Syed Mudassir Jeelani

Cytology of five species of subfamily Papaveroideae from the Western Himalayas

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.

Meiotic studies in some selected angiosperms from the Kashmir Himalayas

Abstract  As a part of our program to explore and evaluate genetic diversity of flowering plants of the Kashmir Himalayas, meiotic studies have been carried out on 150 wild species. Of these, Caltha alba (2n= 32), Delphinium roylei (2n= 16), D. uncinatum (2n= 16), Ranunculus palmatifidus (2n= 28), and Sedum heterodontum (2n= 14) have been cytologically worked out for the first time. New intraspecific diploid or polyploid cytotypes have been recorded for Alchemilla vulgaris (2n= 34, 96), Arabis amplexicaulis (2n= 16), Impatiens amphorata (2n= 14), I. racemosa (2n= 12), I. sulcata (2n= 16, 12), Meconopsis latifolia (2n= 14), Potentilla supina (2n= 14), Saxifraga cernua (2n= 16), Sium latijugam (2n= 24), and Vicatia coniifolia (2n= 44). Four species, Arabidopsis thaliana (2n= 10), Berberis vulgaris (2n= 28), Potentilla nubicola (2n= 14), and P. sericea (2n= 28), have been cytologically reported for the first time from India. A large number of meiotic abnormalities have been observed in most of these species, leading to a reduction in pollen fertility and production of heterogeneous‐sized pollen grains.

Cytomorphological studies of genus Saxifraga L. from Western Himalaya

Cytomorphological studies have been carried out for analysing the cyto-genetic diversity in 14 populations covering 5 species belonging to the genus Saxifraga L. (fam. Saxifragaceae) from Western Himalaya. New intraspecific cytotypes in Saxifraga diversifolia Wall. ex Ser. (n = 8 and n = 16), S. filicaulis Wall. ex Ser. (n = 8) and S. siberica Linn. (n = 16) are added on world-wide basis. Cytotypes of S. flagellaris Willd. (n = 8), S. ligulata Wall. (n = 17) and S. siberica Linn. (n = 8) although worked out earlier from other countries are being reported for the first time from India. Further, comparison of the different cytotypes studied at present for Saxifraga diversifolia Wall. ex Ser and S. siberica Linn. show significant variation in their morphology, and also increased size for morphphological features in the polyploids. The course of meiosis has been observed to be abnormal in all the populations of S. filicaulis Wall. ex Ser., S. flagellaris Willd. and S. siberica Linn., but in S. diversifolia Wall. ex Ser. it exhibited patterns of normal to abnormal behaviour in different populations.

An overview of chromosome and basic numbers diversity in cytologically investigated polypetalous genera from the Western Himalayas (India)

Intensive exploration and evaluation of cytomorphological diversity has been carried out on 380 species of 127 genera belonging to 28 families of sub-class Polypetalae of flowering plants from Kashmir (Jammu and Kashmir) and Kangra and Sirmaur districts (Himachal Pradesh) of the Western Himalayas. The cytological investigations of these species over a period of three years revealed new and varied chromosome numbers for 100 species globally and 50 species in India, making a substantial addition to the knowledge of the genera to which these species belong. To obtain a comprehensive cytological picture of each of these genera, chromosomal data have been updated by compiling the literature on previous chromosomal numbers and supplementing it from the present studies. The final form is now ready to show the status both at global and Indian levels for various parameters like total number of taxonomically known species, number of cytologically determined species along with intraspecifically added number of cytological taxa, presently inferred basic numbers, level and frequency of polyploids, and information on number of species per genus carrying inter- and intraspecific euploid and aneuploid variability at the genus level. Of the total 127 genera, 39 genera have 75% or more cytologically worked out species. Addition of cytotypes in many cytologically known species has resulted in an enhanced number of chromosomal races/cytological taxa over such species, in the majority of genera, justifying the ever growing need to make population based intensive studies of any plant species. The data show that monobasic and dibasic genera are less common than tribasic and polybasic ones. Genera with x = 8 are most common, followed by x = 7 and x = 6. Of 127 genera, 47 genera exhibit polyploidy of up to 25%; 22 genera have 26–50%; 15 genera have 51–70%; and 26 genera have 76–100% polyploidy, while 17 genera lack polyploidy altogether. Interspecific and/or intraspecific euploid cytotypes such as diploids plus polyploids or with “polyploid series” are present in most of the 107 genera. Intraspecific aneuploid chromosome numbers are also shown by 100 genera. Since these genera belong to different families, so no generalization can be made at family level. However, at genus level chromosomal observations show the active role of various evolutionary processes responsible for chromosomal diversity in the majority of these genera distributed in the Western Himalayas of India.

