Department Of Plant Science Research Articles

2011 U.S. Barley Production and Quality Updates

According to the November 9 United States Department of Agriculture, National Agricultural Statistics Service (USDA-NASS) Crop Production Report, U.S. 2011 barley production is 155,780 thousand bushels* from 2,239 thousand harvested acres. This is an increase from the September USDA <i>Small Grains 2011 Summary,</i> which reported production at 155.0 million bushels. The revised report was prepared because the wet growing season delayed small grain harvest nationwide. Although the reported number of harvested acres remained steady in the second report, yields in Idaho and Washington increased, and the average U.S yield increased from 69.2 to 69.6 bu/acre. However, 2011 production was the lowest of the last 10 years. Quality surveys conducted by the Institute of Barley and Malt Sciences (IBMS) in Montana, Minnesota, and North Dakota were completed in November. Sample collection was coordinated by the USDA-NASS, Fargo, ND. Grain quality evaluations were performed by the Department of Plant Sciences at North Dakota State University (NSDU) and grade determinations were completed by the North Dakota Grain Inspection Service in Fargo, ND. An evaluation of Idaho barley quality coordinated by the Idaho Barley Commission was completed in October. Idaho barley samples were graded at the Idaho Grain Inspection Service in Pocatello, ID. Seventy-six percent of 2011 U.S. barley was produced in Idaho, Montana, North Dakota, Colorado, Washington, and Wyoming. Except for Washington, which produces mostly feed varieties, the majority of production in these states is malting varieties.

Ecological connectivity and niche differentiation between two closely related fish species in the mangrove-seagrass-coral reef continuum

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 477:201-215 (2013) - DOI: https://doi.org/10.3354/meps10171 Ecological connectivity and niche differentiation between two closely related fish species in the mangrove-seagrass-coral reef continuum Charlotte Berkström*, Tove L. Jörgensen, Micaela Hellström Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91 Stockholm, Sweden *Email: charlotte.berkstrom@su.se ABSTRACT: We aim to understand ontogenetic shifts in habitat use and feeding patterns by 2 fish species, Lutjanus fulviflamma and L. ehrenbergii, within a tropical seascape in East Africa. Stomach contents and stable isotope signatures of muscle tissues (δ13C and δ15N) were compared between and within species. Fish of all life stages and potential food items were sampled from mangrove creeks, seagrass beds, and coral reefs around Mafia Island, Tanzania. Due to similarities in morphology between species, correct species identity was confirmed using genetic barcoding (mtDNA, partial sequence of cytochrome oxidase subunit I [COI]). Stable isotope analysis in R (based on mixing models) confirmed that δ13C and δ15N values in L. fulviflamma and L. ehrenbergii reflected those of prey items caught in different habitats. Diets and mean δ13C and δ15N values of muscle tissue differed between life stages of fish, indicating ontogenetic changes in habitat and diet. L. fulviflamma and L. ehrenbergii differed in diet and δ13C and δ15N values of muscle tissue, although they overlapped in habitat use, suggesting food resource partitioning between the 2 species. Furthermore, diet overlap indexes were low between subadult species in mangrove and seagrass or coral habitats. L. fulviflamma displayed a diet shift with decreasing importance of small crustaceans in juveniles and an increasing importance of prey fishes in subadults and adults. L. ehrenbergii showed the opposite pattern. The study verifies feeding interlinkage within the mangrove-seagrass-coral reef continuum in Mafia Island by providing strong evidence of ontogenetic migration. Understanding these connections will enhance our ability to manage tropical seascapes, and highlights the need to include multiple habitats in marine protected areas. KEY WORDS: Stable isotopes · Stomach content · Ontogenetic shifts · Connectivity · Resource partitioning · Coral reef · Seagrass · Mangrove Full text in pdf format PreviousNextCite this article as: Berkström C, Jörgensen TL, Hellström M (2013) Ecological connectivity and niche differentiation between two closely related fish species in the mangrove-seagrass-coral reef continuum. Mar Ecol Prog Ser 477:201-215. https://doi.org/10.3354/meps10171 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 477. Online publication date: March 12, 2013 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2013 Inter-Research.

