Chromosomal studies, pollen morphology and fertility in Dioscorea ayardei (Dioscoreaceae)
Background and Aims: The great variability of characters in Dioscorea makes it difficult to define the species, therefore additional studies are necessary to identify them. Dioscorea ayardei, a recently described endemic species from the Sierras de Calilegua (Jujuy, Argentina), differs by the partic...
| Hlavní autoři: | , , , , |
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| Médium: | Online |
| Jazyk: | spa |
| Vydáno: |
Instituto de Ecología, A.C.
2022
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| On-line přístup: | https://abm.ojs.inecol.mx/index.php/abm/article/view/2095 |
| _version_ | 1799771420848291840 |
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| author | Asesor, Patricia N. Andrada, Aldo R. Páez, Valeria de los A. Reyes, Nora J. F. Bulacio, Eva |
| author_facet | Asesor, Patricia N. Andrada, Aldo R. Páez, Valeria de los A. Reyes, Nora J. F. Bulacio, Eva |
| author_sort | Asesor, Patricia N. |
| collection | ABM |
| description | Background and Aims: The great variability of characters in Dioscorea makes it difficult to define the species, therefore additional studies are necessary to identify them. Dioscorea ayardei, a recently described endemic species from the Sierras de Calilegua (Jujuy, Argentina), differs by the particularity of the androecium of its staminate flowers which consists of a navicular structure with a single anther in the center and three erect dendriform appendages. The aim of this paper was to carry out an ensemble study of its chromosomal and palynological characters that, added to the morphological ones, provide complementary information for its correct delimitation.
Methods: The studied material was identified according to the classic methods in taxonomy and deposited in the LIL Herbarium, of the Fundación Miguel Lillo. For study of meiosis, young flower buds were randomly selected, which were fixed in Farmer for 24 hours and preserved in 70° to -4°C ethyl alcohol. For chromosome staining, 2% propionic hematoxylin was used. Fertility of pollen grains was estimated using the Mützing and DAPI techniques. For the pollen morphology description the material was processed according to the conventional techniques of acetolysis and natural pollen; photographs were taken with light microscope (LM) and scanning electron microscope (SEM).
Key results: Dioscorea ayardei presented a gametophytic number n=20II. Meiotic behavior was generally regular. The techniques to estimate viability and fertility of the pollen grain revealed a value of 90-93%, respectively. The morphology showed a small (16-24 µm) to medium (25-30 µm) sized disulcate grain with microreticulate tectum.
Conclusions: The basic chromosome number for the genus x=10 is reaffirmed. Dioscorea ayardei is a tetraploid with n=20, with normal meiotic behavior consistent with the potential viability of the pollen grain. The exine ornamentation and chromosome number relates with the New World II clade. |
| format | Online |
| id | oai:oai.abm.ojs.inecol.mx:article-2095 |
| institution | Acta Botanica Mexicana |
| language | spa |
| publishDate | 2022 |
| publisher | Instituto de Ecología, A.C. |
| record_format | ojs |
| spelling | oai:oai.abm.ojs.inecol.mx:article-20952022-12-15T21:03:42Z Chromosomal studies, pollen morphology and fertility in Dioscorea ayardei (Dioscoreaceae) Estudios cromosómicos, morfología y fertilidad polínica en Dioscorea ayardei (Dioscoreaceae) Asesor, Patricia N. Andrada, Aldo R. Páez, Valeria de los A. Reyes, Nora J. F. Bulacio, Eva gametophytic chromosome number meiotic behavior pollen morphology pollen viability. comportamiento meiótico morfología polínica número cromosómico gametofítico viabilidad de polen. Background and Aims: The great variability of characters in Dioscorea makes it difficult to define the species, therefore additional studies are necessary to identify them. Dioscorea ayardei, a recently described endemic species from the Sierras de Calilegua (Jujuy, Argentina), differs by the particularity of the androecium of its staminate flowers which consists of a navicular structure with a single anther in the center and three erect dendriform appendages. The aim of this paper was to carry out an ensemble study of its chromosomal and palynological characters that, added to the morphological ones, provide complementary information for its correct delimitation. Methods: The studied material was identified according to the classic methods in taxonomy and deposited in the LIL Herbarium, of the Fundación Miguel Lillo. For study of meiosis, young flower buds were randomly selected, which were fixed