Development of improved medium grain rice variety for Southern US challenges and opportunities Xueyan Sha Rice Research and Extension Center, University of Arkansas, USA
Length/width ratio 2.0-2.9 Amylose content 12-19% Gelatinization temperature 60-65ºC Used in breakfast cereals, confections, and snack type products as puffed rice Used in desserts and puddings for its creamy consistency Flours used in extruded products for energy bars, snacks and cereals or as thickeners in baby foods Table rice
HECTARES (X1,000) Fluctuation of Medium-grain (MG) Acreage in Southern US, 2007-2016 (USDA-ERS) 340 290 240 190 140 90 40 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Southern MG California MG US MG
Southern Medium-grain Rice Varieties Released since 1992 Variety Pedigree Grain Type* Releasing state Release year Titan M-206//Bengal/Lafitte/3/Jupiter MG Arkansas 2016 CL272 Neptune//Bengal/CL161 CL MG Louisiana 2015 MM14 Unknown MG Missouri 2015 CL271 Neptune//Bengal/CL161 CL MG Louisiana 2013 Caffey Bengal//Mercury/Rico 1/3/Mercury/Rico 1//Bengal MG Louisiana 2010 CL261 Bengal/CL161 CL MG Louisiana 2010 Neptune Bengal//Mercury/Rico 1/3/Mercury/Rico 1//Bengal MG Louisiana 2007 Jupiter Bengal/Rico 1/3/Bengal//Mercury/Rico 1 MG Louisiana 2005 Medark Bengal/Short Rico MG Arkansas 2004 Earl Mercury/Rico 1//Bengal MG Louisiana 2000 Lafitte Mercury//Mercury/Koshihikari MG Louisiana 1995 Bengal Mars//M-201/Mars MG Louisiana 1992 *MG = Medium-grain, and CL MG = Clearfield medium-grain
Challenges and Prospective of Southern MG A niche market as compared to long-grain rice Any new medium-grain variety has to be approved by Kellogg s for its prosperous future, and Kellogg s will not approve anything until they satisfy with the plant scale evaluation (requiring a large quantity of rice) Narrower gene pool, less breeding efforts, and few pre-breeding germplasm available Prone to bacterial panicle blight (Burkholderia spp.) However, unlimited potential (plenty of water), stable yielder, and performs well in some problematic soils, such as those with the high PH
Medium-grain Rice Breeding Goals Higher yield potential Good and stable milling yields Standard grain and cooking quality for Southern mediumgrain rice Minimum or no chalkiness Lodging resistance Disease resistance sheath blight, blast, and bacterial panicle blight Early maturity
Breeding Methodology Medium Grain
Breeder Headrows - CLX1111
2016 Breeding Populations 625 transplanted single cross F 1, 96 testcrosses, and 23 backcross populations. 700 Space-planted F 2 populations with over half a million unique individual plants. 58,640 panicle rows ranging from F 3 to F 6. 1,030 new breeding lines tested in CSIT/SIT trials. 60 elite breeding lines and varieties tested in AYT at 3 Arkansas locations. 25 advanced medium- and long-grain breeding lines tested in ARPT, 22 in URRN trials, and 2 in Arkansas on-farm (PREP). 3 Puerto Rico winter nurseries were planted and selected. 691 new crosses were made to incorporate the desirable traits from various sources into elite Arkansas rice genotypes.
Marker-assisted Selection of Breeding Lines and Segregating Progenies, 2012-2016 Year Target Traits Trait/ Markers Breeding Materials Data Points 2016 Blast resist and cooking quality, Clearfield trait Pi-ta, Pi-k, Pi-z, Alk, Waxy CSIT/SIT yield entries and BC1F1/Topcross F1 13,248 2015 Blast resist and cooking quality Pi-ta, Pi-k, Pi-z, Alk, Waxy CSIT/SIT yield entries and germplasm 6,528 2014 Blast resist and cooking quality Pi-ta, b, z, Waxy and Alk BC1F1/Topcross F1, visually selected pan rows, and CSIT/SIT yield entries 2,495 2013 Cooking quality Waxy and Alk Visually selected pan rows 1,280
Jupiter Titan TITAN Variety Days to 50% Heading Plant Height (cm) Lodging (%) Yield (t/ha) 2012-2016 Head Rice (%) Total Rice (%) Titan 79 99 13 9.9 56 68 Jupiter 85 95 18 9.1 61 68
Performance of Promising Breeding Lines and Selected Check Varieties in 2016 ARPT Trials Variety/Line Pedigree Grain Type Days to 50% Heading Height (cm) Lodging (%) 16ARPT269 EARL/4/ORIN//MERC/RICO/3/9602134 MG 85 104 6 9.1 16ARPT271 EARL/9902028//RICO/BNGL MG 85 100 4 9.0 16ARPT272 EARL/9902028//JPTR MG 86 103 23 8.9 RU1601050 RU1301124/CL261 CL MG 81 102 2 9.1 Titan Titan MG 80 102 7 9.7 Jupiter Jupiter MG 86 98 17 8.4 CL272 CL272 CL MG 85 102 0 8.9 CL153 CL153 CL LG 85 105 0 8.5 Diamond Diamond LG 85 109 5 9.5 Mermentau Mermentau LG 85 102 0 8.0 Yield (t/ha)
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