Genome-wide association study of root-lesion nematodes Pratylenchus species and crown rot Fusarium culmorum in bread wheat

Triticum aestivum L., also known as common wheat, is affected by many biotic stresses. Root diseases are the most difficult to tackle due to the complexity of phenotypic evaluation and the lack of resistant sources compared to other biotic stress factors. Soil-borne pathogens such as the root-lesion nematodes caused by the Pratylenchus species and crown rot caused by various Fusarium species are major wheat root diseases, causing substantial yield losses globally. A set of 189 advanced spring bread wheat lines obtained from the International Maize and Wheat Improvement Center (CIMMYT) were genotyped with 4056 single nucleotide polymorphisms (SNP) markers and screened for root-lesion nematodes and crown rot resistance. Population structure revealed that the genotypes could be divided into five subpopulations. Genome-Wide Association Studies were carried out for both resistances to Pratylenchus and Fusarium species. Based on our results, 11 different SNPs on chromosomes 1A, 1B, 2A, 3A, 4A, 5B, and 5D were significantly associated with root-lesion nematode resistance. Seven markers demonstrated association with P. neglectus, while the remaining four were linked to P. thornei resistance. In the case of crown rot, eight different markers on chromosomes 1A, 2B, 3A, 4B, 5B, and 7D were associated with Fusarium crown rot resistance. Identification and screening of root diseases is a challenging task; therefore, the newly identified resistant sources/genotypes could be exploited by breeders to be incorporated in breeding programs. The use of the identified markers in marker-assisted selection could enhance the selection process and cultivar development with root-lesion nematode and crown rot resistance

Phytochemical Analysis, Antioxidant, and Antimicrobial Activities of Ducrosia flabellifolia: A Combined Experimental and Computational Approaches

Ducrosia flabellifolia Boiss. is a rare desert plant known to be a promising source of bioactive compounds. In this paper, we report for the first time the phytochemical composition and biological activities of D. flabellifolia hydroalcoholic extract by using liquid chromatography-electrospray tandem mass spectrometry (ESI-MS/MS) technique. The results obtained showed the richness of the tested extract in phenols, tannins, and flavonoids. Twenty-three phytoconstituents were identified, represented mainly by chlorogenic acid, followed by ferulic acid, caffeic acid, and sinapic acid. The tested hydroalcoholic extract was able to inhibit the growth of all tested bacteria and yeast on agar Petri dishes at 3 mg/disc with mean growth inhibition zone ranging from 8.00 ± 0.00 mm for Enterococcus cloacae (E. cloacae) to 36.33 ± 0.58 mm for Staphylococcus epidermidis. Minimal inhibitory concentration ranged from 12.5 mg/mL to 200 mg/mL and the hydroalcoholic extract from D. flabellifolia exhibited a bacteriostatic and fungistatic character. In addition, D. flabellifolia hydroalcoholic extract possessed a good ability to scavenge different free radicals as compared to standard molecules. Molecular docking studies on the identified phyto-compounds in bacterial, fungal, and human peroxiredoxin 5 receptors were performed to corroborate the in vitro results, which revealed good binding profiles on the examined protein targets. A standard atomistic 100 ns dynamic simulation investigation was used to further evaluate the interaction stability of the promising phytocompounds, and the results showed conformational stability in the binding cavity. The obtained results highlighted the medicinal use of D. flabellifolia as source of bioactive compounds, as antioxidant, antibacterial, and antifungal agent

Determination of Root Traits in Wild, Landrace and Modern Wheats and Dissection of Quantitative Trait Loci (QTL) for Root Characters in Bread Wheat

Bread wheat is an allohexaploid crop with a large and complex genome structure. It was one of the first crops domesticated by human beings in the Near East and it had dramatic effects on human history. The amount of energy gained per hour of work from wheat was much higher than hunting and gathering. Ancient farmers continuously selected it to increase seed size, grain yield, and straw yield to feed a growing population; this scenario has not changed for thousands of years. Plant scientists, breeders, and farmers are still working to improve grain yield to support growing demand. Introduction of genetic variation with novel alleles has been a major component of plant breeding, especially after the major genetic bottlenecks of the last century. I have aimed to retrieve some of the available genetic variation within the Triticeae tribe by screening wild wheat relatives, landraces, modern wheats, and a synthetic wheat population. All of the above materials were evaluated to genetically locate and identify root system traits. Breeding for drought tolerance requires selection for traits that improve water uptake and use efficiency. Root system traits are a major component to improve water acquisition. Here we report significant genotypic variation for root traits within and between wheat wild relatives, bread wheat landraces, modern wheats, and the Synthetic W7984* Opata M 85 doubled haploid (SynOpDH) mapping population. Up to four-fold difference for root size within wild accessions, eight-fold difference within landraces and modern wheats and fourteen-fold difference within the progeny of the SynOpDH population was observed. This large range in genotypic variation may provide many useful alleles for breeders, especially those who target rain-fed growth conditions in their breeding programs. Even though studying the root system is technically challenging, and time and labor intensive, an urgent need for drought tolerant crops makes it a necessity. There is a major need for research leading to a complete understanding of the genetic control of the wheat root system. Advances in genotyping technologies, marker assisted selection, and fast / accurate phenotyping may provide useful tools to select root traits such as, deep root biomass, number of seminal and nodal roots, and root angle with less labor and time, to develop drought tolerant wheat cultivated varieties

