Screening of French Bean (Phaseolus vulgaris L.) Genotypes against Alternaria Leaf Spot Caused by (Alternaria alternata) under Dryland Conditions of Kashmir

Sixty-three genotypes of french bean was screened against leaf spot (Alternaria alternata) in sick plots at Research Farm of Dryland Agriculture Research Srinagar, Rangreth during Kharif 2018 and 2019. The highest mean disease incidence ranged from 0.00 to 85.00 per cent with the mean disease intensity ranged from 0.00 to 53.26 per cent .One genotype namely ‘Local Pulwama’ was highly susceptible in their disease reaction. Among the screened germplasm, ‘Highly Resistant’ genotypes was SKU-R-601, SKUA-R-105, SKU-R-927, DARS-25, DARS-66, DARS-R-615, while as ‘Susceptible’ genotypes was DARS-8, DARS-12, DARS-11, SKUAST-R-155, SKU-R-928, DARS-7, DARS-R-4, Bhaderwah (L), Local Kupwara black and Raj Jawala. Local Pulwama was found to be a highly susceptible (HS) genotype. Twenty nine genotypes namely., DARS-16, DARS-9, DARS-54, DARS-39, VL-125, DARS-63, ENTO-504, SKUAST-204,SKU-R-925, DARS-60, DARS-109, DARS-43, DARS-44, SKU-R-23, DARS-4, DARS-74, SKU-R-105, DARS-40, DARS-23, DARS-18, SKU-R-71, WB-341, SKU-R-605, Uri local, Shopian (L), SKU-R-23, DARS-71, SSGB-729, DARS-R-19 showed resistant reaction to disease. The selection for resistance was based on the reaction of varieties on leaves.

Associated SNPs, Heritabilities, Trait Correlations, and Genomic Breeding Values for Resistance in Snap Beans (Phaseolus vulgaris L.) to Root Rot Caused by Fusarium solani (Mart.) f. sp. phaseoli (Burkholder)

Root rot is a major constraint to snap bean (Phaseolus vulgaris) production in the United States and around the world. Genetic resistance is needed to effectively control root rot disease because cultural control methods are ineffective, and the pathogen will be present at the end of one season of production on previously clean land. A diversity panel of 149 snap bean pure lines was evaluated for resistance to Fusarium root rot in Oregon. Morphological traits potentially associated with root rot resistance, such as aboveground biomass, adventitious roots, taproot diameter, basal root diameter, deepest root angle, shallowest root angle, root angle average, root angle difference, and root angle geometric mean were evaluated and correlated to disease severity. A genome wide association study (GWAS) using the Fixed and random model Circulating Probability Unification (FarmCPU) statistical method, identified five associated single nucleotide polymorphisms (SNPs) for disease severity and two SNPs for biomass. The SNPs were found on Pv03, Pv07, Pv08, Pv10, and Pv11. One candidate gene for disease reaction near a SNP on Pv03 codes for a peroxidase, and two candidates associated with biomass SNPs were a 2-alkenal reductase gene cluster on Pv10 and a Pentatricopeptide repeat domain on Pv11. Bean lines utilized in the study were ranked by genomic estimated breeding values (GEBV) for disease severity, biomass, and the root architecture traits, and the observed and predicted values had high to moderate correlations. Cross validation of genomic predictions showed slightly lower correlational accuracy. Bean lines with the highest GEBV were among the most resistant, but did not necessarily rank at the very top numerically. This study provides information on the relationship of root architecture traits to root rot disease reaction. Snap bean lines with genetic merit for genomic selection were identified and may be utilized in future breeding efforts.

