Ramesh Pal Singh Verma

Molecular and phenotypic diversity of ICARDA spring barley (Hordeum vulgare L.) collection

Plant breeders are interested in using diverse genotypes in hybridization that can segregate for traits of importance with possibility of selection and genetic gain. Information on molecular and agro-morphological diversity helps the breeders reduce the effort for parental selection and helps the advancement of generations. A phenotypic and molecular diversity study, using 24 traits (agronomic and disease) and 6519 SNPs in a diverse collection of 336 spring barley genotypes, was carried out at Marchouch and Jemma Shiam research stations in Morocco. Based on structure and multivariate analyses, strong differentiation between the two- and six-row types were observed. The linkage disequilibrium (LD) decay of the current collection (for the combined population) was up to 3.58xa0cM (r2xa0=xa00.15) while LD decay were estimated 3.91 and 2.36xa0cM for two- and six-row barley, respectively. PCA of agro-morphological traits revealed grain per spike, net form of net blotch (NFNB), spot form of net blotch (SFNB), and 1000 kernel weight were the most discriminatory traits in the current collection. Association mapping in the two independent populations will be ideal for identification of markers, and QTL related to traits. The generated information on relatedness between individuals will help identify diverse genotypes for breeding programs.

Genome wide association studies (GWAS) of spot blotch resistance at the seedling and the adult plant stages in a collection of spring barley

Spot blotch (SB) in barley is caused by the fungal pathogen Cochliobolus sativus and considered one of the major constraints to successful barley production. Resistance to C. sativus was evaluated, using a barley collection of 336 genotypes (AM-2014), at the seedling and adult stages. Seedling resistance was evaluated by using a mixture of 19 virulent isolates in Morocco. Virulent isolates prevalent in Uttar Pradesh were used for phenotyping resistance at the adult stage in India. The AM-2014 panel was genotyped with 9-K single-nucleotide polymorphism (SNP) markers using iSelect Illumina Infinium. Genome wide association studies (GWAS) were carried out using SNP markers, infection responses, disease severity, and area under the disease progress curve (AUDPC). The mixed linear model was employed in TASSEL using principal component analysis (PCA) and Kinship matrix (K) as covariates. Higher SB severity, 82.3u2009±u200913.5 (meanu2009±u2009SD), was recorded at the Banaras Hindu University (BHU) compared to 47.6u2009±u200915.0 at the Narendra Dev University of Agriculture and Technology (NDUAT). Nine QTL, Rcs-qtl-1H-126.9, Rcs-qtl-2H-148.16, Rcs-qtl-3H-25.27, Rcs-qtl-5H-80.35, Rcs-qtl-6H-58.24, Rcs-qtl-7H-29.62, Rcs-qtl-7H-29.72, Rcs-qtl-7H-32.81, and Rcs-qtl-7H-34.74, were detected for SB resistance at the seedling stage. For SB severity at the adult stage, a QTL, Rcs-qtl-7H-32.81, was detected at BHU while seven QTL, Rcs-qtl-2H-91.09, Rcs-qtl-3H-145.64, Rcs-qtl-4H-14.43, Rcs-qtl-6H-6.49, Rcs-qtl-7H-114.43, Rcs-qtl-7H-151.66, and Rcs-qtl-7H-150.36, were found for SB severity at NDUAT. Three QTL, Rcs-qtl-4H-18.61, Rcs-qtl-4H-67.91, and Rcs-qtl-5H-110.25, were significant for AUDPC of SB at BHU. The QTLs reported in this study are important to advance marker-assisted selection and gene pyramiding of SB resistance in South Asia and North Africa in future.

Genome-wide association studies of net form of net blotch resistance at seedling and adult plant stages in spring barley collection

Net form of net blotch (NFNB) of barley (Hordeum vulgare L.), caused by Pyrenophora teres f. teres (Ptt) Drechsler (anamorph: Drechslera teres [Sacc.] Shoem.), is considered one of the major constraints of successful barley production in major barley growing regions of the world. Resistance to NFNB was evaluated in a barley collection of 336 genotypes (AM-2014), at seedling stage using isolates LGDPtt.19 and TD10 in the USA, and adult stage in seven hotspot environments in Morocco. The AM-2014 panel was genotyped with 9K SNP markers and genome-wide association studies (GWAS) were carried out using mixed linear model (MLM: Qu2009+u2009K) accounting for population structure (Q) and kinship (K) as covariates. Significant (Pu2009<u20090.001) marker trait associations were corrected for false discovery rate (FDR) at the qu2009<u20090.05. Four genotypes showed an average infection response (IRsxa0≤xa02) to both isolates, LGDPttt.19 and TD10, at the seedling stage, and 30 genotypes showed resistance in all environments in the field while three genotypes exhibited the highest resistance at both stages. The GWAS of NFNB identified 31 distinct QTLs on all seven barley chromosomes, of which 8 with resistance at seedling stage, 21 were associated with resistance at the adult stage, and two QTLs, QRptt.2H-132.15 and QPtt.6H-54-55, conferred resistance at both stages. Of 31 resistance QTLs reported in this study, 10 QTLs coincided with previously mapped QTL while 21 are novel, thereby validating the GWAS approach used in this study. The resistance sources identified in AM-2014 and QTL mapped in this study are valuable resources for marker-assisted breeding for NFNB resistance in the future.

