Pea Cultivars Research Articles

Effect of Pea Legumin-to-Vicilin Ratio on the Protein Emulsifying Properties: Explanation in Terms of Protein Molecular and Interfacial Properties.

In isolates from different pea cultivars, the legumin-to-vicilin (L:V) ratio is known to vary from 66:33 to 10:90 (w/w). In this study, the effect of variations in the L:V ratio on the pea protein emulsifying properties (emulsion droplet size (d3,2) vs protein concentration (Cp)) at pH 7.0 was investigated using a purified pea legumin (PLFsol) and pea vicilin fraction (PVFsol). Despite a different Γmax,theo, the interfacial properties at the oil-water interface and the emulsifying properties were similar for PLFsol and PVFsol. Hence, the L:V ratio did not affect the pea protein emulsifying properties. Further, PLFsol and PVFsol were less efficient than whey protein isolate (WPIsol) in stabilizing the emulsion droplets against coalescence. This was explained by their larger radius and thus slower diffusion. For this reason, the difference in diffusion rate was added as a parameter to the surface coverage model. With this addition, the surface coverage model described the d3,2 versus Cp of the pea protein samples well.

High-density linkage mapping and genetic dissection of resistance to broomrape (Orobanche crenata Forsk.) in pea (Pisum sativum L.).

Pea (Pisum sativum L.) is a widely cultivated legume of major importance for global food security and agricultural sustainability. Crenate broomrape (Orobanche crenata Forsk.) (Oc) is a parasitic weed severely affecting legumes, including pea, in the Mediterranean Basin and the Middle East. Previously, the identification of the pea line "ROR12", displaying resistance to Oc, was reported. Two-year field trials on a segregant population of 148 F7 recombinant inbred lines (RILs), originating from a cross between "ROR12" and the susceptible cultivar "Sprinter", revealed high heritability (0.84) of the "ROR12" resistance source. Genotyping-by-sequencing (GBS) on the same RIL population allowed the construction of a high-density pea linkage map, which was compared with the pea reference genome and used for quantitative trait locus (QTL) mapping. Three QTLs associated with the response to Oc infection, named PsOcr-1, PsOcr-2, and PsOcr-3, were identified, with PsOcr-1 explaining 69.3% of the genotypic variance. Evaluation of the effects of different genotypic combinations indicated additivity between PsOcr-1 and PsOcr-2, and between PsOcr-1 and PsOcr-3, and epistasis between PsOcr-2 and PsOcr-3. Finally, three Kompetitive Allele Specific PCR (KASP) marker assays were designed on the single-nucleotide polymorphisms (SNPs) associated with the QTL significance peaks. Besides contributing to the development of pea genomic resources, this work lays the foundation for the obtainment of pea cultivars resistant to Oc and the identification of genes involved in resistance to parasitic Orobanchaceae.

Challenges in pea breeding for tolerance to drought: Status and prospects

AbstractDrought is increasingly frequent in the context of climate change and is considered a major constraint for crop yield. Water scarcity can impair growth, disturb plant water relations and reduce water use efficiency. Pea (Pisum sativum) is a temperate grain legume rich in protein, fibre, micronutrients and bioactive compounds that can benefit human health. In reducing pea yield because of drought, the intensity and duration of stress are critical. This review describes several drought resistance mechanisms in pea based on morphology, physiology and biochemical changes during/after the water deficit period. Drought tolerance of pea can be managed by adopting strategies such as screening, breeding and marker‐assisted selection. Therefore, various biotechnological approaches have led to the development of drought‐tolerant pea cultivars. Finally, the main objective of the current research is to point out some useful traits for drought tolerance in peas and also, mention the methods that can be useful for future studies and breeding programmes.

First Report of Botrytis cinerea Causing Stem Rot on Pea (Pisum sativum L.) in China.

