2017 Beltwide Cotton Conferences, Dallas, TX, January 4-6, 2017

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1 2017 Beltwide Cotton Conferences, Dallas, TX, January 4-6, RENIFORM NEMATODE REPRODUCTION ON SOYBEAN CULTIVARS AND BREEDING LINES IN 2016 R. T. Robbins University of Arkansas Fayetteville, AR P. Arelli USDA Jackson TN P. Chen University of Arkansas Fayetteville, AR G. Shannon University of Missouri Portageville, MO S. Kantartzi Southern Illinois University Carbondale, IL B. Fallen Clemson University Florence, SC Z. Li University of Georgia Athens, GA T. Faske University of Arkansas Lonoke, AR J. Velie E. Gbur D. Dombek D. Crippen University of Arkansas Fayetteville, AR Abstract In 2016, 142 private soybean cultivars and lines from the Arkansas Variety Testing Program and 211 breeding lines and varieties from Public Soybean Breeders: 5 from USDA Jackson TN (Arelli), 35 from Arkansas (Chen), 17 from Missouri (Shannon), 91 from Southern Illinois (Kantartzi), 19 from Clemson (Fallen), and 44 from Georgia (Li) were tested in the greenhouse to determine their suitability as hosts for the reniform nematode (RN), Rotylenchulus reniformis. Resistant soybean lines provide an economically effective management tactic to suppress RN population densities for a subsequent cotton crop. All genotypes were inoculated with 2,000 vermiform RN in two separate greenhouse studies grown for 84 days. The RN resistant varieties Anand and Hartwig, the RN susceptible cultivars Braxton and Ellis, and fallow reniform nematode infested soil (to show survival without a host) served as controls. The reproductive index (RI = Pf/Pi) was calculated based on the average number of vermiform nematodes extracted from the soil of each treatment. Soybean lines with a greater (P = 0.05) RI than the resistant controls were considered suitable hosts for R. reniformis. Of the 142 Arkansas Variety test lines, 137 were considered suitable hosts; however private lines Dyno-Gro S49xs76, Delta Grow DG4995 RR, Armor AR5206C, Go Soy 4914GTS, and Go Soy 49G16 had a magnitude of resistance that was similar to the resistant checks. The Reniform nematode did not reproduce more than the resistant checks on Anand (22 of the 211) and on Hartwig (17 of the 211) on breeding lines and varieties submitted by the Public Soybean Breeders. These lines may be of interest for developing reniform resistant cultivars in a soybean breeding programs. The five commercially available soybean lines from the Arkansas variety test may be useful in a cotton - soybean rotation to reduce the numbers of reniform nematodes and allow cotton to be grown economically.

2 2017 Beltwide Cotton Conferences, Dallas, TX, January 4-6, Introduction The reniform nematode (Rotylenchulus reniformis) causes considerable damage and yield loss to cotton in the United States from the middle-atlantic states south then west thru Texas. Presently no commercial upland cotton varieties have reniform nematode resistance, whereas several sources of reniform nematode resistance exist in soybean. Soybean reniform nematode resistance is most often linked to resistance to the soybean cyst nematode (SCN (Heterodera glycines)) obtained from Peking, PI90763, and PI It has been shown that SCN resistance obtained from PI lacks resistance to reniform nematode (Robbins & Rakes, 1996). This is unfortunate because the majority (about 98%) of soybean varieties with SCN resistance are linked to PI The reniform nematode non-host crops of corn, sorghum and rice would also be useful in rotation with cotton. The use of reniform nematode resistant soybean in a rotation with cotton can be a useful management option. Public soybean breeding lines from programs at the University of Arkansas, Clemson University, University of Missouri, University of Southern Illinois, and USDA from Jackson Tennessee that have a low rate of reniform nematode reproduction may prove very useful in breeding soybean for reniform nematode resistance. Information on the reproduction of the reniform nematode on contemporary soybean cultivars is limited. Robbins, et al. (1994) reported on the reproduction of the reniform nematode on 30 soybean cultivars. In 1996, Robbins & Rakes reported reniform nematode reproduction on 16 soybean cultivars, 45 germplasm lines, and the differentials used in the soybean cyst nematodes race determination tests (Peking, PI90763, PI88788). A history of the reniform nematode in the South was given to the Southern Soybean Disease Workers (Robbins 2013b). During the 1999 to 2016 period yearly tests have determined the host status for over 2,600 soybean lines (Robbins et al., 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007a, 2008, 2009, 2010, 2011, 2012, 2013a, 2014, 2015, 2016). These papers are the basis for reniform nematode reproduction information on contemporary soybean lines. The breeding lines tested for reniform nematode reproduction are given by Robbins et al. (2007b, 2008, 2009, 2010, 2011, 2012, 2013a, 2014, 2015, and 2016). The objectives of the 2016 studies were to: 1) identify new soybean cultivars that are poor hosts for the reniform nematode that could be useful in rotation with cotton or other reniform nematode susceptible crops in reniform nematode infested fields. 2) to identify useful breeding soybean lines for use in selection of new reniform nematode resistant cultivars and 3) to list useful lines for cotton-soybean rotations from 2012 to Materials and Methods The soybean lines and cultivars tested in 2016 were from both private and public sources. Seeds of all cultivars were germinated in vermiculite and transplanted into 10-cm-diam. clay pots containing 500 cm 3 of pasteurized fine sandy loam soil (approximately 86% sand, 8% silt, 6 % clay, <1% O.M.) for the private lines and 8 ounce Styrofoam cups containing 180 cm 3. The reniform nematode inoculum was obtained by washing the soil from the roots of the susceptible cultivar Braxton grown in the greenhouse for at least 10 weeks, suspending the nematodes in water, and pouring the nematode suspension through nested 850- and 38-μm-pore sieves. The material on the 38-μm-pore sieve was placed on a tissue in a Baermann funnel. All vermiform stages of R. reniformis were collected after 16 hours. A total of 2,000 vermiform reniform nematodes were injected with an autopipe into two, 2.5 cm-deep holes made in the soil in each pot containing one seedling in the cotyledon stage the day of transplanting. Pots were arranged in a randomized complete block design, with five replications per line or cultivar. Soybean cultivars Anand and Hartwig were included as resistant controls, Braxton as a susceptible control and an inoculated pot with no plant (fallow) as an inoculum survivor control. After 84 days the number of vermiform reniform nematodes in the soil of each pot was determined (Jenkins, 1974). A reproductive index (RI), defined as the number of eggs + vermiform nematodes at test termination (Pf)/initial inoculation level (Pi), was calculated for each cultivar. In addition, the ratio of the RI of each cultivar to the RI of Anand (RA) and Hartwig (RH) was calculated. The log ratio data of both [log10 (RA + 1)] and [log10 (RH + 1)] were analyzed as a randomized complete block using analysis of variance. Log ratio transformations were used because of the high degree of variation in nematode counts within a cultivar. All statistical analyses were carried out using SAS version 8 (SAS Institute, Cary, NC).

