Welcome to Acta Agronomica Sinica,

Acta Agron Sin ›› 2014, Vol. 40 ›› Issue (04): 611-621.doi: 10.3724/SP.J.1006.2014.00611

• CROP GENETICS & BREEDING·GERMPLASM RESOURCES·MOLECULAR GENETICS • Previous Articles     Next Articles

Resistance Genes of Wheat Variety Shannong 20 Identified by Diagnostic Molecular Markers

LI Ji-Fa1,**,DENG Zhi-Ying1,**,SUN Fu-Lai2,GUAN Xi-Zhen1,WANG Yan-Xun1,TIAN Ji-Chun1,*   

  1. 1 State Key Laboratory of Crop Biology / Shandong Provincial Key Laboratory of Crop Biology, Shandong Agricultural University, Tai’an 271018, China;
    2 Binzhou Seed Management Station of Shandong Province, Binzhou 256600, China
  • Received:2013-08-28 Revised:2014-01-12 Online:2014-04-12 Published:2014-02-14
  • Contact: 田纪春, E-mail: jctian@sdau.edu.cn, Tel: 0538-8242040

Abstract:

Shannong 20 is a newly released winter wheat variety in the National Regional Trials for North and South Yellow-Huai River Valleys, which exhibits excellent resistance to major diseases of wheat. In this study, the possible resistance genes in Shannong 20 were identified by using SSR, SCAR, and STS markers tightly linked to resistance genes/loci against powdery mildew, stripe rust, leaf rust, sheath blight, and scab. A total of 15 resistance genes were detected, including six (Pm12, Pm24, Pm30, Pm31, Pm35, and Pm36) for powdery mildew resistance, six (Yr5, Yr9, Yr15, Yr24, Yr26, and YrTp1) for stripe rust resistance, two (Lr21 and Lr26) for leaf rust resistance, and one (Ses1) for sheath blight resistance. However, no resistance locus to scab was found. The result may partially explain the multi- resistance in Shannong 20, and provide some references for cultivating new varieties with disease resistance and stable yield by using molecular marker-assisted selection.

Key words: Shannong 20, Disease resistance genes, Molecular markers

[1]Xiao M G, Song F J, Jiao J F, Wang X M, Xu H X, Li H J. Identification of the gene Pm47 on chromosome 7BS conferring resistance to powdery mildew in the Chinese wheat landrace Hongyanglazi. Theor Appl Genet, 2013, 126: 1397–1403



[2]Alam M A, Xue F, Wang C Y, Ji W Q. Powdery mildew resistance genes in wheat: identification and genetic analysis. J Mol Biol Res, 2011, 1: 21–39



[3]Lillemo M, Asalf B, Singh R P, Huerta-Espino J, Chen X M, He Z H, Bjørnstad Å. The adult plant rust resistance loci Lr34/Yr18 and Lr46/Yr29 are important determinants of partial resistance to powdery mildew in bread wheat line Saar. Theor Appl Genet, 2008, 116: 1155–1166



[4]兰彩霞. 普通小麦条锈病和白粉病成株抗性QTL定位. 中国农业科学院博士学位论文, 2010



Lan C X. QTL Mapping for adult-Plant Resistance to Stripe Rust and Powdery Mildew in Common Wheat. PhD Dissertation of Chinese Academy of Agricultural Sciences, Beijing, China, 2010 (in Chinese with English abstract)



[5]伍玲. 小麦条锈病成株抗性QTL定位和分子标记检测. 四川农业大学博士学位论文, 2011



Wu L. QTL Mapping and Molecular Characterization of Adult-Plant Resistance to Stripe Rust in Common Wheat. PhD Dissertation of Sichuan Agricultural University, Ya’an, China, 2011 (in Chinese with English abstract)



[6]刘子记, 梁永, 朱婕, 李根桥, 杨作民, 孙其信, 刘志勇. 小麦抗叶锈病基因 Lr9的分子标记及其检测. 麦类作物学报, 2013, 33: 236–242



Liu Z J, Liang Y, Zhu J, Li G Q, Yang Z M, Sun Q X, Liu Z Y. Genetic improvement and marker assisted selection of wheat with leaf rust resistance gene Lr9. J Triticere Crops, 2013, 33: 236–242 (in Chinese with English abstract)



