Cytogenetical Studies of Some Species of Himalayan Anemone and Ranunculus (Ranunculaceae).

Vaidya, Buddha Laxmi; Joshi, Kunjani

doi:10.1508/cytologia.68.61

Cited by 6 publications

(3 citation statements)

References 15 publications

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“…Further, the species is also known to have intraspecific diploid, 2n=16 (Kabu et al, 1988, Vaidya andJoshi, 2003), and tetraploid, 2n=32 cytotypes (based on x=8), reported by other researchers from India and Pakistan (cf. Standard Cytological Indices).…”

Section: Ranunculus Laetusmentioning

confidence: 78%

Cytological Studies of Some Dicots from the Hills of Mandi District (Himachal Pradesh) in Northwest Indian Himalayas

Singhal¹,

Garg²,

Kumar³

2013

CYTOLOGIA

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Summary Details of male meiotic course and pollen fertility have been investigated in 45 species of dicotyledonous plants from the chromosomally unexplored area of the Mandi district, between the altitudinal ranges of 800 to 3360 m. All the species have been worked out cytologically for the first time from the study area. The meiotic chromosome count of n=9 for Impatiens micranthemum is the first ever chromosome report for the species. A new intraspecific 12x cytotype (n=42) has been reported in Potentilla gerardiana, supplementing the earlier reported cytotypes (2x, 8x). A new cytotype has been reported in Gentiana argentea (n=9), supplementing the earlier Indian report of n=10. Out of a total 45 species, 31 species (68.89%) showed normal meiotic course and high pollen fertility (91-100%), while 14 species (31.11%) depicted various meiotic irregularities and some pollen sterility (4-40%). The phenomenon of cytomixis involving inter-pollen mother cells (PMCs) migration of chromatin material has been reported in 3 species, Clematis grata (n=8), Gentiana aprica (n=10) and Lamium album (n=9). In these species, cytomixis induces various meiotic abnormalities (enucleated, hypo-, hyperploid, tripolar and multipolar PMCs, chromatin stickiness, laggards and chromatin bridges at anaphases and telophases and micronuclei) and consequently some pollen sterility and variable sized pollen grains. Besides, non-synchronous disjunctions of bivalents at anaphases, abnormal spindles, and interbivalent connections during diakinesis/metaphase-I, univalents and multivalents have also been reported in certain cases. The chromosome counts in the remainder of the species substantiate previous counts by other researchers. Mandi district, a gateway to Himachal Pradeshʼs most famous places, including Kullu, Manali, and Lahaul-Spiti, lies between 31°13′50″ and 32°04′30″N latitude and between 76°37′20″ and 77°23′15″E longitude and is situated on the left bank of the river Beas in the foot hills of the Shivalik range. The vegetation of hills around Mandi is varied and the geographical location, climate, and topography of the district have contributed to characteristic vegetation and flora. The forests here support and preserve a variety of flora and fauna. The region is primarily dominated by deciduous trees. It is sub-tropical in the valley and tends to be temperate on the hill tops. The vegetation constituting the forests falls under four main categories: (1) Himalayan Sub-Tropical Pine Forests, (2) Himalayan Moist Temperate Forests, (3) Sub-Alpine Forests, and (4) Alpine Forests. Key wordsFor many decades, the Himalayas have attracted a galaxy of researchers from various disciplines on a global scale. So far, studies undertaken pertain either to floristic diversity or ethnobotany (Chowdhary and

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Section: Ranunculus Laetusmentioning

confidence: 78%

Cytological Studies of Some Dicots from the Hills of Mandi District (Himachal Pradesh) in Northwest Indian Himalayas

