The present study is aimed to identify genetic variability between two species of Amaranthus viz., A. caudatus and A. hybridus subsp. cruentus, two economically important species, cultivated mainly for grain production. Karyomorphological studies in Amaranthus are scarce, probably due to higher number of small sized chromosomes. Karyomorphological studies were conducted using mitotic squash preparation of young healthy root tips. Karyological parameters and karyotypic formula were established using various software programs and tabulated the karyomorphometric and asymmetry indices viz., Disparity index, Variation coefficient, Total forma percentage, Karyotype asymmetry index, Syi index, Rec index, Interchromosomal and Intrachromosomal asymmetry index and Degree of asymmetry of karyotypes. The mitotic chromosome number observed for A. caudatus was 2n = 32 with a gametic number n = 16 and A. hybridus subsp. cruentus was 2n = 34 with a gametic number n = 17. In A. caudatus the chromosome length during somatic metaphase ranged from 0.8698 to 1.7722 μm with a total length of 39.1412 μm. In A. hybridus subsp. cruentus the length of chromosome ranged from 0.7756 to 1.9421 μm with a total length of 44.9922 μm. Various karyomorphometry and asymmetry indices analyzed revealed the extend of interspecific variation and their evolutionary status.
This is a preview of subscription content, log in to check access.
First author kindly acknowledges Kerala State Council for Science, Technology and Environment for providing financial assistance through KSCSTE fellowship.
Compliance with ethical standards
Conflict of interest
The authors declare that there are no conflicts of interest.
Abraham Z, Prasad PN (1983) A system of chromosome classification and nomenclature. Cytologia 48:95–101CrossRefGoogle Scholar
Anil SR, Suhara Beevy S, Siril EA (2013) Karyosystematic studies in Amorphophallus Blume ex Decne. J Root Crops 39:39–50Google Scholar
Arno H (1963) Cytological studies in subfamily Carduoideae (Compositae) of Japan. IX. The karyotype analysis and phylogenetic considerations on Pertya and Ainsliaea. Bot Mag (Tokyo) 76:32–39CrossRefGoogle Scholar
Venora G, Blangiforti S, Castiglione MR, Pignone D, Losavio F, Cremonini R (2002) Chromatin organization and computer aided karyotyping of Triticum durum Desf. Cv. Timilia. Caryologia 55:91–98CrossRefGoogle Scholar
Verma BN (1980) Karyotype analysis in three species of Rhizoclonium Kütz. Cytologia 45:433–440CrossRefGoogle Scholar
Watanabe K, Yahara T, Denda T, Kosuge K (1999) Chromosomal evolution in the genus Brachyscome (Asteraceae, Astereae): statistcal tests regarding correlation between changes in karyotype and habit using phylogenetic information. J Plant Res 112:145–161CrossRefGoogle Scholar