[7]孙一, 胡亚亚, 杨文香, 刘大群. 六个小麦品系的抗叶锈性评价. 麦类作物学报, 2011, 31: 762–768



Sun Y, Hu Y Y, Yang W X, Liu D Q. Evaluation of the resistance to leaf rust of 6 wheat lines. J Triticere Crops, 2011, 31: 762–768 (in Chinese with English abstract)



[8]张小村, 李斯深, 赵新华, 范玉顶, 李瑞军. 小麦纹枯病抗性的QTL分析和抗病基因的分子标记. 植物遗传资源学报, 2005, 6: 276–279



Zhang X C, Li S S, Zhao X H, Fan Y D, Li R J. QTL and molecular markers for resistance gene of wheat sharp eyespot. J Plant Genet Resour, 2005, 6: 276–279 (in Chinese with English abstract)



[9]周淼平, 任丽娟, 张旭, Olga-E Scholten, 黄益洪, 马鸿翔, 陆维忠. 小麦赤霉病抗性QTL分析. 作物学报, 2004, 30: 739–744



Zhou M P, Ren L J, Zhang X, Olga-E Scholten, Huang Y H, Ma H X, Lu W Z. Analysis of QTL for Fusarium head blight resistance in wheat. Acta Agron Sin, 2004, 30: 739–744 (in Chinese with English abstract)



[10]Buerstmayr H, Ban T, Anderson J. QTL mapping and marker-assisted selection for Fusarium head blight resistance in wheat: a review. Plant Breed, 2009, 128: l–26



[11]李春鑫, 许为钢. 小麦白粉病抗病基因分子标记开发及应用研究进展. 中国农学通报, 2009, 25(10): 53–58



Li C-X, Xu W G. Researches and application on molecular markers of powdery mildew resistant genes in wheat. Chin Agric Sci Bull, 2009, 25(10): 53–58 (in Chinese with English abstract)



[12]邱永春, 张书绅. 小麦抗白粉病基因及其分子标记研究进展. 麦类作物学报, 2004, 24: 127–132



Qiu Y C, Zhang S S. Researches on powdery mildew resistant genes and their molecular markers in wheat. J Triticere Crops, 2004, 24: 127–132 (in Chinese with English abstract)



[13]董淑静, 许为钢. 小麦条锈病抗性基因研究进展及分子标记辅助聚合育种. 中国农学通报, 2009, 25(13): 190–196



Dong S J, Xu W G. Progress on stripe rust resistance genes and resistant breeding in wheat. Chin Agric Sci Bull, 2009, 25(13): 190–196 (in Chinese with English abstract)



[14]Li Z F, Zheng T C, He Z H, Li G Q, Xu S C, Li X P, Yang G Y, Singh R P, Xia X C. Molecular tagging of stripe rust resistance gene YrZH84 in Chinese wheat line Zhou 8425B. Theor Appl Genet, 2006, 112: 1098–1103



[15]殷学贵. 小麦抗条锈新基因YrTp1和YrTp2的发现和分子标记定位. 甘肃农业大学博士论文, 2005



Yin X G. Discovery and Molecular Mapping of Two Novel Genes YrTp1 and YrTp2 Conferring Resistance to Wheat Stripe Rust. PhD Dissertation of Gansu Agricultural University, Lanzhou, China, 2005 (in Chinese with English abstract)



[16]Kolmer J A. Enhanced leaf rust resistance in wheat conditioned by resistance gene pairs with Lr13. Euphytica, 1992, 61: 123–130



[17]German S E, Kolmer J A. Effect of gene Lr34 in the enhancement of resistance to leaf rust of wheat. Theor Appl Genet, 1992, 84: 97–105



[18]Komer J A. Genetics of resistance to wheat leaf rust. Annu Rev Phytopathol, 1996, 34: 435–455



[19]袁军海, 陈万权. 中国小麦主要抗叶锈病基因的有效性评价. 麦类作物学报, 2011, 31: 994–999



Yuan J H, Chen W Q. Estimate on the effectiveness of main resistant genes for leaf rust in Chinese wheat. J Triticeae Crops, 2011, 31: 994–999 (in Chinese with English abstract)



[20]Buerstmayr H, Lemmens M, Hartl L, Doldi L, Steiner B, Stierschneider M. Ruckenbauer P. Molecular mapping of QTLs for Fusarium head blight resistance in spring wheat. I. Resistance to fungal spread (Type II resistance). Theor Appl Genet, 2002, 104: 84–91