3 2017 Beltwide Cotton Conferences, Dallas, TX, January 4-6, Results Of the 144 Arkansas Variety test lines, 139 were considered suitable hosts to reniform; however; Dyno-Gro S49xs76, Delta Grow DG4995 RR, Armor AR5206C, Go Soy 4914GTS, and Go Soy 49G16 had a magnitude of resistance that was similar to the highly resistant controls Anand and Hartwig. These commercially available reniforn nematode resistant soybean lines may be useful in a cotton - soybean rotation to reduce the numbers of reniform nematodes and allow the economically growing of cotton (Table 1). The reniform nematode did not reproduce more than Anand on 22 lines (17 than Hartwig) of the 211 breeding lines and varieties submitted by Public Soybean Breeders. These lines may be of interest for developing reniform resistant cultivars in a soybean breeding programs (Table 2). Public breeding lines with a useful level of reniform resistance in varieties and breeding lines tested in 2016 are listed in Table 2. Of 2016 s 211 public breeding lines, varieties, and lines up to 22 would be useful in reniform resistance breeding programs. In table 3 all soybean varieties with levels of resistance to reniform nematode useful in cotton-soybean rotations of tests since 2013 are listed. Annual Reproductive Indexes of Reniform nematode have been reported by the senior author since Finding the older varieties may be a challenge as many private varieties last only a very few seasons (years). Table 1. Rotylenchulus reniformis data of Average Soil Count per Pot (500 cm 3), Reproduction index (Pf/Pi) and Disease Rating on 144 selected soybean cultivars and lines from the Arkansas Soybean Variety Testing Program 2016 tests. Converted Soil RI Disease Test line RI Count (Pf/Pi) Rating Fallow Survival Check Anand Resistant Check Go Soy 49G Resistant Hartwig Resistant Check Go Soy 5214GTS Resistant Armor AR5206C Resistant Delta Grow DG4995 RR Resistant Dyna-Gro S49XS Resistant Asgrow AG 53X Moderate Resistant Progeny P 5016RXS Moderate Resistant GS43R Moderate Resistant USG 7536XT Moderate Susceptible Progeny P 4588RY Moderate Susceptible GS48R Moderate Susceptible NK S42-E5 Brand Moderate Susceptible Delta Grow DG4977 LL/STS Moderate Susceptible Armor 47-D Moderate Susceptible AvDx-F Susceptible LG C4615RX Susceptible Delta Grow DG4790 RR Susceptible Armor 48-D Susceptible Delta Grow DG5580 RR Susceptible Eagle Seed ES4998RR Susceptible

4 2017 Beltwide Cotton Conferences, Dallas, TX, January 4-6, AvZx-D Susceptible GS45R Susceptible NK S47-C8 Brand Susceptible Progeny P 4944RX Susceptible Asgrow AG 42X Susceptible Armor 47-R Susceptible S Susceptible Progeny P 5768RX Susceptible GS47R Susceptible REV 49L Susceptible Go Soy 4912LL Susceptible Eagle Seed ES4870RYX Susceptible Go Soy 4913LL Susceptible Go Soy 483.C Susceptible S Susceptible Delta Grow DG4845 RR2X Susceptible REV 48A Susceptible Mycogen 5N424R Susceptible Armor ARX Susceptible NK S49-B1 Brand Susceptible Progeny P 4516RXS Susceptible REV 45A Susceptible Delta Grow DG4680 RR Susceptible Delta Grow DG4781 LL Susceptible Delta Grow DG4855 RR2X/STS Susceptible Eagle Seed ES4460RYX Susceptible AvDx-E Susceptible NK S48-D9 Brand Susceptible Mycogen 5N480R Susceptible Armor AR Susceptible CZ 4898 RY Susceptible Asgrow AG 48X Susceptible Progeny P 4613RYS Susceptible Delta Grow DG5461 LL Susceptible Asgrow AG 49X Susceptible LG C4900RX Susceptible Eagle Seed ES5930RYX Susceptible USG 74B83RS Susceptible Dyna-Gro S48XT Susceptible Asgrow AG 46X Susceptible UAX 59313GT Susceptible AvDx-D Susceptible UAX 59013C Susceptible

