Low Temperature Delays Metabolism of Quizalofop in Resistant Winter Wheat and Three Annual Grass Weed Species

Quizalofop-resistant wheat is the core component of the recently commercialized CoAXium™ Wheat Production System. As with other herbicides, quizalofop provides better weed control at early growth stages and under optimum temperature. However, in regions with winter wheat production, quizalofop application may be affected by unpredictable, rapid temperature decreases. Temperature shifts can cause crop injury or impact weed control efficacy. In the following study, we examine the effect of reduced temperature on quizalofop content and metabolism in CoAXium™ winter wheat and three winter weed species: downy brome (Bromus tectorum L.), feral rye (Secale cereale L.), and jointed goatgrass (Aegilops cylindrica Host). Temperature conditions include either 19 or 4.5°C daytime temperatures with tissue sampling over 5 timepoints (1–16 or 18 days after treatment, DAT). Analysis features liquid chromatography coupled to tandem mass spectrometry detection of the active form of quizalofop, quizalofop acid. Quizalofop content trends reveal delayed metabolism under cooler conditions for wheat and weeds. Quizalofop content peaks within 1–2 DAT in the warmer temperatures for all species and decreases thereafter. In contrast, content peaks between 8 and 9 DAT at cooler temperatures except for downy brome. Minimal decreases in content over time generally follow cooler temperature peaks. Further, the absence of differences in maximum quizalofop content in all species suggests absorption and/or de-esterification of quizalofop proherbicide to the active form is not reduced at cooler temperatures. Final dry shoot tissue biomass does not necessarily correspond to differences in metabolism, as biomass of wheat treated with a field rate of quizalofop does not differ between temperatures. Weeds were treated with sublethal doses of quizalofop in order to monitor herbicide metabolism without causing plant death. Under this condition, weed biomass only differs for jointed goatgrass, which has a greater biomass in the cooler temperature.

Molecular diversity analysis in hexaploid wheat (Triticum aestivum L.) and two Aegilops species (Aegilops crassa and Aegilops cylindrica) using CBDP and SCoT markers

Background Evaluation of genetic diversity and relationships among crop wild relatives is an important task in crop improvement. The main objective of the current study was to estimate molecular variability within the set of 91 samples from Triticum aestivum, Aegilops cylindrica, and Aegilops crassa species using 30 CAAT box–derived polymorphism (CBDP) and start codon targeted (SCoT) markers. Results Fifteen SCoT and Fifteen CBDP primers produced 262 and 298 fragments which all of them were polymorphic, respectively. The number of polymorphic bands (NPB), polymorphic information content (PIC), resolving power (Rp), and marker index (MI) for SCoT primers ranged from 14 to 23, 0.31 to 0.39, 2.55 to 7.49, and 7.56 to 14.46 with an average of 17.47, 0.34, 10.44, and 5.69, respectively, whereas these values for CBDP primers were 15 to 26, 0.28 to 0.36, 3.82 to 6.94, and 4.74 to 7.96 with a mean of 19.87, 0.31, 5.35, and 6.24, respectively. Based on both marker systems, analysis of molecular variance (AMOVA) indicated that the portion of genetic diversity within species was more than among them. In both analyses, the highest values of the number of observed (Na) and effective alleles (Ne), Nei’s gene diversity (He), and Shannon’s information index (I) were estimated for Ae. cylindrica species. Conclusion The results of cluster analysis and population structure showed that SCoT and CBDP markers grouped all samples based on their genomic constitutions. In conclusion, the used markers are very effective techniques for the evaluation of the genetic diversity in wild relatives of wheat.

