An Introduction to Plant Cell, Tissue, and Organ Culture: Current Status and Perspectives.

Plant cell, tissue, and organ cultures (PCTOC) have been used as experimental systems in basic research, allowing gene function demonstration through gene overexpression or repression and investigating the processes involved in embryogenesis and organogenesis or those related to the potential production of secondary metabolites, among others. On the other hand, PCTOC has also been applied at the commercial level for the vegetative multiplication (micropropagation) of diverse plant species, mainly ornamentals but also horticultural crops such as potato or fruit and tree species, and to produce high-quality disease-free plants. Moreover, PCTOC protocols are important auxiliary systems in crop breeding crops to generate pure lines (homozygous) to produce hybrids for the obtention of polyploid plants with higher yields or better performance. PCTOC has been utilized to preserve and conserve the germplasm of different crops or threatened species. Plant genetic improvement through genetic engineering and genome editing has been only possible thanks to the establishment of efficient in vitro plant regeneration protocols. Different companies currently focus on commercializing plant secondary metabolites with interesting biological activities using in vitro PCTOC. The impact of omics on PCTOC is discussed.

The invasive bumblebee Bombus terrestris (Linnaeus, 1758) disrupts the adaptive function of heteranthery by indiscriminately visiting the pollinating and feeding anthers of Senna arnottiana flowers.

Heteranthery, the presence of different types of anthers on the same flower, is a floral adaptation that aims to balance the need for pollinators to collect pollen as a food resource while ensuring sufficient pollen for pollination. We investigate the role of heteranthery in the pollination of Senna arnottiana flowers and how it is affected by the behaviour of visiting bee species, with a particular focus on the impact of the invasive bumblebee Bombus terrestris. In three populations of S. arnottiana we measured the size of three sets of anthers and style, stigma-anther separation, pollen quantity and fruit set, and contrasted it with the body size, behaviour, and pollination effectiveness of all floral visitors. Different bee species visited S. arnottiana flowers, and their foraging behaviour varied. Large-bodied native bees, including Centris cineraria, Caupolicana sp. and Cadeguala occidentalis, preferentially visited short anthers, whereas B. terrestris, an exotic bumblebee, foraged from both short and long anthers without distinction. In addition, B. terrestris contacted the stigma at a lower rate than large-bodied native bees. Instead of concentrating its pollen-gathering efforts on the feeding anthers, as predicted by the "division of labor" hypothesis, B. terrestris indiscriminately visited both types of anthers similarly. This behaviour of B. terrestris may disrupt the adaptive significance of heteranthery by mixing the roles of pollination and feeding anthers of S. arnottiana. Therefore, our results highlight the potential disruption of this relationship by exotic pollinators and the need to consider it in conservation efforts.

Connective modifications and origin of stamen diversity in Melastomataceae.

The androecium of Melastomataceae presents notable modifications in its merosity, morphology between whorls and in prolonged connectives and appendages. We carried out a comparative study of six Melastomataceae species to shed light on the developmental processes that originate such stamen diversity. The development of stamens was studied using scanning electron microscopy and histological observations. The stamens of all species studied have a curved shape because they emerge on a plane displaced by the perigynous hypanthium. They are the last flower organs to initiate and therefore their growth is inwards and towards the floral center. Despite the temporal inversion between carpels and stamens in Melastomataceae, the androecium maintains the centripetal pattern of development, the antepetalous stamens emerging after antesepalous stamens. The isomerous androecium can be the result of abortion of the antepetalous stamens, whereas heterostemony seems to be caused by differences in position and the stamen development time. Pedoconnectives and ventral appendages originate from the basal expansion of the anther late in floral development. The delay in stamen development may be a consequence of their dependence on the formation of a previous space so that they can grow. Most of the stamen diversity is explained by the formation of the connectives and their appendages. The formation of a basal-ventral anther prolongation, which culminates in the development of the pedoconnective, does not differ from other types of sectorial growth of the connective, which form shorter structures.

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.

Light and electron microscopies reveal unknown details of the pollen grain structure and physiology from Brazilian Cerrado species.