5 2017 Beltwide Cotton Conferences, Dallas, TX, January 4-6, Eagle Seed ES4680RYX Susceptible Delta Grow DG5170 RR2/STS Susceptible MSX 48XDS Susceptible Asgrow AG 55X Susceptible NK S52-Y2 Brand Susceptible Armor 48-D Susceptible USG 7506XTS Susceptible S Susceptible USG 7487XTS Susceptible UAX 59012C Susceptible Armor 43-D Susceptible Mycogen 5N406R Susceptible Asgrow AG 45X Susceptible UAX Susceptible Shillinger e Susceptible Asgrow AG 47X Susceptible Blue River 50SK Susceptible Eagle Seed ES5650RR Susceptible Asgrow AG 44X Susceptible MSX 46XDS Susceptible Delta Grow DG5067 LL Susceptible Progeny P 4816RX Susceptible Armor AR Susceptible Armor 44-D Susceptible CZ 4222 LL Susceptible Dyna-Gro S49XT Susceptible Mycogen 5N414R Susceptible LG C4845RX Susceptible Go Soy 4814GTS Susceptible Progeny P 4799RXS Susceptible NK S47-K5 Brand Susceptible Blue River 47FC Susceptible Armor AR Susceptible Go Soy 42L Susceptible Eagle Seed ES5420RYX Susceptible NK S45-W9 Brand Susceptible Eagle Seed ES5015RYX Susceptible UAX 59011C Susceptible USG 7496XTS Susceptible S Susceptible Dyna-Gro S45XS Susceptible NK S42-P6 Brand Susceptible Dyna-Gro S45LL Susceptible

6 2017 Beltwide Cotton Conferences, Dallas, TX, January 4-6, Delta Grow DG4587 LL/STS Susceptible USG 756XT Susceptible Armor ARX Susceptible Armor 46-D Susceptible MSX 49XD Susceptible UAX 59113GT Susceptible Delta Grow DG4545 RR2X/STS Susceptible Mycogen 5N433R Susceptible Armor 39-D Susceptible Armor ARX Susceptible Go Soy 43L Susceptible REV 48L Susceptible USG 7497XT Susceptible Dyna-Gro SX16844XS Susceptible Armor 53-D Susceptible Asgrow AG Susceptible CZ 4656 RY Susceptible Progeny P 4620RXS Susceptible Asgrow AG 46X Susceptible USG 7557XT Susceptible Shillinger e Susceptible Dyna-Gro S45XS Susceptible NK S56-M8 Brand Susceptible Progeny P 5417RX Susceptible Shillinger e Susceptible Armor 49-D Susceptible Armor 49-D Susceptible Progeny P 4247LL Susceptible Asgrow AG 54X Susceptible UAX Susceptible Armor 55-R Susceptible REV 48A Susceptible MSX 49XD Susceptible GS4915R Susceptible USG 7547XT Susceptible UAX 59111C Susceptible Ellis Susceptible Check Braxton Susceptible Check Blue = Resistant Red = Moderate Resistant Green = Moderate Susceptible Black = Susceptible

7 2017 Beltwide Cotton Conferences, Dallas, TX, January 4-6, Table 2. Rotylenchulus reniformis data of Breeder, Line, Soil Count Average per Pot (500 cm 3 ), Reproduction Index = (Pf/Pi) and Disease Rating on 219 selected soybean breeding lines from cooperating Southern Soybean Breeders 2015 tests. Test Line Breeder Soil Count RI (Pf/Pi) Disease Rating Fallow Survival Check S Shannon Resistant S Shannon Resistant S Shannon Resistant Hartwig Resistant Check SC RR1 Fallen Resistant SC R2 Fallen Resistant S Shannon Resistant S Shannon Resistant Anand Resistant Check S Shannon Resistant S Shannon Resistant SC10-07 Fallen Resistant JTN-5316 Arelli Resistant G R2 Li Resistant JTN-5516 Arelli Resistant S Shannon Resistant SC R2 Fallen Resistant G R2 Li Moderate Resistant ExF12 Kantartzi Moderate Resistant ExF1 Kantartzi Moderate Resistant G R2 Li Moderate Resistant G R2 Li Moderate Resistant R Chen Moderate Resistant ExF39 Kantartzi Moderate Resistant ExF10 Kantartzi Moderate Resistant Forrest (Tartartzi CK) Kantartzi Moderate Resistant JTN-5216 Arelli Moderate Resistant ExF59 B Kantartzi Moderate Susceptible ExF88 Kantartzi Moderate Susceptible ExF76 Kantartzi Moderate Susceptible S Shannon Moderate Susceptible R Chen Moderate Susceptible S Shannon Moderate Susceptible SC R2 Fallen Moderate Susceptible ExF17 Kantartzi Moderate Susceptible

8 2017 Beltwide Cotton Conferences, Dallas, TX, January 4-6, JTN-5416 Arelli Moderate Susceptible ExF2 Kantartzi Moderate Susceptible ExF7 Kantartzi Moderate Susceptible ExF59 A Kantartzi Moderate Susceptible S Shannon Susceptible S Fallen Susceptible SC Fallen Susceptible ExF63 Kantartzi Susceptible ExF4 Kantartzi Susceptible JTN-5116 Arelli Susceptible SC RR1 Fallen Susceptible SC07-108RR Fallen Susceptible Hartwig Li Susceptible ExF30 Kantartzi Susceptible ExF9 Kantartzi Susceptible ExFF38 Kantartzi Susceptible S Shannon Susceptible ExF77 Kantartzi Susceptible ExF67 Kantartzi Susceptible R Chen Susceptible S Shannon Susceptible ExF24 Kantartzi Susceptible G R2 Li Susceptible ExF52 Kantartzi Susceptible ExF55 Kantartzi Susceptible ExF98 Kantartzi Susceptible SC RR Fallen Susceptible ExF62 Kantartzi Susceptible ExF91 Kantartzi Susceptible ExF31 Kantartzi Susceptible ExF29 Kantartzi Susceptible R Chen Susceptible ExF57 Kantartzi Susceptible ExF74 Kantartzi Susceptible ExF73 Kantartzi Susceptible R Chen Susceptible G R2 Li Susceptible R Chen Susceptible S Shannon Susceptible ExF8 Kantartzi Susceptible

