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Distinguishing among commercial varieties or accessions in a germplasm repository presents considerable challenges when dealing with common crops or large collections. In the genus Pisum L. the third intron of the gene STAYGREEN (SGR), responsible for the green/yellow cotyledon variation, contains a complex of repeat sequences that display considerable indel and single nucleotide (SNP) polymorphism. In a sample of 137 Pisum L. accessions obtained from various germplasm collections 76 alleles were identified, ranging from about 600 to 1500 nucleotides in length. In most cases alleles differed by insertion/deletion (indel) polymorphisms in addition to single base changes. The amplicon was particularly useful for distinguishing wild accessions (those with dehiscent pods and dormant seeds). Among the 51 P. sativum L. accessions examined with a definite wild phenotype there were 44 SGR alleles. When this allelic variation was combined with location data for the wild accessions, each allele could be assigned a unique geographical location. Similarly, of the 10 P. fulvum Sibth. & Sm. accessions analyzed, only a group of three had the same allele, two of which are known to be replicates. We were able to confirm the identities of several P. sativum accessions from different germplasm collections, as well as identifying two cases where supposedly synonymous accessions gave different intron sequences. In addition, a group of wild pea accessions from Greece, Sicily, and Portugal exhibited a unique repeat sequence not found in any other wild accession, suggesting that these accessions constitute a distinct lineage. The rate of nucleotide site variation in this fragment of the SGR locus was found to be about 2.22 × 10–8 substitutions per site per year. This value is similar to those found for many other sequences in herbaceous papilionoid tribes, although it is at the faster end of the distribution of herbaceous legume substitution rates. We propose that both a fast substitution rate as well as the formation and rearrangement of indels have contributed to the high level of variation we detected at SGR. This PCR product should prove valuable in the identification of Pisum accessions, for quality control operations in germplasm repositories, and for exploring the evolutionary relationships within the genus.

White mold caused by Sclerotinia sclerotiorum is an important constraint to field pea (Pisum sativum L.) production worldwide. To transfer white mold resistance into an adapted background, and study the genetics of the disease, two recombinant inbred line (RIL) populations (PRIL17 and PRIL19) were developed by crossing two partially resistant plant introductions with two susceptible pea cultivars. PRIL17 (Lifter × PI240515), and PRIL19 (PI169603 × Medora) were evaluated for resistance to white mold by measuring lesion expansion inhibition (LEI) and nodal transmission inhibition (NTI) at 3, 7, and 14 days post inoculation (dpi) under controlled environmental conditions. Lesion expansion inhibition percentage (LEIP), survival rate (SR), and area under disease progress curves (AUDPC) were also calculated accordingly. Because of a positive correlation between LEI and NTI with height, short and long internode individuals of each population were analyzed separately to avoid any confounding effect of height to pathogen response. A total of 22 short genotypes demonstrated partial resistance based on at least two Porter's resistance criteria. Only two pea genotypes with partial resistance to white mold (PRIL19-18 and PRIL19-124) had both semi-leafless (afila) and short internode traits. Both the RIL populations were genotyped using genotyping by sequencing (GBS). For PRIL17 and PRIL19, genetic maps were constructed from a total of 1,967 and 1,196 single nucleotide polymorphism (SNP) and spanned over 1,494 cM and 1,415 cM representing seven and nine linkage groups, respectively. A consensus map constructed using data from both populations, had 1,486 unique SNPs over 2,461 cM belonging to seven linkage groups. Inclusive composite interval mapping (ICIM) identified thirteen quantitative trait loci (QTL) associated with white mold resistance traits in both populations. Three of them were co-located with height genes (a morphological trait that reduces infection risk and acts as disease avoidance) and the other ten QTL were associated with two forms of physiological resistance (seven for LEI and three for NTI) with LOD and r2 ranging from 3.0 to 28.5 and 5.1 to 64.3, respectively. The development of resistance lines, genetic dissection and identification of markers associated will help accelerate breeding efforts for white mold resistance using molecular breeding approaches.

