustrations, and maps of occurrence are presented for the new species, as are data on the ecology, geographic distribution, and risk assessments. An updated key for Eriocaulon species from the Tocantins-Araguaia River Basin is also provided.

Structure and Development of Flowers and Inflorescences in Burmannia (Burmanniaceae, Dioscoreales).

Species of the genus Burmannia possess distinctive and highly elaborated flowers with prominent floral tubes that often bear large longitudinal wings. Complicated floral structure of Burmannia hampers understanding its floral evolutionary morphology and biology of the genus. In addition, information on structural features believed to be taxonomically important is lacking for some species. Here we provide an investigation of flowers and inflorescences of Burmannia based on a comprehensive sampling that included eight species with various lifestyles (autotrophic, partially mycoheterotrophic and mycoheterotrophic). We describe the diversity of inflorescence architecture in the genus: a basic (most likely, ancestral) inflorescence type is a thyrsoid comprising two cincinni, which is transformed into a botryoid in some species via reduction of the lateral cymes to single flowers. Burmannia oblonga differs from all the other studied species in having an adaxial (vs. transversal) floral prophyll. For the first time, we describe in detail early floral development in Burmannia. We report presence of the inner tepal lobes in B. oblonga, a species with reportedly absent inner tepals; the growth of the inner tepal lobes is arrested after the middle stage of floral development of this species, and therefore they are undetectable in a mature flower. Floral vasculature in Burmannia varies to reflect the variation of the size of the inner tepal lobes; in B. oblonga with the most reduced inner tepals their vascular supply is completely lost. The gynoecium consists of synascidiate, symplicate, and asymplicate zones. The symplicate zone is secondarily trilocular (except for its distal portion in some of the species) without visible traces of postgenital fusion, which prevented earlier researchers to correctly identify the zones within a definitive ovary. The placentas occupy the entire symplicate zone and a short distal portion of the synascidiate zone. Finally, we revealed an unexpected diversity of stamen-style interactions in Burmannia. In all species studied, the stamens are tightly arranged around the common style to occlude the flower entrance. However, in some species the stamens are free from the common style, whereas in the others the stamen connectives are postgenitally fused with the common style, which results in formation of a gynostegium.

A revised phylogenetic classification of tribe Phyllantheae (Phyllanthaceae)

The majority of tribe Phyllantheae (Phyllanthaceae) is currently placed in the paraphyletic genus Phyllanthus and discussions have persisted on how to resolve this issue. Here, we split Phyllanthus into ten monophyletic genera, which are all reinstatements of former genera, but with changes made to the circumscription and constituent species of each group. The genera Breynia, Glochidion and Synostemon were recently found to be nested within Phyllanthus and discussions ensued whether or not to subsume everything into Phyllanthus s.l. Instead of combining all these genera, we here implement the solution of splitting Phyllanthus into strictly monophyletic genera to ensure that the classification is consistent with the latest phylogenetic results. The new classification is based on a phylogenetic framework combined with differences in habit, branching type, floral, fruit and pollen morphology. With this new division of the genus Phyllanthus, tribe Phyllantheae will consist of the following 18 genera: Breynia, Cathetus, Cicca, Dendrophyllanthus, Emblica, Flueggea, Glochidion, Heterosavia, Kirganelia, Lingelsheimia, Lysiandra, Margaritaria, Moeroris, Nellica, Nymphanthus, Phyllanthus, Plagiocladus and Synostemon. As a result of the reinstated genera, five new names for illegitimate combinations or previous overlooked nomenclatural anomalies and 645 new combinations are proposed. Several keys are provided to distinguish the reinstated genera. Full species lists are given for the reinstated genera treated here except for Breynia, Synostemon and Glochidion.