Pea (Pisum sativum L.) is one of the most important cool season legumes consumed as vegetable in the world. In March 2022, a severe stem rot was observed on pea cultivars in vegetative stage in Wuhan, Hubei Province, China (30°39' N, 114°66' E). The infection started on the lower stems, and the lesions were water soaked, then girdled the stem, resulting in wilting of the leaves. Eventually, the entire plant died, and some necrotic stems were covered with gray conidia. To investigate the causal agent, small pieces cut from diseased stems were surface sterilized with 2% NaOCl for 1 min, then incubated on potato dextrose agar (PDA) at 25°C for 3 days. Pure cultures were obtained by hyphal tip transfer and five isolates were studied further. Colonies initially appeared white, turned gray from the center, then became taupe with cottony aerial mycelia, and finally black hard, round or irregular sclerotia (0.92 to 5.34 × 0.86 to 4.42 mm, n = 20) developed. The sealing film of several plates were removed after 5 days, and abundant conidia were produced 3 days later. The conidia are terminally arranged at the end of long, grayish branched conidiophores, conidia are unicellular, hyaline and round or elliptical, (9.2 to 11.4 × 6.7 to 9.2 μm, n = 50), and the conidiophores are (10.7 to 13.0 μm × 760 to 1080 μm, n=20) in size. The morphological characteristics were consistent with descriptions of Botrytis cinerea (Li et al., 2016). Genomic DNA of the five isolates was extracted, and the internal transcribed spacer region (ITS), glyceraldehyde-3-phosphate dehydrogenase (G3PDH) gene, heat-shock protein 60 (HSP60) gene, and DNA-dependent RNA polymerase subunit II (RPB2) gene were amplified using the primers described by Aktaruzzaman et al. (2018). The sequences were deposited in GenBank (accession nos. ON533694 and ON566787-ON566790 for ITS; ON600613 to ON600617 for HSP60; ON600608 to ON600612 for G3PDH; ON600603 to ON600607 for RPB2). The BLASTn analysis of these sequences showed that the isolates had high similarity (99 to 100%) with other B. cinerea isolates. A phylogenetic tree was constructed by MEGA11, and our isolates clustered in the B. cinerea clade. In pathogenicity test, 2-week-old seedlings of pea cultivar 'Zhongqin1' were inoculated. Mycelial plugs (5 mm diameter) taken from a 3-day-old colony of each isolate were placed on the axil of a stipule at the 4th node of potted pea plants (n=5 per isolate), and PDA plugs were placed on the same location of control (n=3). Inoculated and control plants were kept in a humid plastic box at 23°C for 2 days, and then placed in a glasshouse. Symptoms with water-soaked lesions were observed on the inoculated plants after 2 days, stems showed soft rot and broke off after 3 to 5 days, disease symptoms similar to those in the field, while the controls remained healthy. The pathogen was re-isolated from the affected stems, fulfilling Koch's postulates. B. cinerea had been reported to cause foliar, pod, seed and stem rot of pea after flowering in many pea production regions in the world (Kraft and Pfleger, 2001). Pea was recorded as a host of B. cinerea in Zhejiang, Sichuan and Yunnan Provinces (Tai, F. L. 1979; Zhuang, W.-Y. 2005; Zhang, Z. 2006.), but there has been no detailed disease description and identification of pathogen. To our knowledge, this is the first report of B. cinerea causing stem rot on pea in vegetative stage in China. Since B. cinerea can infect pea at any developmental stage, it could have a high economic impact as green pea production increases in China.

