Meiotic Configurations and Secondary Chromosome Associations in Indigofera tinctoria L. (Family: Fabaceae)

Abstract

Meiotic analysis performed in Indigofera tinctoria L. (Family: Fabaceae) reveals n=8 chromosomes with an average chromosomal association of 7.79II+0.44I at metaphase I (MI). Predominance of 8II formation (87.86%) has been noted. The bivalents form rods (mean per cell – rod: 5.88±0.21; ring: 1.87±0.19; association: 7.75II+0.50I) mostly at diplotene with a mean chiasma of 9.62±0.21 per cell. Anaphase I cells (94.12%) are mostly cytologically balanced (8/8) with an average pollen fertility of 93.60%. A persistent feature (89.39%) in MI cells has been the presence of secondary association of chromosomes and the chromosomes assort themselves into variable groups of two (6.04%), three (7.04%), four (25.50%), five (56.71%), six (4.02%) and seven (0.67%). Out of 25 different associations studied among the group classes, 3II(1)+2II(1)+1II(3) under the five group class (25.83%) was the most frequent. Statistical analysis of cytological data reveals that the probable basic chromosome number in the species is x=5, suggesting polyploid lineage.