Efeito da salinidade na emergência e crescimento inicial de plântulas de flamboyant

Objetivou-se avaliar o efeito de diferentes concentrações salinas na água de irrigação na emergência e desenvolvimento inicial de plântulas de flamboyant (Delonix regia (Bojer ex Hook.) Raf.). O experimento foi desenvolvido em casa de vegetação do Departamento de Ciências Vegetais da Universidade Federal Rural do Semiárido - UFERSA, Mossoró-RN. O delineamento estatístico utilizado foi o inteiramente casualizado, com cinco tratamentos e quatro repetições, com 25 sementes cada. Os tratamentos consistiram das concentrações salinas (0,5; 1,5; 3,0; 4,5 e 6,0 dS m-1), que foram obtidas através da adição de NaCl em água de forma que as soluções fossem calibradas para as condutividades elétricas pré-estabelecidas. As variáveis avaliadas foram: porcentagem de emergência de plântulas, índice de velocidade de emergência, área foliar, altura de plântula, número de folíolos, comprimento de raiz e massa seca da parte aérea. A salinidade interfere negativamente em todas as variáveis avaliadas de forma proporcional ao seu aumento na água de irrigação das plântulas de flamboyant, sendo o maior desenvolvimento das plântulas obtido na dose 0,5 dS m-1.

Floristic Account of the Asclepiadaceous Species from the Flora of Dera Ismail Khan District, KPK, Pakistan

In the present study an account is given of an investigation based on the results of the floristic research work conducted between 2005 and 2007 in Dera Ismail Khan District, north western Pakistan. The area was surveyed and 8 Asclepi- adaceous plant species were collected. These plant species are Calotropis procera (Aiton) W. T. Aiton. Caralluma edulis (Edgew.) Benth., Leptadenia pyrotecnica (Forssk.) Decne., Oxystelma esculentum (L. f.) R. Br., Pentatropis nivalis (J. F. Gmel.) D. V. Field & J. R. I. Wood, Pergularia daemia (Forssk.) Blatt.& McCann., Periploca aphylla Decne. and Stapelia gigantea N.E.Br. The study showed that five plants were used ethnobotanically in the area. All the plants were deposited as voucher specimens in the Department of plant sciences, Quaid-i-Azam University, Islamabad, for future references. Complete macro & microscopic detailed morphological features of the species have been discussed. Taxo- nomic key was developed to differentiate closely related taxa.

Extraordinary transgressive phenotypes of hybrid tomato are influenced by epigenetics and small silencing RNAs

Hybrid organisms may fail to develop, be sterile or they may be more vigorous than either of the parents. Examples of hybrid vigour or hybrid necrosis in the F1 are often not inherited stably in subsequent generations if they are associated with overdominance. There can also be transgressive phenotypes that are inherited stably in these later generations, but the underlying mechanisms are not well understood. Here we have investigated the possibility that stable transgressive phenotypes in the progeny of crosses between cultivated tomato (Solanum lycopersicum cv. M82) and a wild relative (Solanum pennellii, accession LA716) are associated with micro or small interfering(si) RNAs. We identified loci from which these small(s)RNAs were more abundant in hybrids than in either parent and we show that accumulation of such transgressive sRNAs correlated with suppression of the corresponding target genes. In one instance this effect was associated with hypermethylation of the corresponding genomic DNA. Our results illustrate a potential role of transgressive sRNAs in plant breeding and in natural evolution with wild plants.

Threshold Concepts as Focal Points for Supporting Student Learning

The Plant Sciences Pedagogy Project conducted research into undergraduate teaching and learning in the Department of Plant Sciences at the University of Cambridge and has translated the research fi...