LİSE 1. SINIF ÖGRENCİLERİNİN BALIK TÜKETİMİ KONUSUNDA GÖRÜSLERİ

Bu arastırma, lise 1 ögrencilerinin balık tüketim alıskanlıklarını ve balıgın besleyici degeri ile ilgili bilgi seviyelerini incelemek; bu konuda interaktif egitim materyali hazırlayarak materyalin etkili olup olmadıgını tespit etmek amacıyla yapılmıstır. Bu çalısma, Ankara ilinde Ege Lisesi, Genç Osman Lisesi ve Ankara Anadolu Lisesi lise 1. sınıf ögrencilerinden olusan toplam 82 kisiye anket uygulanarak gerçeklestirilmistir. Arastırmacı tarafından hazırlanan anketin güvenilirligi (Cronbach = 0.767) uygun bulunmustur. Ögretim öncesi beslenme ve balık tüketimi hakkında hazırlanan anket öntest olarak uygulanmıstır. nteraktif egitim materyalinin ögrencilere uygulanmasından on gün sonra aynı anket sontest olarak uygulanmıs ve test sonuçlarında anlamlı bir fark gözlenmistir. Çalısma sonucunda; kisilerin beslenme üzerine okulda aldıkları egitimin tam ve yeterli olmadıgı, ayrıca bu konuda egitim verilmesi gerektigi ögrenciler tarafından vurgulanmıstır. Ancak egitimin interaktif bir materyalle uygulanmasının daha yararlı olacagını belirten ögrenci görüsleri çalısmanın önemini göstermektedir. Balık tüketim bilincinin artırılması, interaktif ögretim materyallerinin gelistirilerek, internet yoluyla topluma ulastırılması sayesinde daha hızlı ve kolay olacaktır. Bu çalısmada hazırlanan materyal, beslenme ve balık tüketimi konusunda gerekli bilgileri kapsaması ve uygulama sonucunda elde edilen veriler açısından önemli bulunmustur. Çalısma sonucunda öntest ve sontest uygulamaları arasında ögrencilerde anlamlı fark görülmesi, hazırlanan materyalin hedefine ulasan etkin bir araç oldugunu göstermektedir. Öntestte okulların bilgi düzeyleri arasında bir fark görülmezken, sontest sonuçlarında anlamlı fark gözlenmistir. Ayrıca bireylerin öntest bilgi düzeylerinin ögrencilerin sosyoekonomik düzeyleri ile yakından ilgili bulunması, ögretimden sonra bu farkın ortadan kalkması, egitimle beslenme ve balık tüketimindeki bilinç ve bilgi düzeyinin ekonomik faktörlerden etkilenmedigini göstermesi açısından önemli görülmektedir.This study was undertaken to determine the knowledge level and fish consumption behaviors of high school first year students; the main aim to determine the effectiveness and applicability of an interactive education material developed. In the present research, a questionnaire was applied to three high schools in Ankara: Ege High School, Genç Osman High School and Ankara Anatolian High School with 82 high school freshman students participating. The reliability coefficient of the questionnaire (Cronbach's = 0.78) was found to be high. The questionnaire on nutrition and fih consumption was applied as a pretest before teaching. The interactive education material as a web page, was applied to the students and after ten days the same test was given as posttest. Results of the tests showed a significant difference between the two tests. The research results show that school education on nutrition is not satisfactory, and the respondants added the need for an education in this field. Respondants views on the necessity for the education to be carried out by using interactive material, depicts the importance of the study. Increase in fish consumption awareness will be easier and faster by developing interactive education materials and making them available via the internet. When the need for nutrition throughout life is considered, the importance of the study is emphasized once more. The material prepared in the present study was found to be significant when considered in terms of amount of information covered and the results obtained. While no difference was seen among schools for the pretest; the results of the posttest was significantly different. In addition, the relationship between respondants with respect to the level of pretest knowledge level and socioeconomic level, and abolishment of this difference after application of the education material, is important in terms of showing that level of knowledge and awareness in nutrition and fish consumption are not affected by economic factors

