*2.3.1 Varieties: NAO Khurkul and KPG1*

These are exotic varieties grown in both tropical and temperate conditions. It possesses wide acclimatization in different agro-climatic conditions (**Figures 5** and **6**). These varieties yields 30,000 to 35,000 kgs of leaves/hector/ year under rain fed land. Leaves are medium, unlobed, light green in color and high moisture retention capacity. Stomatal frequency was found to be 290.80/mm<sup>2</sup> & size 190.80μm<sup>2</sup> and 262.44/mm<sup>2</sup> & size 198.30 μm<sup>2</sup> respectively.

Both the varieties were found to be 42 chromosomes (2n = 3x = 42) in their shoot somatic cells, during mitotic division, thereby confirming their triploid status. Triploids produced from the cross between diploids and tetraploids. Triploid is the characterized by three genomes or three sets of chromosomes in each somatic cells. Thus, a triploid originates by the fusion of haploid gamete (n) with a diploid gamete (2n), the later of which may be originated by irregularities during meiosis. Most of the naturally occurring polyploids are either allo-polyploids or complexes

**7**

and high temperature.

*2.4.1 Varieties Kokuso and Icheihei*

**2.4** *Morus latifolia*

**Figure 6.** *Variety KPG1.*

and 340.40/mm2

polyploid ones.

unreduced gametes.

*Studies on Basic Chromosome Number, Ploidy Level, Chromosomal Association…*

between allopolyploids and auto-polyploids. Agronomic ally, the triploid mulberry varieties are known to be superior to other ploidy levels in rooting, chemical components and silkworm rearing performance. They also posses resistance to cold

Morphological characters of these varieties are entirely different from other varieties (**Figures 7** and **8**). *Morus latifolia is e*asily distinguishable from *M. alba* and *M. indica* by cylindrical fruits and hairy leaves. Leaves of tetraploid varieties are smaller, thin, rough, lobed, highly dissected, less moisture content and coriaceous due to the presence of many cystoliths, on the leaf surface, the calcium oxalate deposit and have a very detrimental effect on the palatability to silkworm larvae. Hence, these leaves are considered as inferior quality and are not suitable to silkworm larvae. The leaves' upper surface is dark green and lustrous with a pale green

 respectively. The above description suggests that diploid and triploid plants of this genus may exist anywhere in the world and that the morphological characteristics of diploid and triploid plants will be different to a certain extent from those of the

The number of chromosomes of both the varieties at metaphase of somatic division were 2n = 4x = 56, which means both are teteraploids. Tetraploid may be originated by the somatic doubling of the chromosome numbers or by union of

& size 238.10μm2

under surface. Stomatal frequency was found to be 310.22/mm<sup>2</sup>

& size 260.30μm2

*DOI: http://dx.doi.org/10.5772/intechopen.97143*

**Figure 5.** *Variety NAO Khurkul.*

*Studies on Basic Chromosome Number, Ploidy Level, Chromosomal Association… DOI: http://dx.doi.org/10.5772/intechopen.97143*

*Cytogenetics - Classical and Molecular Strategies for Analysing Heredity Material*

chromosome numbers.

*2.3.1 Varieties: NAO Khurkul and KPG1*

**2.3** *Morus alba*

& size 190.80μm<sup>2</sup>

(2n = 30) in their shoot somatic cells, during mitotic division, thereby confirming their uneuploid nature. Uneuploids plants have incomplete genomes. Individual chromosomes may either be less than diploid number (monosomic and nullisomic), or more than the diploid number (polysomic). Uneuploid chromosome number recorded in present work as well as reported by others are mainly due to extensive vegetative propagation followed for the multiplication of *Morus* spp. Therefore, the genus *Morus* has monobasic number x = 14. The polyploid numbers found in this taxa must have derived from this base number (x = 14) an account of auto and allopolyploidizaton. No doubt, vegetative propagation has helped for the perpetuation of uneuploids rather than their origin. Out breeding has played an important role in the origin of uneuploids due to the formation of gametes with unbalanced

These are exotic varieties grown in both tropical and temperate conditions.

& size 198.30 μm<sup>2</sup>

Both the varieties were found to be 42 chromosomes (2n = 3x = 42) in their shoot

respectively.

(**Figures 5** and **6**). These varieties yields 30,000 to 35,000 kgs of leaves/hector/ year under rain fed land. Leaves are medium, unlobed, light green in color and high moisture retention capacity. Stomatal frequency was found to be 290.80/mm<sup>2</sup>

somatic cells, during mitotic division, thereby confirming their triploid status. Triploids produced from the cross between diploids and tetraploids. Triploid is the characterized by three genomes or three sets of chromosomes in each somatic cells. Thus, a triploid originates by the fusion of haploid gamete (n) with a diploid gamete (2n), the later of which may be originated by irregularities during meiosis. Most of the naturally occurring polyploids are either allo-polyploids or complexes

It possesses wide acclimatization in different agro-climatic conditions

and 262.44/mm<sup>2</sup>

**6**

**Figure 5.**

*Variety NAO Khurkul.*

between allopolyploids and auto-polyploids. Agronomic ally, the triploid mulberry varieties are known to be superior to other ploidy levels in rooting, chemical components and silkworm rearing performance. They also posses resistance to cold and high temperature.

#### **2.4** *Morus latifolia*

#### *2.4.1 Varieties Kokuso and Icheihei*

Morphological characters of these varieties are entirely different from other varieties (**Figures 7** and **8**). *Morus latifolia is e*asily distinguishable from *M. alba* and *M. indica* by cylindrical fruits and hairy leaves. Leaves of tetraploid varieties are smaller, thin, rough, lobed, highly dissected, less moisture content and coriaceous due to the presence of many cystoliths, on the leaf surface, the calcium oxalate deposit and have a very detrimental effect on the palatability to silkworm larvae. Hence, these leaves are considered as inferior quality and are not suitable to silkworm larvae. The leaves' upper surface is dark green and lustrous with a pale green under surface. Stomatal frequency was found to be 310.22/mm<sup>2</sup> & size 238.10μm2 and 340.40/mm2 & size 260.30μm2 respectively.

The above description suggests that diploid and triploid plants of this genus may exist anywhere in the world and that the morphological characteristics of diploid and triploid plants will be different to a certain extent from those of the polyploid ones.

The number of chromosomes of both the varieties at metaphase of somatic division were 2n = 4x = 56, which means both are teteraploids. Tetraploid may be originated by the somatic doubling of the chromosome numbers or by union of unreduced gametes.

**Figure 7.** *Variety Kokuso.*

**Figure 8.** *Variety Icheichei.*