Pollen grains have a relatively simple structure and microscopic size, with two or three cells surrounded by the protective sporoderm at maturity. The viability and efficiency of pollen transport from anther to stigma depends on pollen physiological properties, especially the relative water content of the vegetative cell. Pollen transport is a crucial fate for most angiosperms that depends on biotic pollinators and studies focusing on understanding the morpho-physiological properties of pollen grains are still scarce, especially to tropical open physiognomies as the Brazilian Cerrado. Therefore, we investigate some structural and physiological aspects of pollen grains from six native species naturally growing in one Cerrado area: Campomanesia pubescens (Myrtaceae), Caryocar brasiliense (Caryocaraceae), Erythroxylum campestre (Erythroxylaceae), Lippia lupulina (Verbenaceae), Pyrostegia venusta (Bignoniaceae), and Xylopia aromatica (Annonaceae). We selected dehiscent anthers and mature pollen grains to analyze (1) the anther wall and pollen microstructure, (2) the pollen water status at the time of anther dehiscence, and (3) the pollen chemical compounds. In all analyzed species, the anther and pollen developed in a successfully way, and except for Caryocar brasiliense, all species were able to emit pollen tubes in the germination tests. As expected for a dry and open environment, most species dispersed their pollen grains in a partially dehydrated form, as indicated by our harmomegathy experiment. As indicated by our study, the pollen ability in preventing dissection, maintaining its viability in a dry and hot environment during its transport from anther to stigma, may be related to the sporoderm apertures and to the reserve compounds, mainly carbohydrates in the form of hydrolysable starch grains.

Anther Culture of the Gametophytic Self-Incompatible Species Physalis ixocarpa Brot.

Here we present an optimized protocol for in vitro embryo formation and plant regeneration through anther culture of the Mexican husk tomato (Physalis ixocarpa Brot.). This protocol relies on the application of an anther thermal shock at a specific developmental stage prior to the in vitro culture, ensures embryo formation from anthers without callus formation, and allows spending less time to regenerate doubled haploid complete plants. This protocol has been used for different cultivars of Physalis ixocarpa (Chapingo, Rendidora, Puebla, Arandaz, Manzano, Tamazula, Salamanca, and Milpero), and also for two wild-type accessions, all of them cultivated in Mexico. Chapingo cultivar responded with the highest percentage of androgenesis on the embryo induction medium (EIM).

The Effect of Temperature and Growth Regulators on Callus Induction in Watermelon Anthers

HIGHLIGHTS Callogenesis was induced from watermelon anthers The auxin 2,4-D at 2.0 and 5.0 μM concentrations induced callus formation. Anthers' responses to the pre-treatment at 4 °C varied according to the watermelon genotype.

Abstract Callus induction is one of the pathways required for haploid plant regeneration through anther culture. Pollen viability, as well as the effect of growth regulators and cold pretreatment on anthers of two watermelon lines (Smile and Sugar Baby) to induce callus formation were herein evaluated. Pollen viability was estimated through the staining technique using 2% acetic carmine. Male flower buds were collected and disinfested to allow removal anthers. These anthers were placed on Murashige and Skoog medium, which was supplemented with 2,4-dichlorophenoxyacetic (2,4-D) at 0.0, 0.5, 1.0, 2.0 or 5.0 μM or with 6-benzylaminopurine at 0.0, 0.5, 1.0, 1.5, or 2.0 μM, in combination with 2.0 μM of 2,4-dichlorophenoxyacetic. Anthers were pretreated at 4 °C, for two days and then placed in vitro. Both watermelon lines provided high pollen viability rates (from 93 to 98%). The 2.0 and 5.0 μM concentrations of 2,4-D stimulated higher friable callus formation. The optimal concentration of 2,4-D was estimated at 3.78 μM and 4.17 μM, which had callus induction rates of 64% and 52%, respectively. The combination of 2.0 μM of 2,4-D and 6-benzylaminopurine did not lead to increased anther response to callus induction. The pre-treatment applied to flower buds at 4 °C enabled callus induction and the anther response to callus induction was genotype-dependent.

Characterization of floral morphoanatomy and identification of marker genes preferentially expressed during specific stages of cotton flower development.