Root and shoot traits in parental, early and late generation Green Revolution wheats (Triticum spp.) under glasshouse conditions

Introduction of stem-dwarfing genes had a major impact on wheat breeding and production. It is estimated that 70–90% of modern wheats carry one or more such genes. These genes were the cornerstone of the Green Revolution. They solved the lodging problem by reducing stem height, thus allowing a marked increase in mineral fertilizer use. These genes also changed biomass allocation and allowed more carbon assimilates to be stored as grain. With heavy fertilization and irrigation, plants had little use for an extensive and expensive root system for uptake of water and nutrients. However, with climate change and limited water and nutrient sources, there is a need to remodel crops with novel genetic variation available in landraces and old varieties. In this study, we evaluated nine accessions of wheat representing gene pools of parental, early-tall and late-semi-dwarf Green Revolution wheats for root and shoot biomass and grain yield under well-watered conditions in a glasshouse. Significant genotypic variation was found for total root biomass and root distribution in the soil profile as well as for plant height and days to anthesis. Modern wheats have reduced root-system size relative to their predecessors. This may be the effect of the dwarfing genes or an indirect effect of negative selection pressure, but the wheatThis work was supported by University of California, Riverside, Botanic Gardens, The California Agricultural Experiment Station, and a doctoral fellowship from the Turkish Republic Ministry of National Education to Harun Bektas

Root and shoot traits of bread wheat (Triticum aestivum L.) landraces and cultivars

In order to break the current grain yield barriers, breeders require genetic variation. Breeding for resistance to abiotic stresses may lead to better plant survival and improved grain yield. Exploring landraces may expand the genetic diversity of modern wheats. Five Turkish bread wheat landraces and 14 modern durum and bread wheat cultivars were evaluated for root and shoot biomass as well as grain yield for 2 years in three experiments. Root and shoot traits were measured in plants grown in 1 and 1.5 m PVC tubes in a glasshouse. Significant genotypic differences were found within and between landraces and modern wheats. Shoot biomass, total root biomass, shallow root weight, deep root weight, number of tillers per plant, and plant height were significantly greater in landraces compared to modern wheats. Correlation coefficients were positive between root biomass and shoot biomass (0.78), and number of fertile tillers (0.76). Plant height, shallow and deep root weights, as well as the total root biomass were positively correlated. Semi-dwarf and mid-height cultivars had greater grain yield than tall lines: winter wheats had greater harvest index, whereas intermediate (facultative) wheats had greater shallow root weights and total root biomass. Results highlight the mode of adaptation in landraces to water stress and suggest that landraces may be a valuable resource in breeding for altered root architecture.This work was supported by the University of California RiversideBotanic Garden and agricultural Experiment Station, and a doctoral fellowship from the Turkish Republic Ministry of National Education to Harun Bektas

Characteristics of the root system in the diploid genome donors of hexaploid wheat (Triticum aestivum L.)

Wild crop relatives are of considerable interest in plant breeding and significant efforts have been made to transfer their genetic variation into modern crops. Of the three diploid progenitors of bread wheat (Triticum aestivum L.), only Aegilops tauschii Coss. has been explored and exploited and only for some above ground characteristics. The three wild progenitors (Aegilops speltoides Tausch., Triticum urartu Tumanian ex Gandilyan, and Aegilops tauschii) have never been assayed for root traits. Here we report such a root study, and include Triticum monococcum L. subsp. boeoticum (Boiss.) Hayek and T. turgidum L. subsp. dicoccoides (Koern. ex Asch. et Graebn.) Thell. Fifteen accessions were selected from the above wild species and tested in the presence of one bread wheat cultivar Pavon F76. Significant variation was observed between and within the taxa. Of all accessions tested, cv. Pavon F76 had the smallest root system at maturity while A. speltoides had the largest root system. Moreover, Aegilops spp. had larger mean values for root biomass when compared with Triticum spp. These results suggest there is significant unexplored potential for the use of wheat wild relatives in wheat breeding to improve the root system, or to develop synthetic mapping populations to study root traits.This work was supported by the California Agricultural Experiment Station, the University of California, Riverside Botanic Gardens, and a doctoral fellowship of the Turkish Republic Ministry of National Education to Harun Bektas

Phenotyping and Genetic Analysis of Root and Shoot Traits of Recombinant Inbred Lines of Bread Wheat Under Well- Watered Conditions

