Pea Cultivars Research Articles

Differential gene expression analyses of ten defence response genes during Fusarium wilt infection in resistant and susceptible pigeonpea cultivars

The present study was undertaken to partly understand the molecular mechanism of defence response during pigeonpea-Fusarium udum interaction. To study the response of defence related gene expression using reverse transcription quantitative real time PCR (RT-qPCR), roots of resistant and susceptible pigeonpea cultivars were infected with F. udum pathogen and samples were collected at 2, 24, 48, and 72 h after inoculation (HAI). PR2, PR10, PAL2, CHS8, IFS1, F3H, LOX, ADC, SPDS, and SPMS were amongst the ten defence response genes studied. The major changes observed in gene expression for all the ten genes are as follows: (i) Out of the ten genes, the expression of three genes, PR2, PR10, and CHS8, peaked at 48 HAI in resistant cultivars compared to susceptible cultivars (ii) the expression of two genes, IFS1 and F3H, was highly induced at all stages in resistant cultivars, while some genotypic differences were observed in susceptible cultivars (iii) the expression of the LOX gene increased only during the early stages at 2 HAI but decreased at later stages in resistant cultivars (iv) In resistant cultivars, the expression of three genes involved in polyamine synthesis, namely ADC, SPDS, and SPMS, peaked at 24 HAI compared to susceptible cultivars. Overall, increased gene expression was found mostly at earlier stages of infection, indicating that these genes are important in providing early resistance to F. udum infection in pigeon pea cultivars. The LOX gene, which codes for the lipooxygenase enzyme, appears to play a role in conferring susceptibility to pigeonea cultivars against F. udum infection, though more research is needed. Further validation studies of all ten genes using overexpression or RNAi technology will provide more information about their roles in the pigeonpea-F.udum interaction.

Evaluation of vegetable pigeonpea [Cajanus cajan (L.) Millsp] genotypes for yield stability

BackgroundVegetable pigeonpea is an important food security crop in the marginal dry areas of the Eastern region of Kenya. The adaptation and stability of vegetable pigeonpea genotypes across different agro-ecological zones in Kenya are not adequately determined. The objective of this study was to evaluate the yield stability and adaptability of genotypes: KAT 60/8, MZ 2/9, ICEAP 00554, ICEAP 00557 and KIONZA based on additive main effects and multiplicative interactions (AMMI) and Genotype plus genotype by environment (GGE biplot) analysis.MethodsEvaluation of vegetable pigeonpea Genotypes was conducted at Kiboko, Katumani and Kambi ya Mawe research stations located in Eastern region and University of Nairobi Field station in central region of Kenya. The genotypes were planted in a Randomized Complete Block design (RCBD), replicated three times at all sites. Rainfall at Kiboko and Kabete were supplemented with irrigation, using sprinklers, for a total of 38 times, providing 832 mm of water. The crop was protected from pests by the application of broad-spectrum, non-systemic, pyrethroid alpha-cypermethrin and dimethoate, after field scouting. All other agronomic and cultural practices were done as recommended for each location.ResultsCombined analysis of variance (ANOVA) at six environments revealed highly significant (P < 0.01) variations in G × E interactions for yield (Kg/ha), 100 Seed mass (g/100 seed), days to flower and maturity (P < 0.05). AMMI model for grain yield interaction principal components analysis (IPCA), explained 96.5% of the total yield variation. The cultivar MZ 2/9 and KAT 60/8 recorded a lower IPCA1, indicating a wider adaptation and stability. Kambi ya Mawe, Katumani and Kiboko had higher IPCA1, indicating greatest interactive environments and adapted genotypes. Kambi ya Mawe, was the most ideal location for evaluating pigeonpea genotypes. While KIONZA was the most ideal genotype for yield performance, MZ 2/9 and KAT 60/8 were most stable with a wider adaptation.ConclusionKIONZA should be used as a reference genotype, while Kambi ya Mawe would be the most ideal location for testing the vegetable pigeonpea genotypes in breeding research. Increased deployment of stable pigeon pea cultivars, MZ 2/9 and KAT 60/8 would enhance food security in the dry areas of Eastern regions of Kenya. These genotypes need to be promoted with farmers for wider adoption in the Eastern region of Kenya.

