Meiotic analysis in wild diploid Arachis species

Abstract

Meiotic behaviour of A. lignosa, A. rigonii (Sect. Procumbentes), A. microsperma, A. simpsonii and A. williamsii (Sect. Arachis) is reported for the first time, and for A. batizocoi, A. stenosperma and A. villosa were studied in different accessions than the previously reported ones. All the species analyzed were diploid forming 10 II at diakinesis-metaphase I, except A. stenosperma which presented 8 II+1 IV in 3% of the pollen mother cells. Most of the bivalents were of the ring type, and only I or 2 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 was observed which is in accordance with the recorded high pollen stainability. Only 1 pair of chromosomes was easily recognized, that being the very small "A" pair in the A genome of Arachis section species. This small pair can be used also at meiosis to distinguish the A and B genomes.