Néhány kiegészítés a Jászság flórájához

Magyarország Flóratérképezési Programja során 2012-ben 9 kvadrát felmérését vé­geztem el a Jászságban. Az adatgyűjtést 2020-ban kiegészítettem. Cikkemben az érdekesebb, regionáli­san fontos florisztikai adatokat közlöm 68 edényes növényfajra vonatkozóan. Közöttük vannak idegen­honos taxonok (pl. Alopecurus myosuroides, Amaranthus deflexus, Juncus tenuis, Phytolacca esculenta) országosan (Silene bupleuroides), vagy regionálisan ritka fajok (pl. Coronopus squamatus, Linaria biebersteinii), a térség egykori erdeinek túlélői (pl. Clematis recta, Elymus caninus, Melica altissima, Sisymbrium strictissimum) és ritka gyomok (pl. Aegilops cylindrica, Bupleurum affine, Myagrum perfolia­tum). Bemutatok egy szikes fajokban gazdag műút menti padkát is (Artemisia santonicum, Chenopodium chenopo­dioides, Hordeum hystrix, Plantago maritima).

Polyphenols, Flavonoids, and Antioxidant Activity Involved in Salt Tolerance in Wheat, Aegilops cylindrica and Their Amphidiploids

Aegilops spp. is the closest genus to wheat (Triticum spp.), which makes Aegilops great candidates to exhibit precursors of wheat features. Aegilops cylindrica Host displays excellent salt tolerance. In the current study, biochemical and phytochemical compounds in the leaves of two wheat cultivars, one hyper-salt tolerant Ae. cylindrica genotype and their amphidiploids (derived from “Chinese Spring” × Ae. cilindrica and “Roshan” × Ae. cylindrica), grown under control and saline field conditions, were assessed. These compounds included total protein content, proline content, electrolyte leakage, total flavonoid content, total phenolic content, DPPH radical scavenging activity, and reducing power. In addition, phenolic components were also identified using HPLC analysis. Chlorogenic acid, ellagic acid, ferulic acid, syringic acid, vanillic acid, p-coumaric acid, caffeic acid, and gallic acid were the most abundant phenolic acids. Luteolin, apigenin, and rutin were the most abundant flavonoids in the leaves. Salt stress significantly increased all biochemical variables, with the exceptions of reducing power and p-coumaric acid. Interestingly, amphidiploid genotypes exhibited intermediate levels of most of the detected phenolic compounds between the two parental species. As demonstrated by bivariate correlations luteolin, chlorogenic acid, caffeic acid and apigenin could predict inhibition percentage by DPPH assay, suggesting a possible role in the cellular defense against oxidative stress in wheat. The amphidiploids and their wild parent performed significantly better than wheat cultivars on phenolic constituents, flavonoids, and maintaining redox homeostasis under salt stress conditions.

Development and Characterization of Wheat-Agropyron cristatum Introgression Lines Induced by Gametocidal Genes and Wheat ph1b Mutant

The P genome of Agropyron cristatum Gaertn. contains many desirable genes that can be utilized as genetic resources to improve wheat. In this research, we used both the gametocidal chromosome 2Cc and the pairing homologous gene (Ph1b) mutant to induce structural aberrations and translocations between wheat and the 4P, 5P, and 6P genome chromosomes. By using the two approaches, a total of 19 wheat-A. cristatum translocations have been identified, in which 13 were induced by the Triticum aestivum cv. Chinese Spring (CS) ph1b mutant (CS ph1b) and six were induced by gametocidal chromosome 2Cc from Aegilops cylindrica Host. The wheat-4P, -5P and -6P A. cristatum translocations were characterized by in situ hybridization and by a set of conserved orthologous set (COS) molecular markers. The aberrations included centromeric translocations, terminal translocations, dicentric translocations, and deletions. The average induction frequency of chromosome structural aberrations was 10.9% using gametocidal 2Cc chromosome and 8.8% using ph1b mutant. The highest frequency obtained was for chromosome 4P using both approaches. All the wheat-A. cristatum translocation lines obtained were valuable for identifying A. cristatum chromosome 4P, 5P, and 6P related genes. In addition, these lines provided genetic resources and new germplasm accessions for the genetic improvement of wheat.