Short Communication: Latent Detection of Downy Mildew (Peronospora pisi) in Bioassays against Pisum sativum

Downy mildew of peas is caused by the obligate parasite Peronospora pisi, which occurs sporadically throughout temperate pea-growing regions across the world. To screen pea lines against this biotrophic pathogen, a suitable and reproducible in vitro method using living plant material is required. Field screening can be influenced by environmental factors, thus giving variable results. The aim of this study was to develop a method that could reliably be used to screen pea cultivars against P. pisi in a laboratory setting. A range of bioassays were used to test various methods of inoculation, utilizing sporangia and naturally infested soil. Latent infection was achieved by planting seeds in soil collected from a site with a known history of P. pisi infection and directly inoculating young pea plants with sporangia. Out of the 108 plants which survived the experimental period, only two plants expressed visible signs of disease; however, through a two-step nested PCR process we detected latent infection in 24 plants. This research highlights the importance of considering the presence of latent infection when screening pea lines against downy mildew.

Effect of Genotype, Year, and Location on the Proximate Composition and In Vitro Protein Quality of Select Pea Cultivars

Peas are grown around the world and are utilized for both human and animal consumption. The variability in the nutritional composition of peas can be attributed to multiple factors, including the genetic background and environmental conditions. This study investigated six seed nutritional parameters across 12 cultivars grown in four locations during four years. A subset of these cultivars were then assayed for amino acid composition and in vitro protein digestibility. The genotype and year of cultivation had the greatest impact on seed quality parameters. The in vitro protein quality of peas was also significantly affected by the genotype and year of cultivation. While the year of cultivation cannot be controlled, identifying the seed characteristics of common cultivars is essential in selecting the optimal cultivar for individual product development.

Isolation and characterization of plant growth promoting rhizobacteria isolated from organically grown high yielding pole type native pea (Pisum sativum L.) variety Dentami of Sikkim, India.

Organic farming is an eco-friendly and sustainable farming practice that enhances soil fertility and helps in improving soil quality. But with the commencement of more sophisticated advances in agricultural techniques, organic farming has gradually become limited in the world. Culture-dependent plant growth-promoting bacterial isolates were isolated from the bulk and rhizospheric soil, of the native high yielding pole type organic pea (Pisum sativum L.) cultivar Dentami of Dentam, West Sikkim, India. Based on the 16S rRNA gene sequencing identification of these isolates, it was found that from the bulk soil, Actinobacteria (58%) was the dominant phyla followed by Firmicutes (28%), and Proteobacteria (14%). In the rhizospheric soil it was dominated by Proteobacteria (56%), followed by Firmicutes (33%), and Bacteriodetes (11%). A total of 40 bacterial isolates were initially screened for the plant growth-promoting (PGP) activity and out of them only four bacterial isolates i.e., Bacillus cereus P8, Arthrobacter woluwensis DP2, Paenarthrobacter nitroguajacolicus PP3, and Bacillus mycoides PP10 with accession numbers MN589697, MN559516, MN519462 and MN589696 respectively were found to possess higher PGP activity (i.e. phosphorous, potassium solubilization and nitrogen-fixing activity) as compared to the other bacteria present in the soil. Based on the indole-3-acetic acid (IAA) quantitative assay and siderophore production assay, it was found that Bacillus cereus (MN589697) produced the highest IAA (65.5µg mL-1) and siderophore (71%) when compared with the other isolates. The statistical correlation suggests that pH and available phosphorus were the strongest influencing factors for the distribution of Proteobacteria in the rhizospheric soil. The results indicate that these isolates can be potential plant growth promoter under the agro-climatic conditions of Sikkim, India. To the best of our knowledge the present study is the first report of its kind and showcases significant findings pertaining to the assessment of diversity, isolation and identification of plant growth-promoting rhizobacteria of organic pea grown in Sikkim.

Three Sclerotinia species as the cause of white mold on pea in Chongqing and Sichuan of China

White mold of pea caused by Sclerotinia sclerotiorum is a common disease in China. However, we discovered that the diverse Sclerotinia species could cause white mold on pea plants in Chongqing and Sichuan of China during recent disease surveys. Thus, the objective of this study was to confirm the causal agents from diseased pea plants. The obtained isolates of white mold from Chongqing and Sichuan were identified by morphological characters and molecular characterization to determine the pathogen species, and their pathogenicity was confirmed on pea through completing Koch's postulates. Fungal isolates of Sclerotinia-like were obtained from diseased plants or sclerotia. Based on morphological characteristics and molecular characterization, 30 isolates were identified to three species, six isolates as S. minor, seven as S. sclerotiorum, and 17 as S. trifoliorum. In pathogenicity tests on pea cultivars Zhongwan 4 and Longwan 1, all 30 isolates caused typical symptoms of white mold on the inoculated plants, and the inoculated pathogens were re-isolated from the diseased plants. This study confirmed that white mold of pea was caused by three Sclerotinia species, S. sclerotiorum, S. minor and S. trifoliorum in Chongqing and Sichuan. It is the first report that S. minor and S. trifoliorum cause white mold of pea in Southwest China.

