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Abstract: Letícia AF is a mutation of the plum cultivar Laetitia that confers self-compatibility. This work compared the Letícia AF mutant cultivar with the standard Laetitia regarding fruit set, self-compatibility, yield, and fruit quality traits during four growing seasons. The study was carried out in two plum orchards with the cultivar Letícia AF (orchard 1) and Laetitia plus pollinizers trees (orchard 2) and in an experimental unit with Letícia AF and Laetitia planted side by side. A self-compatibility test was performed on covered branches to prevent pollinating insects from reaching the flowers. Fruit set occurs in covered branches of Letícia AF, whereas it was rare in Laetitia. In commercial orchards, Leticia AF plums yield was higher than that of Laetitia over the years. The results suggest that the oscillation in productivity across the years, mainly due to unfavorable conditions for insect pollination, may be lower in the plum Leticia AF orchard. On the other hand, the requirement for fruit thinning may be greater in Leticia AF. No significant differences were found between the mutant and the standard cultivar regarding fruit quality at harvest and after 30 days of cold storage, indicating the mutation did not alter the fruit characteristics.

Background: Argemone ochroleuca is a worldwide invasive weed but is also highly valuable for their chemical compounds. Knowledge about its reproduction will help create plans for its control or its propagation. Questions: Does A. ochroleuca has an incompatibility system like other Papaveraceae species? Which are the reproductive strategies that favor the seed formation in A. ochroleuca? Studied species: A. ochroleuca is an annual species with bisexual flowers. Study site and dates: Mexico City, Mexico. The fieldwork was performed from February to May in 2013, 2014, and 2017. Methods: Direct observations were made to describe the flower cycle of A. ochroleuca. We used self-pollinated flowers to analyze if this species is self-incompatible by following the pollen tube growth through gynoecium. Controlled pollinations were made to quantify and compare the number of seeds produced per treatment to know the mating system and explore if the species presents a mechanism of reproductive assurance through autogamy, or exhibits inbreeding depression. Results: A. ochroleuca is self-compatible and exhibits a mixed mating system. Although outcrossing is how more seeds are produced, both autogamy and pseudocleistogamy are present as reproductive assurance mechanisms. Naturally pollinated flowers produce the maximum number of seeds, but inbreeding depression is present in the population. Thus, the number of seeds will be affected by continuous selfing. Conclusions: This study highlights the mixed mating system and reproductive assurance mechanisms as successful strategies for A. ochroleuca, a common pattern in invasive weeds.

Background: Self-compatibility is common on endemic plant species, but pollen limitation and self-pollination could be risk factors. Study species: The endemic Cienfuegosia yucatanensis (Malvaceae), whose distribution is mainly restricted to the north coast of the peninsula of Yucatán, México. Questions: a) Are flowers of C. yucatanensis autonomous for pollination? b) Are C. yucatanensis fruit or seed-set limited by pollen deposition? and, c) Is there evidence of early inbreeding depression in C. yucatanensis? Study sites and dates: Two sites in the north of the peninsula of Yucatán in a seasonally dry scrubland, in the rainy season of 2013 and 2014. Methods: Number of flowers and fruits were weekly recorded. Flowers were collected to count the number of conspecific pollen load and the number of pollen tubes. Autonomous pollination and pollen limitation were evaluated with a hand-pollination experiment. Inbreeding depression on fruit and seed production, and seed weight was evaluated. Results: Flower and fruit production occur simultaneously and last from August to October. Conspecific pollen deposition on stigmas occurred through the whole flowering season and a maximum of pollen tubes was observed in August. Autonomous pollination treatment lead to similar fruit and seed production than cross-pollination, but open pollination produced significantly more seeds. No significant differences among self- and cross-pollination treatments on fruit and seed production or seed weight, were found. Conclusions: Our results suggest that self-compatibility combined with a relatively efficient autonomous pollination, are suitable mechanisms for the reproductive assurance in C. yucatanensis, with no apparent effects of early inbreeding depression.

