During the present course, population-based meiotic studies were carried out on five species of subfamily Papaveroideae from selected localities of Kashmir and Himachal Pradesh in the Western Himalayas (India). Varied intraspecific chromosome counts were reported for the first time in Argemone mexicana and Meconopsis latifolia, both existing on 2n = 2x = 14. The x = 7, confirmed for the first time from the newly found diploid cytotype, is suggested to be the primary chromosomal basic number for the Meconopsis. Furthermore, meiotic course was noted to be normal in Argemone ochroleuca, it varied from normal to abnormal in the populations of A. mexicana and Papaver dubium whereas it was invariably found to be abnormal in all the populations of Meconopsis aculeata and M. latifolia. These anomalous taxa were marked with meiotic abnormalities in the form of cytomixis, chromosomal stickiness, unoriented bivalents, formation of laggards and bridges resulting in abnormal microsporogenesis, and production of heterogeneous-sized fertile pollen grains along with reduced pollen fertility.
SummaryThe 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 (nϭ7, 8) and I. reidii (nϭ7). Six aneuploid cytotypes have been reported for the first time for the species I. arguta (nϭ7), I. bicornuta (nϭ7), I. brachycentra (nϭ8), I. glandulifera (nϭ6), I. scabrida (nϭ6) and I. sulcata (nϭ8) 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 (nϭ7 and nϭ8), I. glandulifera (nϭ9 and nϭ6), I. laxiflora (nϭ7 and nϭ8) and I. scabrida (nϭ6 and nϭ7) highlighting the morphological changes coupled with chromosomal changes.
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