Dynamics of Fusarium Mycotoxins and Lytic Enzymes during Pea Plants' Infection.

Fusarium species are common plant pathogens that cause several important diseases. They produce a wide range of secondary metabolites, among which mycotoxins and extracellular cell wall-degrading enzymes (CWDEs) contribute to weakening and invading the host plant successfully. Two species of Fusarium isolated from peas were monitored for their expression profile of three cell wall-degrading enzyme coding genes upon culturing with extracts from resistant (Sokolik) and susceptible (Santana) pea cultivars. The extracts from Santana induced a sudden increase in the gene expression, whereas Sokolik elicited a reduced expression. The coherent observation was that the biochemical profile of the host plant plays a major role in regulating the fungal gene expression. In order to uncover the fungal characteristics in planta, both pea cultivars were infected with two strains each of F. proliferatum and F. oxysporum on the 30th day of growth. The enzyme activity assays from both roots and rhizosphere indicated that more enzymes were used for degrading the cell wall of the resistant host compared to the susceptible host. The most commonly produced enzymes were cellulase, β-glucosidase, xylanase, pectinase and lipase, where the pathogen selectively degraded the components of both the primary and secondary cell walls. The levels of beauvericin accumulated in the infected roots of both cultivars were also monitored. There was a difference between the levels of beauvericin accumulated in both the cultivars, where the susceptible cultivar had more beauvericin than the resistant one, showing that the plants susceptible to the pathogen were also susceptible to the toxin accumulation.

Comparison of the Proximate Compositions, Nutritional Minerals, Pasting Properties, and Aroma Differences of Flours from Selected Yellow Pea Cultivars Grown across the Northern Great Plains

Comparison of the Proximate Compositions, Nutritional Minerals, Pasting Properties, and Aroma Differences of Flours from Selected Yellow Pea Cultivars Grown across the Northern Great Plains

Comparative analysis of the physicochemical composition of pea cultivars

Peas are an inexpensive nutrient source. Basic information about variation in physicochemical composition is required to manage breeding programs and postharvest operations effectively. Different properties were measured in seeds from 16 promising pea genotypes to study variability between lines, degree of genetic parameters, and associations among different traits. Seed weight and diameter, pH, and titratable acidity showed the highest values for broad-sense heritability and the most negligible differences between the phenotypic and genetic coefficient of variation, indicating that these traits’ variability was predominately due to genotypic differences. Genotypes had a wide-range profile that could be related to morphological and physiological properties. Yellow varieties showed superior values for weight and sizes (27.84 g; 0.57 cm) and small changes in diameter after hydration (48.35 %), while wrinkled varieties showed inferior moisture content (9.54 %), higher hydration capacity (1,314.66 g H2O/kg seeds), and protein content (28.88 %). Cuarentina and B315 were the more resistant and firmer materials; B315 also had the highest water hydration capacity, which would be appropriate for canning. Polyacrylamide gels demonstrated differences in protein composition; Gypsi contained more legumin (47.27 %) than the other genotypes, which is more beneficial nutritionally, and contained less convicilin (7.06 %), making it suitable for the food industry. Using accelerated aging, we studied color changes due to storage and established that the Viper line was highly tolerant to it. We could identify lines that may be exploited by industry or quality breeding programs.