9 2017 Beltwide Cotton Conferences, Dallas, TX, January 4-6, ExF3 Kantartzi Susceptible ExF69 Kantartzi Susceptible SC Fallen Susceptible R Chen Susceptible S Shannon Susceptible ExF90 Kantartzi Susceptible ExF81 Kantartzi Susceptible R Chen Susceptible G R2 Li Susceptible Ellis Susceptible Check ExF60 Kantartzi Susceptible R Chen Susceptible ExF75 Kantartzi Susceptible G R2 Li Susceptible R Chen Susceptible R RY Chen Susceptible G R2 Li Susceptible ExF48 Kantartzi Susceptible R RY Chen Susceptible R Chen Susceptible S Shannon Susceptible SC Fallen Susceptible ExF71 Kantartzi Susceptible G Li Susceptible G R2 Li Susceptible ExF56 Kantartzi Susceptible R Chen Susceptible Essex (Tartartzi CK) Kantartzi Susceptible ExF78 Kantartzi Susceptible G R2 Li Susceptible ExF49 Kantartzi Susceptible R RR Chen Susceptible ExF87 Kantartzi Susceptible ExF40/41 Kantartzi Susceptible ExF19 Kantartzi Susceptible G R2 Li Susceptible R Chen Susceptible R Chen Susceptible ExF37 Kantartzi Susceptible ExF83 Kantartzi Susceptible R Chen Susceptible

10 2017 Beltwide Cotton Conferences, Dallas, TX, January 4-6, ExF94 Kantartzi Susceptible SC10-455RR Fallen Susceptible R Chen Susceptible R RR Chen Susceptible G R2 Li Susceptible G R2 Li Susceptible R Chen Susceptible ExF11 Kantartzi Susceptible R Chen Susceptible R Chen Susceptible SC10-406RR Fallen Susceptible G R2 Li Susceptible SC Fallen Susceptible CNS Li Susceptible G R2 Li Susceptible ExF68 Kantartzi Susceptible ExF45 Kantartzi Susceptible ExF36 Kantartzi Susceptible G Li Susceptible R Chen Susceptible ExF46 Kantartzi Susceptible G R2 Li Susceptible G12PR-63R2 Li Susceptible G R2 Li Susceptible ExF93 Kantartzi Susceptible Bossier Li Susceptible G R2 Li Susceptible ExF84 Kantartzi Susceptible ExF79 Kantartzi Susceptible ExF28 Kantartzi Susceptible R Chen Susceptible ExF80 Kantartzi Susceptible R RY Chen Susceptible Hagood Li Susceptible G R2 Li Susceptible ExF53 Kantartzi Susceptible Cook Li Susceptible ExF5 Kantartzi Susceptible R Chen Susceptible R Chen Susceptible ExF27 Kantartzi Susceptible

11 2017 Beltwide Cotton Conferences, Dallas, TX, January 4-6, ExF89 Kantartzi Susceptible G R2 Li Susceptible ExF21 Kantartzi Susceptible ExF43/44 Kantartzi Susceptible SC10-79 Fallen Susceptible Benning Li Susceptible ExF50 Kantartzi Susceptible R Chen Susceptible UA 5612 Chen Susceptible R Chen Susceptible G Li Susceptible ExF58 Kantartzi Susceptible ExF18 Kantartzi Susceptible G Li Susceptible G R2 Li Susceptible ExF51 Kantartzi Susceptible G R2 Li Susceptible G11PR-56151R2 Li Susceptible R Chen Susceptible ExF22 Kantartzi Susceptible S Shannon Susceptible ExF23 Kantartzi Susceptible ExF26 Kantartzi Susceptible R Chen Susceptible ExF34 Kantartzi Susceptible R Chen Susceptible ExF72 Kantartzi Susceptible G R2 Li Susceptible ExF6 Kantartzi Susceptible G Li Susceptible G Li Susceptible Braxton Susceptible Check ExF20 Kantartzi Susceptible ExF65 Kantartzi Susceptible ExF54 Kantartzi Susceptible G R2 Li Susceptible ExF32+33 mix Kantartzi Susceptible ExF15/16 Kantartzi Susceptible R RY Chen Susceptible ExF25 Kantartzi Susceptible SC RR Fallen Susceptible

12 2017 Beltwide Cotton Conferences, Dallas, TX, January 4-6, ExF64 Kantartzi Susceptible G11PR-56238R2 Li Susceptible SC09-210RR Fallen Susceptible ExF66 Kantartzi Susceptible ExF70 Kantartzi Susceptible G R2 Li Susceptible G R2 Li Susceptible Haskell Li Susceptible ExF97 Kantartzi Susceptible SC10-69 Fallen Susceptible GaSoy 17 Li Susceptible ExF35 Kantartzi Susceptible ExF47 Kantartzi Susceptible ExF95 Kantartzi Susceptible ExF61 Kantartzi Susceptible ExF42 Kantartzi Susceptible ExF13 Kantartzi Susceptible Blue = Resistant Red = Moderate Resistant Green = Moderate Susceptible Black = Susceptible A list of Public Soybean Breeders commercial lines and varieties from the test years 2013 to 2016 are given (Table 3). These varieties would be especially important for a cotton-soybean rotation where reniform is a problem. Other earlier tests are not given because of rapid replacement of these varieties by new varieties and their subsequent unavailability. Table 3. Private commercial soybean varieties tested in 2012, 2013, 2014, and 2015 that exhibit variety reniform resistance Delta Grow 4940 Delta Grow DG4940RR Delta Grow DG 4995 RR Armor AR5206C ARMOR X1410 Armor AX4520 Go Soy 4914GTS Delta Grow DG4995 RR MPG-S-5214NRR Eagle Seed ES5335RY Delta Grow DG 5128 Dyno-Gro S49xs76 Willcross RY2513N LG Seeds C5252R2 Go Soy Leland Go Soy 4914GTS Leland Asgrow AG5535 GENRR2Y Go Soy 49G16 ARMOR X47C Schillinger 4712R2 Eagle Seed 5650RR Willcross WX 2524N Armor AX4450 Dyna-Gro S52RY75 Delta Grow DG5230GENRR2Y Mycogen X54522NR2