FATTY ACID CONTENTS IN GRASS PEA ELITE LINES GROWN IN DIFFERENT ENVIRONMENTS

used as food and feeding. This study was conducted to characterize 15 superior grass pea genotypes grown in two locations (Antalya and Isparta) with respect to fatty acids, oil content and oil yield (Seed yield (g plant-1) × Oil content (%)). Grass pea seeds were sown in a randomized complete blocks design and an augmented experimental design in Antalya and Isparta, respectively. In the first step of study, the seeds were harvested on 25 May 2021 and 15 June 2021 in Antalya and Isparta respectively. Linoleic acid was the dominant fatty acid present in all grass pea genotypes, with its contents ranging from 39.38% (GP213) to 42.61% (GP150). Lauric, tridecanoic, pentadecanoic, palmitic and erucic acid were found at trace levels; meanwhile, oleic acid was determined as the second excess fatty acid in all genotypes, ranging from 19.12 to 21.41%. The amounts of saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids were calculated to be in the ranges of 23.82-28.57%, 19.63-22.36% and 51.06-54.43%, respectively. The oil ratios and oil yields of the genotypes varied between 0.59 and 0.80% and between 0.01 and 0.24 g plant-1. The significance t-test for mean values indicated that there were no significant differences between the locations for all fatty acid features and oil traits. These presented data showed these collection presents new superior lines with respect to oil traits

Assessment of genetic diversity in pigeon pea (Cajanus cajan) using micro satellite markers

An effective way to use germplasm for genetic improvement is to be aware of the genetic variation among crop genotypes. The objective of the present study was to assess the genetic diversity and population structure of 30 genotypes of pigeonpea from populations that were collected from various sources. In order to show a new structure within the pigeonpea genetic pool and to give crucial information for pigeonpea breeding operations, the predetermined study's goal was to define pigeonpea genotypes using a microsatellite marker technique. The genomic DNA of 30 pigeon pea genotypes were amplified with 20 SSR primers that produced 46 amplified bands, out of which 30 band were polymorphic (65.21%) and 16 bands were monomorphic (34.82%). Primer CcM 2977 generated a maximum number of amplified bands, of which 2 bands were polymorphic. Among 20 primers, only 8 primers showed the highest polymorphism (100%) and 5 primers were monomorphic in nature. Average of 2.30 bands per primer was amplified. The dendrogram constructed from the pooled data revealed six distinct clusters of which five were solitary. Cluster analysis of pigeon pea genotypes was based on Unweighted Pair Group Method with the Arithmetic average (UPGMA) method and the 30 pigeon pea genotypes were classified into six main groups. The present study indicated that the performance of SSR markers for the evaluation of genetic diversity could be beneficial for pigeon pea breeding. They could additionally be useful in genomic mapping research, developing pigeon pea cultivars with various genetics and reaping advanced crop productivity.

Effect of Organic Mulches on Yield, Water Productivity and Economy of Garden Pea Cultivars

Mulching techniques that are adaptive and extremely successful may be able to reduce the detrimental impacts of crop production and water stress on different varieties of peas in a climate change scenario. Field experiment was carried out in the Umroi region of Meghalaya during the rabi season (2020–2021) for this reason. This study used a split-plot design with three organic mulches as the main plot treatment and four pea types as the sub-plot treatments, which was replicated three times. The field trial showed that paddy straw mulch significantly outperformed both weed mulch and no mulch in terms of green pod yield, water productivity, and benefit cost ratio, with values of 89.33, 54.14 kg ha-1 mm-1, and 3.16, respectively.VM 12 greatly topped other cultivars in terms of green pod yield, water productivity, and benefit-cost ratio (BCR), with values of 89.78 kg ha-1, 54.41 kg ha-1 mm-1 and 3.33, respectively. The investigation showed that the best alternative agronomic strategy for achieving the maximum yield output of garden pea was paddy straw mulch, followed by weed mulch and un-mulch.

Aluminum-Immobilizing Rhizobacteria Modulate Root Exudation and Nutrient Uptake and Increase Aluminum Tolerance of Pea Mutant E107 (brz).

