Cytology and reproductive behavior of diploid, tetraploid and hexaploid germplasm accessions of a wild forage grass: Paspalum compressifolium

• Published in: Euphytica 1996, Vol.90 (3), p.345-349
• Main Authors: Quarin, C.L. (Instituto de Botanica del Nordeste, Corrientes (Argentina)), Pozzobon, M.T, Valls, J.F.M
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; AUTOESTERILIDAD; AUTOSTERILITE; Biological and medical sciences; BRASIL; BRAZIL; BRESIL; CITOLOGIA; Cytogenetics; CYTOLOGIE; CYTOLOGY; EMBRIONES VEGETALES; EMBRYON VEGETAL; Fundamental and applied biological sciences. Psychology; Generalities. Genetics. Plant material; Genetic resources, diversity; Genetics and breeding of economic plants; GERMOPLASMA; GERMPLASM; Heterosis. Floral biology applications: apomixy, male sterility, incompatibility, varia; PASPALUM; Plant breeding: fundamental aspects and methodology; PLANT EMBRYOS; Plant material; POLIPLOIDIA; POLYPLOIDIE; POLYPLOIDY; SELF STERILITY
• ISSN: 0014-2336; 1573-5060
• DOI: 10.1007/bf00027486

Fourteen germplasm accessions of Paspalum compressifolium native from southern Brazil were cytologically and embryologically analysed. The study revealed that one accession was diploid (2n = 20), twelve were tetraploid (2n = 40) and one was hexaploid (2n = 60). This is the first report of diploid and hexaploid cytotypes for this species. Studies on microsporogenesis, megasporogenesis, and embryo sac development indicated that the diploid cytotype had regular meiotic behavior and reproduces sexually. Tetraploid cytotype usually had an important proportion of chromosomes that associated as quadrivalents during meiosis and reproduced by mean of aposporous apomixis. The hexaploid cytotype showed irregular meiotic behavior with about one third of the chromosomes associated as multivalents and reproduced by aposporous apomixis. Thus, P. compressifolium could be an agamic complex. Breeding in this complex is possible due to the presence of diploid sexuals which can be treated by colchicine and pollinated by apomicts.