13 2017 Beltwide Cotton Conferences, Dallas, TX, January 4-6, Summary Commercial reniform nematode resistant soybean varieties may be useful in cotton-soybean rotations. Of the 142 private soybean lines tested in 2016 five exhibited adequate resistance to be considered useful in a cotton-soybean rotation (Table 1). All Commercial Varieties tested in 2016 can be found in Table 1. References Jenkins, W. R., A rapid centrifugal-flotation technique for separating nematodes from soil. Plant Disease Reporter 48:692. Robbins, R. T., L. Rakes, and C. R. Elkins Reproduction of the reniform nematode on thirty soybean cultivars. Supplement to the Journal of Nematology 26: Robbins, R. T., and L. Rakes Resistance to the reniform nematode in selected soybean cultivars and germplasm lines. Journal of Nematology 28: Robbins, R. T., L. Rakes, L. E. Jackson, and D. G. Dombek Reniform nematode resistance in selected soybean cultivars. Supplement to the Journal of Nematology 31: Robbins, R. T., L. Rakes, L. E. Jackson, E. E. Gbur, and D. G. Dombek Host suitability in soybean cultivars for the reniform nematode, 1999 tests. Supplement to the Journal of Nematology Vol. 32: Robbins, R. T., L. Rakes, L. E. Jackson, E. E. Gbur, and D. G. Dombek Host suitability in soybean cultivars for the reniform nematode, 2000 tests. Supplement to the Journal of Nematology Vol. 33: Robbins, R. T., E. R. Shipe, L. Rakes, L. E. Jackson, E. E. Gbur, and D. G. Dombek Host suitability in soybean cultivars for the reniform nematode, 2001 tests. Supplement to the Journal of Nematology Vol Robbins, R. T., E. R. Shipe, L. Rakes, L. E. Jackson, E. E. Gbur, and D. G. Dombek Host suitability in soybean cultivars for the reniform nematode, 2001 tests. Proceeding, Beltwide Cotton Conferences, Nashville, TN, January Robbins, R. T., L. Rakes, L. E. Jackson, E. E. Gbur, and D. G. Dombek Reniform Nematode Reproduction on Soybean in Tests conducted in Proceeding, Beltwide Cotton Conferences, San Antonio, TX, January Robbins, R. T., P. Chen, L. Rakes, L. E. Jackson, E. E. Gbur,D. G. Dombek, and E. Shipe Reniform nematode reproduction on soybean cultivars in tests conducted in Proceedings of the Beltwide Cotton Conferences, New Orleans, Robbins, R. T., L. Rakes, L. E. Jackson, E. E. Gbur, D. G. Dombek, P. Chen, E. Shipe and G. Shannon Reniform nematode reproduction on soybean cultivars and breeding lines in 2005 tests. Proceedings of the Beltwide Cotton Conferences, San Antonio, Robbins, R. T., E. Shipe, P. Arelli, P. Chen, G. Shannon, L. Rakes, L. E. Jackson, E. E. Gbur, and D. G. Dombek. 2007a. Reniform nematode reproduction on soybean cultivars and breeding lines in 2006 tests. Proceedings of the Beltwide Cotton Conferences, New Orleans, Robbins, R. T., E. Shipe, G. Shannon, P. Arelli, and P. Chen. 2007b. Public soybean breeding lines tested for reniform nematode (Rotylenchulus reniformis) reproduction. Journal of Nematology 39:92. Robbins, R. T., E. Shipe, P. Arelli, P. Chen, L. Rakes, L. E. Jackson, E. E. Gbur and D. G. Dombek Reniform Nematode Reproduction on Soybean Cultivars and Breeding Lines in Proceedings of the Beltwide Cotton Conferences, Nashville, TN,

14 2017 Beltwide Cotton Conferences, Dallas, TX, January 4-6, Robbins, R. T., E. Shipe, P. Arelli, P. Chen, L. Rakes, L. E. Jackson, E. E. Gbur and D. G. Dombek Reniform Nematode Reproduction on Soybean Cultivars and Breeding Lines in Proceedings of the2009 Beltwide Cotton Conferences, San Antonio, TX Pgs Robbins, R.T., P. Chen, L. E. Jackson, E. E. Gbur, D. G. Dombek, E. Shipe, P. Arelli, G. Shannon, and C. Overstreet Reniform Nematode Reproduction on Soybean Cultivars and Breeding Lines in Proceedings of the 2010 Beltwide Cotton Conferences, New Orleans, LA Pgs Robbins, R. T., E. Shipe, P. Arelli, P. Chen, G. Shannon, K. M. Rainey, L. E. Jackson, E. E. Gbur, D. G. Dombek, and J. T. Velie Reniform nematode reproduction on soybean cultivars and breeding lines in Proceedings of the 2011 Beltwide Cotton Conferences, Atlanta, Georgia, January 4-7, 2011, Pgs Robbins, R. T., E. Shipe, P. Arelli, P. Chen, G. Shannon, S. K. Kantartzi, L. E. Jackson, E. E. Gbur, D. G. Dombek, and J. T. Velie Reniform nematode reproduction on soybean cultivars and breeding lines in Proceedings of the 2012 Beltwide Cotton Conferences, Orlando, FL, January 3-6, Pgs Robbins, R. T., G. Shannon, P. Chen, S. K. Kantartzi, L. E. Jackson, E. E. Gbur, D. G. Dombek, and J. T. Velie. 2013a. Reniform nematode reproduction on soybean cultivars and breeding lines in Proceedings of the2013 Beltwide Cotton Conferences, San Antonio, TX. Pgs Robbins, R. T., 2013b. A History of the Reniform Nematode in the South. Southern Soybean Disease Workers, March (Abst.). Robbins, R. T., G. Shannon, P. Chen, S. K. Kantartzi, L. E. Jackson, E. E. Gbur, D. G. Dombek, J. T. Velie, and T. R. Faske Reniform Nematode Reproduction on Soybean Cultivars and Breeding Lines in Proceeding of the 2014 Beltwide Cotton Conferences, New Orleans Jan 6-8. Pgs Robbins, R. T., Ben Fallen, G. Shannon, P. Chen, S. K. Kantartzi, Travis R Faske, L. E. Jackson, E. E. Gbur, D. G. Dombek and J. T. Velie Reniform Nematode Reproduction on Soybean Cultivars and Breeding Lines in Proceedings Beltwide Conferences 2015, San Antonio. Robbins, R. T., P. Chen, G. Shannon, S. Kantartzi, Z. Li, T. Faske, J. Vellie, L. Jackson, E. Gbur, and D. Dombek Reniform nematode reproduction on soybean cultivars and breeding lines in 2015, Proceeding of the 2016 Beltwide Cotton Conferences, New Orleans Pg