in Farmer for 24 hours and preserved in 70° to -4°C ethyl alcohol. For chromosome staining, 2% propionic hematoxylin was used. Fertility of pollen grains was estimated using the Mützing and DAPI techniques. For the pollen morphology description the material was processed according to the conventional techniques of acetolysis and natural pollen; photographs were taken with light microscope (LM) and scanning electron microscope (SEM). Key results: Dioscorea ayardei presented a gametophytic number n=20II. Meiotic behavior was generally regular. The techniques to estimate viability and fertility of the pollen grain revealed a value of 90-93%, respectively. The morphology showed a small (16-24 µm) to medium (25-30 µm) sized disulcate grain with microreticulate tectum. Conclusions: The basic chromosome number for the genus x=10 is reaffirmed. Dioscorea ayardei is a tetraploid with n=20, with normal meiotic behavior consistent with the potential viability of the pollen grain. The exine ornamentation and chromosome number relates with the New World II clade. Antecedentes y Objetivos: La gran variabilidad de caracteres en Dioscorea dificultan la delimitación de las especies, por lo que estudios complementarios son necesarios para lograr su identificación. Dioscorea ayardei, especie endémica descrita recientemente de las Sierras de Calilegua (Jujuy, Argentina), se diferencia por la particularidad del androceo en sus flores estaminadas, la cual consiste en una estructura navicular con una sola antera en el centro y tres apéndices dendriformes erectos. El objetivo de este trabajo fue realizar un estudio conjunto de sus caracteres cromosómicos y palinológicos, que sumados a los morfológicos aporten información complementaria para su correcta delimitación. Métodos: El material estudiado fue identificado según los métodos clásicos en taxonomía y depositado en el Herbario LIL, de la Fundación Miguel Lillo. Para estudiar la meiosis se seleccionaron al azar botones florales jóvenes, que fueron fijados en Farmer durante 24 horas y conservados en alcohol etílico 70° a -4°C. La tinción de los cromosomas se realizó con hematoxilina propiónica al 2%. La fertilidad de los granos de polen se estimó mediante las técnicas de Mützing y DAPI. Para describir la morfología polínica, el material fue procesado según las técnicas convencionales de acetólisis y polen natural; se tomaron fotos con microscopía óptica (MO) y electrónica de barrido (MEB). Resultados clave: Dioscorea ayardei presentó un número gametofítico n=20II. El comportamiento meiótico fue generalmente regular. Las técnicas para estimar viabilidad y fertilidad del grano de polen revelaron un valor de 90-93% respectivamente. La morfología muestra un grano disulcado de tamaño pequeño (16-24 µm) a mediano (25-30 µm) con tectum microreticulado. Conclusiones: Se reafirma el número cromosómico básico para el género x=10. Dioscorea ayardei es un tetraploide con n=20, de comportamiento meiótico normal que concuerda con la viabilidad potencial del grano de polen. La ornamentación de la exina y el número cromosómico la relaciona con el clado Nuevo Mundo II. Instituto de Ecología, A.C. 2022-09-15 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion artículo evaluado por pares application/pdf text/xml application/epub+zip https://abm.ojs.inecol.mx/index.php/abm/article/view/2095 10.21829/abm129.2022.2095 Acta Botanica Mexicana; No. 129 (2022) Acta Botanica Mexicana; Núm. 129 (2022) 2448-7589 0187-7151 spa https://abm.ojs.inecol.mx/index.php/abm/article/view/2095/4269 https://abm.ojs.inecol.mx/index.php/abm/article/view/2095/4338 https://abm.ojs.inecol.mx/index.php/abm/article/view/2095/4270 https://creativecommons.org/licenses/by-nc/4.0 |
| spellingShingle | Asesor, Patricia N. Andrada, Aldo R. Páez, Valeria de los A. Reyes, Nora J. F. Bulacio, Eva Chromosomal studies, pollen morphology and fertility in Dioscorea ayardei (Dioscoreaceae) |
| title | Chromosomal studies, pollen morphology and fertility in Dioscorea ayardei (Dioscoreaceae) |
| title_full | Chromosomal studies, pollen morphology and fertility in Dioscorea ayardei (Dioscoreaceae) |
| title_fullStr | Chromosomal studies, pollen morphology and fertility in Dioscorea ayardei (Dioscoreaceae) |
| title_full_unstemmed | Chromosomal studies, pollen morphology and fertility in Dioscorea ayardei (Dioscoreaceae) |
| title_short | Chromosomal studies, pollen morphology and fertility in Dioscorea ayardei (Dioscoreaceae) |
| title_sort | chromosomal studies, pollen morphology and fertility in dioscorea ayardei (dioscoreaceae) |
| url | https://abm.ojs.inecol.mx/index.php/abm/article/view/2095 |
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