Productive performance of lettuce at different amounts and times of decomposition of dry scarlet starglory

The use of spontaneous species as green manure in the production of vegetables is slowly starting to produce satisfactory results. The purpose of the present study was to evaluate the productive performance of lettuce at different quantities and times of decomposition of dry scarlet starglory (Merremia aegyptia L.) incorporated into the soil. The present study was carried out from October to December 2006 in a vegetable garden of Plant Sciences Department of the Universidade Federal Rural do Semi-Arido (UFERSA), Mossoro-RN¸ Brazil. The experimental design was a randomized complete block with the treatments arranged in a factorial 4 x 4 + 1, with three replications. The treatments consisted of the combination of four dry scarlet starglory amounts incorporated into the soil (2.6; 5.2; 7.8 and 10.4 t ha-1 of dry matter) with four different decomposition times (0; 10; 20 and 30 days before transplanting of lettuce - DBT), plus one additional treatment (80 t ha-1 of cattle manure, a traditional treatment in the lettuce cropping). The lettuce cultivar grown was 'Baba de Verao'. The evaluated characteristics were: height and diameter of plants, number of leaves per plant, fresh and dry mass of the lettuce shoots. The incorporation of dry scarlet starglory into the soil influenced the productive performance of lettuce in a positive way, thereby showing promise for use as a green manure. The highest fresh mass amount of the lettuce (15.33 t ha-1) was obtained with the incorporation of 6.68 t ha-1 of dry scarlet starglory to the ground in time of 30 days before transplanting of the lettuce.

Anomalous areas and awkward ages: alleviating concerns

Department of Plant and Environmental Protection Sciences,The University of Hawaii, Honolulu, HI, U.S.A.Brower & Vane-Wright (2011) critique our recent paper(Wahlberg & Rubinoff, 2011) and bring up some veryimportant points concerning the use of algorithms such asdiva (Ronquist, 1997) and beast (Drummond & Rambaut,2007). Although we agree that the use of algorithms such asthese may have some pitfalls and problems, we feel that theirjudicious use can be informative about the evolutionary historyof a group in question. We see the process of delving into agroup of organisms as iterative, with each successive studybringing new understanding that can be used to inform thebasis of following studies. This is how we have approached ourstudy of the genus

Extração de nutrientes e produção de biomassa de aveia-preta cultivada em solo submetido a dezoito anos de adubação orgânica e mineral

This work aimed to quantify the content and accumulation of macronutrients (N, P and K) in the dry biomass of oats-black ( Avena strigosa Schreb) and in soil (P and K), recycled by the oats-black after the waste left in the soil by successive fertilizations organic and mineral carried out in maize. The experiment was conducted at the Experimental Field of Coimbra, located in the city of Coimbra / MG from the Department of Plant Science (DFT) of the Federal University of Vicosa (UFV). The planting of oats-black was conducted in the agricultural year 2003/2004. The treatments were: no fertilization, mineral fertilization at 150 kg ha -1 of 8-28-16 formulation with the addition of 50 kg ha -1 N topdressing (AM1); mineral fertilization at 300 kg ha -1 of 8-28-16 formulation with the addition of 100 kg ha -1 N topdressing (AM2) and organic manure (AO) with 40 m 3 ha -1 of compost. These treatments were applied sequentially in corn cultivation for a period of eighteen. The treatments were arranged in a randomized block design with four replications. Was determined the accumulation of dry mass of aerial part, content and accumulation of N, P and K in shoots of oats-black, P and K content in soil, base saturation and CTC. The treatment with organic fertilization provided higher accumulation of dry matter of aerial part of oats-black and nutrient uptake. The nutrients determined in the soil were directly proportional to the accumulation of dry mass and specific nutrients in shoots of oats-black.

Effect of spent mushroom substrate on tomato wilt disease

An investigation was carried out on the effect of spent mushroom substrateon the wilt disease of tomato when the spent substrate is used as soilamendment. The experiment was carried out at the teaching and researchFarm of the Faculty of Agriculture and the Mycology/Plant Pathology Laboratoryof the Department of Plant Science and Biotechnology, University ofPort Harcourt. Two tomato varieties tropimech (TT 3) and tomate U82B(TT2)at 4 ‐6wks old stage were transplanted into potted soil amended with spentmushroom substrate at the ratio 1:3, 1:4, 1:5 and 1:6 in plastic pots. Stemdiameter, plant height, number of leaves, disease incidence and disease severitywere evaluated. Fusarium oxysporum was implicated as the causalagent of the disease; Aspergillus sp and Rhizopus sp were also isolated fromthe soil though not pathogenic to the plants. The ratio 1:4 was observed tohave the most positive effect on the disease, while the ratio 1:5 had the leasteffect on the disease.