15 2016 Beltwide Cotton Conferences, New Orleans, LA, January 5-7, RENIFORM NEMATODE REPRODUCTION ON SOYBEAN CULTIVARS AND BREEDING LINES IN 2015 Robert T. Robbins Pengyin Chen University of Arkansas Fayetteville, AR Grover Shannon University of Missouri Portageville, MO Stella Kantartzi Southern Illinois University Carbondale, IL Zenglu Li University of Georgia Athens, GA Travis Faske University of Arkansas Lonoke, AR Jeff Velie Larry Jackson Edward Gbur Donald Dombek University of Arkansas Fayetteville, AR Abstract In 2015, 116 private soybean cultivars and lines from the Arkansas Variety Testing Program and 219 breeding lines and varieties from Public Soybean Breeders: 68 from Arkansas (Chen), 21 from the Missouri (Shannon), 40 from Georgia (Li) and 90 from Southern Illinois (Kantartzi) were tested in the greenhouse to determine their suitability as hosts for the reniform nematode (RN), Rotylenchulus reniformis. Resistant soybean lines provide an economically effective management tactic to suppress RN population densities for a subsequent cotton crop. All genotypes were inoculated with 2,000 vermiform RN in two separate greenhouse studies, with private tested lines grown for 91 days and the public breeders lines tested 83 days. The RN resistant varieties Anand and Hartwig, the RN susceptible cultivars Braxton and Ellis, and fallow reniform nematode infested soil (to show survival without a host) served as controls. The reproductive index (RI = Pf/Pi) was calculated based on the average number of vermiform nematodes extracted from the soil of each treatment. Soybean lines with a greater (P = 0.05) RI than the resistant controls were considered suitable hosts for R. reniformis. Of the 116 Arkansas Variety test lines, 109 were considered suitable hosts; however private lines Delta Grow DG 4995 RR, Go Soy 4914GTS, Delta Grow DG 5128, and Go Soy Leland had a magnitude of resistance that was similar to the resistant controls while lines S , S , and S are public breeder lines submitted by Missouri. The Reniform nematode did not reproduce more than the resistant checks Anand on (22 of the 219) and on (7 of the 219) Hartwig on breeding lines and varieties submitted by the Public Soybean Breeders. These lines may be of interest for developing reniform resistant cultivars in a soybean breeding programs. The four commercially available soybean lines from the Arkansas variety test may be useful in a cotton - soybean rotation to reduce the numbers of reniform nematodes and allow cotton to be grown economically. Introduction The reniform nematode (Rotylenchulus reniformis) causes considerable damage and yield loss to cotton in the United States from the middle-atlantic states south and west to Texas. Presently no commercial upland cotton varieties have reniform nematode resistance, whereas several sources of reniform nematode resistance exist in soybean. Soybean reniform nematode resistance is most often linked to resistance to the soybean cyst nematode (SCN (Heterodera