[21]田大刚, 林峰, 张彩琴, 张政值, 薛树林, 曹勇, 李春军, 马正强. 利用“永久F2”群体定位抗赤霉病QTL. 作物学报, 2008, 34: 539–544



Tian D G, Lin F, Zhang C Q, Zhang Z Z, Xue S L, Cao Y, Li C J, Ma Z Q. Mapping QTLs associated with resistance to Fusarium head blight using an “immortalized F2” population. Acta Agron Sin, 2008, 34: 539–544 (in Chinese with English abstract)



[22]Molher V, Jahoor A. Allele-specific amplification of polymorphic sites for the detection of powdery mildew resistance loci in cereals. Theor Appl Genet, 1996, 93: 1078-1082



[23]Mohler V, Hsam S L K, Zeller F J, Wenzel G. An STS marker distinguishing the rye-derived powdery mildew resistance alleles at the Pm8/Pm17 locus of common wheat. Plant Breeding, 2001, 120: 448-450



[24]王军. 与小麦抗白粉病基因Pm12和Pm16紧密连锁的SSR分子标记建立. 中国农业大学硕士学位论文, 2004



Wang J. Establishment of SSR molecular markers tightly linked to wheat powdery mildew resistance genes Pm12 and Pm16. MS Thesis of China Agricultural University, Beijing, China, 2004 (in Chinese with English abstract)



[25]Cenci A, D’Ovidio R, Tanzarella O A, Ceoloni C, Porceddu E. Identification of molecular markers linked to Pm13, an Aegilops longissima gene conferring resistance to powdery mildew in wheat. Theor Appl Genet, 1999, 98: 448–454



[26]Chen X M, Luo Y H, Xia X C, Xia L Q, Chen X, Ren Z L, He Z H, Jia J Z. Chromosomal location of powdery mildew resistance gene Pm16 in wheat using SSR marker analysis. Plant Breeding, 2005, 124: 225–228



[27]Liu Z, Sun Q, Ni Z and Yang T. Development of SCAR markers linked to the Pm21 gene conferring resistance to powdery mildew in common wheat. Plant Breed, 1999, 118: 215–219



[28]Huang X Q, Hsam S L K, Zeller F J, Wenzel G, Mohler V. Molecular mapping of the wheat powdery mildew resistance gene Pm24 and marker validation for molecular breeding. Theor Appl Genet, 2000, 101: 407–414



[29]Hsam S L K, Lapochkina I F, Zeller F J. Chromosomal location of genes for resistance to powdery mildew in common wheat (Triticum aestivum L. em Thell.): 8. Gene Pm32 in a wheat-Aegilops speltoides translocation line. Euphytica, 2003, 133: 367–370



[30]Zhu Z D, Zhou R H, Kong X Y, Dong Y C, Jia J Z. Microsatellite markers linked to 2 powdery mildew resistance genes introgressed from Triticum carthlicum accession PS5 into common wheat. Genome, 2005, 48: 585–590



[31]Miranda L M, Murphy J P, Leath S, Marshall D. Pm34: a new powdery mildew resistance gene transferred from Aegilops tauschii Coss. to common wheat (Triticum aestivum L.). Theor Appl Genet, 2006, 113: 1497–1504



[32]Miranda L M, Murphy J P, Marshall D, Cowger C, Leath S. Pm35: a novel Aegilops tauschii derived powdery mildew resistance gene introgressed into common wheat (Triticum aestivum L.). Theor Appl Genet, 2007, 114: 1451–1456



[33]Blanco A, Gadaleta A, Cenci A, Carluccio A V, Abdelbacki A M, Simeone R. Molecular mapping of the novel powdery mildew resistance gene Pm36 introgressed from Triticum turgidum var. dicoccoides in durum wheat. Theor Appl Genet, 2008, 117: 135–142



[34]He R L, Chang Z J, Yang Z J, Yuan Z Y, Zhan H X, Zhang X J, Liu J X. Inheritance and mapping of powdery mildew resistance gene Pm43 introgressed from Thinopyrum intermedium into wheat. Theor Appl Genet, 2009, 118: 1173–1180