Variedades de milho a diferentes espaçamentos no Planalto de Vitória da Conquista – BA

This research was carried out to evaluate the performance of maize varieties in different spacings. The study was developed in the experimental area of the Department of Plant and Animal Science, of Universidade Estadual do Sudoeste da Bahia in Vitória da Conquista, Bahia, Brazil, during the growing season 2008/2009. The experiment was carried out in a randomized blocks design, in a factorial scheme 3 x 4 with three varieties (AL Bandeirante, BR 106 and Arapuim), 4 spacings (0.40, 0.60, 0.80 and 1.0 m) between rows and three replications, with a population of 50.000 plants ha-1. The following agronomic characteristics were evaluated: flowering days, plants number, ears number, plant height, ear height, stalk diameter, ear length, ear diameter, ear rate and productivity. It was observed that varieties promoted significant results on most of the corn agronomic characteristics. The varieties Arapuim, which was more prolific, and AL Bandeirante produced more ear than BR 106. The spacing reduction increased the ears number.

Effects of carbofuran and metsulfuron-methyl on the benthic macroinvertebrate community in flooded ricefields

AIM: This study evaluated the effect of the insecticide carbofuran and the herbicide metsulfuron-methyl on the abundance and diversity of benthic macroinvertebrates in a paddy ricefield. METHODS: To achieve this goal, two pesticide treatments [the insecticide carbofuran (IC) and the herbicide metsulfuron-methyl (HM)] and a control (Co) treatment with no added pesticide were established in an experimental area of the Plant Science Department of the Federal University of Santa Maria. Soil samples were collected in triplicate from each treatment 30 days before and 1, 10, and 51 days after the pesticide application, for macrofauna identification. RESULTS: Among the 21 taxa identified, Trichoceridae was present only in Co, Hydroptilidae was recorded only in IC, and Corixidae in HM. In Co, the most abundant group was Annelida, while in IC and HM Diptera (Chironomidae) was dominant. Significant differences were observed between Co and IC, in the density of Odontoceridae (Control&gt;IC) and Hydrophilidae (Control&lt;IC), and between Co and HM in the density of Odontoceridae (Control&gt;HM) and Hirudinea (Control&lt;HM). CONCLUSION: In spite of the possible negative effects of the pesticides on the benthic community, the assemblages recovered rapidly.

Desempenho agronômico da cenoura adubada com jitirana antes de sua semeadura

A jitirana é uma planta herbácea nativa que se apresenta como uma fonte potencial para adubação verde no nordeste semi-árido do Brasil e gera inúmeros benefícios, com destaque para o aumento da disponibilidade de nutrientes para as culturas. O objetivo do presente trabalho foi avaliar o desempenho agronômico da cenoura adubada com jitirana antes de sua semeadura. Um experimento foi conduzido na horta didática do Departamento de Ciências Vegetais da Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró-RN, no período de setembro a dezembro de 2008. O delineamento experimental usado foi em blocos completos casualizados com os tratamentos arranjados em esquema fatorial 4 x 4 + 1, com três repetições. O primeiro fator foi constituído pelas quantidades de jitirana incorporadas ao solo (5,4; 8,8; 12,2 e 15,6 t ha-1 em base seca) e o segundo fator pelos tempos de incorporação da jitirana (0; 10; 20 e 30 dias antes da semeadura da cenoura - DAS). O tratamento adicional (testemunha) foi de 80 t ha-1 de esterco bovino. As características avaliadas na cenoura foram: altura das plantas, número de folhas por planta, massa seca da parte aérea, produtividade comercial, produtividade refugo e produtividade classificada. Não houve interação significativa entre os fatores quantidades de jitirana incorporadas ao solo e seus tempos de incorporação antes da semeadura da cenoura em nenhuma das características avaliadas. O melhor desempenho produtivo da cenoura foi obtido na quantidade de 15,6 t ha-1 de jitirana incorporada ao solo e no tempo de 20 dias antes de sua semeadura.