Singhal¹,

Garg²,

Kumar³

2013

CYTOLOGIA

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“…ex Royle (family: Ranunculaceae), a highly polymorphic species [ 1 , 2 ], has been studied chromosomally quite extensively from various regions of the Himalayas in India and outside of India from the hills of Nepal, Russia, China, and Pakistan (Figures 1(a) and 1(b) ). The species exhibited a great amount of heterogeneity in chromosome number and level of ploidy with 2x ((2 n = 14) [ 3 ], Cangshan Mountains, Yunnan, China; (2 n = 16) [ 4 ], Nepal), 4x ((2 n = 28), [ 1 , 5 , 6 ], Kashmir Himalayas; [ 7 , 8 ], Eastern Himalayas; [ 9 ], Northwest Himalayas; [ 10 , 11 ], Russia; [ 12 , 13 ], Garhwal Himalayas; [ 14 ], Kinnaur in Himachal Pradesh; [ 15 , 16 ], Chamba, Lahaul-Spiti, Kinnaur and Dalhousie hills in Himachal Pradesh; (2 n = 32) [ 1 ], Shimla hills in Himachal Pradesh; [ 17 ], Indian Himalayas; [ 18 ], Kashmir Himalayas; [ 19 , 20 ], Western Pakistan; [ 21 , 22 ] Pakistan), 6x ((2 n = 42) [ 8 ], Eastern Himalayas), 8x ((2 n = 56) [ 20 ], Pakistan) based on two different basic chromosome numbers (2x, 4x, 6x, 8x on x = 7, 2x, 4x on x = 8).…”

Section: Introductionmentioning

confidence: 99%

Erratic Male Meiosis Resulting in2nPollen Grain Formation in a 4x Cytotype (2n=28) ofRanunculus laetusWall. ex Royle

Kumar

Singhal

2012

The Scientific World Journal

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Two accessions were studied for male meiosis in Ranunculus laetus from the cold regions of Northwest Himalayas. One accession showed the presence of 14 bivalents at diakinesis and regular segregation of bivalents at anaphase I which lead to normal tetrad formation with four n microspores and consequently n pollen grains and 100% pollen fertility. Second accession from the same locality revealed the erratic meiosis characterized by the presence of all the 28 chromosomes as univalents in meiocytes at metaphase I. Univalent chromosomes failed to segregate during anaphases and produced restitution nuclei at meiosis I and II. These restitution nuclei resulted into dyads and triads which subsequently produced two types of apparently fertile pollen grains. On the basis of size, the two types of pollen grains were categorized as n (normal reduced) and 2n (unreduced, 1.5-times larger than the n pollen grains). The estimated frequency of 2n pollen grains from dyads and triads (61.59%) was almost the same as that of the observed one (59.90%), which indicated that 2n pollen grains in R. laetus were the result of dyads and triads. The present paper herein may provide an insight into the mechanisms of the formation of various intraspecific polyploids through sexual polyploidization in R. laetus.

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“…Important contributors from outside India include Zhou et al (2002), Lihová et al (2003), Ghaffari (2004), Yan-Jun et al (2006), Wang et al (2008), Sheng et al (2010), Gholipour and Sheidai (2010), Gömürgen et al (2011), Ranjbar et al (2012), Chung et al (2013), and de Resende et al (2013). Major contributions over the past few decades from India include Sarkar (1967-1968), Sharma (1970), Roy and Sharma (1971), Chatterjee and Sharma (1972), Sanjappa (1979), Hore (1971Hore ( , 1980, Panigrahi and Purohit (1984), Subramanian (1985), Govindarajan and Subramanian (1986) and Vaidya and Joshi (2003). Some of the recent contributors for the Western Himalayan polypetalous plants in particular include Pimenov et al (2006), Kumar and Singhal (2008, Singhal and Kumar (2008), Gupta et al (2009), , Singhal et al ( , 2010Singhal et al ( , 2011, Kaur et al (2010), and Kumar et al (2010).…”

Section: Number Of Cytologically Known Speciesmentioning

confidence: 99%

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

et al. 2014

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Cytogenetical Studies of Some Species of Himalayan Anemone and Ranunculus (Ranunculaceae).

Cited by 6 publications

References 15 publications

Cytological Studies of Some Dicots from the Hills of Mandi District (Himachal Pradesh) in Northwest Indian Himalayas

Cytological Studies of Some Dicots from the Hills of Mandi District (Himachal Pradesh) in Northwest Indian Himalayas

Erratic Male Meiosis Resulting in2nPollen Grain Formation in a 4x Cytotype (2n=28) ofRanunculus laetusWall. ex Royle

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

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