Meiotic behaviour in wild diploid Arachis (Leguminosae) species

Abstract

Meiotic studies of A. chiquitana, A. matiensis, A. subcoriacea (Sect. Procumbentes), A. triseminata (Sect. Triseminatae), A. benensis, A. diogoi, A. herzogii and A. kempff-mercadoi (Sect. Arachis) are reported for the first time. Meiotic behaviour was essentially regular in most of the species, with 10 II at diakinesis-metaphase I, except in A. benensis which presented 8 II+1 IV in 2% of the pollen mother cells. Most of the bivalents were of the ring type, and only one or two bivalents were usually of the rod type. Chiasmata were always located in distal to terminal position even at diplotene and diakinesis. Normal segregation of bivalents is in accordance with the recorded high meiotic indexes and pollen stainability. Only one pair of chromosomes was easily recognized, that being the very small “A” pair in the species with A genome of Arachis section. This small pair can be used at meiosis to distinguish between the A and B genomes species and may be a useful marker to detect allopolyploids involving both genomes.