[35]刘燕, 张增艳, 辛志勇, 林志珊, 杜丽璞, 徐惠君, 刘丽, 陈孝, 张改生. 利用分子标记解析小麦新种质YW243的抗锈病基因. 中国农业科学, 2006, 39: 295–299



Liu Y, Zhang Z Y, Xin Z Y, Lin Z S, Du L P, Xu H J, Liu L, Chen X, Zhang G S. Analysis on the rust resistance genes of a new wheat germplasm YW243 by molecular markers. Sci Agric Sin, 2006, 39: 295–299 (in Chinese with English abstract)



[36]Sun Q, Wei Y, Ni Z, Xie C, Yang T. Microsatellite marker for yellow rust resistance gene Yr5 in wheat introgressed from spelt wheat. Plant Breed, 2002, 121: 539–541



[37]翁东旭, 徐世昌, 万安民, 李景鹏, 吴立仁. 小麦条锈菌鉴别寄主抗条锈病基因Yr9的微卫星标记. 遗传学报, 2005, 32: 937–941



Weng D X, Xu S C, Wan A M, Li J P, Wu L R. Microsatellite marker linked with stripe rust resistant gene Yr9 in wheat. Acta Genet Sin, 2005, 32: 937–-941 (in Chinese with English abstract)



[38]Shao Y T, Niu Y C, Zhu L H, Zhai W X, Xu S C, Wu L R. Identification of an AFLP marker linked to the stripe rust resistance gene Yrl0 in wheat. Chin Sci Bull, 2001, 46: 669–672



[39] Sun G L, Fahima T, Korol A B, Turpeinen T, Grama A, Ronin Y I, Neve E. Identification of molecular markers linked to the Yr15 stripe rust resistance gene of wheat originated in wild emmer wheat, Triticum dicoccoides. Theor Appl Genet, 1997, 95: 622–628



[40]贾举庆, 雷孟平, 刘成, 李光蓉, 杨足君. 小麦抗条锈基因Yr17的新SCAR标记的建立与应用. 麦类作物学报, 2010, 30: 11–16



Jia J Q, Lei M P, Liu C, Li G R, Yang Z J. Exploitation and application of a new SCAR marker linked to strip rust resistance gene Yr17 in wheat. J Triticeae Crops, 2010, 30: 11–16 (in Chinese with English abstract)



[41]Lagudah E S, McFadden H, Singh R P, Huerta-Espino J, Bariana H S, Spielmeyer W. Molecular genetic characterization of the Lr34/Yr18 slow rusting resistance gene region in wheat. Theor Appl Genet, 2006, 114: 21–30



[42]刘亚萍, 曹双河, 王献平, 徐志斌, 张相岐. 小麦抗条锈病基因Yr24的SSR标记. 植物病理学报, 2005, 35: 478–480



Liu Y P, Cao S H, Wang X P, Xu Z B, Zhang X Q. Molecular mapping of stripe rust resistance gene Yr24 in wheat. Acta Phytopathol Sin, 2005, 35: 478–480 (in Chinese with English abstract)



[43]Ma J X, Zhou R G, Dong Y S, Wang L, Wang X, Jia J. Molecular mapping and detection of the yellow rust resistance gene Yr26 in wheat transferred from Triticum turgidum L1 using microsatellite markers. Euphytica, 2001, 120: 219–226



[44]Chicaiza O, Khan I A, Zhang X, Brevis J C, Jackson L, Chen X, Dubcovsky J. Registration of five wheat isogenic lines for leaf rust and stripe rust resistance genes. Crop Sci, 2006, 46: 485–487



[45]王冰悦, 徐世昌, 徐仲, 刘太国, 蔺瑞明. 小麦条锈菌国际鉴别寄主Vilmorin23的抗条锈病基因YrV23微卫星标记. 遗传, 2006, 28: 306–310



Wang B Y, Xu S C, Xu Z, Liu T G, Lin R M. A microsatellite marker linked to the stripe rust resistance gene YrV23 in the wheat variety Vilmorin23. Hereditas (Beijing), 2006, 28: 306–310 (in Chinese with English abstract)



[46]Qiu J W, Schürch A C, Yahiaoui N, Dong L L, Fan H J, Zhang Z J, Ling H Q. Physical mapping and identification of a candidate for the leaf rust resistance gene Lr1 of wheat. Theor Appl Genet, 2007, 115: 159–168



