mutation breeding of cotton by yanal alkuddsi

Yanal AlkuddsiPh.D Student

Dept. of Genetics and Plant BreedingUniversity of Agricultural Sciences

Dharwad, Karnataka, India, 580005

INTRODUCTIONINTRODUCTIONTAXONOMYTAXONOMY::

• Family: Malvaceae• Tribe:Gossypia• Genus:Gossipium• 4 cultivated species :1. G. hirsutum2. G. arboreum3. G. barbadense4. G. herbaceum

Major Producers of Cotton

• United States

• Russia

• China

• India

Characteristics of Cotton

Advantages•Inexpensive

•Soft and absorbent

•Does not pill

•Blends well

•Can be treated

Disadvantages•Wrinkles easily

•Shrinks

•Not resilient

•Burns easily

•Absorbent

Genetics of Cotton :

•Diploid species (2n=26) are found on all continents, and a few are of some agricultural importance. •The( A )genome is restricted in diploids to two species (G. arboreum, and G. herbaceum) of the Old World. •The (D )genome is restricted in diploids to some species of the New World, such as G. thurberi.

Cotton as a Crop

• Major fiber crop .• Four species of the genus Gossypium are known

as cotton, which is grown primarily for the seed hairs that are made into textiles.

• Cotton is predominant as a textile fiber because the mature dry hairs twist in such a way that fine, strong threads can be spun from them. Other products, such as cottonseed oil, cake, and cotton linters are byproducts of fiber production.

Plant breeding

• Conventional breeding:

1. Yield and adaptation2. Fibre quality3. Disease resistance4. Host plant resistance

BIOTECHNOLOGY:

• Transgenic varieties(RR,INGARD).

• New traits.

• Marker assisted breeding.

Syrian science harvests naturally coloured cotton:

•Scientists in Syria have produced naturally coloured cotton by causing random changes in the genetic material of cotton seeds.

•Naturally coloured cotton varieties have been developed before but have not been used in Syria, a leading cotton producer, because they are not suited to local soils and climatic conditions.

• .naturally coloured cotton does not fade with washing the way conventionally dyed cotton does .

.The new varieties were produced by exposing cotton seeds to chemicals that cause random, unpredictable changes, or mutations, in their genetic material. Some of the mutations produced undesirable traits and the plants were destroyed, but others had beneficial effects, such as natural colour and stronger fibres.

MutationsDefinition

A Mutation: occurs when a DNA gene is damaged or changed in such a way as to alter the genetic message carried by that gene.

Role of mutation breedingin cotton improvement

The role of induced mutations in cotton improvement has been critically reviewed by Singh et al.(1994)and Waghmare et al.2000.Induced mutations have played significant role in developing breeding material with:

1-EARLINESS

Earliness has been achieved with the use of both physical and chemical mutagens.Early maturing mutants have been obtained in upland cotton with gamma irradiation.An early maturing and high yielding mutant of Egyptian cotton Ashmouni was obtained by treatment of seed with sodium azide.

2-Dwarfness and Compactness

• Dwarf and compact plant types have been developed through induced mutations .

• Zero branch type mutants were obtained in Egyptian cotton.

• Early and compact mutants were obtained by amixture of thermal neutrons and gamma rays

• Short and compact mutants were obtained by injecting ethylene imine –EI- into the base of ovary.

Case study 1

CytogeneticCytogenetic Study of Gamma Irradiated Lines of Study of Gamma Irradiated Lines of Cotton (Cotton (GossypiumGossypium HirsutumHirsutum L.)L.)

M. Sheidai1

Department of Biology

Islamic Republic of Iran

OBJECTIVEOBJECTIVE

•cytogenetic characteristics of gamma irradiated lines of Shirpan cultivar in order to study the effects of gamma irradiation on meiotic cells compared to that of control line. •also if possible correlate any particular cytogenetic features with morphological and agronomic characteristics .

Materials and Methods

seeds of seeds of ShirpanShirpan cultivar were treated with cultivar were treated with 150, 200, 250, 300 and 350 gray (150, 200, 250, 300 and 350 gray (GyGy) of ) of gamma raysgamma rays using Cobalt 60using Cobalt 60.