Species arguments: clarifying competing concepts of species delimitation in the pseudo-copulatory orchid genus Ophrys

Jodrell Laboratory, Royal Botanic Gardens Kew, Richmond, Surrey, TW9 3AB, UK School of Plant Sciences, University of Reading, Whiteknights, Reading, RG6 6AS, UK John Innes Centre, Norwich Research Park, Colney Lane, Norwich, NR4 7RH, UK Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK Radagatan 8, SE 531-52, Lidkoping, Sweden Department of Botany, University of Debrecen, Egyetem ter 1, Debrecen, H-4010, Hungary

The Role of Headwater Wetlands in Altering Streamflow and Chemistry in a Maine, USA Catchment1

Water Resources Research Institute and the Environmental Protection Agency 104(b)(3). The Maine Outdoor Heritage Fund and the Department of Plant, Soil, and Environmental Sciences at the University of Maine provided additional support.

The Emerging Emphasis on Nanometer‐Scale Processes in Soil Environments

Soil Science Society of America JournalVolume 75, Issue 2 p. 333-334 Nanoparticles In the Environment The Emerging Emphasis on Nanometer-Scale Processes in Soil Environments N.J. Kabengi, Corresponding Author N.J. Kabengi nadine.kabengi@uky.edu Plant and Soil Sciences Department, University of Kentucky, Lexington, KY, 40546Corresponding author (nadine.kabengi@uky.edu)Search for more papers by this authorA. Thompson, A. Thompson Department of Crop and Soil Sciences, University of Georgia, Athens, GA, 30602Search for more papers by this author N.J. Kabengi, Corresponding Author N.J. Kabengi nadine.kabengi@uky.edu Plant and Soil Sciences Department, University of Kentucky, Lexington, KY, 40546Corresponding author (nadine.kabengi@uky.edu)Search for more papers by this authorA. Thompson, A. Thompson Department of Crop and Soil Sciences, University of Georgia, Athens, GA, 30602Search for more papers by this author First published: 01 March 2011 https://doi.org/10.2136/sssaj2011.000npsintroCitations: 1 All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permission for printing and for reprinting the material contained herein has been obtained by the publisher. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume75, Issue2March 2011Pages 333-334 RelatedInformation

In vitro ploidy manipulation in the genomics era

Angiosperm (flowering) plants are the most diverse group of seeds plants on Earth. Although the majority of extant plants are diploid, wherein somatic cells possess two sets of chromosomes, a significant number of plant species has evolved into polyploids, wherein somatic cells contain three or more sets of chromosomes. These polyploid plants frequently exhibit many distinctive morphological characteristics, such as larger-sized organs, as with flowers and fruits of many tetraploid plants, and seedless fruits of triploid plants. Developing polyploid plants has been of considerable interest for horticulturists, agronomists, and foresters. However, due to their multiple sets of chromosomes, determination of genetic control of traits of interest in polyploids has been much more challenging than that in diploid plants. Moreover, incidence of heterozygosity, even in diploid plants, can further complicate the elucidation of genetic inheritance of a given trait. Thus, developing haploids from polyploid plants or generating monoploids from diploid plants followed by their dihaploidization, via induced or natural doubling of chromosomes from monoploid plants, has become highly desirable for geneticists and plant breeders alike. Over the last several decades, plant breeders, geneticists, and biotechnologists have been attempting to utilize various approaches towards production of haploids (mostly monoploids) and polyploids, primarily triploids and tetraploids, both for genetic analysis studies and applied plant production. Although traditional breeding techniques such as hybridization and mutagenesis have played significant roles in generating desirable polyploid and haploid plants, various in vitro techniques have become routine in manipulating ploidy levels. In the twenty-first century, the field of plant biology has rapidly moved into the genomics era, first signaled by completing the whole genome sequence of Arabidopsis in 2000. Upon further detailed analysis of this smallest genome of angiosperm species, it is revealed that Arabidopsis is a paleopolyploid plant, or an ancient polyploid, that has resulted from ancient whole genome duplications. This phenomenon has been confirmed to be widely spread among other higher plant species, based on several recently completed whole genome sequences. Therefore, this begs the question as to how these ancient polyploid plants have evolved and diverged into today’s plants. This has become a hot research topic of investigation in recent years. One of the research tools that has become widely available to the scientific community is the artificial synthesis of various autoand allo-polyploid plants followed by studies on how these synthesized polyploids have evolved and diverged over time. Likewise, haploid and dihaploid plants have increasingly been employed for studying allelism at the whole genome level. Based on the above, we have assembled this special issue on ‘‘In vitro ploidy manipulation in the genomics era’’, which is divided into different sections. The first section covers reviews and updates of various techniques in generating haploid plants, including anther culture, isolated microspore culture, unfertilized ovary/ovule culture, and distant hybridization/chromosome elimination in cereal crops. The second section covers progress on various techniques in generating polyploids, including production Z.-M. Cheng (&) Department of Plant Sciences, University of Tennessee, Knoxville, TN 37996, USA e-mail: zcheng@utk.edu