Yield Components Stability Assessment of Peas in Conventional and Low-Input Cultivation Systems

The primary purpose of this study was to explore yield stability of pea (Pisum sativum L.) cultivars based on stability index, with specific aim at studying cultivar behavior regarding yield of peas under both conventional and low-input cultivation systems. Five cultivars of peas were used in a strip-plot design. Correlations showed a significant positive relation between seed yield and some other traits. Indirect seed yield improvement may be implemented by improving pod length, which generally showed high stability indices in Greek mega-environment. Comparisons between conventional and low-input farming systems generally did not affect stability estimations, but revealed cultivars that exhibited stable performance, even in low-input farming systems. The additive main effects and multiplicative interaction (AMMI) biplot analysis, genotype by environment interaction (GGE) biplot analysis and analysis of variance (ANOVA) showed statistically significant differences between genotypes and environments, and also the farming system. This way, we have certain cultivars of peas to recommend for specific areas and farming system, in order to achieve the most stable performance. Vermio proved to be a stable cultivar for seed yield performance, in Giannitsa, Trikala and Kalambaka area, in low-inputs farming systems, while Olympos was the best in Florina area and low-input farming.

AAC Profit field pea

AAC Profit is a semi-leafless, yellow cotyledonary field pea (Pisum sativum L.) cultivar developed at Agriculture and Agri-Food Canada Lacombe Research and Development Centre, Lacombe, Alberta, Canada. It has a maturity of 101 d, thousand-seed weight of 218 g, and a lodging score of 4.1 on the scale of 1–9 (1 = upright, 9 = prostrate). The seed crude protein content of AAC Profit is 24.5%. AAC Profit is resistant to powdery mildew (caused by Erysiphe pisi), and moderately susceptible to mycosphaerella blight (caused by Mycosphaerella pinodes) and fusarium wilt (caused by Fusarium oxysporum).

First characterization of a newly emerging phytopathogen, Sclerotinia sclerotiorum causing white mold in pea.

Pea (Pisum sativum L.) is of global importance as a food crop for its edible pod and seed. A new disease causing the tan to light brown blighted stems and pods has occurred in pea (P. sativum L.) plants in Chapainawabganj district, Bangladesh. A fungus with white-appressed mycelia and large sclerotia was consistently isolated from symptomatic tissues. The fungus formed funnel-shaped apothecia with sac-like ascus and endogenously formed ascospores. Healthy pea plants inoculated with the fungus produced typical white mold symptoms. The internal transcribed spacer sequences of the fungus were 100% similar to Sclerotinia sclerotiorum, considering the fungus to be the causative agent of white mold disease in pea, which was the first record in Bangladesh. Mycelial growth and sclerotial development of S. sclerotiorum were favored at 20°C and pH 5.0. Glucose was the best carbon source to support hyphal growth and sclerotia formation. Bavistin and Amistar Top inhibited the radial growth of the fungus completely at the lowest concentration. In planta, foliar application of Amistar Top showed the considerable potential to control the disease at 1.0% concentration until 7 days after spraying, while Bavistin prevented infection significantly until 15 days after spraying. A large majority (70.93%) of genotypes, including tested released pea cultivars, were susceptible, while six genotypes (6.98%) appeared resistant to the disease. These results on identification, characterization, host resistance, and fungicidal control of white mold could be valuable to achieve improved management of a new disease problem for pea cultivation.

Identification of Root Rot Resistance QTLs in Pea Using Fusarium solani f. sp. pisi-Responsive Differentially Expressed Genes.

Pisum sativum (pea) yields in the United States have declined significantly over the last decades, predominantly due to susceptibility to root rot diseases. One of the main causal agents of root rot is the fungus Fusarium solani f. sp. pisi (Fsp), leading to yield losses ranging from 15 to 60%. Determining and subsequently incorporating the genetic basis for resistance in new cultivars offers one of the best solutions to control this pathogen; however, no green-seeded pea cultivars with complete resistance to Fsp have been identified. To date, only partial levels of resistance to Fsp has been identified among pea genotypes. SNPs mined from Fsp-responsive differentially expressed genes (DEGs) identified in a preceding study were utilized to identify QTLs associated with Fsp resistance using composite interval mapping in two recombinant inbred line (RIL) populations segregating for partial root rot resistance. A total of 769 DEGs with single nucleotide polymorphisms (SNPs) were identified, and the putative SNPs were evaluated for being polymorphic across four partially resistant and four susceptible P. sativum genotypes. The SNPs with validated polymorphisms were used to screen two RIL populations using two phenotypic criteria: root disease severity and plant height. One QTL, WB.Fsp-Ps 5.1 that mapped to chromosome 5 explained 14.8% of the variance with a confidence interval of 10.4 cM. The other four QTLs located on chromosomes 2, 3, and 5, explained 5.3–8.1% of the variance. The use of SNPs derived from Fsp-responsive DEGs for QTL mapping proved to be an efficient way to identify molecular markers associated with Fsp resistance in pea. These QTLs are potential candidates for marker-assisted selection and gene pyramiding to obtain high levels of partial resistance in pea cultivars to combat root rot caused by Fsp.

