Pigeonpea is an important crop for food security in India and other parts of the world as it is drought tolerant and a source of protein and nutrients. It has a genome size of 858 million base pairs. The first draft genome sequence of the popular pigeonpea variety Asha was completed in 2012 using 454 sequencing, assembling over 500 million base pairs across 11 chromosome pairs. A new reference genome was published in 2018 using Illumina sequencing, assembling over 605 million base pairs across 72.7% of the 833 million base pair genome. The new genome provides insights into drought tolerance genes and will help improve pigeonpea varieties.

1. PREPARED By:-
Varsha Gaitonde
BHU, Varanasi, India
PIGEONPEA GENOMICS

2.  Pigeonpea (Cajanus cajan (L.) Millspaugh) belongs to family
Fabaceae with chromosome no. 2n=22 and genome size of 858 Mbp
 A major source of protein to about 20% of the world population (Thu
et al., 2003).
 An abundant source of minerals and vitamins (Saxena et al., 2002).
 Most versatile food legume with diversified uses such as food, feed,
fodder and fuel.
 It is hardy, widely adaptable crop with better tolerance to drought and
high temperature.
 Plays an important role in sustaining soil productivity by fixing
atmospheric nitrogen.
 Pigeonpea or red gram (‘Arhar’ or ‘Tur’) is an important grain legume
(Pulse) crop of India. About 85% of the world pigeonpea is produced
and consumed in India where it is a key crop for food and nutritional
security of the people.

3. • Number of chromosomes=11 pairs
• Genome size (Physical)=858 Mb(million base pairs)
• Genome size (Genetic)=1057 cM
(as per ICAR database)

4. • Pigeonpea is an important high protein (20–22%)food legume of
rainfed tropics and sub-tropics.
• It is the second most important pulse crop only after chickpea.
• It is Adoptable to a wide range of cropping system, soil, and
climatic variation in semi-arid tropics.
• Pigeonpea being a leguminous plant is capable of fixing
atmospheric nitrogen.
• Pigeonpea is unique among legumes as its floral morphology
allows both self – as well as insect-aided cross pollination and
their extents vary from one place to another.
• International Pigeonpea Genomics Initiative offer a good
scopeto characterize CMS (A-) lines along with their
maintainers(B-) and restorer (R-) lines at molecular level
(Varshney et al. 2009) .

5. • According to van der Maesen(1990) pegiopea
is originated in India and secondary center of
diversity is reported to be eastern Africa.
• Vaviov(1951) listed pegiopea of Indian origin.
• Proginator : cajanus cajanifolius

6. Comman mame : pigeon pea
Botanical Name : Cajanus cajan L. Millp.
Tribe : Phaseoleae
Subtribe : Cajaninae
Subfamily : Leguminosae
Genus : Cajanus
Species : cajan

8. Genome
Sequenced
in 2012……..

10. • First draft of the genome sequence of a popular pigeonpea variety ‘Asha’.
• The genome was assembled using long sequence reads of 454 GS-FLX
sequencing chemistry
• Mean read lengths of >550 bp
• >10-fold genome coverage, resulting in 510,809,477 bp of high quality
sequence.
• Total 47,004 protein coding genes and 12,511 transposable elements related
genes were predicted.
• Identified 1,213 disease resistance/defense response genes and 152 abiotic
stress tolerance genes
• In comparison to soybean, pigeonpea has relatively fewer number of genes
for lipid
biosynthesis and larger number of genes for cellulose synthesis.
• The sequence contigs were arranged in to 59,681 scaffolds, which were
anchored to eleven chromosomes of pigeonpea with 347 genic-SNP markers
of an intra-species reference genetic map.

11. Fig. The whole plant anddifferent parts of the pigeonpeacultivar ‘Asha’ (ICPL 87119).a
whole plant at fruiting stage;b a defoliated branch with pods;c a branch with heavy
flowering; d mature seeds;e dehusked split seedsor ‘Dal’; f 22 chromosomes in a root
tip cell

14. • Used the Illumina next-generation sequencing platform to generate
237.2 Gb of sequence, which along with Sanger-based bacterial
artificial chromosome end sequences and a genetic map.
• Assembled into scaffolds representing 72.7% (605.78 Mb) of the
833.07 Mb pigeonpea genome.
• Genome analysis predicted 48,680 genes for pigeonpea and also
showed the potential role that certain gene families, for example,
drought tolerance–related genes,
• reference genome sequence facilitates the identification of the genetic
basis of agronomically important traits, and accelerate the
development of improved pigeonpea varieties that could improve food
security in many developing countries.