Repetibilidade em características biométricas do fruto de macaúba

Estimativas do coeficiente de repetibilidade têm sido utilizadas no estudo de caracteres de várias espécies de palmeiras, auxiliando na definição do número e período adequado de avaliações dos genótipos para maior eficiência dos programas de melhoramento. Para macaúba, não há relatos de estudos dessa natureza. Nesse contexto, faz-se importante a determinação do coeficiente de repetibilidade das seguintes características biométricas dos frutos: peso do fruto, volume do fruto, diâmetro equatorial do fruto, peso da amêndoa, volume da amêndoa, diâmetro da amêndoa e espessura do endocarpo; e a determinação do número mínimo de avaliações para um eficiente processo de seleção e avaliação de subamostras de macaúba. O trabalho foi desenvolvido no Departamento de Fitotecnia da Universidade Federal de Viçosa, analisando-se 145 subamostras de macaúba, provenientes de coletas realizadas nos estados de Minas Gerais, São Paulo, Mato Grosso do Sul, Pará, Maranhão e Pernambuco. Houve diferença significativa para todas as características analisadas e observou-se concordância nas magnitudes dos coeficientes de repetibilidade de cada característica, obtidos pelos diferentes métodos. No entanto, os coeficientes de repetibilidade variam entre as oito características, de 0,68 a 0,99, observados para a característica espessura do endocarpo e volume da amêndoa, respectivamente. As estimativas dos coeficientes de determinação obtidas a partir das 10 repetições para as oito características e pelos quatro métodos foram superiores a 95%. A avaliação de quatro frutos é suficiente para compreensão das características estudadas das subamostras de macaúba com 90% de acurácia.

Potencial alelopático de extratos aquosos de Melissa officinalis L. e Mentha x villosa L. na germinação e vigor de sementes de Plantago major L.

O objetivo do trabalho foi avaliar o efeito dos extratos aquosos de hortelã e melissa na germinação e vigor de sementes de tanchagem. O experimento foi conduzido no Departamento de Fitotecnia da Universidade Federal de Viçosa, no mês de abril de 2011. O delineamento utilizado foi o inteiramente casualizado com cinco tratamentos (testemunha, 25%, 50%, 75% e 100 % do extrato aquoso de hortelã e melissa) e quatro repetições. Os extratos foram preparados utilizando a parte aérea das plantas, na proporção de 100g de planta para 1 L de água destilada. Foram utilizadas 50 sementes de tanchagem em cada caixa gerbox, previamente umedecido com os extratos aquosos (correspondentes aos tratamentos), estas foram levadas para germinar em câmara de germinação, em temperatura de 20°C, fotoperíodo de 16 horas luz e 8 horas escuro, por 14 dias. Durante esse tempo foram feitas às contagens diárias das sementes germinadas para calcular o índice de velocidade de germinação e ao final dos 14 dias foi calculada a porcentagem de germinação. Sementes de tanchagem não submetidas aos extratos aquosos de melissa e hortelã apresentaram-se mais vigorosas quando comparado com as concentrações, evidenciando o potencial alelopático de melissa e hortelã sobre a sua qualidade fisiológica.