MAIN CONCLUSION: Characterization of anther and ovule developmental programs and expression analyses of stage-specific floral marker genes in Gossypium hirsutum allowed to build a comprehensive portrait of cotton flower development before fiber initiation. Gossypium hirsutum is the most important cotton species that is cultivated worldwide. Although cotton reproductive development is important for fiber production, since fiber is formed on the epidermis of mature ovules, cotton floral development remains poorly understood. Therefore, this work aims to characterize the cotton floral morphoanatomy by performing a detailed description of anther and ovule developmental programs and identifying stage-specific floral marker genes in G. hirsutum. Using light microscopy and scanning electron microscopy, we analyzed anther and ovule development during 11 stages of flower development. To better characterize the ovule development in cotton, we performed histochemical analyses to evaluate the accumulation of phenolic compounds, pectin, and sugar in ovule tissues. After identification of major hallmarks of floral development, three key stages were established in G. hirsutum floral development: in stage 1 (early-EF), sepal, petal, and stamen primordia were observed; in stage 2 (intermediate-IF), primordial ovules and anthers are present, and the differentiating archesporial cells were observed, marking the beginning of microsporogenesis; and in stage 6 (late-LF), flower buds presented initial anther tapetum degeneration and microspore were released from the tetrad, and nucellus and both inner and outer integuments are developing. We used transcriptome data of cotton EF, IF and LF stages to identify floral marker genes and evaluated their expression by real-time quantitative PCR (qPCR). Twelve marker genes were preferentially expressed in a stage-specific manner, including the putative homologs for AtLEAFY, AtAPETALA 3, AtAGAMOUS-LIKE 19 and AtMALE STERILITY 1, which are crucial for several aspects of reproductive development, such as flower organogenesis and anther and petal development. We also evaluated the expression profile of B-class MADS-box genes in G. hirsutum floral transcriptome (EF, IF, and LF). In addition, we performed a comparative analysis of developmental programs between Arabidopsis thaliana and G. hirsutum that considered major morphoanatomical and molecular processes of flower, anther, and ovule development. Our findings provide the first detailed analysis of cotton flower development.

Structure and development of anthers and connective glands in two species of Stigmaphyllon (Malpighiaceae): are heteromorphic anthers related to division of labour?

Heteranthery has been largely associated with a division of labour between anthers. Most species of Stigmaphyllon (Malpighiaceae) present heteromorphic anthers and glandular connectives of different development; yet, the functional meaning of this condition has never been explored in the genus. The aims of this study were to provide a comparative description of the structure and development of anthers and their connective glands in S. bonariense and S. jatrophifolium and to assess the existence of division of functions. Natural populations were selected to collect flowers at different stages. Anthers were subjected to morpho-anatomical, histochemical and pollen viability studies. For both species, abundance of pollen grains and size of anther and their connective glands were estimated. Three types of stamens are recognized: stamen with small, intermediate and large anthers. Anthers of both species exhibit a similar glandular tissue in the connective, and the histochemical analysis revealed that it produce a mucilagous secretion. The pattern of anther wall development, stainability and release of pollen grains was identical among anther types. For both species, we observed a positive relationship between anther size and abundance of pollen grains, but an inverse relationship between area of anthers and size (area and thickness) of connective glands in small anthers vs. intermediate and large ones. Our results evidence a specialization of anthers related to division of labour between heteromorphic stamens in two species of Stigmaphyllon. Thus, one set of anthers produces large amount of pollen grains for pollination and another sets large quantities of mucilage, which would improve pollen transport (better adherence to pollinator body and dampness maintenance). Nevertheless, heteranthery in both Stigmaphyllon species would represent a transitional state towards the division of labour rather than a stable state.

Improvement of anther cultures conditions using the Taguchi method in three cereal crops

Background: Plant tissue cultures have the potential to reprogram the development of microspores from normal gametophytic to sporophytic pathway resulting in the formation of androgenic embryos. The efficiency of this process depends on the genotype, media composition and external conditions. However, this process frequently results in the regeneration of albino instead of green plants. Successful regeneration of green plants is affected by the concentration of copper sulfate (CuSO4) and silver nitrate (AgNO3) and the length of induction step. In this study, we aimed at concurrent optimization of these three factors in barley (Hordeum vulgare L.), wheat (Triticum aestivum L.), and triticale (x Triticosecale spp. Wittmack ex A. Camus 1927) using the Taguchi method. We evaluated uniform donor plants under varying experimental conditions of in vitro anther culture using the Taguchi approach, and verified the optimized conditions. Results: Optimization of the regeneration conditions resulted in an increase in the number of green regenerants compared with the control. Statistic Taguchi method for optimization of the in vitro tissue culture plant regeneration via anther cultures allowed reduction of the number of experimental designs from 27 needed if full factorial analysis is used to 9. With the increase in the number of green regenerants, the number of spontaneous doubled haploids decreased. Moreover, in barley and triticale, the number of albino regenerants was reduced. Conclusion: The statistic Taguchi approach could be successfully used for various factors (here components of induction media, time of incubation on induction media) at a one time, that may impact on cereals anther cultures to improve the regeneration efficiency

Presence of the anther gland is a key feature in pollination of the early-branching papilionoids Dipteryx alata and Pterodon pubescens (Leguminosae).

