Cytomorphological diversity in some species of Impatiens Linn. (Balsaminaceae) from Western Himalayas (India)

Abstract

The genus Impatiens Linn. belongs to the family Balsaminaceae and includes mostly wild as well as commonly cultivated ornamental plants. Nearly 91% of Indian species of Impatiens are reported to be endemic. To generate basic information on genetic diversity required for the improvement of germplasm, the present study has been carried out from the different selected parts of Western Himalayas such as Kashmir (J&K) and the Kangra and Sirmaur districts (H.P). During this study, 23 accessions belonging to 9 species of the genus Impatiens have been cytomorphologically observed. The species being cytologically worked out for the first time on a worldwide basis include 2 species as I.laxiflora (n=7, 8) and I. reidii (n=7). Six aneuploid cytotypes have been reported for the first time for the species I. arguta (n=7), I. bicornuta (n=7), I. brachycentra (n=8), I. glandulifera (n=6), I. scabrida (n=6) and I. sulcata (n=8) on a worldwide basis. The meiotic course in most of these accessions has been observed to be normal except for some of the accessions of I. brachycentra, I. glandulifera, I. scabrida and I. sulcata marked with abnormal meiosis. Out of 4 species (6 accessions) marked with cytomixis, in 2 accessions, one for each of I. scabrida and I. sulcata, the percentage of cytomixis has been seen to be relatively higher with production of heterogenous sized fertile pollen grains. The presence of B-chromosomes in I. balsamina is in conformity with the earlier reports for this species. Morphological comparison at intraspecific level has also been made for the different aneuploid cytotypes of I. brachycentra (n=7 and n=8), I. glandulifera (n=9 and n=6), I. laxiflora (n=7 and n=8) and I. scabrida (n=6 and n=7) highlighting the morphological changes coupled with chromosomal changes. © 2010 The Japan Mendel Society.