chromosome analyzis methods in plants?

Question

about ploidy levels of family zingiberaceae and methods of analyzing them

Answer 1

Zingiber= Ginger

Zingiberaceous plants vary a great deal in morphology and chromosome numbers, 2n = 20 -96

Actively growing apical root tips at about 1 to 2 cm in length were used for chromosome
counts. They were pretreated in saturated para-
dichlorobenzene (PDB) solution for 4 hours at
12 o C and fixed in Carnoy’s fluid (3 parts 95%
ethanol and 1 part glacial acetic acid) for 24 hours at 12
o C and stored in 70% ethanol at 12
o C. Slides were prepared by Feulgen squash method (Sharma
and Sharma, 1980) and examined under the light
microscope (Olympus, model CH30). Chromosome
numbers of 20 cells of each species were deter-
mined at well spread metaphase stage. Photo-
graphs were taken using a Nikon OPTIPHOT-2
phase-contrast microscope at 100x magnification
with a Nikon FX series model UFX-DX II camera
attached.
Results and Discussion
The somatic chromosome numbers (2n)
of twenty two Thai species of Zingiberaceae in-
cluding the data reported by other authors are
presented in Table 1.
Not only the basic number but also ploidy
level of each Zingiberaceous species are different
(Darlington & Wylie, 1955 and Beltran & Kiew,
1984). Chen (1989) reported that several polyploids
exist in tropical Asian Zingiberaceae, especially
in Globbeae and Alpineae.