The presence of glandular appendages in the anthers is a rare condition in angiosperms. In Leguminosae it occurs in species of the Mimosoid clade and in early-branching clades of papilionoids such as Dipterygeae. In Dipterygeae such appendages surprisingly exhibit a secretory cavity instead of secretory emergences as is the case for the Mimosoid clade. Thus, the objective of this study was to elucidate the function of anther glands in Dipteryx alata and Pterodon pubescens, species in the Dipterygeae clade that exhibit a pollen release mechanism that is intermediate between the explosive and valvular types. Flower buds and flowers were processed for surface, anatomical, histochemical and ultrastructural analyses. Anther glands consist of a cavity secreting sticky substances (oleoresins and polysaccharides) that play a key role during the flower's lifespan by aggregating pollen grains and attaching them to the floral visitor's body. Other floral features that are important for understanding the pollen release mechanism that is intermediate between the valvular and the explosive types are: (i) keel petals intertwined with tector trichomes; (ii) glandular appendages in the abaxial and lateral sepals and in petals composed of secretory ducts; and (iii) a continuous secretion process of the anther glands followed by an asynchronous dehiscence of anthers. The well-adapted papilionoid flag blossom with anther glands and keel petals intertwined with trichomes provided the foundation for a successful canalisation toward a pollen release mechanism intermediate between the explosive and valvular types inside early-branching papilionoids.

Modulation of Auxin Levels in Pollen Grains Affects Stamen Development and Anther Dehiscence in Arabidopsis.

Auxin regulates diverse aspects of flower development in plants, such as differentiation of the apical meristem, elongation of the stamen, and maturation of anthers and pollen. It is known that auxin accumulates in pollen, but little information regarding the biological relevance of auxin in this tissue at different times of development is available. In this work, we manipulated the amount of free auxin specifically in developing pollen, using transgenic Arabidopsis lines that express the bacterial indole-3-acetic acid-lysine synthetase (iaaL) gene driven by a collection of pollen-specific promoters. The iaaL gene codes for an indole-3-acetic acid-lysine synthetase that catalyzes the conversion of free auxin into inactive indole-3-acetyl-l-lysine. The transgenic lines showed several abnormalities, including the absence of short stamina, a diminished seed set, aberrant pollen tubes, and perturbations in the synchronization of anther dehiscence and stamina development. This article describes the importance of auxin accumulation in pollen and its role in stamina and anther development.

Heteranthery as a solution to the demand for pollen as food and for pollination - Legitimate flower visitors reject flowers without feeding anthers.

Heteranthery, the presence of feeding and pollinating anthers in the same flower, seems to mediate the evolutionary dilemma for plants to protect their gametes and yet provide food for pollinators. This study aims to elucidate the role of heteranthery in the buzz-pollinated Senna reniformis. The fecundity of pollen from long-, medium- and short-sized anthers was determined by hand cross-pollination experiments, and the quantity, size, ornamentation and viability of pollen of different anthers were compared. Rates of flower rejection by bees were measured in anther removal experiments to assess the preferences of flower visitors for feeding or pollinating anthers. Large bees, which were the effective pollinators of self-incompatible S. reniformis, avoided flowers without short feeding anthers, but not those without medium or long anthers. Illegitimate small and medium-sized bees were unresponsive to anther exclusion experiments. Long anthers deposited pollen on the back and short anthers on the venter of large bees. Pollen from long anthers had higher in vitro viability and higher fruit and seed set after cross-pollination than pollen from other sized anthers. Short anthers produce feeding pollen to effective pollinators and long anthers are related to pollination of S. reniformis. Bee behaviour and size was found to directly influence the role of anthers in the 'division of labour'. Only large bee pollinators that carry the pollinating pollen from long anthers in 'safe sites' associated short anthers with the presence of food. In the absence of these larger bee pollinators, the role of heteranthery in S. reniformis would be strongly compromised and its function would be lost.

High species richness of native pollinators in Brazilian tomato crops / Alta riqueza de espécies de polinizadores nativos em plantações Brasileiras de tomateiro

Abstract Pollinators provide an essential service to natural ecosystems and agriculture. In tomatoes flowers, anthers are poricidal, pollen may drop from their pore when flowers are shaken by the wind. However, bees that vibrate these anthers increase pollen load on the stigma and in fruit production. The present study aimed to identify the pollinator richness of tomato flowers and investigate their morphological and functional traits related to the plant-pollinator interaction in plantations of Central Brazil. The time of anthesis, flower duration, and the number and viability of pollen grains and ovules were recorded. Floral visitors were observed and collected. Flower buds opened around 6h30 and closed around 18h00. They reopened on the following day at the same time in the morning, lasting on average 48 hours. The highest pollen availability occurred during the first hours of anthesis. Afterwards, the number of pollen grains declined, especially between 10h00 to 12h00, which is consistent with the pollinator visitation pattern. Forty bee species were found in the tomato fields, 30 of which were considered pollinators. We found that during the flowering period, plants offered an enormous amount of pollen to their visitors. These may explain the high richness and amount of bees that visit the tomato flowers in the study areas. The period of pollen availability and depletion throughout the day overlapped with the bees foraging period, suggesting that bees are highly effective in removing pollen grains from anthers. Many of these grains probably land on the stigma of the same flower, leading to self-pollination and subsequent fruit development. Native bees (Exomalopsis spp.) are effective pollinators of tomato flowers and are likely to contribute to increasing crop productivity. On the other hand, here tomato flowers offer large amounts of pollen resource to a high richness and amount of bees, showing a strong plant-pollinator interaction in the study agroecosystem.