16 2016 Beltwide Cotton Conferences, New Orleans, LA, January 5-7, glycines)) obtained from Peking and PI It is known that SCN resistance obtained from PI lacks reniform resistance (Robbins & Rakes, 1996), which is unfortunate as the majority (over 95%) of soybean varieties with SCN resistance is linked to PI The use of reniform nematode resistant soybean in a rotation with cotton can be a useful management option. Public soybean breeding lines from programs at the University of Arkansas, Clemson University, University of Missouri, University of Southern Illinois, and USDA from Jackson Tennessee that have a low rate of reniform nematode reproduction may prove very useful in breeding for reniform nematode resistance. Information on the reproduction of the reniform nematode on contemporary soybean cultivars is limited. Robbins, et al. (1994) reported on the reproduction of the reniform nematode on 30 soybean cultivars. In 1996, Robbins & Rakes reported reniform nematode reproduction on 16 soybean cultivars, 45 germplasm lines, two cultivars Hartwig and Cordell with resistance from PI s and 90763, respectively, and the differentials used in the soybean cyst nematodes race determination tests. A history of the reniform nematode in the South was given to the Southern Soybean Disease Workers (Robbins 2013b). During the 1999 to 2015 period yearly tests have determined the host status for over 2,400 soybean lines (Robbins et al., 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007a, 2008, 2009, 2010, 2011, 2012, 2013a, 2014, 2015). These papers form the basis for reniform nematode reproduction information on contemporary soybean lines. The breeding lines tested for reniform nematode reproduction are given by Robbins et al. (2007b, 2008, 2009, 2010, 2011, 2012, 2013a, 2014, 2015). The objectives of the 2015 study were to: 1) identify new soybean cultivars that are poor hosts for the reniform nematode that would be useful in rotation with cotton or other reniform nematode susceptible crops in reniform nematode infested fields. 2) to identify useful breeding lines for use in selection of new reniform nematode resistant cultivars and 3) to list useful lines for cotton-soybean rotations from 2012 to Materials and Methods The soybean lines and cultivars tested in 2015 were from both private and public sources. Seeds of all cultivars were germinated in vermiculite and transplanted into 10-cm-diam. clay pots containing 500 cm3 of pasteurized fine sandy loam soil (approximately 86% sand, 8% silt, 6 % clay, <1% O.M.). The reniform nematode inoculum was obtained by washing the soil from the roots of the susceptible cultivar Braxton grown in the greenhouse for at least 10 weeks, suspending the nematodes in water, and pouring the nematode suspension through nested 850- and 38-μm-pore sieves. The material on the 38-μm-pore sieve was placed on a tissue in a Baermann funnel. All vermiform stages of R. reniformis were collected after 16 hours. A total of 2,000 vermiform reniform nematodes were injected with an autopipe into two, 2.5 cm-deep holes made in the soil in each pot containing one seedling in the cotyledon stage the day of transplanting. Pots were arranged in a randomized complete block design, with five replications per line or cultivar. Soybean cultivars Anand and Hartwig were included as resistant controls, Braxton as a susceptible control and an inoculated pot with no plant (fallow) as an inoculum survivor control. After 91 days for the private and 83 days for public varieties and lines, the number of vermiform reniform nematodes in the soil of each pot was determined (Jenkins, 1974). A reproductive index (RI), defined as the number of eggs + vermiform nematodes at test termination (Pf)/initial inoculation level (Pi), was calculated for each cultivar. In addition, the ratio of the RI of each cultivar to the RI of Anand (RA) and Hartwig (RH) was calculated. The log ratio data of both [log10 (RA + 1)] and [log10 (RH + 1)] were analyzed as a randomized complete block using analysis of variance. Log ratio transformations were used because of the high degree of variation in nematode counts within a cultivar. All statistical analyses were carried out using SAS version 8 (SAS Institute, Cary, NC). Results Of the Arkansas Variety test lines, 104 were considered suitable hosts; however; Delta Grow DG 4995 RR, Go Soy 4914GTS, Delta Grow DG 5128, and Go Soy Leland were commercial varieties and Missouri lines S , S , and S ; 2524N had a magnitude of resistance that was similar to the highly resistant controls Anand and Hartwig. Four commercial varieties (Morsoy Xtra 55X75, Willcross WXR2524N, Progeny P 5752RY, USG 75B75R) and one Missouri line (S ) were considered to be moderately resistant. The commercially available reniform nematode resistant soybean lines may be useful in a cotton - soybean rotation to reduce the numbers of reniform nematodes and allow cotton to be grown economically (Table 1).

17 2016 Beltwide Cotton Conferences, New Orleans, LA, January 5-7, Table 1. Rotylenchulus reniformis data of Average Soil Count per Pot (500 cm 3), Reproduction index (Pf/Pi) and Disease Rating on 116 selected soybean cultivars and lines from the Arkansas Soybean Variety Testing Program 2015 tests. Soil RI = Disease Test Line Rating Count Pf/Pi Fallow - Survival Check Check Delta Grow DG 4995 RR Resistant Anand - Check Check S (Missouri Line) Resistant Go Soy 4914GTS Resistant Hartwig - Check Check S (Missouri Line) Resistant S (Missouri Line) Resistant Delta Grow DG Resistant Go Soy Leland Resistant S Mod Res Morsoy Xtra 55X Mod Res Willcross WXR2524N Mod Res Progeny P 5752RY Mod Res USG 75B75R Mod Res CZ 5147LL Mod Susc Armor AR Mod Susc Delta Grow DG 5230 RR Mod Susc Mycogen 5N522R Mod Susc CZ 5150LL Susceptible Go Soy 5115LL Susceptible Armor 53-L Susceptible Progeny P 5226RYS Susceptible HBK 4653LL Susceptible HALO 4: Susceptible Armor AR Susceptible Willcross WXR2494NS Susceptible Go Soy 4714GTS Susceptible Armor AR Susceptible CZ 4590RY Susceptible AvDx-D Susceptible Pioneer P49T09BR Susceptible CZ 4959RY Susceptible Armor 44X5L Susceptible UA 5014C Susceptible Armor AR Susceptible Dyna-Gro S44LS Susceptible Mycogen 5N404R Susceptible

18 2016 Beltwide Cotton Conferences, New Orleans, LA, January 5-7, UA 5414RR Susceptible Mycogen 5N433R Susceptible LG Seeds C4867R Susceptible UA 5814HP Susceptible Delta Grow DG 4977 LL/STS Susceptible Progeny P 5414LL Susceptible HBK 4950LL Susceptible Croplan R2C4914S Susceptible Go Soy 4415LL Susceptible Armor 57-R Susceptible Go Soy 5215LL Susceptible Go Soy 4915R Susceptible USG 74A74RS Susceptible Eagle Seed ES4772RY Susceptible HALO 4: Susceptible Armor AR53X Susceptible Go Soy 5315LL Susceptible HBK 4953LL Susceptible Delta Grow DG 4935 RR2/STS Susceptible CZ 4105LL Susceptible Pioneer P50T15BR Susceptible LG Seeds C4780R Susceptible Armor AR Susceptible Eagle Seed ES5508RY Susceptible Willcross WXE2535NS Susceptible REV 44A Susceptible LG Seeds C4322R Susceptible Armor 48-C Susceptible Armor 41X5L Susceptible Go Soy Ireane Susceptible Dyna-Gro S48RS Susceptible Morsoy Xtra 46X Susceptible S Susceptible CZ 4540LL Susceptible Go Soy Glider Susceptible Armor 49X5L Susceptible Dyna-Gro S42RY Susceptible Go Soy 4714LL Susceptible NK S55-Q3 Brand Susceptible CZ 4044LL Susceptible Delta Grow DG 4781 LL Susceptible

