Multi-location evaluation of field pea in Indian climates: eco-phenological dynamics, crop-environment relationships, and identification of mega-environments.

Characterization of crop-growing environments in relation to crop's genotypic performance is crucial to harness positive genotype-by-environment interactions (GEI) in systematic breeding programs. Given that, the study aimed to delineate the impact of diverse environments on crop phenology and yield traits of dwarf-statured field pea, pinpointing location(s) favoring higher yield and distinctiveness within breeding lines. We tested twelve field pea breeding lines across twenty locations in India, covering Central Zone (CZ), North Western Plain Zone (NWPZ), North Eastern Plain Zone (NEPZ), and Northern Hill Zone (NHZ). Across these locations, maximum and minimum temperatures during flowering (TMAXF, TMINF) and reproductive period (TMAXRP, TMINRP) ranged 18.9-28.3, 3.3-18.0, 15.0-30.8, and 7.9-22.1oC, respectively. Meanwhile, notable variations in phenological and agronomic traits (coefficient of variation) were observed: flowering (31%), days to maturity (21%), reproductive period (18%), grain yield (48%), and 100-seed weight (18%). Combined ANOVA demonstrated an oversized impact of environment (81%) on yield, while genotype and GEI effects were 2% and 14%, respectively. The variables TMINF, TMINRP, and cumulative growing degree-day showed positive correlations with yield, while extended vegetative and maturity durations negatively influenced yield (p < 0.05). Additionally, linear mixed-models and PCA results explained that instability in crop phenology had significant influence on field pea yield. Seed weight was markedly varied within the locations (9.9-20.8 g) and both higher and lower seed weights were associated with lower yields (Optimal = 17.1 g). HA-GGE biplot-based on environment focus-scaling demonstrated three mega-environments and specific locations viz. Kota (CZ), SK Nagar (CZ), Raipur (CZ), Sehore (CZ), and Pantnagar (NWPZ) as the ideal testing-environments with high efficiency in selecting new genotypes with wider adaptability. The study findings highlight distinct impact of environments on crop phenology and agronomic traits of field pea (dwarf-type), hold substantial value in designing efficient field pea (dwarf-type) breeding program at mega-environment scale.

Metabolic-GWAS provides insights into genetic architecture of seed metabolome in buckwheat.

BACKGROUND: Buckwheat (Fagopyrum spp.), belonging to the Polygonaceae family, is an ancient pseudo-cereal with high nutritional and nutraceutical properties. Buckwheat proteins are gluten-free and show balanced amino acid and micronutrient profiles, with higher content of health-promoting bioactive flavonoids that make it a golden crop of the future. Plant metabolome is increasingly gaining importance as a crucial component to understand the connection between plant physiology and environment and as a potential link between the genome and phenome. However, the genetic architecture governing the metabolome and thus, the phenome is not well understood. Here, we aim to obtain a deeper insight into the genetic architecture of seed metabolome in buckwheat by integrating high throughput metabolomics and genotyping-by-sequencing applying an array of bioinformatics tools for data analysis. RESULTS: High throughput metabolomic analysis identified 24 metabolites in seed endosperm of 130 diverse buckwheat genotypes. The genotyping-by-sequencing (GBS) of these genotypes revealed 3,728,028 SNPs. The Genome Association and Prediction Integrated Tool (GAPIT) assisted in the identification of 27 SNPs/QTLs linked to 18 metabolites. Candidate genes were identified near 100 Kb of QTLs, providing insights into several metabolic and biosynthetic pathways. CONCLUSIONS: We established the metabolome inventory of 130 germplasm lines of buckwheat, identified QTLs through marker trait association and positions of potential candidate genes. This will pave the way for future dissection of complex economic traits in buckwheat.

Delineating Marker-Trait Associations for Fusarium Wilt in Chickpea Using the Axiom® CicerSNP Array.