Unique transcriptome features of pea (&lt;i&gt;Pisum sativum&lt;/i&gt; L.) lines with differing responses to beneficial soil microorganisms

BACKGROUND: Garden pea (Pisum sativum L.) possesses the ability to form beneficial symbioses with various soil microorganisms. However, different pea cultivars, genotypes, and lines gain more or less benefit from these interactions, so the trait named efficiency of interaction with soil microorganisms (EIBSM) was suggested to describe this phenomenon. The molecular mechanisms underlying the manifestation of the EIBSM trait are not properly studied, and only few works focusing on plant responses to combined microbial preparations have been published to date.&#x0D; METHODS: Eight pea lines previously described as contrasting in manifestation of the EIBSM trait were grown in pots with soil under combined inoculation with nodule bacteria and arbuscular mycorrhizal fungi, and the transcriptome profiles of the whole root systems of the plants were investigated using 3'MACE RNA sequencing.&#x0D; RESULTS: The relatedness of the lines inferred from the analysis of transcripts SNVs (Single Nucleotide Variants) corresponded to the manifestation of the EIBSM trait: three high-EIBSM lines and three low-EIBSM lines formed two distinct clusters. Thus, the gene expression profiles were compared between these two clusters, which enabled identification of transcriptome signatures characteristic for each group. The lines previously described as high-EIBSM have lower symbiotic activity, and the expression levels of pathogen response genes were elevated compared to the lines with low EIBSM.&#x0D; CONCLUSION: This result suggests that the mechanism of high interaction efficiency may be connected to stricter host control of symbionts, allowing such plants to expend less on the symbioses.

The Effect of a Preparation Containing Rhizobial Nod Factors on Pea Morphological Traits and Physiology

The aim of the study was to determine the possibility of increasing the pea yields by improving the symbiotic nitrogen fixation through the use of a preparation containing bacterial Nod factors (NFs). Two pea cultivars were included in the experiment: Wiato (with traditional foliage) and Model (afila type). Before sowing, the seeds were soaked in distilled water (control) and in a preparation of Nod factors at a concentration of 10−12 M dm−3 H2O. As a result, of the Nod factor preparation use, an acceleration of the date and uniformity of pea plant emergence was observed. The treatment had also a positive effect on the number and weight of root nodules, which resulted in a significant increase in the yield of vegetative and generative plant organs. A positive effect of seed soaking with NFs preparation was also observed in the dynamics of pea weight increase, chlorophyll content in leaves and the values of gas exchange parameters. Model cultivar of pea had generally higher values of the analysed traits than Wiato, but the response of both cultivars to Nod factors was similar. This means that application of the preparation containing NFs, may improve the growth, development, and yield of both types of pea.

Environmental trial of pea breeding acessions

The aim of the study was to determine the information content and adequacy of the ecological testing points of the pea breeding material and to identify the "ideal" genotype.&#x0D; Materials and methods. The breeding material in the experiments was represented by cultivars bred at the PPI nd.a. V.Ya. Yuriev (Tsarevych, Oplot, Otaman, Metsenat, Korvet, Haiduk, and Malakhit) and ten breeding lines (SL 11-129, SL 11-213, SL 11-55, SL 11-58, SL 10-37, SL 11-32, SL 10-132, SL 09-118, SL 11-166, and SL 11-176). In addition there was one cultivar (Svit) bred at the Plant Breeding and Genetics Institute. All the cultivars are leafless, semi-dwarf, mid-ripening, except for Tsarevych (mid-early). The field experiments were carried out in accordance with the methods of field experimentation, using the conventional pea growing technology. The seeding rate was 1.2 million germinable seeds/ha; the plot area was 10 m2. To evaluate the accessions for the variability in different environments, we used a regression model developed by S.A. Eberhart and W.A. Russel, where the regression coefficient is an indicator of the genotype-environment interaction. This model is included in "Guidelines for Environmental Trials of Corn".&#x0D; Results and discussion. Thus, comparing the regression coefficient in pea cultivars Oplot, Tsarevych, Haiduk, Korvet, and Metsenat, we could conclude that these accessions were highly intensive in the OSES conditions and extensive in the PPI NAAS conditions (except for Metsenat). Regarding the regression coefficient in the breeding lines, none of them had a regression coefficient of 1.0. Over the study period, the regression coefficient was 1.4 only in line SL 11-58 (PPI NAAS) and 1.2 (OSES), characterizing this line as intensive regardless of the place of cultivation.&#x0D; Taking into account that the regression coefficient values of &lt;1 are intrinsic to extensive accessions, lines SL 10-132 (RC = 0.4) and SL 11-176 (RC = 0.8) are preferred. Because these accessions also have a high genotypic effect. In addition, the regression coefficient in breeding line SL 09-118 was 0.9, with a genotypic effect of 0.07. Such combination of the indicators characterizes the line as relatively stable, with sufficient potential performance, and this breeding line will not be demanding to growing conditions similar to the OSES ones.&#x0D; Conclusions. Thus, the evaluation of both cultivars and breeding lines in the environmental trial showed that the pea breeding at the Plant Production Institute named after VYa Yuryev had a significant potential to create cultivars that would be well-adapted to both eastern and southern conditions, and that environmental trials remained an effective tool for assessing breeding material and selecting accessions with the maximum fulfillment of the genetic potential

