Cytogenetical Investigations into Some Garden Ornamentals

III. Chromosomes in some monocot taxa

Abstract

Cytological data with respect to 18 monocotyledonous ornamental taxa are presented. Sanseveria hahnii (2n=40) and Haworthia limifolia var. marlothiana (2n=28) were cytologically undocumented earlier. Earlier known chromosome counts are confirmed in the remaining taxa. Anew base number x=10 is suggested for Drimiopsis. Following karyotypes are established.
Gasteria armstrongii: K(2n)=14=A^st₂+C^st₆+H^st₂+H^sm₂+I^sm₂
Haworthia fasciata: K(2n)=14=C^st₆+D^st₂+H^st₄+I^st₂
H. limifolia var. marlothiana: K(2n)=28=D^st*₂+D^st₁₀+E^st₄+I^st₆+I^sm₂+I^sm*₂+J^st₂
H. subulata: K(2n)=14=C^st₈+H^st₂+I^st₄
Crinum asiaticum: K(2n)=22=A^sm₂+B^sm₄+C^sm*₃+C^st₅+D^m₂+D^sm₂+E^sm₂+G^m₂
Zephyranthes candida: K(2n)=38=C^m₂+C^sm₅+D^m₄+D^sm₄+E^sm₁+E^st₂+F^sm₄+F^st₂+G^sm₁₂+G^st₂
Z. grandiflora: K(2n)=50=C^m₁+D^sm₂+E^sm₁₀+F^st₇+G^m₂+G^sm₉+G^st₁₂+H^m₂+H^sm₃+I^sm₂
Z. sulphurea: K(2n)=48=B^m₂+C^m₂+C^sm₄+D^sm₂+D^st₃+E^sm₂+E^st₂+F^m₂+F^sm₄+F^st₁₁+G^sm₁₂+H^m₂
Belamcanda chinensis: K(2n)=32=G^sm₂+G^st*₂+H^sm₈+I^m₄+I^sm₈+I^st₄+J^sm₄
Karyotype analysis indicate chromosomal repatterning and/or hybrid nature of most of the taxa. Role of vegetative reproduction in the preservation of new genetic combinations is discussed particularly in the genera Haworthia and Zephyranthes. Accessory chromosomes are recorded in Anthurium acaule (2n=30+2-5B). Their origin is evident from the A's with which these pair during meiosis. Cytological distinctness of Sanseveria from other genera of Agavaceae is apparent.