It is well known that plant-growth-promoting rhizobacteria (PGPRs) increase the tolerance of plants to abiotic stresses; however, the counteraction of Al toxicity has received little attention. The effects of specially selected Al-tolerant and Al-immobilizing microorganisms were investigated using pea cultivar Sparkle and its Al-sensitive mutant E107 (brz). The strain Cupriavidus sp. D39 was the most-efficient in the growth promotion of hydroponically grown peas treated with 80 µM AlCl3, increasing the plant biomass of Sparkle by 20% and of E107 (brz) by two-times. This strain immobilized Al in the nutrient solution and decreased its concentration in E107 (brz) roots. The mutant showed upregulated exudation of organic acids, amino acids, and sugars in the absence or presence of Al as compared with Sparkle, and in most cases, the Al treatment stimulated exudation. Bacteria utilized root exudates and more actively colonized the root surface of E107 (brz). The exudation of tryptophan and the production of IAA by Cupriavidus sp. D39 in the root zone of the Al-treated mutant were observed. Aluminum disturbed the concentrations of nutrients in plants, but inoculation with Cupriavidus sp. D39 partially restored such negative effects. Thus, the E107 (brz) mutant is a useful tool for studying the mechanisms of plant-microbe interactions, and PGPR plays an important role in protecting plants against Al toxicity.

Influence of Biofungicides Containing Microorganisms Such as Pythium oligandrum and Bacillus subtilis on Yield, Morphological Parameters, and Pathogen Suppression in Six Winter Pea Cultivars

Field peas (Pisum sativum L.) are a valuable source of protein and help to support crop biodiversity in a sustainable agriculture system. To maintain varied crop rotation in sustainable production, it is advisable to include the winter form of pea, which is an excellent alternative to the spring form. However, the prolonged development of winter peas when weather patterns are unfavorable can adversely affect the morphological features and the health of the plants. The literature lacks studies on this issue. The objective of this study was to evaluate the morphological characteristics, yield, and canopy health of selected cultivars of winter peas. The study was conducted at the Prusy Experimental Station of the University of Agriculture in Krakow, located near Krakow, Poland (50°07′28″ N, 20°05′34″ E), during two growing seasons. The study evaluated six cultivars of winter peas and two means of protecting the canopy, with biological products containing Pythium oligandrum (Polyversum WP) or Bacillus subtilis (Serenade ASO). The yield, yield structure, efficiency of N uptake, and health of the plants were assessed. Crop protection treatments using Polyversum WP and Serenade ASO were shown to effectively protect winter peas against Fusarium wilt, which occurred only in the Specter and Arkta cultivars sprayed with Serenade. Polyversum WP increased the productivity of winter peas on average by 0.5 t ha−1 and increased the efficiency of nitrogen uptake on average by 10 kg ha−1 in comparison to the control. The Aviron and Arkta cultivars are recommended for cultivation in the conditions of Central Europe due to their high yield potential, high efficiency of nitrogen uptake, and good canopy health.

Characterization of CcTFL1 Governing Plant Architecture in Pigeon pea (Cajanus cajan (L.) Millsp.).

Growth habits are among the essential adaptive traits acted upon by evolution during plant speciation. They have brought remarkable changes in the morphology and physiology of plants. Inflorescence architecture varies greatly between wild relatives and cultivars of pigeon pea. The present study isolated the CcTFL1 (Terminal Flowering Locus 1) locus using six varieties showing determinate (DT) and indeterminate (IDT) growth habits. Multiple alignments of CcTFL1 sequences revealed the presence of InDel, which describes a 10 bp deletion in DT varieties. At the same time, IDT varieties showed no deletion. InDel altered the translation start point in DT varieties, resulting in the shortening of exon 1. This InDel was validated in ten varieties of cultivated species and three wild relatives differing in growth habits. The predicted protein structure showed the absence of 27 amino acids in DT varieties, which was reflected in mutant CcTFL1 by the absence of two α-helices, a connecting loop, and shortened β-sheet. By subsequent motif analysis, it was found that the wild-type protein had a phosphorylation site for protein kinase C, but the mutant protein did not. In silico analysis revealed that the InDel-driven deletion of amino acids spans, containing a phosphorylation site for kinase protein, may have resulted in the non-functionality of the CcTFL1 protein, rendering the determinate growth habit. This characterization of the CcTFL1 locus could be used to modulate growth habits through genome editing.