Plants were raised from M1 to M4 by Plants were raised from M1 to M4 by selfingselfingand selection was performed based on and selection was performed based on important agronomic characters like important agronomic characters like earliness, lint quality and yieldearliness, lint quality and yield.

Experimental LinesExperimental Lines::

The experimental lines studied, are The experimental lines studied, are presented in Tablepresented in Table (1)(1), the names with , the names with C15 and C35 indicate treatment with C15 and C35 indicate treatment with 150 and 350 Gy150 and 350 Gy. . The plants were The plants were cultivated in 3 rows of 10 m length with cultivated in 3 rows of 10 m length with 20 cm interplant distance, in the 20 cm interplant distance, in the experimental field of Varamin Cotton experimental field of Varamin Cotton Research Center of Iran, according to a Research Center of Iran, according to a completely randomized design completely randomized design ((CRDCRD) ) with 3 replicationswith 3 replications..

Table 1. Genotypes and their cytogenetical characteristics. Characters number as in Table2

0.00

0.00

6.00

0.00

0.00

0.00

35.18

21.64

13.55

0.00

6.09

19.91

7.09

19.72

8.45

0.00

0.00

Control

0.00

1.00

8.10

2.50

0.00

8.00

28.15

17.90

10.25

0.35

10.55

15.10

50.00

9.33

12.00

2.00

0.00

C35-11

0.00

0.00

16.67

2.00

1.00

9.00

31.44

17.39

14.06

0.26

8.58

17.16

23.78

14.81

7.41

6.00

0.00

C35-10

0.00

4.50

20.00

0.00

0.00

3.00

31.23

15.85

15.39

0.17

11.00

14.83

20.00

3.92

2.94

0.00

0.00C35-9

1.00

3.00

14.43

2.00

0.00

1.00

37.32

21.25

16.06

0.19

6.38

19.44

4.90

18.33

25.83

5.00

2.00C15-8

0.00

1.00

13.13

1.00

0.00

1.00

33.07

20.93

12.13

0.12

7.53

18.35

19.86

16.35

4.81

1.00

0.00C15-5

0.00

6.00

32.31

1.50

0.00

1.00

36.22

19.83

16.39

0.11

8.32

17.58

25.69

30.77

3.26

0.00

0.00C15-4

0.00

3.00

24.35

0.00

0.00

2.00

34.00

19.00

15.00

0.22

8.78

17.00

29.91

6.35

13.49

1.00

0.00C15-3

0.00

10.00

10.00

0.00

0.00

4.00

31.30

17.80

13.50

0.50

9.80

15.70

13.46

16.81

14.16

2.00

1.00C15-2

0.00

15.00

26.67

1.50

0.00

1.00

30.83

19.00

11.83

0.33

9.00

16.67

8.33

1.67

3.33

0.00

1.00C15-1

2322212019181716151413121110987

Cytogenetic charactersGenotype

Cytogenetic Studies: ••For For cytogeneticalcytogenetical studies, 50 flower buds studies, 50 flower buds were used randomly from 10 randomly were used randomly from 10 randomly selected plants of each line making the total selected plants of each line making the total collection 50collection 50××1010××10=5000. The flower buds 10=5000. The flower buds were fixed in ethanol (70%) and glacial acetic were fixed in ethanol (70%) and glacial acetic acid (3:1) for about 24 h. The flower buds acid (3:1) for about 24 h. The flower buds were then preserved in 75% ethanol at 4were then preserved in 75% ethanol at 4°°C C until used. Squash technique was employed until used. Squash technique was employed for meiotic preparation using 2% for meiotic preparation using 2% acetocarmineacetocarmine as the stain [20,23]. Meiotic as the stain [20,23]. Meiotic analyses were performed using 50analyses were performed using 50--100 100 metaphasemetaphase--I & II cells, 500 anaphaseI & II cells, 500 anaphase--I & II I & II cells and 500 cells and 500 telophasetelophase--I & II cells.I & II cells.

