Pigeonpea has considerable extent of insect-aided natural out-crossing that impedes genetic purity of seeds. Pre-anthesis cleistogamy in pigeonpea promotes self-pollination which helps in maintaining genetic purity. The cleistogamous flowers are linked with shriveled seeds, an undesirable trait from variety adoption point of view, and breeding using genomics tools can help in overcoming this constraint. Therefore, in order to identify genomic regions governing these target traits, one recombinant inbred line (RIL) population was developed using contrasting parents (ICPL 99010 and ICP 5529) for flower shape and shriveled seeds. The RILs were phenotyped for two years and genotyped using the Axiom Cajanus SNP Array. Out of the 56,512 unique sequence variations on the array, the mapping population showed 8634 single nucleotide polymorphism (SNPs) segregating across the genome. These data facilitated generation of a high density genetic map covering 6818 SNPs in 974 cM with an average inter-marker distance of 0.1 cM, which is the lowest amongst all pigeonpea genetic maps reported. Quantitative trait loci (QTL) analysis using this genetic map and phenotyping data identified 5 QTLs associated with cleistogamous flower, 3 QTLs for shriveled seed and 1 QTL for seed size. The phenotypic variance explained by these QTLs ranged from 9.1 to 50.6%. A consistent QTL “qCl3.2” was identified for cleistogamous flower on CcLG03 covering a span of 42 kb in the pigeonpea genome. Epistatic QTLs were also identified for cleistogamous flower and shriveled seed traits. Identified QTLs and genomic interactions for cleistogamous flower, shriveled seed and seed size will help in incorporating the required floral architecture in pigeonpea varieties/lines. Besides, it will also be useful in understanding the molecular mechanisms, and map-based gene cloning for the target traits.
1 January 2015 in Indian Journal Of Genetics and Plant Breeding
Pigeonpea is one of the important pulse crops grown in many states of India and plays a major role in sustainable food and nutritional security for the smallholder farmers. In order to overcome the productivity barrier the Translational Pigeonpea Genomics Consortium (TPGC) was established, representing research institutes from six different states (Andhra Pradesh, Karnataka, Madhya Pradesh, Maharashtra, Telangana, and Uttar Pradesh) of India. To enhance pigeonpea productivity and production the team has been engaged in deploying modern genomics approaches in breeding and popularizing modern varieties in farmers’ fields. For instance, new genetic stock has been developed for trait mapping and molecular breeding initiated for enhancing resistance to fusarium wilt and sterility mosaic disease in 11 mega varieties of pigeonpea. In parallel, genomic segments associated with cleistogamous flower, shriveled seed, pods per plant, seeds per pod, 100 seed weight, and seed protein content have been identified. Furthermore, 100 improved lines were evaluated for yield and desirable traits in multi-location trials in different states. Furthermore, a total of 303 farmers’ participatory varietal selection (FPVS) trials have been conducted in 129 villages from 15 districts of six states with 16 released varieties/hybrids. Additionally, one line (GRG 152 or Bheema) from multi-location trials has been identified by the All India Coordinated Research Project on Pigeonpea (AICRP-Pigeonpea) and released for cultivation by the Central Variety Release Committee (CVRC). In summary, the collaborative efforts of several research groups through TPGC is accelerating genetics gains in breeding plots and is expected to deliver them to pigeonpea farmers to enhance their income and improve livelihood.
20 February 2023 in Agricultural Science Digest - A Research Journal
Background: Pigeonpea is an important legume crop in India. The super early genotypes which matures within 100 days have been developed at ICRISAT. They are photo-insensitive, aids in crop intensification and escapes abiotic and biotic stresses. The super early genotypes were exploited for genetic diversity for further improvement of the genotypes. Methods: The study was conducted at International Crop Research Institute for the Semi-Arid Tropics, Patancheru, Telangana during kharif, 2017. The thirty-super early pigeonpea genotypes developed at ICRISAT were subjected for the study of genetic diversity (Mahalanobis D2 method) based on twelve quantitative characters. Result: The 30 super early genotypes were grouped into five clusters. The largest number of genotypes were confined to cluster III (19 genotypes) followed by cluster IV (6 genotypes), cluster I and II (2 genotypes). Cluster V is a solitary cluster with the check MN1.The inter cluster distance was high between the clusters III and IV followed by cluster I and III. The intra cluster distance was highest for the cluster III indicating the presence of variation among the genotypes within the cluster. The highest mean for single plant yield was observed for the cluster III followed by cluster V. The clusters with more inter cluster distance can be used to select parents to be involved in hybridization programmes.
About Me
Scientist-Pigeonpea Breeding
Asia Program
ICRISAT, Patancheru
INDIA
Scientist-Pigeonpea Breeding
Asia Program
ICRISAT, Patancheru
INDIA