Assessment and quantification of some short term ecosystem services in garden pea field

It is necessary to classify, quantify, and evaluate ecosystem services (ES) for understanding related ecosystem value. Garden pea (Pisums ativum L.), also called pea, herbaceous annual plant in the family leguminous, grown nearly worldwide for edible seeds. It contributes to the sustainability of the agricultural ecosystems. However, there is no information about the provision and consumption of ES in garden pea fields. The main objective of this study was to provide a first evidence base from ES provided by garden pea fields. Therefore, we developed a quantitative framework for assessing and quantifying ES of four different varieties of garden pea. For this purpose, a field experiment was carried out in the research farm of Gorgan University of Agricultural Sciences and Natural Resources (northeast of Iran), during 2019–2020. In this study, we developed a framework for quantifying of ES based on the modified Millennium Ecosystem Assessment (MEA). The results showed that garden pea cultivation increased microbial respiration, soil organic matter, and carbon accumulation. Based on the results, varieties had significant effects on soil carbon accumulation. Peas Wolf and Pea Wolf cultivars with 1206.6 kg/ha carbon accumulation had the highest amount, and Reyna cultivar with −1876.9 kg/ha carbon accumulation had the lowest value. In this experiment, Peas Wolf and Utrillo cultivars provided more ES in terms of dry weight, the number of nodule, and root volume as nitrogen biofixation potential. In general, Peas Wolf compared to Utrillo cultivar was more successful in providing regulating services. However, Utrillo cultivar provided more provision services (14,520 kg/ha green yield, 23,680 kg/ha green biomass and 23,62% protein). In addition, different cultivars of garden pea had positive effects on the transfer of carbon from the atmosphere to the soil.

Effects of Different Temperatures on the Biology of Acyrthosiphon pisum on Different Pea Cultivars

The research studies were carried out at Key Laboratory of Entomology, Northwest A & F University, Yangling, Shaanxi under 60±5% Relative Humidity, light: dark photoperiod at 14h: 10h to assess different range temperature effects on the population of Acyrthosiphon pisum on different pea cultivars during, 2018. The results indicated that the shortest pea aphid nymph development period up to (5.75±0.31 days) were lasted on cv. Feizai-3 at 36oC and longest (9.38±0.34 days) were noted on cv. Nenzao at 30oC. The shortest A. pisum adult development period (4.16±0.20 days) were recorded on cv. Hanyi-401 at 39oC and the longest (5.72±0.33 days) on cv. Hanyi-401 at 30oC. The shortest A. pisum longevity period (5.43±0.72 days) were recorded on cv. Feizai-3 at 39oC and longest (11.83±0.72 days) on cv. Hanyi-401 at 30oC. The shortest A. pisum oviposition period (3.61±0.32 days) were recorded on cv. Hanyi-401 at 33oC and longest (4.41±0.35 days) on Guangzhong-604 at 36oC. The minimum nymph survival period was counted (0.23±0.07) on Guangzhong-604 at 36oC and maximum on cv. Hanyi-401 (0.73±0.08) at 30oC. According to the DMRT, Test, non-significant difference was reported in all the above parameters between the cultivars in all temperature regimes. The present study suggests that temperature fluctuations also affect on the life expectancy of A. pisum. In future endeavors more work should be carried out to restrict the pest population of sap-sucking insects to secure the legumes varieties

Role of Salicylic Acid in the Alleviation of Salt Stress on Pea Cultivars Using Growth, Biochemical and Physiological Attributes

Role of Salicylic Acid in the Alleviation of Salt Stress on Pea Cultivars Using Growth, Biochemical and Physiological Attributes

Molecular characteristics and pathogenicity of infectious cDNA clones of the Chinese isolates of pea enation mosaic virus 1 and pea enation mosaic virus 2