[47]Schachermayr G, Siedler H, Gale M D, Winzeler H, Winzeler M, Keller B. Identification and localization of molecular markers linked to the Lr9 leaf rust resistance gene of wheat. Theor Appl Genet, 1994, 88: 110–115



[48]Schachermayr G, Feuillet C, Keller B. Molecular markers for the detection of the wheat leaf rust resistance gene Lr10 in diverse genetic backgrounds. Mol Breed, 1997, 3: 65–74



[49]Prins R J, Groene W Z, Marais G F, Snape J W, Koebner R M D. AFLP and STS tagging of Lr19, a gene conferring resistance to leaf rust in wheat. Theor Appl Genet. 2001, 103: 618–624



[50]Neu C, Stein N, Kelley B. Genetic mapping of the Lr20-Pm1 resistance locus reveals suppressed recombination on chromosome arm 7AL in hexaploid wheat. Genome, 2002, 45: 737–744



[51]Huang L, Gill B S. An RGA-like marker detects all known Lr21 leaf rust resistance gene family members in Aegilops tauschii and wheat. Theor Appl Genet, 2001, 103: 1007–1013



[52]Schachermayr G M, Messmer M M, Feuillet C, Winzeler H, Winzeler M, Keller B. Identification of molecular markers linked to the Agropyron elongatum-derived leaf rust resistance gene Lr24 in wheat. Theor Appl Genet, 1995, 90: 982–990



[53]Mago R, Spielmeyer W, Lawrence G, Lagudah E S, Ellis J G, Pryor A. Identification and mapping of molecular markers linked to rust resistance genes located on chromosome 1RS of rye using wheat-rye translocation lines. Theor Appl Genet, 2002, 104: 1317–1324



[54]Tar M, Purnhauser L, Csosz L, Mesterhazy A, Gyulai G. Identification of molecular markers for an efficient leaf rust resistance gene Lr29 in wheat. Acta Biologica szegediensis, 2002, 46: 133–134



[55]Gold J, Harder D, Townley-Smith F, Aung T, Procunier J. Development of a molecular marker for rust resistance genes Sr39 and Lr35 in wheat breeding lines. Electron J Biotechnol, 1999, 2: 36–41



[56]闫红飞, 杨文香, 褚栋, 刘大群. 小麦抗叶锈基因Lr38的一个新标记. 中国农业科学, 2008, 41: 3604–3609



Yan H F, Yang W X, Chu D, Liu D Q. A new marker tagged to the leaf rust resistance gene Lr38. Sci Agric Sin, 2008, 41: 3604–3609