The extent to which plants depend on pollinators for outcross pollen transportation is a key issue in plant reproductive ecology. We evaluated the putative breeding system, foral display, and natural pollination in two Southern Cone of South American orchids, Gavilea araucana and G. venosa, by performing four hand pollination trials (agamospermy, autogamy, geitonogamy, and xenogamy tests) and by counting each fower and fruit produced by plants in natural conditions. Fruit set differed signifcantly depending on the origin of pollen as well as on the presence of a pollen vector. None of these species produced fruits by the agamospermy tests, therefore indicating that they require the presence of pollen on the stigmas for fruit setting. By contrast, only G. araucana was capable of fruit setting following the autogamy test, therefore demostrating that this orchid needs not depend on pollinators for fruit set. Furthermore, G. araucana and G. venosa produced 100% fruits by geitonogamy and by xenogamy, thereby indicating that both plants are totally self-compatible. The mean number of fowers per plant was 2.1 times higher in G. venosa with respect to G. araucana; however, natural fruiting success was 28.8% and 98.9%, respectively. Furthermore, while the increase in fruiting success signifcantly and positively correlated with an increase in foral display in G. araucana, in G. venosa these variables were unrelated. Certainly, further studies concerning the reproductive strategies in orchids of southern South America are of great importance.El alcance al cual las plantas dependen de polinizadores para el transporte de polen para los exocruzamientos es uno de los temas claves en ecología reproductiva de las plantas. Evaluamos el sistema reproductivo potencial, despliegue foral y polinización natural en dos orquídeas del Cono Sur de Sudamérica, Gavilea araucana y G. venosa, efectuando cuatro ensayos de polinización manual (agamospermia, autogamia, geitonogamia y xenogamia) y contando cada for y fruto producidos por las plantas en condiciones naturales. La producción de frutos difrió signifcativamente dependiendo del origen del polen así como de la presencia de un vector polínico. Ninguna de las especies produjo frutos en las pruebas de agamospermia indicando, por lo tanto, que ellas requieren de la presencia de polen en los estigmas para producir frutos. Por el contrario, solamente G. araucana fue capaz de producir frutos siguiendo la prueba de autogamia demostrando, por ende, que esta orquídea no necesita depender de polinizadores para producir frutos. Además, G. araucana y G. venosa produjeron un 100% de frutos por geitonogamia y xenogamia, indicando esto, que ambas plantas son autocompatibles. El número promedio de fores por planta fue 2,1 veces mayor en G. venosa con respecto a G. araucana; sin embargo, el éxito en la fructifcación natural fue de 28,8% y 98,9%, respectivamente. Además, mientras el incremento en el éxito de la fructifcación se correlacionó positiva y signifcativamente en G. araucana, en G. venosa estas variables no estuvieron relacionadas. Ciertamente, estudios adicionales referidos a las estrategias reproductivas de las orquídeas del sur de Sudamérica son de gran importancia.

Plant breeding systems have been viewed as mechanisms to promote outcrossing in order to increase genetic variability and prevent inbreeding depression. However, reduced fitness after crossing, outbreeding depression, has been often observed between individuals from different populations and more rarely, within populations. We studied the breeding system of Colutea hispanica using experimental hand pollinations in field conditions in one population in Central Spain in 2004 and 2006. Pollination experiments showed that C. hispanica set fruits from both self and cross-pollinations, suggesting that the species is highly self-compatible. In addition, fruit set was highest following geitonogamy in both years and no flowers set fruits from xenogamy in 2004. Although such enhanced reproductive success following selfing rather than crossing has been largely ignored in many studies on plant reproduction, it seems to be not as rare in plants as previously thought.

The breeding system, the floral characteristics and the visitors of the polymorphic Passiflora suberosa were studied in different natural populations of Corrientes and Misiones provinces, and at a partially-opened greenhouse in Buenos Aires. The different reproductive indexes calculated evidenced that, although it is highly self-compatible, autogamy is partial. The reproductive efficiency was similar in the field and in the greenhouse. The major relative reproductive success obtained by induced self-pollination suggests that the reproductive output may be improved with the help of pollinations, either natural or artificial. Although the single flower and the blooming are inconspicuous, the floral characters may be involved in wasps attraction. The scarcity or even absence of pollinators (depending on the sites) seems to be compensated with the capacity of autogamy and the extended flowering period. The successful treatments performed in the greenhouse and the long period of time the fruits remain on the plants constitute stimulant features to cultivate this ornamental, medicinal, edible and tinctoreous species.El sistema reproductivo, las características florales y los visitantes de la polimórfica P. suberosa fueron estudiados en distintas poblaciones naturales de las provincias de Corrientes y Misiones y en un invernáculo parcialmente abierto en Buenos Aires. Los distintos índices reproductivos calculados evidenciaron que, a pesar de que es altamente autocompatible, la autogamia es parcial. La eficacia reproductiva fue similar en el campo y en el invernáculo. El mayor éxito reproductivo relativo obtenido por autopolinización inducida sugiere que la reproducción puede ser mejorada con la ayuda de polinizaciones, ya sean naturales o artificiales. Aunque las flores por sí solas y la floración son inconspicuas, los caracteres florales pueden estar involucrados en la atracción de avispas. La escasez o incluso la ausencia de polinizadores (dependiendo de los sitios) parecen estar compensada con la capacidad de autogamia y el período extendido de floración. Los tratamientos fructíferos llevados a cabo en el invernáculo y el largo tiempo que los frutos permanecen en las plantas constituyen aspectos estimulantes para cultivar esta especie ornamental, medicinal, comestible y tintórea.