3. History
⢠Thomas Fairchild (1717): First interspecific hybrid
Carnation Sweet William
(Dianthus caryophyllus) (Dianthus barbatus)
x
4. ⢠Rimpau (1890): Produced the first intergeneric hybrid Triticale
Wheat Rye
x
5. ⢠Karpechenko (1928): Intergeneric hybrid- Raphanobrassica
Raphanus sativus B. oleracea var. capitata
X
x
6. Main features of Distant hybridizatiton
ď§ It is used when the desirable character is not found within the species
of a crop
ď§ It is an effective method of transferring desirable gene into cultivated
plants from their related cultivated or wild species.
ď§ It gives rise to three types of crosses viz. a) fully fertile, b) Partially
fertile and c) Fully sterile in different crop species.
ď§ It leads to Introgression which refers to transfer of some genes from
one species into genome of another species.
ď§ F1 hybrid between two genus are always sterile. The fertility has to be
restored by doubling of chromosome through colchicine treatment.
7. Types of crosses obtained during distant hybridization
⢠Fully fertile crosses: Between species that have complete chromosomal
homology. Chromosome in such hybrids have normal pairing at meiosis.
E.g., Mango, citrus
⢠Partially fertile crosses: Between species which differ in chromosome
number but have some chromosome in common. In such situation , F1
plants are partially fertile and partially sterile.
⢠Fully sterile crosses: Between species which do not have chromosomal
homology. Such hybrids can be made self fertile by doubling the
chromosomes.
9. Cross Incompatibility
ďPre âfertilization barriers
⢠Lack of pollen germination
⢠Insufficient growth of pollen tube to reach ovule
⢠Inability of male gamete to unite with the egg cell.
ďOvercome by
⢠Reciprocal crosses
⢠Bridge crosses
⢠Using pollen mixtures
⢠Pistil manipulations
⢠Use of growth regulators etc.
10. Hybrid Inviability
ďdevelopment of the zygote is arrested
ďembryo gets aborted
⢠Unfavourable interactions between chromosomes
⢠Unfavourable interaction of the endosperm with the embryo
⢠Disharmony between cytoplasm and nuclear genes
ďovercome by
⢠Reciprocal crosses
⢠application of growth hormones
⢠embryo rescue
11. Hybrid Sterility
⢠Inability of a hybrid to produce viable
offspring
⢠Incomplete pairing of chromosomes.
⢠overcome by amphidiploidization using
colchicine
12. Hybrid Breakdown
⢠F1 hybrid plants of an interspecific crosses
are vigorous and fertile but there F2 progeny
is weak and sterile
⢠Due to the structural difference of chromosomes
or problems in gene combinations
13. Techniques To Overcome Barriers In Wide
Hybridization
Manipulation of ploidy level
Strawberry:
Fragaria x annanasa X Fragaria nilgerrensis
(Cultivated strawberry) (wild species having peach aroma)
Sterile Hybrid having peach aroma
chromosome doubling
Fertile hybrid having peach aroma
14. Use of nutrient solution or growth regulators
Resistance source for PRSV and cold- Vasconcellea genus
Incompatible with cultivated species-Carica papaya
Using nutrient solution (sucrose 5%) (Jayavalli et al.,2011)
enhanced pollen germination and pollen tube growth
generation of viable hybrid embryo
18. ďCarica papaya and V. candamarcensis are incompatible
ďVasconcellea parviflora is compatible with both the species
ďAs a bridge species Vasconcellea parviflora can be utilized
Use of Bridge Species
19. Desirable gene sources
Mango
