26 research outputs found
Multiomics approach unravels fertility transition in a pigeonpea line for a two‐line hybrid system
Pigeonpea [Cajanus cajan (L.) Millsp.] is a pulse crop cultivated in the semi-arid
regions of Asia and Africa. It is a rich source of protein and capable of alleviating
malnutrition, improving soil health and the livelihoods of small-holder farmers.
Hybrid breeding has provided remarkable improvements for pigeonpea productivity,
but owing to a tedious and costly seed production system, an alternative
two-line hybrid technology is being explored. In this regard, an environmentsensitive
male sterile line has been characterized as a thermosensitive male sterile
line in pigeonpea precisely responding to day temperature. The male sterile
and fertile anthers from five developmental stages were studied by integrating
transcriptomics, proteomics and metabolomics supported by precise phenotyping
and scanning electron microscopic study. Spatio-temporal analysis of anther\ud
transcriptome and proteome revealed 17 repressed DEGs/DEPs in sterile anthers
that play a critical role in normal cell wall morphogenesis and tapetal cell development.
The male fertility to sterility transitionwasmainly due to a perturbation
in auxin homeostasis, leading to impaired cellwallmodification and sugar transport.
Limited nutrient utilization thus leads to microspore starvation in response
to moderately elevated day temperature which could be restored with auxin-treatment in the male sterile line. Our findings outline a molecular mechanism
that underpins fertility transition responses thereby providing a process-oriented
two-line hybrid breeding framework for pigeonpea
Genetic Variability for Yield, Physiological and Quality Traits in Novel Super-Early Pigeonpea (Cajanus cajan (L.) Millsp.)
Super-early pigeonpea are novel genotypes that are reported to be photoperiod insensitive making it possible to grow it in non-traditional regions. Estimation of genetic parameters would be useful in developing appropriate selection and breeding strategies. A study was conducted to evaluate 37 super-early pigeonpea genotypes to access the magnitude of variability and to study heritable component of variation present in the yield, physiological and quality traits. The results revealed that traits leaf area duration between 60 DAS & maturity followed by leaf area & leaf area index at maturity, net assimilation between 60 DAS & maturity, leaf area index & leaf area at 60 DAS, leaf area duration between 60 DAS & maturity and plant height had high had higher PCV and GCV values. In general, phenotypic coefficients of variation (PCV) estimates were higher than genotypic coefficients of variation (GCV) estimates for all the characters under study, but the difference was relatively small indicating that these characters were less influenced by the environment and selection to improve those traits might be effective. High heritability combined with high genetic advance as a percent of mean was noted for all the traits except protein content conveying the governance of additive gene on trait expression. Anticipating these traits as selection index reaps competent improvement in yield, physiological and quality traits in early maturing pigeonpea
Genetic Divergence for Yield, Physiological and Quality Traits in Super-Early Pigeon pea (Cajanus cajan. (l.) Millsp.)
The present investigation aimed to study genetic divergence and clustering pattern of 37super-early pigeon pea genotypes. Analysis of variance and hierarchical cluster analysis of tocher’s method revealed significant differences among the genotypes for all the traits under study. Based on genetic distance (D2 value), the 37 genotypes were grouped into 9 distinctive clusters, of which cluster I and II formed the largest clusters with 10 genotypes in each. Among all the characters understudy, leaf area index(LAI) at 60 DAS contributed more to the divergence followed by leaf area (17.02) and leaf area index (12.71) at maturity. Based on the average inter-cluster distance, the cluster III and IX (66.93) tailed by cluster III and VIII (64.86) and cluster VI and VIII (64.06) showed higher inter-cluster distance depicting the wider divergence. Trait-wise selection of diverse parents from the above clusters aids in exploitation of heterosis in superearly pigeon pea
Next generation sequencing based transcriptomic studies for crop improvement in pigeonpea
Transcriptomic studies are rapidly evolving as a powerful tool
with next-generation sequencing technology to understand gene
functions and molecular mechanisms. RNA sequencing (RNAseq)
provides a dynamic range for transcript detection and a
better quantification of expression levels.With the availability of
genome sequence in pigeonpea, RNA-seq was used to link the
sequence information to phenotypic traits resulting from specific
developmental processes. In pigeonpea, three-line hybrid
breeding system is well-established; however, it is technically
demanding and cumbersome. In order to explore the possibility
of a two-line hybrid breeding system, a coherent transcriptomic
approach supported by physiological and cytological data has
led to the identification of a temperature-sensitive male sterile
(TSMS) line. This line has been characterized for critical (tetrad)
stage and temperature (23°C), and the identification of candidate
genes involved in abscisic acid signaling for fertility reversion.
Furthermore, a gene expression atlas (CcGEA) has been developed
and transcriptomic profiles generated for studying pod
and seed development with a dataset of 590.84 and 342 million
paired-end reads, respectively in pigeonpea. These data have
been analyzed for genes with differential, specific, spatio-temporal
and constitutive expression. In addition, CcGEA identified a
gene network of 28 co-expressed genes, including two regulatory
genes, a pollen specific SF3 and a sucrose-proton symporter to
be involved in pollen fertility, which has potential implication in
seed yield improvement. In summary, this study, especially identification
of TSMS and development of CcGEA, will accelerate
on-going efforts to enhance genetic gains in pigeonpea
Next generation sequencing based transcriptomic studies for crop improvement in pigeonpea
Transcriptomic studies are rapidly evolving as a powerful tool with next-generation sequencing technology to understand gene functions and molecular mechanisms. RNA sequencing (RNAseq) provides a dynamic range for transcript detection and a better quantification of expression levels.With the availability of genome sequence in pigeonpea, RNA-seq was used to link the sequence information to phenotypic traits resulting from specific developmental processes. In pigeonpea, three-line hybrid breeding system is well-established; however, it is technically demanding and cumbersome. In order to explore the possibility of a two-line hybrid breeding system, a coherent transcriptomic approach supported by physiological and cytological data has led to the identification of a temperature-sensitive male sterile (TSMS) line. This line has been characterized for critical (tetrad) stage and temperature (23°C), and the identification of candidate genes involved in abscisic acid signaling for fertility reversion. Furthermore, a gene expression atlas (CcGEA) has been developed and transcriptomic profiles generated for studying pod and seed development with a dataset of 590.84 and 342 million paired-end reads, respectively in pigeonpea. These data have been analyzed for genes with differential, specific, spatio-temporal and constitutive expression. In addition, CcGEA identified a gene network of 28 co-expressed genes, including two regulatory genes, a pollen specific SF3 and a sucrose-proton symporter to be involved in pollen fertility, which has potential implication in seed yield improvement. In summary, this study, especially identification of TSMS and development of CcGEA, will accelerate on-going efforts to enhance genetic gains in pigeonpea