A plant with 3X in gametic stage, would become hexaploid sporophytic phase 2N=3X may generally result from a cross between a diploid and a tetraploid, and would be sterile and perish soon, unless it multiplies vegetatively, or else duplication of chromosomes occurs to make it hexaploid, a phenomenon commonly seen in Senecio and Tragopogon.
-- Dr. Gurcharan Singh Retired Associate Professor SGTB Khalsa College, University of Delhi, Delhi-110007 Res: 932 Anand Kunj, Vikas Puri, New Delhi-110018. Phone: 011-25518297 Mob: 9810359089 http://people.du.ac.in/~singhg45/ On Sat, Sep 25, 2010 at 10:51 AM, Pankaj Kumar <[email protected]>wrote: > I imagine if it was a correction of addition. Anyways, just a > querry...So you mean to say a plant with 3x chromosome is not a > polyploid? > Pankaj > > On Sat, Sep 25, 2010 at 9:30 PM, Gurcharan Singh <[email protected]> > wrote: > > Pankaj ji > > A slight correction. Every plant has N (gametic) and 2N (sporophytic) > > chromosomes. Every plant has basic number X, usually same for a genus. A > > diploid would have 2N=2X, whereas a polyploid would have 2N=4X > (tetraploid), > > 6X (hexaploid), 8X (octaploid), etc. Plant is known as polyploid and > > phenomenon as polyploidy. > > -- > > Dr. Gurcharan Singh > > Retired Associate Professor > > SGTB Khalsa College, University of Delhi, Delhi-110007 > > Res: 932 Anand Kunj, Vikas Puri, New Delhi-110018. > > Phone: 011-25518297 Mob: 9810359089 > > http://people.du.ac.in/~singhg45/ > > > > > > On Sat, Sep 25, 2010 at 6:59 AM, Pankaj Kumar <[email protected]> > > wrote: > >> > >> Usually the chromosoe number is 2n or diploid, when an organism has > >> more than two sets of chromosomes then they are called polyploid and > >> the phenomena is called Polyploidy. > >> It is not a very uncommon phenomena in plants. Highest polyploidy is > >> found in ferns. Orchidaceae is supposed to be one group with high > >> polyploidy too. > >> Regards > >> Pankaj > >> > >> > >> > >> On Sat, Sep 25, 2010 at 7:17 PM, promila chaturvedi > >> <[email protected]> wrote: > >> > Dear All, > >> > I want to know what is Polyploid and Polyploidy. This is > >> > usuall occurance in > >> > Passifloras, but can bein other plants as well. > >> > Promia > >> > >> > >> > >> -- > >> *********************************************** > >> "TAXONOMISTS GETTING EXTINCT AND SPECIES DATA DEFICIENT !!" > >> > >> > >> Pankaj Kumar Ph.D. (Orchidaceae) > >> Research Associate > >> Greater Kailash Sacred Landscape Project > >> Department of Habitat Ecology > >> Wildlife Institute of India > >> Post Box # 18 > >> Dehradun - 248001, India > > > > > > > > > > > > > > -- > *********************************************** > "TAXONOMISTS GETTING EXTINCT AND SPECIES DATA DEFICIENT !!" > > > Pankaj Kumar Ph.D. (Orchidaceae) > Research Associate > Greater Kailash Sacred Landscape Project > Department of Habitat Ecology > Wildlife Institute of India > Post Box # 18 > Dehradun - 248001, India >
