International Journal of Agriculture, Enviornment and Biotechnology
Year : 2010, Volume : 3, Issue : 1
First page : ( 67) Last page : ( 70)
Print ISSN : 0974-1712. Online ISSN : 2230-732X.

Ploidy Level and Basic Chromosome Number in Some Species of Jatropha L.

Sasikala R., Paramathma M.*

Cytogenetics Laboratory, Centre for Plant Breeding and Genetics, Tamilnadu Agricultural University, Coimbatore-641 003, India.

*Email: paramathmam@yahoo.com

Received:  18  December,  2010.

Abstract

The young developing inflorescence of ten species of the genus Jatropha and one interspecific hybrid between Jatropha curcas × Jatropha integerrima were fixed in Carnoy's fluid. Pollen mother cells were well stained with 2% acetocarmine. Eight species and one hybrid (J.curcas × J.integerrima) exhibited 11 bivalents and 2n =22 and x=11. But the other two species, J.villosa var. villosaand and J.villosa var. ramnadensis showed only 10 bivalents and 2n number of 20 chromosomes and x=10. The study concluded the occurrence of two kinds of haploid chromosome numbers of n =10 and n =11. Except Jatropha tanjorensis, cytological investigation in all species exhibited normal and complete pairing and bivalent formation in metaphase I with equal separation of chromosomes in anaphase indicating that the course of meiosis was normal. Jatropha tanjorensis did not exhibit normal course of meiosis and no proper count of chromosomes could be made. The present investigation revealed the existence of two basic chromosome numbers x = 5 and x = 6 in the genus Jatropha.

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Keywords

Jatropha, basic chromosome number, polyploidy, course of meiosis, chromosome pairing, Carnoy's fluid.

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