Planting wheat (Triticum aestivum L.) cultivars that carry the aluminum (Al) resistance gene TaAlmt1 is a potentially lower cost alternative to lime applications in acidic agricultural soils. However, the relative importance of TaAlmt1 expression and adaptedness (to regional environmental conditions) for preserving grain yield in acidic soils is not well understood. Adaptation trials were established in low‐pH soils to compare lime‐amended (YL) and unamended grain yield (YU) among regionally adapted spring wheat cultivars with and without TaAlmt1. Averaged across YL and YU (YAVG), yield of adapted TaAlmt1 carriers was similar to adapted noncarriers (p = .939) but greater than nonadapted noncarriers (p = .024). Soil pH‐driven spatial heterogeneity appears to inflate yield coefficients of variation and the probability of committing type II errors in cultivar yield comparisons. Our results support the use of YAVG as a suitability index and decision support tool for cultivar selection in acid‐affected soils.

Genome-wide association study (GWAS) was conducted to identify loci associated with agronomic (days to flowering, days to maturity, plant height, seed yield and seed weight), seed morphology (shape and dimpling), and seed quality (protein, starch, and fiber concentrations) traits of field pea (Pisum sativum L.). A collection of 135 pea accessions from 23 different breeding programs in Africa (Ethiopia), Asia (India), Australia, Europe (Belarus, Czech Republic, Denmark, France, Lithuania, Netherlands, Russia, Sweden, Ukraine and United Kingdom), and North America (Canada and USA), was used for the GWAS. The accessions were genotyped using genotyping-by-sequencing (GBS). After filtering for a minimum read depth of five, and minor allele frequency of 0.05, 16,877 high quality SNPs were selected to determine marker-trait associations (MTA). The LD decay (LD1/2max,90) across the chromosomes varied from 20 to 80 kb. Population structure analysis grouped the accessions into nine subpopulations. The accessions were evaluated in multi-year, multi-location trials in Olomouc (Czech Republic), Fargo, North Dakota (USA), and Rosthern and Sutherland, Saskatchewan (Canada) from 2013 to 2017. Each trait was phenotyped in at least five location-years. MTAs that were consistent across multiple trials were identified. Chr5LG3_566189651 and Chr5LG3_572899434 for plant height, Chr2LG1_409403647 for lodging resistance, Chr1LG6_57305683 and Chr1LG6_366513463 for grain yield, Chr1LG6_176606388, Chr2LG1_457185, Chr3LG5_234519042 and Chr7LG7_8229439 for seed starch concentration, and Chr3LG5_194530376 for seed protein concentration were identified from different locations and years. This research identified SNP markers associated with important traits in pea that have potential for marker-assisted selection towards rapid cultivar improvement.

Gray mold caused by Botrytis spp. is one of the most important diseases of chickpea. In August 2019, chickpea plants with gray mold symptoms were submitted to the Regional Pulse Crop Diagnostic Laboratory (RPCDL) at Montana State University (MSU). To identify the causal agent, leaves were surface sterilized and plated on potato dextrose agar (PDA). The fungus was off white color and did not sporulate on PDA; sclerotia were observed after 10 days of incubation. The pathogen was identified as Botrytis euroamericana by the amplification of part of the G3PDH, HSP60, and RPB2 genes and by phylogenetic analysis. Pathogenicity tests revealed that the isolate was able to cause lesions on chickpea, lentil, dry pea, and fava bean foliage.