Resumo Polinizadores fornecer um serviço essencial para os ecossistemas naturais e para agricultura. Em tomateiros, as anteras são poricidas e o pólen pode sair a partir dos poros quando as flores são agitadas pelo vento. No entanto, as abelhas que vibram as anteras aumentam a carga de pólen no estigma e na produção de frutos. O presente estudo teve como objetivo identificar a riqueza dos polinizadores das flores de tomate e investigar suas características morfológicas e funcionais relacionadas com a interação planta-polinizador em plantações do Brasil central. Foram registrados o tempo de antese, duração flor, bem como o número e viabilidade de grãos de pólen e óvulos. Os visitantes florais foram observados e coletados. Os botões florais abriram-se em torno 06h30 e fechou em torno de 18h00. As flores reabrem no dia seguinte ao mesmo tempo na parte da manhã, com longevidade média de 48 horas. A maior disponibilidade de pólen ocorreu durante as primeiras horas da antese. Depois disso, o número de grãos de pólen diminuiu, especialmente entre as 10h00 às 12h00, o que é consistente com os padrões de visitação de polinizadores. Quarenta espécies de abelhas foram encontradas nos campos de tomate, 30 das quais foram consideradas polinizadores. Durante o período de floração, as plantas oferecem enorme quantidade de pólen para os seus visitantes. Isto pode explicar a alta riqueza e quantidade de abelhas que visitam as flores de tomate nas áreas de estudo. O período de disponibilidade e redução de pólen durante todo o período do dia é sobreposto com o período de alimentação das abelhas, o que sugere que elas são altamente eficazes na remoção de grãos de pólen das anteras. Muitos desses grãos provavelmente são depositados no estigma da mesma flor, levando à auto-polinização e o desenvolvimento de frutos. Abelhas nativas (Exomalopsis spp.) são polinizadores efetivos de flores de tomate, podendo contribuir para o aumento da produtividade das culturas. Por outro lado, as flores de tomate oferecem grandes quantidades de pólen de recursos para uma alta riqueza e quantidade de abelhas, que mostram um estudo forte interação planta-polinizador nos agroecossistemas.

High species richness of native pollinators in Brazilian tomato crops

Abstract Pollinators provide an essential service to natural ecosystems and agriculture. In tomatoes flowers, anthers are poricidal, pollen may drop from their pore when flowers are shaken by the wind. However, bees that vibrate these anthers increase pollen load on the stigma and in fruit production. The present study aimed to identify the pollinator richness of tomato flowers and investigate their morphological and functional traits related to the plant-pollinator interaction in plantations of Central Brazil. The time of anthesis, flower duration, and the number and viability of pollen grains and ovules were recorded. Floral visitors were observed and collected. Flower buds opened around 6h30 and closed around 18h00. They reopened on the following day at the same time in the morning, lasting on average 48 hours. The highest pollen availability occurred during the first hours of anthesis. Afterwards, the number of pollen grains declined, especially between 10h00 to 12h00, which is consistent with the pollinator visitation pattern. Forty bee species were found in the tomato fields, 30 of which were considered pollinators. We found that during the flowering period, plants offered an enormous amount of pollen to their visitors. These may explain the high richness and amount of bees that visit the tomato flowers in the study areas. The period of pollen availability and depletion throughout the day overlapped with the bees foraging period, suggesting that bees are highly effective in removing pollen grains from anthers. Many of these grains probably land on the stigma of the same flower, leading to self-pollination and subsequent fruit development. Native bees (Exomalopsis spp.) are effective pollinators of tomato flowers and are likely to contribute to increasing crop productivity. On the other hand, here tomato flowers offer large amounts of pollen resource to a high richness and amount of bees, showing a strong plant-pollinator interaction in the study agroecosystem.

