Cytogeographical and reproductive behaviour analyses in four Paspalum species from North-eastern Argentina

REUTEMANN A.V.; ANA I. HONFI; HOJSGAARD D.H.; MARTINEZ E.J.

FOZ DO IGUAZU

Congreso; 2018 INTERNATIONAL CONGRESS OF GENETICS; 2018

INTERNATIONAL FEDERATION OF GENETICS, SOCIEDADE BRASILERA DE GENETICA, ASOCIACION LATINOAMERICANA DE GENETICA

Natural populations of Paspalum indecorum, P. pumilum, P cromyorrhizon and P. maculosum were collected in northeastern Argentina. The aim of this work was to describe the geographical distribution of cytotypes and the reproductive behaviour of these taxa. Four populations of each species were analized. The ploidy level of them was determined usingchromosome counts by Feulgen technique and DNA relative content measure by flow cytometry. Cytotypes distribution maps were made using DIVA-GIS software. Cytoembriological analyses of mature embryo sacs were made to determine the reproductive behaviour. All the P. pumilum populations were diploid and sexual. Paspalum indecorum populations were diploid and onetriploid individual was found. Most plants were sexual and a few showed potential for apomixis by the presence of aposporous embryo sacs (AES) and meiotic ones sharing the same ovule. Two P. maculosum populations were homogeneously diploid and two populations have diploids, triploids and tetraploids plants. Diploid populations showed only meiotic embryo sacs (MES) but some individuals showed ovules with AES joining meiotic sacs. Multiploid populations showed mostly MES associated with AES. Paspalum cromyorrhizon showed three populations consisting only of tetraploid plants and one mixed population (2x and 4x). Tetraploid populations showed three types of ovules: with single MES, combination of MES and AES, and with only AES. The mixed population of P. cromyorrhizon showed mostly MES only, with some cases of AES accompanying meiotic ones.Diploid populations behaved predominantly as sexual, whilemultiploid populations showed both types of reproduction (sexual and apomictic).