The disease white mold caused by the fungus Sclerotinia sclerotiorum is a significant threat to pea production, and improved resistance to this disease is needed. Nodal resistance in plants is a phenomenon where a fungal infection is prevented from passing through a node, and the infection is limited to an internode region. Nodal resistance has been observed in some pathosystems such as the pea (Pisum sativum L.)-S. sclerotiorum pathosystem. In addition to nodal resistance, different pea lines display different levels of stem lesion size restriction, referred to as lesion resistance. It is unclear whether the genetics of lesion resistance and nodal resistance are identical or different. This study applied genome-wide association studies (GWAS) and RNA-Seq to understand the genetic makeup of these two types of resistance. The time series RNA-Seq experiment consisted of two pea lines (the susceptible 'Lifter' and the partially resistant PI 240515), two treatments (mock inoculated samples and S. sclerotiorum-inoculated samples), and three time points (12, 24, and 48 hr post inoculation). Integrated results from GWAS and RNA-Seq analyses identified different redox-related transcripts for lesion and nodal resistances. A transcript encoding a glutathione S-transferase was the only shared resistance variant for both phenotypes. There were more leucine rich-repeat containing transcripts found for lesion resistance, while different candidate resistance transcripts such as a VQ motif-containing protein and a myo-inositol oxygenase were found for nodal resistance. This study demonstrated the robustness of combining GWAS and RNA-Seq for identifying white mold resistance in pea, and results suggest different genetics underlying lesion and nodal resistance.

Climate over the northern Great Plains has generally warmed over the last 60 yr. The rate of warming has varied temporally and spatially, confounding trend analysis for climate indicators such as increased length of the growing season. Change in precipitation has been even more variable. Despite this variability, present-day trends in temperature and precipitation generally coincide with the predicted direction of climate change. The synchrony of current and future trends reinforces the need for investigating adaptation in agriculture to changing climate. Our review is focused on sustainability of pulse crops in the northern Great Plains and the repercussions of climate change, focusing on the growth and yield response to temperature and water, and the climate restrictions that define their current geographic locations. The resilience of pulse crops to present-day weather extremes such as drought, excess water, heat, cool weather during grain filling, and early frost are considered to predict adaptation to future climate change. Features discussed include changes to crop water-use efficiency brought on by increased CO 2 fertilization, accelerated growth rates resulting from higher air temperatures, and total crop failures caused by an increased occurrence and magnitude of weather extremes. Adaptation strategies that are discussed include earlier seeding of pulse crops, use of winter pulses, crop sequencing within crop rotations, and alterations to the microclimate such as direct seeding into standing stubble.

Winter pea (Pisum sativum L.) and lentil (Lens culinaris Medik.) have potential agronomic advantages over spring types in the Pacific Northwest (PNW) and northern Great Plains (NGP). The objectives of this study were to: (i) determine suitable seeding date and cereal stubble height in no-till systems for winter pea and lentil; (ii) quantify and compare biomass and seed yield of winter pea and lentil with spring types; and (iii) compare adaptation of winter pea and lentil between the PNWand the NGP. Two breeding lines each of winter pea (PS9430706 and PS9530726) and winter lentil [LC9979010 (‘Morton’) and LC9976079] and two commercial cultivars each of spring pea (CDC Mozart and Delta) and spring lentil (Brewer and CDC Richlea) were sown on different dates (early and late fall dates for winter lines and spring date only for spring cultivars) and into different stubble heights (0.1 and 0.3 m) and compared for yield and agronomic adaptation in no-till systems at four locations: Moccasin and Amsterdam, MT; Genesee, ID; and Rosalia, WA. Stubble height did not influence winter or spring pea biomass production or seed yield. Tall stubble increased lentil biomass by 220 to 530 kg ha 21 and seed yield by 100 to 260 kg ha 21 in five out of nine site–years. Fall-seeded winter pea lines produced as much as 1830 kg ha 21 more seed yield than spring cultivars at the PNW sites, but not at the NGP sites. Early fall-seeded lentil yielded as much as 480 and 590 kg ha 21 greater than spring types in the NGP and PNW, respectively. Delayed fall seeding and reduced stubble height decreased yields more frequently in the NGP than in the PNW.