Atacamallium minutiflorum (Amaryllidaceae, Allioideae), new genus and species from the coastal desert of northern Chile

AbstractAtacamallium, a new genus in Amaryllidaceae‐Allioideae‐Leucocoryneae, is introduced with a description of its type Atacamallium minutiflorum, endemic to the coastal Atacama Desert of northern Chile. Phylogenetic analyses of DNA sequences, along with morphological characters and its distribution pattern, support the new genus and place it as a putative sister to Leucocoryne, which is readily distinguished from Atacamallium by its floral morphology. Atacamallium minutiflorum differs from other species of Leucocoryneae by its overall smaller flowers, tepals fused only at the base, six stamens in a single series, and trifid stigma. A morphological description, a distribution map, an illustration, and the assessment of the conservation status of the new species, besides an updated key to the genera of Leucocoryneae, are provided. Additional data from multiple single‐copy nuclear genes are needed to clarify the relationships within the tribe.

Study of Various Floral Types on Different Plants of Garcinia indica (Thouars) Choisy and Correlation of Its Functionality in Sexual Reproduction

ABSTRACT Genus Garcinia shows high diversity of sexual systems; most of them are dioecious in nature. The other reported sexual systems of Garcinia include gynodioecious, androdioecious, monoecious, and andromonoecious. Garcinia indica (Thouars) Choisy was reported as facultative apomictic polygamodioecious species. There is a large diversity in floral types. Hence, a detailed study of various floral types found on different types of plants of G. indica and to correlate its functionality with sexual reproduction was undertaken. The study at Kokum Plot, BSSKVV, Dapoli, revealed that the male plants could be categorized into four types – androecious, functional males, andromonoecious, and hermaphrodites. The female plants displayed large variation in number and viability of stamens/staminodes. Each category showed significant difference in phenology, floral morphology and pollen types. In December, the percentage of staminate flowers (79.13 ± 2.93%) in androecious trees was significantly higher than functional males (58.61 ± 8.60%) or andromonoecious trees (56.36 ± 2.77%) (p ≤ .01). As female plants started flowering, all male morphotypes bore significantly higher numbers of staminate flowers and carpellate flowers were significantly reduced. Pollen viability was highest in androecious flowers at 90.11 ± 1.10% and lowest at 64.70 ± 2.09% in hermaphrodite trees. Earlier studies reported female flowers bore well-developed female gametophyte, but the embryo development was not observed. Thus, the fruit formation might be apomictic, but in present embryological investigation; more than 60% of female and andromonoecious flowers, a well-developed embryo was formed between 8 and 24 h after anthesis. Thus, the embryo formation might be sexual or apomictic. Floral types favoring sexual reproduction are essential for conservation of highly endemic species.

Targeted suppression of gibberellin biosynthetic genes ZmGA20ox3 and ZmGA20ox5 produces a short stature maize ideotype.

SummaryMaize is one of the world’s most widely cultivated crops. As future demands for maize will continue to rise, fields will face ever more frequent and extreme weather patterns that directly affect crop productivity. Development of environmentally resilient crops with improved standability in the field, like wheat and rice, was enabled by shifting the architecture of plants to a short stature ideotype. However, such architectural change has not been implemented in maize due to the unique interactions between gibberellin (GA) and floral morphology which limited the use of the same type of mutations as in rice and wheat. Here, we report the development of a short stature maize ideotype in commercial hybrid germplasm, which was generated by targeted suppression of the biosynthetic pathway for GA. To accomplish this, we utilized a dominant, miRNA‐based construct expressed in a hemizygous state to selectively reduce expression of the ZmGA20ox3 and ZmGA20ox5 genes that control GA biosynthesis primarily in vegetative tissues. Suppression of both genes resulted in the reduction of GA levels leading to inhibition of cell elongation in internodal tissues, which reduced plant height. Expression of the miRNA did not alter GA levels in reproductive tissues, and thus, the reproductive potential of the plants remained unchanged. As a result, we developed a dominant, short‐stature maize ideotype that is conducive for the commercial production of hybrid maize. We expect that the new maize ideotype would enable more efficient and more sustainable maize farming for a growing world population.