Resumo Polinizadores fornecer um serviço essencial para os ecossistemas naturais e para agricultura. Em tomateiros, as anteras são poricidas e o pólen pode sair a partir dos poros quando as flores são agitadas pelo vento. No entanto, as abelhas que vibram as anteras aumentam a carga de pólen no estigma e na produção de frutos. O presente estudo teve como objetivo identificar a riqueza dos polinizadores das flores de tomate e investigar suas características morfológicas e funcionais relacionadas com a interação planta-polinizador em plantações do Brasil central. Foram registrados o tempo de antese, duração flor, bem como o número e viabilidade de grãos de pólen e óvulos. Os visitantes florais foram observados e coletados. Os botões florais abriram-se em torno 06h30 e fechou em torno de 18h00. As flores reabrem no dia seguinte ao mesmo tempo na parte da manhã, com longevidade média de 48 horas. A maior disponibilidade de pólen ocorreu durante as primeiras horas da antese. Depois disso, o número de grãos de pólen diminuiu, especialmente entre as 10h00 às 12h00, o que é consistente com os padrões de visitação de polinizadores. Quarenta espécies de abelhas foram encontradas nos campos de tomate, 30 das quais foram consideradas polinizadores. Durante o período de floração, as plantas oferecem enorme quantidade de pólen para os seus visitantes. Isto pode explicar a alta riqueza e quantidade de abelhas que visitam as flores de tomate nas áreas de estudo. O período de disponibilidade e redução de pólen durante todo o período do dia é sobreposto com o período de alimentação das abelhas, o que sugere que elas são altamente eficazes na remoção de grãos de pólen das anteras. Muitos desses grãos provavelmente são depositados no estigma da mesma flor, levando à auto-polinização e o desenvolvimento de frutos. Abelhas nativas (Exomalopsis spp.) são polinizadores efetivos de flores de tomate, podendo contribuir para o aumento da produtividade das culturas. Por outro lado, as flores de tomate oferecem grandes quantidades de pólen de recursos para uma alta riqueza e quantidade de abelhas, que mostram um estudo forte interação planta-polinizador nos agroecossistemas.

Isolation and characterization of CaMF3, an anther-specific gene in Capsicum annuum L.

Previous work on gene expression analysis based on RNA sequencing identified a variety of differentially expressed cDNA fragments in the genic male sterile-fertile line 114AB of Capsicum annuum L. In this work, we examined the accumulation of one of the transcript-derived fragments (TDFs), CaMF3 (male fertile 3), in the flower buds of a fertile line. The full genomic DNA sequence of CaMF3 was 1,951 bp long and contained 6 exons and 5 introns, with the complete sequence encoding a putative 25.89 kDa protein of 234 amino acids. The predicted protein of CaMF3 shared sequence similarity with members of the isoamyl acetate-hydrolyzing esterase (IAH1) protein family. CaMF3 expression was detected only in flower buds at stages 7 and 8 and in open flowers of a male fertile line; no expression was observed in any organs of a male sterile line. Fine expression analysis revealed that CaMF3 was expressed specifically in anthers of the fertile line. These results suggest that CaMF3 is an anther-specific gene that may be essential for anther or pollen development in C. annuum.

Nuevos genotipos de arroz resistentes a la Piriculariosis obtenidos por cultivo de anteras / New blast resistant rice genotypes obtained by and anthers culture

En la Estación Experimental del Arroz Los Palacios, perteneciente al Instituto Nacional de Ciencias Agrícolas de Cuba (INCA), se efectuaron cruzamientos entre cuatro cultivares resistentes a la Piriculariosis y seis de buen comportamiento agronómico y las anteras de las plantas F2 fueron cultivadas in vitro para evaluar la formación de callos en tres medios líquidos: N6-1, N6-m y NL, así como la regeneración de plantas verdes y albinas, en el medio MS. Las dos primeras generaciones de las nuevas líneas obtenidas fueron evaluadas para caracteres agronómicos y la segunda generación, además, para resistencia frente a la Piriculariosis. Las líneas que combinaron resistencia a la Piriculariosis y buenos caracteres agronómicos fueron evaluadas en condiciones de infección natural, con alta presión del patógeno. La utilización de la técnica del cultivo de anteras mostró alta dependencia del genotipo y el medio de cultivo. Con el medio NL se lograron los valores más altos para la formación de callos. Se obtuvieron nuevos genotipos resistentes a la Piriculariosis y de alto rendimiento agrícola.

Crosses were made between four blast resistant and six rice varieties of good agronomic performance, at the Los Palacios Rice Research Station of the National Agricultural Sciences Institute of Cuba (INCA) and the anthers from F2 plants were in vitro culture using three liquid media: N6-1, N6m, and NL, for callus formation and after plants regenerations using MS medium. The first two generations of breeding lines were evaluated for agronomic characters and the second generations, also, for Blast resistant. The lines that combined resistance to Blast and good agronomic performance were evaluated under high pressure of natural Blast infection conditions. The success rate of anther culture was highly dependent on the genotype and culture media used. NL medium led to the highest callus formation values. In the process, new blast resistant and high yielding genotypes were obtained.