The pea enation mosaic disease (PEMD) causes significant yield losses worldwide. PEMD is caused by two taxonomically unrelated but symbiotic viruses, pea enation mosaic virus 1 (PEMV-1) and pea enation mosaic virus 2 (PEMV-2). In this study, the complete genomes of four isolates of PEMV-1 and PEMV-2 from Yunnan Province of China were determined and analyzed. The four isolates of PEMV-1 or PEMV-2 shared ≥ 98.7% nucleotide sequence identities at whole genome level. The four Chinese PEMV-1 isolates were most closely related to PEMV-1-Ramsey-1 with nucleotide sequence identities of 97.8–98.0%, while the four Chinese PEMV-2 isolates were most closely related to PEMV-2-DSMZ PV-0088, with nucleotide sequence identities of 94.3–94.5%. The two full-length infectious cDNA clones of the Yunnan-Dali isolates of the two viruses (PEMV-1-YDL and PEMV-2-YDL) were constructed. Co-inoculation of PEMV-1-YDL and PEMV-2-YDL in pea seedlings caused systemic infection, with typical enation and mosaic symptoms on new leaves after inoculation, while the inoculated Nicotiana benthamiana plants showed curling symptoms. Inoculation of pea seedlings with either PEMV-1-YDL or PEMV-2-YDL did not cause obvious symptoms on the new leaves. It has been known that PEMV-2 helps the systemic infection of PEMV-1. However, our results showed that PEMV-1-YDL alone could cause a systemic infection. The pathogenicity of the two infectious clones was tested on different pea cultivars, and some cultivars were PEMD-tolerant. This is the first report of the infectious clones constructed from the Chinese isolates of PEMV-1 and PEMV-2. The current approach will facilitate determination of the synergistic relationship between PEMV-1 and PEMV-2 and their interactions with the host plant by reverse genetic analysis.

Registration of ‘ND Victory’ green field pea

Abstract‘ND Victory’ (Reg. no. CV‐31, PI 701908) is the first semi‐leafless, green cotyledon field pea cultivar (Pisum sativum L.) developed by the North Dakota State University Pulse Crops Breeding Program and approved for release by the North Dakota Agricultural Experiment Station. It has white flowers, opaque seed coat, and smooth, round seed. It is semi‐dwarf, with lodging score of 3.3/9 and canopy height of 57 cm. Based on 30 environments (location‐year) of replicated yield trials in North Dakota, seed yield of ND Victory (2847 kg ha−1) was similar to commercial cultivar ‘CDC Striker’ (2819 kg ha−1) but significantly greater than ‘Cruiser’ (2653 kg ha−1) and ‘Aragorn’ (2639 kg ha−1) by 7.3 and 7.9%, respectively. ND Victory was also tested across 14 environments in Montana, where it had an average seed yield of 3264 kg ha−1, which was similar to ‘Hampton’ (3355 kg ha−1) but significantly greater than Aragorn (3110 kg ha−1) by 4.9%. ND Victory matures in approximately 90 days. ND Victory is a high protein cultivar, with protein content of 25.2%, exceeding the premium protein threshold of 24%. ND Victory (20%) is resistant to powdery mildew and performed similarly with resistant check ‘Spider’ (15%) and had significantly lower disease severity than ‘Salamanca’ (97%, susceptible check) and CDC Striker (82%). In irrigated field trials conducted under high Ascochyta blight pressure, ND Victory (5%) had lower disease severity than ‘AC Agassiz’ (10%) and CDC Striker (14%). ND Victory and CDC Striker exhibited similar response but significantly lower severity than AC Agassiz to Fusarium root rot inoculated with multiple Fusarium species pathogenic to pea.

Organic dry pea (Pisum sativum L.): A sustainable alternative pulse-based protein for human health.