Pollination-precision hypothesis: support from native honey bees and nectar bats.

The evolution of floral traits is often considered to reflect selection for increased pollination efficiency. Known as the pollination-precision hypothesis, increased pollination efficiency is achieved by enhancing pollen deposition on precise areas of the pollinator. Most research to date addressing this hypothesis has examined plant species that are a priori predicted to place pollen precisely, but we still lack comparisons with species predicted to have low pollination efficiency. We studied 39 plant species with diverse floral morphologies and measured the precision of pollen placement on two pollinator groups: honey bees (genus Apis) and nectar bats (family Pteropodidae). Pollen was collected from four locations of each pollinator's body (bees: dorsal thorax, ventral thorax, dorsal abdomen, ventral abdomen; bats: crown, face, chest, wing) to calculate pollen placement precision using Pielou's evenness index. We also quantified variation in floral design by scoring floral symmetry, corolla fusion, floral orientation and stamen number. We confirm the importance of four floral character states (bilateral symmetry, fused corollas, horizontal orientation and reduced stamen number) in promoting precise pollen placement on diverse pollinators. Our findings provide phylogenetically corrected, empirical support that the evolution of the four floral characters reflect selection for enhanced precision of pollen placed on pollinators.

Novelties in Myanmar Agapetes (Ericaceae) with an updated checklist of species from the country

We provide novel taxonomic information for Agapetes (Ericaceae) from Myanmar, describe the new species A. oligodonta, provide a supplemental description of the floral morphology of A. epacridea, and raise A. odontocera var. stenosepala to the rank of species. Line illustrations and photographs of living plants of A. oligodonta and A. epacridea are included, as well as an updated checklist of Agapetes from Myanmar (56 species, 9 varieties and 1 form) with discussion on the distribution of some species.

A new putative natural hybrid of Cyrtopodium (Orchidaceae) from the south coast of Brazil

A new putative natural hybrid of Cyrtopodium, C. × flavopunctatum, from sandy coastal plain vegetation, known as restinga, in the state of Santa Catarina in southern Brazil is described and illustrated. It was found growing among a population of C. flavum and is similar to that species in vegetative and overall floral morphology, but distinguished by the sepals and petals with brown spots, lateral lobes of lip and base of the central lobe orange or orange-spotted, very short isthmus (1–2 mm long), lip midlobe margins slightly verrucose and flowers slightly citrusy-scented. In the color of the flowers, it is intermediate between C. flavum, with completely yellow flowers, and C. gigas or C. palmifrons, epiphytic species with profusely dotted flowers that occur in the same region and bloom at the same time as C. flavum. Additional studies with genetic data are needed to confirm the possible hybrid origin and the identity of the second parental species.

Green and facile synthesis of EuBDC coordination polymer: Effects of ultrasound and stabilizing agent on morphological, structural and photophysical properties

In this study, a facile, green and fast method to produce the coordination polymer (CP) EuBDC is proposed for the first time using a stabilizing agent and ultrasonic irradiation. The crystal structure was investigated by XRD crystallography and it was demonstrated that the crystallographic profile was not affected by the addition of different amounts of PVP or the degree of crystallinity (which presented a value of ∼75%). The results showed that EuBDC synthesized in the absence of PVP exhibited a floral microcrystalline morphology, which changes to lamellar crystals with nanometric thickness with an increase in the PVP content. A notable result is that the surface area of the CP is approximately tripled in the presence of the stabilizer, and higher than values reported in the literature for this compound. The photoluminescence of all CPs displays a strong red emission characteristic of Eu(III) ions. Therefore, our study offers a fast, green, and economical synthetic route for the preparation of the coordination polymer EuBDC, in a controllable way with improved properties, which can promote the scale-up and broaden the applications of this material.

Variations in Structure among Androecia and Floral Nectaries in the Inverted Repeat-Lacking Clade (Leguminosae: Papilionoideae).