Mangifera caesia White pulp, sweet and fragrant
M. decandra, M. gedebe Rootstock for water-logged conditions
M. Indica var. mekongensis Fruits twice a year
M. pajang Fruits can be peeled like Banana
M. similis Freestone mangoes
Annona
A. purpurea Orange flesh, thick fruit skin resistant to
cracking
A. scleroderma, A. festudinea Thick and hard shell
20. Grapes
Disease/ pest/ stress Resistance source
Downy mildew V. riparia, V. rupestris, V. labrusca
anthracnose V. simpsoni, V. rotundifolia
powdery mildew V. aestivalis, V. cinerea, V. barlendieri
RKN V. champini, V. candicans
pierceâs disease V. rotundifolia, V. vulpina
cold damage V. riparia, V. labrusca, V. amurensis
Iron chlorosis V. Berlandieri
salinity V. champini, V. berlandieri
21. Disease/ pest/ stress Resistance source
Papaya
Papaya ringspot virus V. cauliflora, quercifolia
Cold hardiness V. candamarcensis
Distortion ringspot virus V. pubescence, V. stipulate, V. heibornii
Guava
wilt Psidium molle, P. guineese
Banana
black sigatoka M. a. ssp malaccensis, M. a. ssp
burmanica
Panama wilt M. balbisiana, M. a. ssp burmanica
22. Apple
Disease/ pest/ stress Resistance source
Rosy leaf curl aphid M. xrobusta
Powdery mildew
M. xrobusta, M. xzumi
Scab
M. baccata, M. floribunda, M.
micromalus
Apricot
cold Prunus sibirica, P. mandschurica
23. Applications
1. Improvement of fruit quality
2. Fruits with less seeds
3. Abiotic stress tolerance
4. Biotic stress tolerance
5. Alternatives for GM crops
32. Fig. 5.Detection of the partial coat protein gene of PLDMV by RT-PCR
C. papaya with severe mosaic
symptoms
V. cundinamarcensis with no
symptoms
Intergeneric hybrid with no
symptoms
Intergeneric hybrid with
necrotic lesions
36. Materials and methods
F. x annanasa cv. Toyonoka X F. nilgerrensis cv. Yunnan
TN-13 (Pentaploid and sterile)
(colchicine treatment)
TN13-113 and TN13-125( Decaploid and fertile)
TN13-125 X F. x annanasa cv. Pajaro
(Back crossing)
TNP-05 and TNP-14
37. Lines
Relative value of peaks (%)
components
Ethyl
acetate
Methyl n-
butyrate
Ethyl n-
butyrate
Butyl
acetate
Formic
acid
Caproic
acid
furano
ne
TN13-125 23.0 1.5 1.3 6.6 4.8 1.5 2.4
TNP-05 5.8 6.9 2.8 12.3 - 0.9 1.2
TNP-14 5.9 1.1 8.7 6.0 - 1.2 1.8
Toyonoka 1.9 8.5 21.5 3.7 1.3 1.4 3.1
Yunnan 19.5 0.0 5.5 7.0 1.4 0.8 3.4
Table 2 : Comparison of the main aroma components of Interspecific
hybrids
44. Table 1. Reaction of resistance (R) or susceptibility (S) to Meloidogyne enterolobii
â˘
45. Table 2. Tolerance reaction (R) or susceptibility reaction (S) assessed 120 days after
inoculating with an initial population of 10,000 eggs
46. Fig 1. Absence of galls in the root
system of the hybrid
GUA161 PE X ARA138 RR
Fig 2. presence of galls in the root
system of the hybrid
GUA161 PE X ARA153 BA
47. Fig 3. Three-months-old plant of the
GUA 161 PE Ă ARA138RR hybrid
grafted with âPalumaâ
Fig 4. Four-months-old plant of the
GUA 161 PE Ă ARA138RR hybrid in
the field infested with M. Enterolobii.
48. CONCLUSION
ďVarieties 1. Resistant to destructive pest and disease
2. Tolerant to abiotic stress
3. With improved quality fruits
ďIncrease in germplasm resources which can be utilized to cross with
different varieties in different combinations
ďAlternatives for GM crops
ďRootstock breeding is needed
ďNeed to develop improved methods of crossing and overcoming
barriers
ďNeed to work on wild species to identify genes of interest