LEAVES AREA AND PHOTOSYNTHETIC PIGMENTS OF DOMINANT PLANTS OF RURAL PASTURES IN THE STEPPE BELT OF MOUNT ARAGATS IN ARMENIA

В статье обобщены результаты исследований ассимиляционной поверхности и содержания фотосинтетических пигментов в листьях растений основных луговых групп юго-западного склона горы Арагац (1300-1900 м н.у.м.). Данные территории находятся под сильным воздействием экологических и антропогенных факторов, отличаются низкой продуктивностью, следовательно, нуждаются в коренном улучшении. В рамках настоящей работы была поставлена задача создать базу экспериментальных данных по биологическим параметрам, ответственным за формирование урожая. Объектами исследований были следующие виды злаковых – Коленница (Aegilops cylindrica), Костер (Bromus tectorium), Мятлик (Poa bulbosa), Пырей (Agropyron repens), Ячмень (Hordeum bulbosum), бобовых – Эспарцет (Onobrychis radiata), Клевер (Trifolium pratense), Вика (Vicia variabilis), Люцерна (Medicago sativa) и разнотравных растений – Молочай (Euphorbia virgata), Пижма (Tanacetum vulgare), Скабиоза (Scabiosa bipinnata), Котовник (Nepeta Мussini), Тысячелистник (Achillea millefolium), Полынь (Artemisia absinthium). Площадь листьев определялась весовым методом, экстракция пигментов проводилась с помощью диметилсульфоксида, а измерение их содержания – на спектрофотометре СФ-16. Выявлен широкий диапазон колебаний площади листьев у индивидуальных видов (0,9-11,5), тогда как разница между луговыми группами была незначительной (4,0-5,9 дм2/растение). Сумма пигментов в листьях разнотравных растений на 22 % была меньше, чем у злаковых и бобовых, а соотношение хлорофиллов А и Б колебалось в пределах 1,8-3,5. Таким образом, на исследуемых кормовых угодьях максимальные размеры площади листьев обнаружены у многолетних злаковых, сумма пигментов и хлорофилл А – бобовых, а хлорофилл Б – разнотравных растений. The article summarizes the scientific results on the assimilation surface and the content of photosynthetic pigments in the leaves of plants in the main meadow groups of the southwestern slope of Mount Aragats (1300-1900 m above sea level). Under the strong influence of environmental and anthropogenic factors these territories are characterized by low productivity, therefore, they need efficient improvement. Within the framework of this scientific article, the task was set to create a database of experimental data on biological parameters responsible for the yield farming. The objects of the current research were the following types of cereals – Goatgrass (Aegilops cylindrica), Cheat grass (Bromus tectorium), Bluegrass (Poa bulbosa), Wheatgrass (Agropyron repens), Barley (Hordeum bulbosum), legumes – Sainfoins (Onobrychis radiata), Clover (Trifolium pratenium), Cow vetch (Vicia variabilis), Alfalfa (Medicago sativa), and herbs – Leafy spurge (Euphorbia virgata), Tansy (Tanacetum vulgare), Scabiosa (Scabiosa bipinnata), Catnip (Nepeta Mussini), Yarrow (Achillea milleteminium), Wormwood (Artemisia absinthium). The leaf area was determined by the gravimetric method, pigment extraction was carried out using dimethyl sulfoxide, and their content was measured on an SF-16 spectrophotometer. A wide range of fluctuations in the leaf area in individual species was revealed (0.9-11.5), while the difference between meadow groups was insignificant (4.0-5.9 dm2/plant). The amount of pigments in the leaves of herbs was 22% less than that in cereals and legumes, and the ratio of chlorophylls A and B varied within 1.8-3.5. Thus, on the studied foraging grounds, the maximum leaf area was found in perennial cereals, the sum of pigments and chlorophyll A – in legumes, and chlorophyll B – in herbs. leaves area, photosynthetic pigments, wild plants, natural pastures, steppe belt