Effect of Pod Sealant Application on the Quantitative and Qualitative Traits of Field Pea (Pisum sativum L.) Seed Yield

Field pea is used for human consumption or as livestock feed. The yield of pea seeds can be significantly decreased due to the genetically determined tendency of peas to pod shattering. This study aimed to evaluate the effect of pod sealant application on the quantitative and qualitative traits of the seed yield of two pea cultivars: Arwena and Tarchalska grown in south-western Poland in the years 2018–2019. Pod sealant application showed higher values of analysed quantitative and qualitative traits: number of pods per plant, number of seeds per plant, seed weight per pod, 1000-seed weight, seed yield, dry matter of seeds, protein content in seeds, and total protein productivity, except the number of seeds per pod. For both years (2018–2019), the interaction of cultivar and pod sealant application showed a significant effect on the number of seeds per plant, total protein content, total protein productivity, and seed weight per pod in 2019. Therefore, the pod sealant application can be a relatively simple way to improve the yielding of field peas.

Rhizosphere Bacterial Networks, but Not Diversity, Are Impacted by Pea-Wheat Intercropping.

Plant-plant associations, notably cereal-legume intercropping, have been proposed in agroecology to better value resources and thus reduce the use of chemical inputs in agriculture. Wheat-pea intercropping allows to decreasing the use of nitrogen fertilization through ecological processes such as niche complementarity and facilitation. Rhizosphere microbial communities may account for these processes, since they play a major role in biogeochemical cycles and impact plant nutrition. Still, knowledge on the effect of intecropping on the rhizosphere microbiota remains scarce. Especially, it is an open question whether rhizosphere microbial communities in cereal-legume intercropping are the sum or not of the microbiota of each plant species cultivated in sole cropping. In the present study, we assessed the impact of wheat and pea in IC on the diversity and structure of their respective rhizosphere microbiota. For this purpose, several cultivars of wheat and pea were cultivated in sole and intercropping. Roots of wheat and pea were collected separately in intercropping for microbiota analyses to allow deciphering the effect of IC on the bacterial community of each plant species/cultivar tested. Our data confirmed the well-known specificity of the rhizosphere effect and further stress the differentiation of bacterial communities between pea genotypes (Hr and hr). As regards the intercropping effect, diversity and structure of the rhizosphere microbiota were comparable to sole cropping. However, a specific co-occurrence pattern in each crop rhizosphere due to intercropping was revealed through network analysis. Bacterial co-occurrence network of wheat rhizosphere in IC was dominated by OTUs belonging to Alphaproteobacteria, Bacteroidetes and Gammaproteobacteria. We also evidenced a common network found in both rhizosphere under IC, indicating the interaction between the plant species; this common network was dominated by Acidobacteria, Alphaproteobacteria, and Bacteroidetes, with three OTUs belonging to Acidobacteria, Betaproteobacteria and Chloroflexi that were identified as keystone taxa. These findings indicate more complex rhizosphere bacterial networks in intercropping. Possible implications of these conclusions are discussed in relation with the functioning of rhizosphere microbiota in intercropping accounting for its beneficial effects.

