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Genomics interventions towards fast-track development of
pigeonpea hybrids
ABSTRACT: Advances in genomics are leading to a new revolution in pigeonpea hybrid breeding, as these inventions facilitate the study of genotype and its relationship with the phenotype. The draft genome
sequence of pigeonpea and Next Generation Sequencing (NGS) technologies has made it possible to sequence multiple genomes. This allows discovering genes, regulatory sequences and provides large collections
of molecular markers across 104 parental lines of hybrids. F1 hybrids along with parental lines have been phenotyped for yield and yield related traits. The availability of genome-wide SNP variations combined
with the phenotypic data should provide clues on candidate genomic regions associated with yield and yield-related traits as well as those associated with heterosis and heterotic pools in pigeonpea for
accelerating hybrid improvement. Sequencing-based approaches have also provided markers for cytoplasmic male sterility and hybrid purity assessment. The tagging of above-mentioned traits/genes will have a
lot of implications in breeding and rapid development of high yielding hybrids.
have demonstrated their potential in increasing the crop productivity
in a number of plant species, including pigeonpea. This technology
has shown promise to overcome the yield stagnation in pigeonpea.
There are difficulties in commercial seed production due to nonavailability of quick purity assessment assays for parental and hybrid
seeds. Besides this, breeding and maintenance of new fertility
restorers and maintainer lines are challenging task. In this direction
markers based seed purity assessment, identification of heterotic
groups; selection of new fertility restorers have been initiated to
strengthen the pigeonpea hybrid breeding.
Approach for defining heterotic pools:
Hybrid parents
+
Re-sequencing
+
Crossing/phenotyping
RESULTS:
Markers for efficient breeding in pigeonpea hybrids
 For male sterile lines testing (The Plant Genome , 2015, 8: 2)
Defining heterotic pools for parental lines of hybrids
INTRODUCTION: Cytoplasmic male sterility (CMS) based hybrids
 For hybrid purity
testing kits
(Molecular Breeding,
2010, 26: 371-380; BMC
Plant Biology, 2011, 11:
56)
DISCUSSIONS:
The sequence genome information have addressed many questions in developmental biology, genetics etc. and revolutionized the crops
research. Therefore, it is highly required to deploy genome sequence information in pigeonpea hybrid breeding and learn from past
experiences to speed up our efforts. In this direction the molecular basis of heterosis, defining the heterotic pools, markers for purity
assessment and parental lines identification are among very first targets.
Bohra A, et al. (2011) Analysis of BAC-end sequences (BESs) and development of BES-SSR markers for genetic mapping and hybrid purity assessment in pigeonpea (Cajanus spp.). BMC Plant Biology 11: 56. Citation: 69
Saxena RK, et al. (2010) Application of SSR markers for molecular characterization of hybrid parents and purity assessment of ICPH 2438 hybrid of pigeonpea [Cajanus cajan (L.) Millspaugh]. Molecular Breeding 26: 371-380.
Citation: 32
Sinha P, et al. (2015) Association of nad7a gene with cytoplasmic male sterility in pigeonpea (Cajanus cajan). The Plant Genome 8:2. Citation: 04
Rachit K Saxena1, CV Sameerkumar1, Obarley Yu2, Vinay Kumar1, Aamir Khan1, Kishan Patel1, Changhoon Kim3, Pallavi Sinha1, Shaun
An2, Kuldeep Tyagi4, Vikas Singh1, MS Kuruvinashetti4, Jihun Kim3, Bellbull Kim3, Muniswamy Sonnappa5, Suryanarayana Vechalapu1,
Lekha Pazhamala1, PazWei Zhang2, Jochen C Reif6, Abhishek Rathore1, KB Saxena1, Anup Karwa4, Rajeev K Varshney1
1ICRISAT-Patancheru,
India, 2Millennium Genomics Inc., Shenzhen, China, 3MACROGEN Inc., Seoul, South Korea, 4Krishidhan Seeds Pvt Ltd, Jalna,
India, 5University of Agricultural Sciences, ARS-Gulbarga, Raichur, India, 6The Leibniz Institute of Plant Genetics and Crop Plant Research (IPK),
Germany
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