Pulses occupy an important place in Indian agriculture. Within this protein-rich group of crops, red gram or pigeonpea occupies an important place among rainfed resource poor farmers because it provides quality food, fuel wood, broom and fodder. Hybrids are plants that result from controlled cross-breeding of two different but specific varieties or breeding lines of the same species of plant. Wild species are important sources of resistance to biotic and abiotic stresses as they have evolved to survive droughts, floods, extremes of temperature (heat/ cold) and have the capability to with stand damage by insect pests and diseases. Ten alleles reported unique to inter-specific derivatives of Cajanus cajan × C. scarabaeoides. The presence of alleles unique to specific population or group indicates an inimitable genetic variability at certain loci. This information is valuable to categorise interspecific hybrids with exclusive genetic variability, whose selection can increase the allele richness of breeding population (Saxena, 2015). High levels of resistance is available in wild Cajanus species, these are not being utilised adequately in pigeonpea breeding programs. The major limitation is due to the linkage drag and different incompatibility barriers between cultivated and wild species. Under such situations, pre-breeding provides a unique opportunity to expand primary gene pool by exploiting genetic variability present in wild species and cultivated germplasm and will ensure continuous supply of new and useful genetic variability into the breeding pipelines to develop new cultivars having high levels of resistance and broad genetic base (Sharma et al., 2013). The major limitation in successfully using Cajanus platycarpus for the improvement of cultivated pigeonpeais embryo abortion in the BC1 generation from the cross C. Platycarpus × C. cajan. This Cajanus platycarpus, although placed in the tertiary gene pool of pigeonpea, is now amenable to gene transfer with the development of suitable embryo rescue techniques (Mallikarjuna et al., 2011).

1. INTER-SPECIFIC HYBRIDIZATION TO INTRODUCE USEFUL
GENETIC VARIABILITY FOR PIGEONPEA IMPROVEMENT
Speaker: Vipin Kumar Pandey (Ph.D. Scholar)
DOCTORAL SEMINAR I (GP-691)
Presentation Date: 4-5-2018 Time:12 noon

2. • Introduction
• Genetic resources of pigeonpea
• Pigeonpea domestications bottlenecks
• Distant hybridization
• Use of interspecific hybridization
• Problems associated with interspecific hybridization
• Interspecific hybridization techniques for pigeonpea
improvement
• Useful genetic variability from interspecific
hybridization
• Case study 1
• Case study 2
• Case study 3

3. INTRODUCTION
• ‘Pigeonpea’ name was coined in Barbados
(Gowda et al., 2011).
• Red Gram or Pigeonpea [Cajanus cajan (L.) Millsp.] an
ideal plant for sustainable agriculture
• It is a diploid (2n=22)
• It’s genome size is 808 Mbp.
(Varshney et al., 2012)
Pigeonpea
Food &
Feed
Bio-
Fertilizer
Nutrient
recycling
Fuel-
wood &
Fodder
Performs
in low
fertility

4. • It have large variation for days to maturity (97days
to 299 days)(Remanandan, 1990)
• It is an excellent source of protein 20-22%
(Saxena et al., 2010)
• In India 2015-2016 its area around 3.96 m ha,
production of 2.56 million tons and productivity of
about 646 kg/ha
(Source : Ministry of Agriculture and Farmers Welfare, Govt. of India, 2015-2016)
INTRODUCTION

5. Genetic resources of Pigeonpea
Source Sharma et al., 2016

6. • Cajanus cajan only domesticated species in
Cajaninae.
• In RS Paroda gene bank at ICRISAT, Patancheru,
india about 13,220 accessions of cultivated, 526
accessions of wild pigeonpea organised/ colected
pigeonpea.
• 18 species from Asia, 15 species from Australia, and
one species from West Africa. Of these 13 are found
only Australia, 1in the Indian subcontinent, 1 in
West Africa.
Source Sharma and Upadhyaya, 2016

7. Wild Cajanus species identified as promising donors for important biotic/abiotic stress and
agronomic traits
Source Sharma et al., 2016

8. Pigeonpea Domestication Bottleneck/s
Source -Mallikarjuna et al., 2011

9. Hybridization
• Crossing between two genetically dissimilar
parent is called hybridization.
• Hybridization between individuals from different
species belonging the same genus (interspecific
hybridization).
• By using hand emasculation

10. Intergeneric hybridization
(different genera of same family )
Distant
Family=A
Genera=2
Family=A
Genera=1
Interspecific hybridization
(different species belonging the
same genus)
hybridization
Genera=1
species =Y
Genera=1
species =X

11. Why use Interspecific hybridization
Desirable character is not found within the species.
For introgression of some genes from one species
into genome of another species.
F1 hybrid between two species are always Partially
fertile.