Effect of Different Spacing and Weed Management Practices on Weeds, Crop Growth and Productivity of Pigeon Pea Variety Pusa Arhar-16

Background: To study effect of various spacing and weed management practices on weed control, growth parameter, yield and yield attributes of pigeon pea variety Pusa Arhar-16, field experiments were conducted at Student’s Research Farm, Khalsa College Amritsar, Punjab, India during kharif season of 2019-20.Methods: The experiment was laid out in Split plot design with three replications. The treatments comprised of four different spacing i.e. S1 (30×10 cm), S2 (30×15 cm), S3 (40×15 cm) and S4 (50×25 cm) which were considered as main plot treatments and three weed management practices W1 (weedy check), W2 (pendimethalin @ 1.5 kg a.i. ha-1 at 1DAS) and W3 (rice straw mulch) as sub-plot treatments.Result: It was found that maximum plant height (218.2 cm) and highest leaf area index (2.104) was recorded in treatment S1 (30×10 cm) whereas treatment S4 (50×25 cm) was superior in rest of growth parameters viz. maximum crop growth rate (0.85 gram per plant per day), number of primary branches (18.2 per plant) and number of secondary branches (13.8 per plant). Among yield and yield attributes, spacing S1 (30×10 cm) showed maximum grain yield (16.29 q ha-1) and stover yield (49.29 q ha-1) whereas, maximum number of pods per plant (154.6), pod length (4.83 cm), number of seeds per pod (3.90) and 100-seed weight (7.14 grams) were recorded in spacing S4 (50×25 cm). The weed management treatments showed non-significant effect on growth and yield parameters due to weed suppressing ability of the crop. which might be due to weed suppressing ability of the crop. It may be concluded that pigeon pea cultivar Pusa Arhar-16 performed better in narrower spacing of 30×10 cm due to its dwarf nature and it also showed good smothering effect on the weeds due to its smothering effect.

Mörk Materia / Dark Matter(s)

The practice-based research carried out throughout several projects and assembled in this exposition is structured around a rhizomatic nexus of still ongoing entries into plant-thinking and co-becoming with plants, partly based on photographic, photosynthetic and biosynthetic processes under the project framework Cogito ergo Pisum, partly based on archival findings, found footage, phenomena and related discourse. "Cogito, ergo sum" is a philosophical statement in Latin by René Descartes, usually translated into English as "I think, therefore I am". The phrase originally appeared in French as je pense, donc je suis in his Discourse on the Method, to reach a wider audience. Connecting and collapsing the notion of thinking with plants – or in this case gray peas of the species Pisum sativum var. arvense, transposed into "Cogito ergo Pisum" – is at the heart of this research. Within the project I am researching, developing and cross-breeding a flora of transdisciplinary experiments, new material studies and processes, that revolve around ways of rethinking, creating for and becoming with other life forms. Photographic, biosynthetic and agricultural methodologies are being used in Cogito ergo Pisum to both analyze and synthesize new ecologies. On the basis of horizontal (gene) transfer, hybridity and hospitality, a number of agents, patients and symbionts have been subject to material-semiotic and transgenic inquiries: Timo the artist and Timo the grey pea — bioart experiments involving horizontal transfer of my DNA to a grey pea cultivar (Pisum sativum var.arvense). Pisum Sativum used by Gregor Mendel in 1856 when unfolding many of the rules of heredity, now referred to as the laws of Mendelian inheritance, constitute a key plant in "Cogito ergo Pisum". Epidermodysplasia verruciformis, also known as Tree Man Syndrome, an extremely rare autosomal recessive genetic hereditary skin disorder, and Foliate heads, also known as Green men, constitute a highly symbolic reading of a hybrid plant-human being. Several works and results of the processes active in Cogito ergo Pisum have been installed in a number of exhibitions, many of which are ongoing or infinite by nature; presented in open archival or horizontal hybrid structures with documents, negative cyanotype photograms, wall drawings and lab notes on paper, mail correspondence, facsimile of illustrated manuscripts, and cultivations of growing grey pea seeds. Some of them, including literature, phenomena, found footage and historical events have later made it into the polyphonic performance reading "Mörk Materia / Dark Matter(s)", which has been adapted and reconfigured to the contexts it has been performed in. Using photographic and moving images, documents, objects, drawings and plant cultivations I am approaching, renegotiating and speculating about our common nature-culture, to both highlight and transform an increasingly dark matter: body, earth, space.