Soil-borne fungal diseases are among the most important factors, limiting the yield of grain legumes in many countries worldwide. Root rot, caused by Aphanomyces euteiches, Rhizoctonia solani, Fusarium solani and wilt, caused by several formae speciales of Fusarium oxysporum are the most destructive soil-borne diseases of pea, chickpea, lentil, fababean and lupin. The most effective control of these diseases is achieved through the use of resistant varieties. In this paper, recent advances in conventional and innovative screening methods for disease resistance are presented. Many grain legume accessions, which are maintained in national and international germplasm collections, have been evaluated for disease resistance and numerous resistant varieties have been released following incorporation of identified resistance genes from these sources. Recent identification of molecular markers tightly linked to resistance genes has greatly enhanced breeding programs by making marker assisted selection (MAS) possible and allowing the development of varieties with multiple disease resistance. Progress in the understanding of the biology of soil-borne fungal pathogens of grain legumes is also reviewed with particular reference to the genetic structure of their populations, diagnosis and host-pathogen interaction.

International audience; This paper aims at providing reliable and cost effective genotyping conditions, level of polymorphism in a range of genotypes and map position of newly developed microsatellite markers in order to promote broad application of these markers as a common set for genetic studies in pea. Optimal PCR conditions were determined for 340 microsatellite markers based on amplification in eight genotypes. Levels of polymorphism were determined for 309 of these markers. Compared to data obtained for other species, levels of polymorphism detected in a panel of eight genotypes were high with a mean number of 3.8 alleles per polymorphic locus and an average PIC value of 0.62, indicating that pea represents a rather polymorphic autogamous species. One of our main objectives was to locate a maximum number of microsatellite markers on the pea genetic map. Data obtained from three different crosses were used to build a composite genetic map of 1,430 cM (Haldane) comprising 239 microsatellite markers. These include 216 anonymous SSRs developed from enriched genomic libraries and 13 SSRs located in genes. The markers are quite evenly distributed throughout the seven linkage groups of the map, with 85% of intervals between the adjacent SSR markers being smaller than 10 cM. There was a good conservation of marker order and linkage group assignment across the three populations. In conclusion,we hope this report will promote wide application of these markers and will allow information obtained by different laboratories worldwide in diverse fields of pea genetics, such as QTL mapping studies and genetic resource surveys, to be easily aligned.

Pea ( Pisum sativum L.) has a genome of about 4 Gb that appears to share conserved synteny with model legumes having genomes of 0.2–0.4 Gb despite extensive intergenic expansion. Pea plant inventory (PI) accession 269818 has been used to introgress genetic diversity into the cultivated germplasm pool. The aim here was to develop pea bacterial artificial chromosome (BAC) libraries that would enable the isolation of genes involved in plant disease resistance or control of economically important traits. The BAC libraries encompassed about 3.2 haploid genome equivalents consisting of partially HindIII-digested DNA fragments with a mean size of 105 kb that were inserted in 1 of 2 vectors. The low-copy oriT-based T-DNA vector (pCLD04541) library contained 55 680 clones. The single-copy oriS-based vector (pIndigoBAC-5) library contained 65 280 clones. Colony hybridization of a universal chloroplast probe indicated that about 1% of clones in the libraries were of chloroplast origin. The presence of about 0.1% empty vectors was inferred by white/blue colony plate counts. The usefulness of the libraries was tested by 2 replicated methods. First, high-density filters were probed with low copy number sequences. Second, BAC plate-pool DNA was used successfully to PCR amplify 7 of 9 published pea resistance gene analogs (RGAs) and several other low copy number pea sequences. Individual BAC clones encoding specific sequences were identified. Therefore, the HindIII BAC libraries of pea, based on germplasm accession PI 269818, will be useful for the isolation of genes underlying disease resistance and other economically important traits.

International audience; Multi-service cover crops are used to provide ecosystem services, particularly for nitrogen management, such as “nitrate catching” and "green manuring" effects. Sowing cover crop mixtures including legumes and non-legumes have the advantage of combining the provision of both services related to N management thanks to phenomena of niche complementarity and/or facilitation in the capture of abiotic resources. When complementarities are optimized, these species mixtures can achieve both effects similarly to those provided by the average of mono specific cover crops, especially for nitrate catching. In addition, the complementarity for the access to light thanks to species having different aerial architectures and contrasted temporal complementarities enable them to obtain services in relay, in particular in the case of the longest fallow periods over mid-Spring. However, in order to achieve the targeted services, attention must be paid to limit competition between species in particular during early stages.