12. Problems associated
Interspecific
hybridization
Hybrid Sterility
Hybrid Breakdown
Hybrid Inviability
Cross
Incompatibility

13. TECHNIQUES TO MAKE INTERSPECIFIC HYBRIDIZATION SUCCESSFUL
1 SELECTION OF PLANTS 2 RECIPROCAL CROSSES
3 MANIPULATION OF PLOIDY 4 BRIDGE CROSSES
5 USE OF POLLEN MIXTURE 6 MANIPULATION OF PISTIL
7 USE OF GROWTH REGULATORS 8 PROTOPLAST FUSION
9 EMBRYO RESCUE
INTERSPECIFIC HYBRID

14. Pre-breeding using wild Cajanus species and pigeonpea cultivars for broadening the genetic
base for pigeonpea improvement Source SHARMA et al., 2016

15. CMS system derived from wild pigeonpea
CMS system Wild species
A1 C. Sericeus (Ariyanayagam et al., 1995)
A2 C. Scarabaeoides (Tikka et al., 1997; Saxena, and Kumar 2003)
A3 C. Volubilis (Wanjari et al., 2001)
A4 C. Cajanifolius (Saxena et al., 2005)
A5 C. acutifolius (Mallikarjuna & Saxena, 2005)
A6 C. lineatus
A7 C. platycarpus (Mallikarjuna et al., 2011)
A8 C. reticulatus

16. USEFUL GENETIC VARIABILITY FROM
INTERSPECIFIC HYBRIDIZATION OF PIGEONPEA
Erect and non spreading plants for mechanizing harvesting
Stable yield production across diverse environments
Lac culture producing insect In pigeonpea
Releasing Soil bound phosphorus
Pigeonpea on slopping hills
Photoperiod insensitivity
Increasing soil fertility

17. ROLE OF INTERSPECIFIC HYBRIDIZATION IN CROP
IMPROVEMENT
Increase Genetic
variability
Introgression
of useful traits
Enriching
variability for
agronomic traits
Nutrition
related traits
Disease
resistance
Insect pest
resistance
Development
of CMS
system
INTERSPECIFIC
HYBRIDIZATION

18. IMPACT ON UTILIZATION OF WILD SPECIES FOR PIGEONPEA
IMPROVEMENT
IMPACT ON
UTILIZATION OF WILD
SPECIES
Development of
CMS system
A4 sterility
system stability
across
environment
Worlds first commercial
pigeonpea hybrid ICPH2671
Changed pigeonpea
cultivation scenario
NEW BIOTIC
AND ABIOTIC
RESISTANCE
VARIETY
Source- Sharma et al. 2016

19. Pod formation in the cross (Cajanus acutifolius × C. cajan) × C. cajan.
Case study 1
Immature seeds seen in BC1F1 hybrid pods
(C. acutifolius × C. cajan) × C.cajan;

20. INTROGRASSION LINEs (ILs) derived from Cajanus acutifolius having varieties for pod and high
100 seed weight
Source – Sharma and Upadhyaya, 2016

21. Female parent,
wild species
Cajanus platycarpus.
Male parent, cultivated pigeonpea
Cajanus cajan.
Case study 2

22. Embryo rescue in recurrent backcrosses

23. Female parent, wild species Cajanus platycarpus. Male parent, cultivated pigeonpea Cajanus cajan. F1 (tetraploid) hybrid
between
C. platycarpus × C. cajan.
In-ovulo embryo culture to save
aborting hybrid embryos.
Hybrid embryo culture. Multiple shoots from
hybrid embryo.
In vitro rooting of
hybrid shoots.

24. Case study 3
Fertile Cajanus cajan,
completely male sterile F1
partially fertile F1 hybrid
Morphology of pods
(Cajanus cajan on the left,
C. lanceolatus on the right
and in the center are the
BC1 pods produced on male
sterile F1 hybrid.
Seed color in (Cajanus cajan
on the left and
C. lanceolatus on the right and
in the center are the BC1
seeds produced on male
sterile F1 hybrid.

25. Anther sterile green contents. Degenerated microspores inside the anther at
anthesis
Sterile anthers devoid of pollen

26. (L.S) of fertile bud at pre-anthesis stage.
(T.S) of fertile bud at pre-anthesis stage.
L.S of sterile bud at pre-anthesis stage.
T.S of sterile anther at pre-anthesis stage.
Sporangium with tetrads. Anther wall layers
showing epidermis, tapetum and inner wall layer
Sterile anther lobe showing normal tetrads.
Sterile anther lobe showing tapetal layer.

27. L.S of sterile anther at staminate stage showing
intact tetrads.
T.S of sterile anther with degenerating tetrads.
Sterile anther shriveled and indehiscent at anthesis.

28. ACHIVEMENTS OF INTER-SPECIFIC HYBRIDIZATION
Source K. B. Saxena et al., 2013

29. CMS LINES FROM INTERSPESIFIC
HYBRIDIZATION

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