Combining High Oleic Acid Trait and Resistance to Late Leaf Spot and Rust Diseases in Groundnut (Arachis hypogaea L.)

Abstract

High oleic trait, resistance to rust and late leaf spot (LLS) are important breeding objectives in groundnut. Rust and LLS cause significant economic loss, and high oleic trait is an industry preferred trait that enhances economic returns. This study reports marker-assisted selection to introgress high oleic content, resistance to LLS and rust into Kadiri 6 (K 6), a popular cultivar. The alleles for target traits were selected using linked allele-specific, simple sequence repeats and single nucleotide polymorphic markers. The F 1 s (384), intercrossed F 1 s (441), BC 1 F 1 s (380), BC 1 F 2 s (195), and BC 1 F 3 s (343) were genotyped to obtain desired allelic combination. Sixteen plants were identified with homozygous high oleic, LLS and rust resistance alleles in BC 1 F 2 , which were advanced to BC 1 F 3 and evaluated for disease resistance, yield governing and nutritional quality traits. Phenotyping with Near-Infrared Reflectance Spectroscopy identified three lines (BC 1 F 3 -76, BC 1 F 3 -278, and BC 1 F 3 -296) with >80% oleic acid. The identified lines exhibit high levels of resistance to LLS and rust diseases (score of 3.0-4.0) with preferred pod and kernel features. The selected lines are under yield testing trials in multi-locations for release and commercialization. The lines reported here demonstrated combining high oleic trait with resistance to LLS and rust diseases.

Comparative Transcriptome Analysis Identified Candidate Genes for Late Leaf Spot Resistance and Cause of Defoliation in Groundnut

“…Another study using a different source performed whole genome sequencing of complete RIL population (Tifrunner × GT-C20) and identified major QTLs on chromosome A05 and B03 with phenotypic variance~47% in US germplasm [23]. These genetic mapping studies confirmed the genomic region on chromosome A03/B03 responsible for LLS resistance and the linked SSR/SNP markers [7] were used in marker assisted selection to develop LLS resistance varieties [9,[24][25][26].…”

Single Seed-Based High-Throughput Genotyping and Rapid Generation Advancement for Accelerated Groundnut Genetics and Breeding Research

“…Currently, diagnostic markers are available in groundnut breeding for resistance to foliar fungal diseases, nematode, bacterial wilt, and high oleic acid, seed weight and fresh seed dormancy traits. Marker-assisted selection (MAS) approaches for different traits such as, nematode resistance [32], high oleic [11,13,19,23] and rust, and LLS [16][17][18] using diagnostic markers of various marker systems such as SSRs, ASP (allelespecific), AhMITE1 (A. hypogaea miniature inverted-repeat transposable element), and SNP markers are used by the groundnut breeding programs in India, the USA, and China. Through a cooperation agreement with Intertek-AgriTech, the HTPG project, directed by ICRISAT, intends to deliver low-cost, high-throughput genotyping services primarily for forward breeding applications [14].…”

“…Through a cooperation agreement with Intertek-AgriTech, the HTPG project, directed by ICRISAT, intends to deliver low-cost, high-throughput genotyping services primarily for forward breeding applications [14]. Deployment of a combination of SNP markers for pyramiding different traits provides cost-effectiveness by deploying MEGS to select desired lines [13,23]. MEGS reduces the population size manageable with limited resources.…”

“…As a result, the current groundnut breeding program at ICRISAT shifted from conventional breeding to marker-assisted breeding by deploying the diagnostic markers to perform MAS as well as marker-assisted backcrossing (MABC) to develop high oleic and foliar disease resistant groundnut varieties. These diagnostic markers were recently used to select high oleic acid content and foliar disease resistance traits [13] using leaf-punching at a cost of $2.0-2.5 per sample at Intertek-AgriTech Pvt. Ltd., Hyderabad, India under High-Throughput Genotyping (HTPG) platform [14].…”

Assessment of the genetic diversity of groundnut (Arachis hypogaeaL.) genotypes for kernel yield, oil and fodder quantity and quality under drought conditions

“…Data were collected on kernel and haulm yields (KY and HY, respectively) from each plot and converted to tons per hectare (t ha −1 ). Oil yield in t ha −1 (OY = oil content in % times kernel yield in t ha −1 ), the contents of total oil (OC), total protein (TPC), palmitic acid (PAC), stearic acid (SAC), oleic acid (OAC), and linoleic acid (LAC) contents of the kernels were estimated using a Near Infrared Spectroscopy (NIRS; XDS monochromator, FOSS Analytical AB, Hillerød, Sweden; Deshmukh et al., 2020). Data on dry HY was collected and expressed in t ha −1 .…”