19 2016 Beltwide Cotton Conferences, New Orleans, LA, January 5-7, CZ 5445LL Susceptible CZ 5225LL Susceptible USG 74K95RS Susceptible Morsoy Xtra 49X Susceptible Pioneer P41T33R Susceptible LG Seeds C4994R Susceptible CZ 4748LL Susceptible Delta Grow DG 5067 LL Susceptible Armor 51X5L Susceptible Croplan R2C Susceptible Progeny P 4757RY Susceptible Dyna-Gro S52LL Susceptible USG 75J45R Susceptible CZ 5242LL Susceptible Mycogen 5N490R Susceptible Mycogen 5N501R Susceptible Armor AR Susceptible REV 51A Susceptible Armor AR Susceptible Armor AR Susceptible Braxton Check Check Delta Grow DG 5367 LL Susceptible Croplan R2C4700S Susceptible NK S58-Z4 Brand Susceptible USG 74D95RS Susceptible USG Ellis Susceptible Armor 47X5L Susceptible Delta Grow DG 4567 LL Susceptible Armor AR Susceptible CZ 4818LL Susceptible REV 48A Susceptible Ellis - Check Check Delta Grow DG 4587 LL/STS Susceptible Progeny P 4214RY Susceptible CZ 4181RY Susceptible Delta Grow DG 4775 RR Susceptible Dyna-Gro S55LS Susceptible Go Soy 5515LL Susceptible Delta Grow DG 4985 RR Susceptible REV 55L Susceptible Progeny P 4814LLS Susceptible

20 2016 Beltwide Cotton Conferences, New Orleans, LA, January 5-7, Armor 49-X Susceptible The reniform nematode did not reproduce more on 16 lines than Anand on the179 breeding lines and varieties submitted by Public Soybean Breeders. These lines may be of interest for developing reniform resistant cultivars in a soybean breeding programs (Table 2). Table 2. Rotylenchulus reniformis data of Breeder, Line, Soil Count Average per Pot (500 cm 3), Reproduction Index = (Pf/Pi) and Disease Rating on 219 selected soybean breeding lines from cooperating Southern Soybean Breeders 2015 tests. Breeder Line Soil Count RI = Pf/Pi Disease Rating Fallow Ck Survival CK Kantartzi FxH Resistant Shannon S Resistant Kantartzi Hartwig Resistant Kantartzi FxH Resistant Kantartzi Peking Resistant Shannon S Resistant Shannon S Resistant Shannon S Resistant Shannon S Resistant Li Hartwig Resistant Res CK Hartwig Resistant Kantartzi FxH Resistant Kantartzi FxH Resistant Res CK Anand Resistant Kantartzi FxH Resistant Kantartzi FxH Resistant Li G R Resistant Kantartzi FxH Resistant Kantartzi FxH Mod. Resistance Shannon S Mod. Resistance Li G R Mod. Resistance Shannon S Mod. Resistance Chen R Mod. Resistance Li G R Mod. Resistance Kantartzi FxH Mod. Susceptible Chen R Mod. Susceptible Kantartzi FxH Mod. Susceptible Kantartzi FxH Susceptible Kantartzi FxH Susceptible Kantartzi FxH Susceptible Kantartzi FxH Susceptible Li G R Susceptible

21 2016 Beltwide Cotton Conferences, New Orleans, LA, January 5-7, Kantartzi FxH Susceptible Li G Susceptible Kantartzi FxH Susceptible Kantartzi FxH Susceptible Kantartzi FxH Susceptible Li G11PR-56238R Susceptible Li G11PR-209R Susceptible Chen RM Susceptible Li G13PR Susceptible Kantartzi FxH Susceptible Chen R Susceptible Kantartzi FxH Susceptible Chen R RR Susceptible Shannon S Susceptible Chen R Susceptible Shannon S Susceptible Shannon R Susceptible Chen S Susceptible Li G R Susceptible Kantartzi R Susceptible Chen FxH Susceptible Kantartzi FxH Susceptible Chen R RR Susceptible Shannon R Susceptible Kantartzi FxH Susceptible Chen S Susceptible Shannon S Susceptible Chen R Susceptible Chen R RR Susceptible Chen R Susceptible Li G R Susceptible Kantartzi FxH Susceptible Chen R Susceptible Kantartzi FxH Susceptible Kantartzi FxH Susceptible Chen R Susceptible Kantartzi FxH Susceptible Kantartzi FxH Susceptible Li G10PR-56444R Susceptible Li G11PR-56151R Susceptible Sus Ck FxH Susceptible

22 2016 Beltwide Cotton Conferences, New Orleans, LA, January 5-7, Kantartzi Braxton Susceptible Chen Osage Susceptible Shannon S Susceptible Kantartzi FxH Susceptible Kantartzi FxH Susceptible Kantartzi FxH Susceptible Kantartzi R Susceptible Chen RM Susceptible Chen FxH Susceptible Li FxH Susceptible Kantartzi G12PR-63R Susceptible Chen R Susceptible Kantartzi FxH Susceptible Chen UA Susceptible Shannon S Susceptible Chen R Susceptible Kantartzi FxH Susceptible Chen RM Susceptible Li G R Susceptible Kantartzi FxH Susceptible Kantartzi FxH Susceptible Chen R Susceptible Li G13LL Susceptible Kantartzi FxH Susceptible Li FxH Susceptible Kantartzi G Susceptible Li R Susceptible Chen CNS Susceptible Chen R RY Susceptible Chen R Susceptible Li FxH Susceptible Kantartzi G R Susceptible Chen R11-89RY Susceptible Li Bossier Susceptible Li G13LL Susceptible Chen R Susceptible Kantartzi FxH Susceptible Li G R Susceptible Li G R Susceptible Kantartzi FxH Susceptible Chen R Susceptible