Desenvolvimento de populações duplo-haplóides de cevada cervejeira associadas à atividade das enzimas (1-3, 1-4)-β-glucanases / Development of doubled-haploids populations in malting barley associated to activity of enzymes (1-3, 1-4)-β-glucanases

Populações duplo-haplóides apresentam especial vantagem para análises genéticas, uma vez que a informação que elas oferecem pode ser maximizada, devido ao fato que todos os locos encontram-se em homozigose. O objetivo deste trabalho foi o desenvolvimento de duas populações duplo-haplóides (DHs) de cevada (Hordeum vulgare ssp. vulgare L.) segregantes para a atividade das enzimas (1-3, 1-4)-β-glucanases, através da técnica de cultura de anteras. Foram realizados dois cruzamentos com cultivares contrastantes para esta característica. As cultivares parentais selecionadas foram 'MN 698' e 'CEV 97047', para o desenvolvimento da população "malte verde" (MV), e 'Embrapa 127' e 'CEV 96025' para o desenvolvimento da população "malte seco" (MS). Foram cultivadas 10.734 anteras da população MS e 4.139 anteras da população MV. A população MV produziu 50 por cento mais plântulas verdes quando comparada à população MS, refletindo a importância do genótipo na resposta à cultura de anteras e na regeneração. A maioria das plantas adultas duplo-haplóides foi obtida através da duplicação espontânea in vitro do genoma haplóide, ocorrendo em 66 por cento das plantas da população MS e 76 por cento das plantas da população MV. Também foram observadas, em menor frequência, plantas haplóides, triplóides e tetraplóides. Através da técnica de cultura de anteras, foram desenvolvidas 204 linhagens duplo-haplóides, das quais 72 linhagens são da população "malte seco" e 132 linhagens são da população "malte verde". Este material constitui um importante germoplasma para o melhoramento genético da cevada.

Doubled haploid populations offer special advantages in genetic analyses, since the information they provide may be maximized due to the fact that all loci are homozygous. The aim of this study was to develop two barley (Hordeum vulgare ssp.vulgare L.) doubled-haploid (DHs) populations segregating to (1-3, 1-4)-β-glucanases activity, utilizing the anther culture protocol. Two crosses were performed with contrasting cultivars to (1-3, 1-4)-β-glucanases activity. Parental cultivars used were 'MN 698' and 'CEV 97047' for the development of 'green malt' population (MV) and Embrapa 127 and 'CEV 96025' for the development of "dry malt" population (MS). For the MS and MV populations, 10,734 and 4,139 anthers were cultured, respectively. MV population produced 50 percent more green seedlings as compared to MS population, which reflects the importance of genotype to the culturing of anthers and to regeneration. Most doubled-haploid adult plants were obtained by in vitro spontaneous duplication of the haploid genome, which occurred in 66 percent of plants from the MS population and 76 percent of plants from the MV population. Haploid, triploid and tetraploid individuals were also observed, though at low frequencies. The anther culture protocol afforded to develop 204 double-haploid lineages, of which 72 were generated by the 'dry malt' population and 132 from the "green malt" population. This material should be considered as important germplasm for barley genetic improvement.

Desenvolvimento de populações duplo-haplóides de cevada cervejeira associadas à atividade das enzimas (1-3, 1-4)--glucanases

Doubled haploid populations offer special advantages in genetic analyses, since the information they provide may be maximized due to the fact that all loci are homozygous. The aim of this study was to develop two barley (Hordeum vulgare ssp.vulgare L.) doubled-haploid (DHs) populations segregating to (1-3, 1-4)--glucanases activity, utilizing the anther culture protocol. Two crosses were performed with contrasting cultivars to (1-3, 1-4)--glucanases activity. Parental cultivars used were 'MN 698' and 'CEV 97047' for the development of 'green malt' population (MV) and Embrapa 127 and 'CEV 96025' for the development of "dry malt" population (MS). For the MS and MV populations, 10,734 and 4,139 anthers were cultured, respectively. MV population produced 50% more green seedlings as compared to MS population, which reflects the importance of genotype to the culturing of anthers and to regeneration. Most doubled-haploid adult plants were obtained by in vitro spontaneous duplication of the haploid genome, which occurred in 66% of plants from the MS population and 76% of plants from the MV population. Haploid, triploid and tetraploid individuals were also observed, though at low frequencies. The anther culture protocol afforded to develop 204 double-haploid lineages, of which 72 were generated by the 'dry malt' population and 132 from the "green malt" population. This material should be considered as important germplasm for barley genetic improvement.