Phenotyping root traits and understanding their inheritance are critical for crop improvement, as the root system plays an important role in crop performance under well-watered and drought conditions. A set of 118 F8 recombinant inbred lines (RILs) of bread wheat (Triticum aestivum L.) derived from the cross Iran #49 (a landrace) × Yecora Rojo (a standard variety) plus the two parents was used to phenotype root traits at mid-tillering stage and at physiological maturity in sand-tube experiments under well-watered conditions. Iran #49 and Yecora Rojo were different for grain yield per plant (20.4 vs.13.8), shallow-root weight per plant (5.3 vs. 1.3 g, roots developed between 0 and 30 cm), deep-root weight per plant (4.5 vs. 0.5 g, roots developed below 30 cm), and root biomass per plant (9.8 vs. 1.8 g). Although there were significant differences among the RILs for number of roots longer than 30 cm, total length of roots longer than 30 cm, longest root, shallow-root weight, deep-root weight, and root biomass, the estimate of narrow-sense heritability was relatively low for shallow-root weight (26%), deep- -root weight (14%), and root biomass (22%) at mid-tillering stage. At maturity, the estimate of heritability for these root traits was 81%, 79%, and 83%, respectively. Additive × additive epistasis was detected for deep-root weight at maturity. Genotypic differences in root traits among the RILs were highest at maturity. The root traits measured at mid-tillering and at maturity showed significant, but weak correlation coefficients ranging from 0.20 to 0.40. Grain yield per plant showed significant genotypic correlation with root traits at maturity. Harvest index showed strong negative correlation with root traits ranging from -0.69 to -0.78. Our studies indicated that the appropriate time for phenotyping root traits in wheat is at maturity.Research supported by the California Wheat Commission, the California Agricultural Experiment Station, and the University of California, Riverside, Botanic Gardens

QTLs for root traits at mid-tillering and for root and shoot traits at maturity in a RIL population of spring bread wheat grown under well-watered conditions

Root system traits have positive effects on wheat grain yield, particularly in drought environments. Root traits are difficult to manipulate using conventional selection procedures. Marker-assistedselection (MAS) could be helpful for the improvement of root morphological traits. A recombinant inbred line (RIL) population of 168 lines derived from the cross Iran #49 9 Yecora Rojo was used to map quantitative trait loci (QTLs) for root traits at midtillering stage for one season and for root and shoot traits at plant maturity for two seasons using two different subsets. The RILs were grown in sand-tube experiments in a glasshouse under well-watered conditions. Longest root (LR), total root length longer 30 cm (TRL30), shallow root weight (roots between 0 and 30 cm, SRW), deep root weight (roots bellow 30 cm, DRW), total root biomass (RBio), ratio of root to shoot (RTS) and to plant (RTP) biomass were measured at mid-tillering. At maturity, number of days to booting (DTB), to heading (DTH), to anthesis (DTA), and to maturity (DTM), plant height (PH), flag leaf area (FLA), number of tillers (NTP) and spikes (NSP) per plant, number of grains (NGP), grain weight (GW), grain yield (GY) per plant, LR, SRW, DRW, RBio, PBio, and RTP were measured. At mid-tillering, a total of 18 putative QTLs were detected with individual QTL accounted for between 6.5 and 26.5 % of the variation in the traits. The QTLs were distributed on chromosomes 1B, 2A, 2D, 4B, 6B, 7A, and 7D. A major and two minor QTLs were identified for LR, with the major QTL (qLR-2D) explaining 26.5 % of variation. Two QTLs were detected for DRW on chromosome 4B between markers Gwm6 and Sukkula.1220 that together explained 23.1 % of variation. One region between marker Wmc198 and Cfa2263 on chromosome 2A contained four QTLs affecting PH, SRW, RTS, and RTP. At maturity, 70 putative QTLs were detected across the two seasons with a single QTL accounted for between 7.7 and 40.6 % of variation in the traits. Three major colocalized QTLs for SRW, DRW, and RBio were identified on chromosome 2D between markers Wms515 andWms102 that accounted for 19.8, 20.5, and 22.4 %0f variation, respectively. Two major colocalized QTLs for SRW and RBio were detected on chromosome 3A that explained 17.8 and 13.4 % of variation, respectively. One major QTL for DRW was identified on chromosome 1B that accounted for 20.3 % of variation. Chromosome 2B harbored major QTLs for GY, NGS, and NGP. A major QTL cluster was detected on chromosome 2D and on chromosome 4A relating 11 and eight QTLs for phenological periods, root traits, RTS, and RTP, indicating pleiotropic effects on these traits. Of the four common root traits studied at mid-tillering and at maturity, only SRW had linked QTLs on chromosome 2A at both stages of plant growth, indicating selection for root traits at seedling stage alone may not be effective in changing root morphological characteristics at later stages of plant growth. It appeared that chromosome 2A, 2D, and 4B harbored genes regulating growth of root traits at early and later stages of plant growth. The molecular markers closely linked to QTLs for root and shoot traits may be used in wheat breeding program using MAS procedures.The research was financed by The California Wheat Commission, The University of California- Riverside Botanic Gardens, and the California Agricultural Experiment Station