Dry pea (Pisum sativum L.) is a cool-season food legume rich in protein (20-25%). With increasing health and ecosystem awareness, organic plant-based protein demand has increased; however, the protein quality of organic dry pea has not been well studied. This study determined the genetic variation of individual amino acids (AAs), total AAs (liberated), total protein, and in vitro protein digestibility of commercial dry pea cultivars grown in organic on-farm fields to inform the development of protein-biofortified cultivars. Twenty-five dry pea cultivars were grown in two USDA-certified organic on-farm locations in South Carolina (SC), USA, for two years (two locations in 2019 and one in 2020). The concentrations of most individual AAs (15 of 17) and the total AA concentration significantly varied with dry pea cultivar. In vitro protein digestibility was not affected by the cultivar. Seed total AA and protein for dry pea ranged from 11.8 to 22.2 and 12.6 to 27.6 g/100 g, respectively, with heritability estimates of 0.19 to 0.25. In vitro protein digestibility and protein digestibility corrected AA score (PDCAAS) ranged from 83 to 95% and 0.18 to 0.64, respectively. Heritability estimates for individual AAs ranged from 0.08 to 0.42; principal component (PCA) analysis showed five significant AA clusters. Cultivar Fiddle had significantly higher total AA (19.6 g/100 g) and digestibility (88.5%) than all other cultivars. CDC Amarillo and Jetset were significantly higher in cystine (Cys), and CDC Inca and CDC Striker were significantly higher in methionine (Met) than other cultivars; CDC Spectrum was the best option in terms of high levels of both Cys and Met. Lysine (Lys) concentration did not vary with cultivar. A 100 g serving of organic dry pea provides a significant portion of the recommended daily allowance of six essential AAs (14-189%) and daily protein (22-48%) for an average adult weighing 72 kg. Overall, this study shows organic dry pea has excellent protein quality, significant amounts of sulfur-containing AAs and Lys, and good protein digestibility, and thus has good potential for future plant-based food production. Further genetic studies are warranted with genetically diverse panels to identify candidate genes and target parents to develop nutritionally superior cultivars for organic protein production.

Combining a multi-environment trial and a diagnosis method to assess potential yield and main limiting factors of three highly different pea types

The evaluation of varieties of cultivated species is based on the implementation of multi-environmental trials that show high performances or strong limitations in some environments. To know the cause of these limitations, and to reason the adaptation of varieties to different environments, we propose a combined approach between the classical analysis of experimental results and a diagnostic approach using the DiagVar tool, which allows to assess the impact of limiting factors in each trial, the potential yield and the sensitivity of cultivars to those factors. This procedure is applied in a large and diversified field trial network including eight locations and three years to the comparison of two to four cultivars of the three agronomical pea types: spring peas, hr-winter peas (non-reactive to photoperiod) and Hr-winter peas (reactive to photoperiod).Estimates of potential yields from DiagVar for the three pea types were consistent with the experimental results, with higher values for hr-winter cultivars than for spring and Hr-winter ones. We shed light on specific limiting factors for each type, some of them being rarely quantified previously, which allows us to better target specific regions or environments for each pea type. Thus, spring types were more impacted by early limiting factors (loss of plants, low temperatures and radiation, lack of water, leading to reduced growth) and end-of-cycle stresses (high temperatures, water stress). Diseases had higher impacts on both winter types. Here we show for the first time that the lack of solar radiation affected particularly hr-winter type and the low crop nitrogen status affected more frequently spring peas. These results highlight the interest of carrying out an agronomic diagnosis in the analysis of varietal multi-environment trials, revealing the most important limiting factors to take into account while breeding new pea cultivars, particularly limiting factors that are difficult to directly observe. This method proves to be reliable and informative for breeders, technicians and agricultural advisors to discuss the adaptation of varieties to specific environment.

Resistance in pea (Pisum sativum) genetic resources to the pea aphid,Acyrthosiphon pisum