Conflicting mapping results for stem rust resistance gene Sr13

Theor Appl Genet (2011) 122:659 DOI 10.1007/s00122-010-1495-2 COMMENT Conflicting mapping results for stem rust resistance gene Sr13 J. Dubcovsky • F. Ordon • D. Perovic B. Admassu • W. Friedt • Z. Abate • W. Zhang • S. Chao Published online: 14 December 2010 O The Author(s) 2010. This article is published with open access at Springerlink.com Two manuscripts with conflicting results on the mapping location of stem rust resistance gene Sr13 in wheat are published in this issue of TAG (Admassu et al. and Simons et al.). Both resistance genes were mapped on the long arm of chromosome 6AL, but the gene mapped by Admassu et al. between markers barc37 and wmc256 is more than 50 cM proximal to the one mapped by Simons et al. between markers CD926040 and BE471213. After the publication of the two manuscripts in TAG online, the authors of both manuscripts became aware of the conflicting results and they exchanged the critical hexaploid wheat cytogenetic stocks Khapstein/9*LMPG (developed by Dr. D. Knott) and the recurrent parent LMPG to deter- mine the source of the differences. In addition, they requested seeds for these two stocks from the U.S. Cereal Disease Laboratory in Saint Paul Minnesota (Dr. Yue Jin) and from Canada Agri-Food, Winnipeg (Dr. Tom Fetch). The online version of the original articles can be found under doi:10.1007/s00122-010-1433-3 and 10.1007/s00122-010-1444-0. J. Dubcovsky (&) Z. Abate W. Zhang Department of Plant Sciences, University of California, Davis, CA 95616, USA e-mail: jdubcovsky@ucdavis.edu F. Ordon D. Perovic B. Admassu Julius Kuehn-Institute, Federal Research Institute for Cultivated Plants (JKI), Institute for Resistance Research and Stress Tolerance, Erwin-Baur-Str. 27, 06484 Quedlinburg, Germany W. Friedt Institute of Crop Science and Plant Breeding I, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany S. Chao USDA-ARS, Biosciences Research Laboratory, 1605 Albrecht Blvd N, Fargo, ND 58102-2765, USA Analysis of these stocks with molecular markers for the long arm of chromosome 6AL revealed that the Khapstein/ 9*LMPG seed stock used in the Admassu et al. paper was different from the other three Khapstein/9*LMPG stocks. Molecular markers barc37, barc107, barc118, barc1165, gwm570, wmc179, wmc256, wmc580, and cfd2 all showed different bands in the seed stock used in the Admassu paper relative to the seed stocks from the University of Califor- nia, the Cereal Disease Laboratory and Agri-Food Canada. These results indicate that the Khapstein/9*LMPG seed stock used in the Admassu paper is different from the other three. Since the Khapstein/9*LMPG hexaploid genetic stock defines the gene name Sr13, the gene mapped by Admassu et al. is most likely not Sr13 and should be renamed. The Khapstein/9*LMPG developed by Dr. D. Knott is polymorphic with the LMPG recurrent parent only for markers closely linked to the stem rust resistance gene mapped in the four tetraploid populations in the distal region of chromosome arm 6AL (barc104b and dupw167) by Simons et al. This observation, together with the fact that Sr13 was originated in tetraploid wheat (Khapli), provides indirect evidence that the gene mapped by Simons et al. is Sr13. Mapping the stem rust resistance gene present in the correct Khapstein/9*LMPG stock in an hexaploid segregating population will provide the final answer. Interestingly, both genes confer resistance to the new stem rust race Ug99 (TTKSK) suggesting that it would be possible to combine the two sources of resistance to Ug99 in the same 6AL arm. We have initiated crosses between the correct Khapstein/9*LMPG genetic stock and the source of the Admassu et al. Ug99 resistance to recombine both genes. Open Access This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which per- mits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.