Populações duplo-haplóides apresentam especial vantagem para análises genéticas, uma vez que a informação que elas oferecem pode ser maximizada, devido ao fato que todos os locos encontram-se em homozigose. O objetivo deste trabalho foi o desenvolvimento de duas populações duplo-haplóides (DHs) de cevada (Hordeum vulgare ssp. vulgare L.) segregantes para a atividade das enzimas (1-3, 1-4)--glucanases, através da técnica de cultura de anteras. Foram realizados dois cruzamentos com cultivares contrastantes para esta característica. As cultivares parentais selecionadas foram 'MN 698' e 'CEV 97047', para o desenvolvimento da população "malte verde" (MV), e 'Embrapa 127' e 'CEV 96025' para o desenvolvimento da população "malte seco" (MS). Foram cultivadas 10.734 anteras da população MS e 4.139 anteras da população MV. A população MV produziu 50% mais plântulas verdes quando comparada à população MS, refletindo a importância do genótipo na resposta à cultura de anteras e na regeneração. A maioria das plantas adultas duplo-haplóides foi obtida através da duplicação espontânea in vitro do genoma haplóide, ocorrendo em 66% das plantas da população MS e 76% das plantas da população MV. Também foram observadas, em menor frequência, plantas haplóides, triplóides e tetraplóides. Através da técnica de cultura de anteras, foram desenvolvidas 204 linhagens duplo-haplóides, das quais 72 linhagens são da população "malte seco" e 132 linhagens são da população "malte verde". Este material constitui um importante germoplasma para o melhoramento genético da cevada.

Desenvolvimento de populações duplo-haplóides de cevada cervejeira associadas à atividade das enzimas (1-3, 1-4)--glucanases

Doubled haploid populations offer special advantages in genetic analyses, since the information they provide may be maximized due to the fact that all loci are homozygous. The aim of this study was to develop two barley (Hordeum vulgare ssp.vulgare L.) doubled-haploid (DHs) populations segregating to (1-3, 1-4)--glucanases activity, utilizing the anther culture protocol. Two crosses were performed with contrasting cultivars to (1-3, 1-4)--glucanases activity. Parental cultivars used were 'MN 698' and 'CEV 97047' for the development of 'green malt' population (MV) and Embrapa 127 and 'CEV 96025' for the development of "dry malt" population (MS). For the MS and MV populations, 10,734 and 4,139 anthers were cultured, respectively. MV population produced 50% more green seedlings as compared to MS population, which reflects the importance of genotype to the culturing of anthers and to regeneration. Most doubled-haploid adult plants were obtained by in vitro spontaneous duplication of the haploid genome, which occurred in 66% of plants from the MS population and 76% of plants from the MV population. Haploid, triploid and tetraploid individuals were also observed, though at low frequencies. The anther culture protocol afforded to develop 204 double-haploid lineages, of which 72 were generated by the 'dry malt' population and 132 from the "green malt" population. This material should be considered as important germplasm for barley genetic improvement.

Populações duplo-haplóides apresentam especial vantagem para análises genéticas, uma vez que a informação que elas oferecem pode ser maximizada, devido ao fato que todos os locos encontram-se em homozigose. O objetivo deste trabalho foi o desenvolvimento de duas populações duplo-haplóides (DHs) de cevada (Hordeum vulgare ssp. vulgare L.) segregantes para a atividade das enzimas (1-3, 1-4)--glucanases, através da técnica de cultura de anteras. Foram realizados dois cruzamentos com cultivares contrastantes para esta característica. As cultivares parentais selecionadas foram 'MN 698' e 'CEV 97047', para o desenvolvimento da população "malte verde" (MV), e 'Embrapa 127' e 'CEV 96025' para o desenvolvimento da população "malte seco" (MS). Foram cultivadas 10.734 anteras da população MS e 4.139 anteras da população MV. A população MV produziu 50% mais plântulas verdes quando comparada à população MS, refletindo a importância do genótipo na resposta à cultura de anteras e na regeneração. A maioria das plantas adultas duplo-haplóides foi obtida através da duplicação espontânea in vitro do genoma haplóide, ocorrendo em 66% das plantas da população MS e 76% das plantas da população MV. Também foram observadas, em menor frequência, plantas haplóides, triplóides e tetraplóides. Através da técnica de cultura de anteras, foram desenvolvidas 204 linhagens duplo-haplóides, das quais 72 linhagens são da população "malte seco" e 132 linhagens são da população "malte verde". Este material constitui um importante germoplasma para o melhoramento genético da cevada.