Includes information regarding Euploidy, Aneuploidy, Haploidy, Diplody, Polyploidy, monosomy, nullisomy, trisoomy, tetrasomy, autoployploid, alloplyploid

1. Euploidy and Aneuploidy
Dr. A. S. Wabale
Assistant Professor and Research Guide
Post Graduate Department of Botany and Research Centre,
Padmashri Vikhe Patil College of Arts, Science and
Commerce, Pravaranagar- 413 713
dranilwabale78@gmail.com

2. CONTENTS
• Numerical changes in chromosomes- Euploidy and Aneuploidy,
• Euploidy- Monoploidy, Origin and production, morphology and uses.
• Polyploidy -Concept and Characteristics of polyploids,
• Autopolyploidy- Origin and production, effects of autopolyploidy, uses.
• Allopolyploidy- Concept, synthesized allopolyploidy (wheat and cotton)
• Evolutionary significance of polyploidy
• Aneuploidy, Monosomy and nullisomy- origin and cytology,
• Trisomy in Datura and humans
December 26, 2020 Dr. A. S. Wabale

3. PLOIDY
HYPOPLOIDY
n-1, 2n-1, n-2, 2n-2
HYPERPLOIDY
n+1, 2n+1, n+2, 2n+2
ANEUPLOIDY
n-1, n+1, 2n-1, 2n-2, 2n+1, 2n+2
EUPLOIDY
n, 2n, 3n, 4n, 5n, 6n…..
HAPLOIDY
n
DIPLOIDY
2n
POLYPLOIDY
3n, 4n, 5n, 6n…..
AUTOPOLYPLOIDY ALLOPOLYPLOIDY
MONOSOMY
n-1, 2n-1
NULLISOMY
n-2, 2n-2
TRISOMY
n+1, 2n+1
TETRASOMY
n+2, 2n+2

4. XX
++
X.X X.X
+.+ +.+
X.X +.+
X.X +.+
X.X +.+
X.X +.+
X.X X.X +.+ +.+
MEIOSIS-I
2N = 4
PRPOPHASE-I METAPHASE-I ANAPHASE-I TELOPHASE-I
X.X
+.+
X.X
+.+
X+
X+
X+
X+
X+
X+
X+
X+
X+
X+
X+
X+
METAPHASE-II ANAPHASE-II TELOPHASE-II
GAMETES (N=2)
NORMAL MEIOSIS-II

5. XX
++
X.X X.X
+.+ +.+
X.X +.+
X.X +.+
X.X +.+
X.X +.+
X.X X.X +.+ +.+
MEIOSIS-I
2N = 4
PRPOPHASE-I METAPHASE-I ANAPHASE-I TELOPHASE-I
X.X
+.+
X.X
+.+
X+X+
X+
X+
X+X+
X+
X+
X+
X+
X+
X+
METAPHASE-II ANAPHASE-II TELOPHASE-II
GAMETES
ABNORMAL
MEIOSIS-II
(2N=4)
(N=2)
(N=2)
ORIGIN AND PRODUCTION OF EUPOLYPLOIDS

6. EXAMPLES OF AUTOPOLYPLOIDS
Autopolyploids are polyploids with multiple chromosome (more than two) sets derived from a
single taxon (Species). Most cases, autopolyploidy result from the fusion of unreduced (2n) gametes,
which results in either triploid (n + 2n = 3n) or tetraploid (2n + 2n = 4n) offspring. In agricultural
systems, autotriploidy can result in seedless, as in watermelons and bananas. Autopolyploids arise
from spontaneous, somatic genome doubling, which has been observed in apple. Artificial polyploidy
can be induced by treatment of chemicals like colchicine, oryzalin or mitotic inhibitors to disrupt
normal mitotic division. This process can be useful in plant breeding or crop improvement

7. Allopolyploids or amphipolyploids or heteropolyploids are polyploids with chromosomes derived from
two or more diverged taxa (Species). As in autopolyploidy, this primarily occurs through the fusion of
unreduced (2n) gametes. The unreduced gametes from each diploid taxa or reduced gametes from two
autotetraploid taxa combine to form allopolyploid offspring. Both bread wheat and cotton are examples
of an allopolyploids. Evolution of hexaploid modern bread wheat Triticum aestivum
Triticum monococcum (AA) X Aegilops speltoides (BB)
2n = 14 2n = 14
F1 Hybrid (Sterile)
AB
2n =14
Doubling of chromosome
Triticum dicoccum (AABB) Aegilops squarosa (DD)
4n = 28 2n = 14
F1 Hybrid (Sterile)
ABD
3n =21
Doubling of chromosome
Triticum aestivum (AABBDD)
6n = 42
EXAMPLES OF ALLOPOLYPLOIDY

8. XX
++
X.X X.X
+.+ +.+
X.X +.+
X.X +.+
X.X +.+
X.X +.+
X.X X.X +.+ +.+
MEIOSIS-I
2N = 4
PRPOPHASE-I METAPHASE-I ANAPHASE-I TELOPHASE-I
X.X
+.+
X.X
+.+
XX+
+
X+
X+
XX+
+
X+
X+
+
XX
+
X+
X+
METAPHASE-II ANAPHASE-II TELOPHASE-II
GAMETES
ABNORMAL
MEIOSIS-II
(N+1=3)
(N=2)
(N=2)
(N-1=1)
ORIGIN AND PRODUCTION OF ANEUPLOIDS

9. + X+
N-1 = 1 N = 2
+ = =
X
+ +
MONOSOMY
2N-1 = 3
+ +
N-1 = 1 N -1 = 1
+ = =
+ + NULLISOMY
2N-2 = 2
X
++
X
+
N+1 = 3 N = 2
+ = =
XX
+ +
+
TRISOMY
2N+1 = 5
X
++
X
++
N+1 = 3 N +1 = 3
+ = =
XX
+ +
+ +
TETRASOMY
2N+2 = 6
X X
+ +
2N = 4
X X
+ +
2N = 4
X
HYPOPLOIDY
HYPERPLOIDY
ORIGIN AND PRODUCTION OF ANEUPOLYPLOIDS