AbstractThe pea aphid (PA),Acyrthosiphon pisum(Harris) (Hemiptera: Aphididae), can cause significant damage to dry and green peas,Pisum sativumL. (Fabaceae). Identifying pea lines with resistance to PA is important to advance available control measures. This research identified lines and putative genes with resistance to PA in the USDAPisum sativumCollection located in Pullman, WA, USA, consisting of 301 lines collected worldwide. Eight commercial pea cultivars were also evaluated. A cluster analysis based on the mean number of adults, nymphs, and total aphids that developed on lines 10 days after the start of infestation by a single adult aphid per plant identified six clusters. Cluster 2, consisting of 48 lines, had the lowest aphid fecundity of all clusters with 2.1 adults, 7.3 nymphs, and 9.4 total aphids produced on average. ‘Lifter’ was the most resistant line based on low aphid fecundity. Lifter is a white‐flowered green dry pea cultivar that can advance PA resistance in food‐type peas. Genotyping by sequencing based on single‐nucleotide polymorphisms (SNPs) were used in genome‐wide association mapping to locate genes or quantitative trait loci (QTL) linked to PA resistance in which three, nine, and six SNPs were associated with resistance to adult, nymph, and total number of PAs that developed on lines, respectively. Seventeen candidate genes were identified in response to PA resistance. The results can effectively be used in breeding programs to target specific genomic regions with PA resistance and in traditional breeding using resistant lines as parents.

A simple method for creating transgenic pea hairy roots using a Japanese pea cultivar and a Japanese Rhizobium radiobacter strain.

Pea (Pisum sativum) is an agriculturally important leguminous crop cultivated worldwide. It is also the plant from which phytoalexin was isolated for the first time. Several studies have investigated gene functions using pea hairy root culture systems. However, the procedures for producing hairy roots are relatively complicated and only a few pea cultivars and Rhizobium strains have been used. In this study, we established a simple method for generating transgenic hairy roots using a pea cultivar and a Rhizobium strain available in Japan. The transformation efficiency for the transgenic hairy roots (approximately 14%) was calculated on the basis of GFP fluorescence because the binary vector used in this study carried a GFP cassette as a marker. Furthermore, we confirmed that the production of the phytoalexin (+)-pisatin was induced by a copper dichloride treatment, indicating that this system can be used to characterize the biosynthesis of (+)-pisatin, which is a compound with a unique pterocarpan structure. Interestingly, some of the hairy roots turned into crown galls during the culture period. In summary, our simple method enables the production of transgenic pea hairy roots using biological materials accessible in Japan. The generated hairy roots can be used to elucidate the molecular mechanisms underlying (+)-pisatin biosynthesis as well as hairy root/crown gall formation.

Maintaining and Improving Peas (Pisum sativum L.) CV. Master Pea (Local Cultivar) Using UPOV Descriptor and Multivariate Analysis in the Vegetable Seed Production Field

Although peas cv. master pea was registered more than 25 years ago in Egypt, this variety showed a remarkable superiority over the varieties grown in all governorates of Egypt in terms of production, quality, and environmental adaptation to climate changes. This study intends to assess this cultivar's genetic and environmental traits, and to determine the degree of its deterioration over time to develop an appropriate plan for the maintenance, improvement, and conservation of this strategic variety to withstand changes in climatic conditions in Egypt. Many types of research have been conducted on the study and production of new varieties and lines of peas in Egypt; yet there is a dearth of multivariate analysis as a technique that can combine all variances for all examined qualities using statistics that rely on the algebra of matrices and extract statistical markers from which the researcher can make an appropriate selection program within cultivars without causing genetic erosion. The present experiment was conducted to achieve the following objectives: to monitor the performance of growth traits in the Master pea cultivar using multivariate analysis and UPOV descriptor; evaluation of yield characteristics, seed yield, and quality of Master pea cultivar using multivariate analysis and UPOV descriptor. In this study, one of the most important results obtained was that the phenotypic diversity within the population (measured using the UPOV descriptor) is an important aspect that reflects genetic diversity and the ability of this genetic diversity to withstand changes in the environment. Natural selection - over the many years of the inherited varieties of countries and societies - affects the diversity of phenotypic traits among the individuals of the population. It can be concluded from this study that the phenotypic traits identified in the UPOV descriptor and data analysis using multivariate analysis can show differences between lines within cultivars. Therefore, we recommend taking advantage of the UPOV descriptor and multivariate analysis as a successful way to obtain differences and relationships between lines in conservation, maintenance, and improvement programs for ancient and promising cultivars in the Arab Republic of Egypt.