Genome Wide Association Mapping of Seedling and Adult Plant Resistance to Barley Stripe Rust (Puccinia striiformis f. sp. hordei) in India

Barley stripe rust is caused by Puccinia striiformis f.sp. hordei, (Psh), occurs worldwide, and is a major disease in South Asia. The aim of this work was to identify and estimate effects of loci underlying quantitative resistance to rust at seedling and adult plant stages. HI-AM panel of 261 barley genotypes consisting of released cultivars from North and South America, Europe, Australia, advanced breeding lines, and local landraces from ICARDA barley program were screened at seedling and adult plant stages for resistance to Psh. Seedling resistance was evaluated with the five prevalent Psh races in India. Screening for the adult plant stage resistance was also performed in two different locations by inoculating with a mixture of the five races used for seedling screeing. The panel was genotyped using DaRT-Seq high-throughput genotyping platform. The genome-wide association mapping (GWAM) showed a total of 45 QTL located across the seven barley chromosomes for seedling resistance to the five races and 18 QTL for adult plant stage resistance. Common QTL for different races at seedling stage were found on all chromosomes except on chromosome 1H. Four common QTL associated with seedling and adult plant stage resistance were found on chromosomes 2, 5, and 6H. Moreover, one of the QTL located on the long arm of chromosome 5H showed stable effects across environments for adult plant stage resistance. Several QTL identified in this study were also reported before in bi-parental and association mapping populations studies validating current GWAM. However 15 new QTL were found at adult plant stage on all chromosomes except the 4H, explaining up to 36.79% of the variance. The promising QTL detected at both stages, once validated, can be used for MAS in Psh resistance breeding program globally.

Seedling and adult stage resistance to spot form of net blotch (SFNB) in spring barley and stability of adult stage resistance to SFNB in Morocco

The aims of this study were to identify resistance to spot form of net blotch (SFNB) in spring barley and to investigate the stability of SFNB resistance in Morocco. The seedling resistance to SFNB was evaluated by inoculating 340 barley genotypes with the Pyrenophora teres F. maculata (Ptm) isolate FGOB10Ptm-1 (FGO) in the greenhouse. The same barely genotypes were evaluated for adult-stage plant resistance to SFNB in field trials in Morocco. All experiments were conducted in alpha-lattices with two replicates. SFNB disease severity was estimated on barley leaves using double digit scale. To investigate the stability of both qualitative and quantitative resistance to SFNB, 104 barley genotypes were subjected to AMMI analysis. Differential responses of SFNB barley resistance to FGO were found at the seedling stage in the greenhouse. Twelve genotypes showing scores of <1.5, at the seedling stage, were determined to be highly resistant to FGO. The ANOVA showed highly significant (pu2009<u20090.001) effects of genotype (G) and Gu2009×u2009E (E-Pathotypes of SFNB) interaction on SFNB severity among the 340 barley genotypes at the adult plant stage. The AMMI ANOVA showed that IPCA1, IPCA2 and IPCA3 accounted for 77.9% of the variation of the Gu2009×u2009E interaction for SFNB severity. The Gu2009×u2009E interaction consisted of divergent genotypic responses to SFNB severity due to different pathotypes prevalent in hot-spot environments. The AMMI stability value demonstrated that barley genotypes AM-14, 30, 31, 68, 107, 108, 112, 149, 170, 185, 204, 240, 304, 326, 326 and 337 were resistant and stable across hot-spot environments against SFNB. Divergent environmental responses of SFNB were recorded in MCH_2015, SE_2015, AT_2016, SE_2016 and JS_2015. Stable SFNB resistant genotypes are valuable resources for the introgression of qualitative and quantitative resistance to barley in Morocco.

Hulless barley as a promising source to improve the nutritional quality of wheat products

Abstract In this study, efforts were made to utilize hulless barley (variety BHS352) to enhance the nutritive value of chapatti and biscuit made from wheat flour. Barley flour was added to wheat flour in different ratios (5 to 30%). Antioxidant activity, total phenolic content and β-glucan content were determined both in flour blends and their products. Changes in physical quality and taste of chapatti and biscuits after blending of hulless barley flour with wheat flour were measured. The chapatti quality score decreased by 15% and biscuit spread factor by 33% after 30% barley flour blending. Significant increase in β-glucan content and antioxidant activity of flour blends and their products was observed at 30% blending level. The phenolic content increased from 63 to 135xa0µg for biscuits and 237 to 287xa0ugxa0GAE/g for chapatti with blending of 30% barley flour.

Mechanized Intercropping of Legumes in Spring Planted Sugarcane

Field experiments were conducted at Chaudhary Charan Singh Haryana Agricultural University, Regional Research Station, Karnal during 2006–07 and 2007–08 followed by demonstrations on intercropping of legumes in sugarcane at farmers’ field in Kaithal district during 2010–11 and 2011–12. Spring planting of sugarcane with different intercrops resulted in higher total equivalent yield (TEY). TEY was highest (116.7 t ha−1) when cluster bean was intercropped in sugarcane. The percent incidence of pink borer, shoot borer, top borer and root borer remained below economical threshold level (ETL). In all intercropping systems, total land equivalent ratio (LERt) was greater than unity. Land equivalent coefficient (LEC) followed the same pattern as LERt. Total area time equivalent ratio (ATERt) values showed an advantage (14–21%) with all intercropping systems than sole cropping with maximum advantage from sugarcane + cluster bean. Higher CR values for the intercrops (CRi) indicated that all the intercrops were more competitive than sugarcane. Total values of actual yield loss (AYLt) showed an advantage of 10.6–40.3% from intercropping systems compared to sole cropping. Maximum intercropping advantage of intercrops (IAi) value was observed in sugarcane + black gram (6738.7) intercropping system. Highest monetary advantage index (MAI) value was obtained from sugarcane + cluster bean (76361) intercropping system. Returns over variable cost in case of sugarcane + black gram, sugarcane + green gram, sugarcane + cowpea and sugarcane + cluster bean were 13320, 18455, 12030 and 30477 ha−1 respectively, which were higher than sole sugarcane.