Seedling and Adult Plant Resistance in the Ethiopian Bread Wheat Landraces to Stripe Rust Disease

High yielding farmers’ bread wheat cultivars are threatened by emerging race(s) of stripe (yellow) rust caused by Puccinia striiformis f.sp. tritici (Pst) in the highlands of Ethiopia. In depletion of rust resistance in commercial cultivars, researchers often look for new sources from close relatives and landraces. The objective of this study was to determine stripe rust resistance in selected Ethiopian bread wheat landraces obtained from the Ethiopian Institute of Biodiversity (IBCE). In 2017, a total of 152 accessions were exposed to the prevailing stripe rust races in hot spot areas (Kulumsa and Meraro) in Arsi zone of Oromia region. In the second year (2018), only promising landraces (57) were evaluated both at seedling and adult plant growth stages. The seedling test was conducted in the greenhouse at Kulumsa research center using three (PstS2 (v32), (PstS11) and (PstS11 v25) Pst races. In field evaluations, terminal severity (TRS), coefficient of infection (CI), area under disease progress curve (AUDPC), disease progress rate (DPR) and head infection (HI) were considred. High disease pressure was noted with 100% severity on susceptible entries at both locations and seasons. Highly significant (P<0.001) differences were noted among the landraces for all disease parameters indicated above. Of the 152 landraces, 57(38%) exhibited lower or equal disease reaction compared to the resistant check(Enkoy) across locations. Overall, 18 accessions showed resistance to the prevailing Pst races both at seedling stage and field conditions whereas14 exhibited susceptible /intermediate reaction at seedling stage, but had lower disease reaction under field conditions. This study has identified potential sources of overall and adult plant resistance in the Ethiopian bread wheat landraces to the prevailing Pst races. The authors recommend further studies to determine the diversity and/or novelity of resistance genes in selected accessions. Future wheat improvement should focus on utilization of these genetic resources to minimize the re-current outbreak of rust diseases.

Variability in pathological characters in Gloeocercospora sorghi isolates from sorghum

Zonate leaf spot caused by Gloeocercospora sorghi Bain and Edgerton (1943) is one of the most destructive diseases of sorghum in India and Uttarakhand is considered as a hot spot for this disease. The present investigation was carried out to record the pathogenic variability of thirty isolates of Gloeocercospora sorghi on five different lines of sorghum. The G. sorghi isolates differed significantly from each other on the basis of pathological attributes viz., latent period, aggressiveness and virulence index and thus, grouped into three virulence categories. The findings suggest that analysis of variance for latent, aggressiveness, per cent disease intensity (PDI) and virulence index showed that the variations in latent period and virulence disease reaction were attributed more to the isolates and aggressiveness to the host lines than to the isolate × host line interactions.

Agronomic evaluation of biofortified beans in Antioquia producers’ farms

The objective of this research was to evaluate genotypes of iron- and zinc-enriched common beans during breeding in producers’ farms. Yield, disease reaction, and commercial grain characteristics were evaluated to achieve this objective. In three locations of Antioquia (Rionegro, Jardín, and Betulia), seven bush beans and eight climbing bean genotypes were planted. A randomized complete block design with four replications was used in each location. There were significant differences between the bush and climbing bean genotypes that were evaluated. The highest yields, in all locations, were for the biofortified bean NUA 45 and the control variety Uribe Rosado, followed by the CAL 96 and AFR 612 genotypes. For the climbing beans, the highest yields were found in the G2333 genotypes, being this treatment equal to the MAC 27, a bean that is adapted to mid-climate and altitudes. The MAC 27 material is presented as a promising variety because of its high yields and tolerance to diseases, mainly anthracnose.

Molecular tagging of botrytis grey mould disease in chickpea

Validation of two primers TA144 and TR29 for their linkage with botrytis grey mould resistance gene was studied in twenty genotypes of chickpea including resistant (GL10006) and susceptible (DCP92-3) checks. The genotypes were also scored for disease reaction under natural exposure at hot spot location. Molecular analysis with primers TA144 and TR29 showed polymorphic bands in GL10006 and DCP92-3. Therefore, it can be concluded that the primers are linked with resistance gene. The genotypes that showed amplicons with both the primers at same or nearby positions of resistant check were HK-2, HK-4, BG-1003, KAK-2 and GNG-1969 and indicated as resistant or moderately resistant ones. The above genotypes were also found resistant under natural field condition. Thus both the primers TA144 and TR29 showed good correlation with phenotypic evaluation in most of the genotypes studied. In future, more number of primers nearby the resistance gene(s) can be tried for their contribution towards overall disease reaction.