...In total, 26 meiotic characteristics were used in cytogenetic analysis (Table 1). Chiasma frequency and distribution as well as association of chromosomes were determined using 50 pollen mother cells (PMCs).Chromosome segregation during anaphase andtelophase was studied in about 500 PMCs. Pollen stainability as a measure of fertility waschecked by staining the pollen grains with 2%acetocarmine and 50% glycerin for 1/2 h.Round/completely stained pollen grains were considered fertile and unstained/ shrunken grains as infertile.

Table 2. Cytogenetical characters studied:

1- Metaphase-I cells showing abnormality (%)

2- Anaphase-I cells showing abnormality (%)

3- Telophase-I cells showing abnormality (%)

4- Metaphase-II cells showing abnormality (%)

5- Anaphase-II cells showing abnormality (%)

6- Telophase-II cells showing abnormality (%)

7- Cells with unequal segregation

8- Cells with cytomixis

9- Cells with stickiness

10- Cells with disorganized chromosomes

11- Cells with laggard chromosomes

12- Chromosomes with two chiasmata

13- Chromosomes with one chiasma

14- Chromosomes with no chiasma

15- Intercalary chiasma/cell

16- Terminal chiasma/cell

17- Total chiasma/cell

18- Cells with two univalents

19- Cells with two trivalents

20- Cells with one quadrivalent

21- Cells with two quadrivalents

22- Cells with three quadrivalents

23- Adjacent quadrivalent

24- Alternate quadrivalent

25- Ring bivalents

26- Rod bivalents

Results and Discussion• The cytogenetic features of the cotton lines

investigated are depicted in Table 2, Figures 1-3. Details of meiotic characters including chiasma frequency and distribution as well as association of chromosomes are presented in Table 1, while frequency of alternate and adjacent quadrivalents are given in Figure 2. The percentage of metaphase, anaphase and telophase cells showing meiotic abnormality are given in Figure 3.

• The following meiotic characteristics was considered abnormal: chromosome stickiness in metaphase and anaphase, disorganized chromosome i.e. chromosome/s not aligned with the others on the equator, laggard chromosomes in anaphase-I and II, micronuclei in telophase-I and II, unequal segregation of chromosomes during anaphase and occurrence of cytomixis. Details of meiotic abnormalities are presented in Table (1)and figure(3)

s.l.AHUJ As.l.AHUJ A and L.S.DHAYALand L.S.DHAYAL

central institute for cotton central institute for cotton Research,RegionalResearch,Regional

Station,sirsa,HaryanaStation,sirsa,Haryana 1 25055,india1 25055,india

CASE STUDY 2

Comparative Characteristics and gene action in three petal-spotted mutants of Gossypium hirsutum

G.hirsutum typically lacks apetal spot.Petal-spottedSpontaneous mutants of the species were identifiedfrom the populations of three genotypes.CSH-

2501 ,AKH-0308 and AKH-961 8.

INTRODUCTIONINTRODUCTION

MAT E R IAL S AND ME T HO DSThe five petals of The five petals of G.hirsutuG.hirsutu have an area of have an area of

anthocyaninanthocyanin pigmentation at the base, called a pigmentation at the base, called a petal spot.petal spot.

GermplasmGermplasm lines of CSHlines of CSH--2501,AKH2501,AKH--0308 and AKH0308 and AKH--9618 were grown at central institute for Cotton research 9618 were grown at central institute for Cotton research ((CICR),RegionalCICR),Regional Station ,Station ,Sirsa,India,inSirsa,India,in the the kharifkharif season season of 2003,population of 45,58 and 63 of 2003,population of 45,58 and 63 plants,respectively,ofplants,respectively,of these strains were raisedthese strains were raised ..

The variants (CSH-2501 Pet, AKH-0308Pet and AKH-961 8Pet)were selfed, and the seeds were sown in off-

season in glass house at CICR .

The three variants CSH-2501 Pet, AKH-0308Petand AKH-961 8Pet were crossed in 2004 crop

season with cultivar RS-201 3which has no petal spot.

R es ults and dis c us s ionIntensity of a nthocyanin pigmentation of the petal-spot

mutants increased with growth/age of the flower.These mutants have higher fibre strength, longer fibre, and

many features similarto those of the parent strains (table 1 ).

All F1 plants in the three crosses were petal-spotted (table 2), indicating complete dominance of the petal-spot trait.