Fusarium wilt (FW) caused by Fusarium oxysporum f. sp. ciceri is a devastating disease of chickpea (Cicer arietinum). To identify promising resistant genotypes and genomic loci for FW resistance, a core set of 179 genotypes of chickpea was tested for FW reactions at the seedling and reproductive stages under field conditions and controlled conditions in the greenhouse. Our results revealed that at the seedling stage, most of the genotypes were resistant, whereas at the reproductive stage, most of the genotypes were susceptible. Genotyping using a 50K Axiom® CicerSNP Array and trait data of FW together led to the identification of 26 significant (P ≤ E-05) marker-trait associations (MTAs) for FW resistance. Among the 26 MTAs, 12 were identified using trait data recorded in the field (three at the seedling and nine at the reproductive stage), and 14 were identified using trait data recorded under controlled conditions in the greenhouse (six at the seedling and eight at the reproductive stage). The phenotypic variation explained by these MTAs varied from 11.75 to 15.86%, with an average of 13.77%. Five MTAs were classified as major, explaining more than 15% of the phenotypic variation for FW, and two were declared stable, being identified in two environments. One of the promising stable and major MTAs (Affx_123280060) detected in field conditions at the reproductive stage was also detected in greenhouse conditions at the seedling and reproductive stages. The stable and major (>15% PVE) MTAs can be used in chickpea breeding programs.

Morpho-Cultural and Pathogenic Variability of Sclerotinia sclerotiorum Causing White Mold of Common Beans in Temperate Climate.

The present systematic research on cultural, morphological, and pathogenic variability was carried out on eighty isolates of Sclerotinia sclerotiorum collected from major common bean production belts of North Kashmir. The isolates were found to vary in both cultural and morphological characteristics such as colony color and type, colony diameter, number of days for sclerotia initiation, sclerotia number per plate, sclerotial weight, and size. The colony color ranged between white and off-white with the majority. The colony was of three types, in majority smooth, some fluffy, and a few fluffy-at-center-only. Colony diameter ranged between 15.33 mm and 29 mm after 24 h of incubation. The isolates took 4 to 7 days for initiation of sclerotia and varied in size, weight, and number per plate ranging between 14 and 51.3. The sclerotial arrangement pattern on plates was peripheral, sub peripheral, peripheral, and subperipheral, arranged at the rim and scattered. A total of 22 Mycelial compatibility groups (MCGs) were formed with seven groups constituted by a single isolate. The isolates within MCGs were mostly at par with each other. The six isolates representing six MCGs showed variability in pathogenicity with isolate G04 as the most and B01 as the least virulent. The colony diameter and disease scores were positively correlated. Sclerotia were observed to germinate both myceliogenically and carpogenically under natural temperate conditions of Kashmir. Germplasm screening revealed a single resistant line and eleven partially resistant lines against most virulent isolates.

Assessment of cold tolerance in chickpea (Cicer spp.) grown under cold/freezing weather conditions of North-Western Himalayas of Jammu and Kashmir, India.

Chickpea is one of the most important grain legume crops in the world. India is the largest producer, consumer as well as importer of chickpea. Cold stress (temperature < 15 °C) is one of the important abiotic stresses limiting chickpea production by hampering its growth and vigor at all phenological stages. This study was aimed to characterize a diverse set of 366 chickpea genotypes for cold tolerance and identify most promising cold tolerant chickpea genotypes in the Western-Himalayas of Jammu and Kashmir, India. The 366 genotypes used during the present study including genotypes belonging to cultivated, primary and secondary gene pools of chickpea. Two important approaches were used including visual screening under field conditions and screening under controlled conditions by measuring cell membrane stability through electrolyte leakage tests. The analysis of trait data collected through both the approaches led to the identification of five most promising/candidate cold tolerant chickpea genotypes including one wild genotype "Ortan-066" from secondary gene pool species (C. echinospermum), one wild genotype "Cudi 1-022" from primary gene pool species (C. reticulatum) and three genotypes (IC 116783, ICC 15200 and AGBLG 170004) from the cultivated species (Cicer arietinum). Wild genotype "Ortan-066" was found best cold tolerance source with the mean Cold Tolerance Rating (CTR) of 2 and Electrolyte Leakage Index (ELI) of 10.82%, followed by wild genotype "Cudi 1-022" (CTR = 3, ELI = 18.89%), and three cultivated genotypes viz., IC 116783, ICC 15200 and AGBL-G-170004, with the mean CTR of 3 and an estimated mean ELI of 21.26%, 21.58% and 21.94%, respectively. The promising, candidate cold tolerant genotypes identified during the present study could be used in chickpea breeding programs aimed at improving cold tolerance of cultivated chickpea worldwide. The candidate lines can be also used for developing bi-parental mapping populations, wild × cultivated introgression lines, transcriptomics and for differential expression analysis of cold tolerant genes in chickpea. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12298-021-00997-1.