Cytological evaluation of Apiaceae Lindl. from Western Himalayas

The present paper deals with cytological studies on 31 populations covering 17 species belonging to 10 genera of Apiaceae from Western Himalayas. The chromosome numbers in the two species as Chaerophyllum capnoides (n = 11) and Heracleum brunonis (n = 11), along with additional cytotypes for Pimpinella acuminata (n = 9) and Sium latijugum (n = 12) have been reported for the first time on world-wide basis. The genus Pleurospermum, although cytologically worked out earlier from outside India, its species densiflorum (n = 11) makes first representation of the genus from India. Besides, the chromosome number in Chaerophyllum aromaticum (n = 11) have been worked out for the first time from India. The course of meiosis varies from normal to abnormal in different populations of Chaerophyllum villosum, Pimpinella achilleifolia and Sium latijugum while abnormal meiotic course has been observed in all the studied populations of Chaerophyllum acuminatum, C. aromaticum, C. capnoides, Pimpinella acuminata, P. diversifolia, Pleurospermum densiflorum and Vicatia coniifolia. Such taxa are marked with meiotic abnormalities in the form of cytomixis, chromatin stickiness, formation of laggards and bridges resulting into abnormal microsporogenesis. The occurrence of structural heterozygosity has been recorded in the Chaerophyllum acuminatum and C. aromaticum. The effect of these abnormalities is clearly seen on the pollen size and fertility.

Cytological studies of Brassicaceae Burn. (Cruciferae Juss.) from Western Himalayas

Cytological studies have been carried out on 12 species of Brassicaceae Burn. on population basis from different geographical areas of Kashmir and Himachal Pradesh in the Western Himalayas. Variable chromosome reports for Barbaraea intermedia (n = 16), Cardamine loxostemonoides (n = 8), Nasturtium officinale (n = 8), Sisymbrium orientale (n = 14) on world-wide basis have been added to the previous reports of these species. The chromosome numbers in seven species as Barbaraea intermedia (n = 8), B. vulgaris (n = 8), Capsella bursa-pastoris (n = 8), Descuriania Sophia (n = 10), Rorippa islandica (n = 8), Sisymbrium strictum (n = 7) and Thlaspi alpestre (n = 7) have been worked out for the first time from India. The meiotic course in the populations of seven species such as Barbaraea intermedia, Capsella bursa-pastoris, Coronopus didymus, Descuriania sophia, Nasturtium officinale, Sisymbrium orientale and S. strictum varies from normal to abnormal while all the populations of two species Barbaraea vulgaris and Sisymbrium irio show abnormal meiotic course. Meiotic abnormalities are in the form of cytomixis, chromosomal stickiness, unoriented bivalents, inter-bivalent connections, formation of laggards and bridges, all resulting into abnormal microsporogenesis. Heterogenous sized fertile pollen grains and reduced reproductive potentialities have invariably been observed in all the meiotically abnormal populations. However, the meiotic course in all the populations of Cardamine loxostemonoides, Rorippa islandica and Thalspi alpestre is found to be normal with high pollen fertility.