The vast majority of highly valuable species of the Leguminosae in temperate latitudes belong to the Inverted Repeat-Lacking Clade (IRLC). Despite having a generally conserved monosymmetric floral morphology, members of this group are remarkable with a pronounced diversity of floral sizes, modes of staminal fusion, and pollination strategies. This paper examined androecia and floral nectaries (FNs) in selected genera of the IRLC. External morphology was investigated using stereomicroscopy and scanning electron microscopy. In some cases, the pattern of staminal fusion was additionally examined in transverse sections using light microscopy. Androecia of all selected genera fell into one of four types, viz., monadelphous, pseudomonadelphous, diadelphous or diadelphous reduced (with inner stamens converted into sterile staminodes). However, there was significant variation in the stamens’ mode of contact, as well as the shape and size of the fenestrae providing access to FNs. Some types seemed to arise independently in different genera, thus providing a high level of homoplasy. FNs were more conserved and comprised areas of secretory stomata in the abaxial part of the receptacle and/or hypanthium. Nectariferous stomata could be found in very miniaturized flowers (Medicago lupulina) and could even accompany monadelphy (Galega). This indicates that preferential self-pollination may nevertheless require visitation by insects.

Development of hybrid DNA-copper phosphate nanoflowers as peroxidase enzyme mimics and for colorimetric sensing of phenol

A facile co-precipitation method was adapted for the synthesis of DNA coated copper phosphate nanoflowers (CuPNF_ctDNA) using calf thymus DNA (ctDNA) and the copper salt in phosphate buffer saline (PBS). The flower growth was monitored using scanning electron microscopy (SEM), wherein a fully formed floral morphology was observed after 36 h. The SEM data further supported a decrease in the size of the nanoflower (NF) and an increase in the density of petals upon increasing the added ctDNA concentration. The coated nanoflowers, viz., CuPNF_ctDNAx {‘x’ is the concentration of ctDNA used for coating} were characterized using spectroscopy, microscopy and diffraction techniques. The petals of the NFs were observed in transmission electron microscopy and the inorganic copper phosphate framework was characterized by powder X-ray diffraction. The surface charge of the NFs (CuPNF_ctDNAx) were measured using zeta potential equipment at different values of ‘x’ used in the preparation. The presence of phosphorous in DNA and that in the copper phosphate were confirmed using X-ray photoelectron spectra. The peroxidase mimetic activity of CuPNF_ctDNA0.3 was measured using 3,3′,5,5′-tetramethylbenzidine (TMB) in presence of H2O2 in acetate buffer at pH 4.5. The enzyme kinetics were evaluated using the Michaelis–Menten steady state curve along with the Lineweaver – Burk plot and the derived Km values were 0.011 and 1.36 mM for TMB and H2O2 respectively. Micromolar detection of phenol in phosphate buffer saline (PBS) at pH = 7.4 was performed using 4-aminoantipyrine as substrate to a limit of detection of 5.2 μM. Thus, the hybrid material, viz., CuPNF_ctDNA0.3 exhibited peroxidase enzyme mimetic activity, besides sensing the common pollutant, phenol.

Impatiens walleriana: perspectivas para el mejoramiento genético

Impatiens walleriana is a plant of the Balsaminaceae family with high ornamental value. It presents very attractive flowers, which can be found in different shapes and colors, due to which, it is part of many gardens worldwide. Genetic improvement in this specie has usually been carried out by conventional methods, however, the advancement of technology has made possible the use of a large number of biotechnological and molecular tools. The objective of this review is to consolidate the bases for a genetic improvement program of I. walleriana. This review covers different aspects that are basic to incur in the genetic improvement of this species; these factors are floral morphology, pollination, karyotyping and studies of genetic variability. In addition, what is known to date about studies focused on genes involved in drought stress processes, tolerance to Plasmopara obducens and floral longevity is presented.