[1] WANG Heng-Bo, CHEN Shu-Qi, GUO Jin-Long, QUE You-Xiong. Molecular detection of G1 marker for orange rust resistance and analysis of candidate resistance WAK gene in sugarcane [J]. Acta Agronomica Sinica, 2021, 47(4): 577-586.
[2] GUO Yan-Chun, ZHANG Li-Lan, CHEN Si-Yuan, QI Jian-Min, FANG Ping-Ping, TAO Ai-Fen, ZHANG Lie-Mei, ZHANG Li-Wu. Establishment of DNA molecular fingerprint of applied core germplasm in jute (Corchorus spp.) [J]. Acta Agronomica Sinica, 2021, 47(1): 80-93.
[3] Jun-Hua YE,Qi-Tai YANG,Zhang-Xiong LIU,Yong GUO,Ying-Hui LI,Rong-Xia GUAN,Li-Juan QIU. Genotyping of SCN, SMV Resistance, Salinity Tolerance and Screening of Pyramiding Favorable Alleles in Introduced Soybean Accessions [J]. Acta Agronomica Sinica, 2018, 44(9): 1263-1273.
[4] LIU Chang,LI Shi-Jin,WANG Ke,YE Xing-Guo,LIN Zhi-Shan*. Developing of Specific Transcription Sequences P21461 and P33259 on D. villosum 6VS and Their Application of Molecular Markers in Identifying Wheat-D. villosum Breeding Materials with Powdery Mildew Resistance [J]. Acta Agron Sin, 2017, 43(07): 983-992.
[5] FU Bi-Sheng,LIU Ying,ZHANG Qiao-Feng,WU Xiao-You,GAO Hai-Dong,CAI Shi-Bin,DAI Ting-Bo,WU Ji-Zhong. Development of Markers Closely Linked with Wheat Powdery Mildew Resistance Gene Pm48 [J]. Acta Agron Sin, 2017, 43(02): 307-312.
[6] JIANG Peng,ZHANG Ping-Ping,ZHANG Xu,CHEN Xiao-Lin,MA Hong-Xiang*. Association Analysis for MixographProperties in Ningmai 9 and Its Derivatives [J]. Acta Agron Sin, 2016, 42(08): 1168-1175.
[7] KONG Xin-Xin,ZHANG Yan,ZHAO De-Hui,XIA Xian-Chun,WANG Chun-Ping,HE Zhong-Hu. Noodle Quality Evaluation of New Wheat Cultivars from Northern China Winter Wheat Regions [J]. Acta Agron Sin, 2016, 42(08): 1143-1159.
[8] JIANG Peng,ZHANG Ping-Ping,ZHANG Xu,CHEN Xiao-Ling,YAO Jin-Bao,MA Hong-Xiang. Genetic Diversity and Association Analysis of Protein Content in Weak Gluten Wheat Ningmai 9 and Its Derived Lines [J]. Acta Agron Sin, 2015, 41(12): 1828-1835.
[9] CAO Ting-Jie,CHEN Yong-Xing,LI Dan,ZHANG Yan,WANG Xi-Cheng,ZHAO Hong,LIU Zhi-Yong. Identification and Molecular Detection of Powdery Mildew Resistance of New Bred Wheat Varieties (Lines) in Henan Province, China [J]. Acta Agron Sin, 2015, 41(08): 1172-1182.
[10] WU Gui-Fen,XU Xian-Jun,XU Jian-Tang,TAO Ai-Fen,ZHANG Li-Wu,WEI Li-Zhen,PAN Mo,FANG Ping-Ping,LIN Li-Hui,QI Jian-Min. Construction of Molecular Fingerprinting Map in Gene Pool of Jute with SRAP, ISSR and SSR Markers [J]. Acta Agron Sin, 2015, 41(03): 367-377.
[11] Lü Rui-Hua,JIN Xiao-Yun,ZHAO Ai-Chun,JI Jie,LIU Chang-Ying,LI Jun,PU Long,LU Cheng,YU Mao-De. Cross Infection, Biological Characteristics and Genetic Relationship between Pathogens of Hypertrophy Sorosis Sclerotenisis from Mulberry and Sclerotinia Stem Rot from Oilseed Rape [J]. Acta Agron Sin, 2015, 41(01): 42-48.
[12] JIN Xiu-Feng,WANG Xian-Guo,REN Wan-Jie,ZHANG Xiao-Ke,XIE Hui-Min,FAN Feng-Gui. Relationship between a Water Stress Responsive Protein and Drought Resistance and Molecular Mapping of the Target Gene in Common Wheat [J]. Acta Agron Sin, 2014, 40(02): 198-204.
[13] ZHANG Fan,JIANG Lei,JU Li-Ping,JIN Xiu-Feng,WANG Xuan,ZHANG Xiao-Ke,WANG Hong-Li,FU Xiao-Jie. Cloning a Novel Gene TaNRX of Trx Superfamily and Developing Its Molecular Markers Related to Drought Resistance in Common Wheat [J]. Acta Agron Sin, 2014, 40(01): 29-36.
[14] LI Bin,DENG Yuan-Bao,YAN Xue-Hai,YANG Yang,LIU Peng-Qiang,DU Yong,XIE Pei,WANG De-Zheng,DENG Qi-Ming,LI Ping. Identification, Genetic Analysis and Gene Mapping of a Rice Blast Resistance Gene in Japonica Rice [J]. Acta Agron Sin, 2014, 40(01): 54-62.
[15] SUN Cui-Hua,HOU Li-Yuan,GUO Hui-Juan,ZHANG Xiao-Jun,JIA Ju-Qing,LI Xin,ZHAN Hai-Xian,CHANG Zhi-Jian. Molecular Mapping of Powdery Mildew Resistance Gene pmCH83 in a Putative Wheat–Thinopyrum intermedium Cryptic Introgression Line [J]. Acta Agron Sin, 2013, 39(12): 2107-2114.
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed   
No Suggested Reading articles found!