Release of A/BTx643, A/BTx644 and A/BTx645 sorghum inbred parental lines

Transcription

1 Release of A/BTx643, A/BTx644 and A/BTx645 sorghum inbred parental lines D. T. Rosenow (deceased) and G.C. Peterson* Texas AgriLife Research and Extension Center, 1102 E FM 1294, Lubbock, TX ; W.L. Rooney and S.D. Collins, Dep. of Soil and Crop Sciences, Texas A&M University, College Station, TX ; C.A. Woodfin, USDA-ARS Plant Stress Laboratory, th Street, Lubbock, TX (Formerly Texas AgriLife Research); G.N. Odvody and K. Schaefer, Texas AgriLife Research and Extension Center, Agnew Street, Corpus Christi, TX ; J. A. Dahlberg, United Sorghum Checkoff Program, 4201 N. Interstate 27, Lubbock, TX Three sorghum [Sorghum bicolor (L). Moench] A/B-line inbred parental line pairs were released by Texas AgriLife Research (formerly the Texas Agricultural Experiment Station), Texas AgriLife Research and Extension Center, Lubbock, TX in A/BTx643, A/BTx644, and A/BTx645 were released based upon agronomic desirability and unique combinations of drought and disease resistance, and grain quality traits. Drought stress response characterization in sorghum is based on the plant growth stage at which the stress occurs. Two distinct responses have been identified (Rosenow and Clark, 1981; Rosenow et al., 1983; Rosenow 1993a, 1993b). Pre-flowering stress occurs when plants have significant moisture stress prior to flowering in growth stage 2, the time from panicle differentiation or shortly thereafter until flowering. Post-flowering stress occurs when plants are under severe moisture stress during growth stage, during grain-filling. Distinct visual plant symptoms differentiate the two types of stress, and the plant can be subjectively rated for each stress response (Rosenow et al., 1997). Methods Each line was developed from an intentional cross using the pedigree method of breeding. BTx643 was derived from the cross (BTx625*B35)-HL19-HL9-B4-BBK-P3- L3-P3-L2 and evaluated as A/B1 (this code does not designate sterility system). The original F 2 was selected at Halfway, TX. BTx644 was derived from the cross (BTx3042*(BTx625*B35))-L3-B3-OG2-OGBK-P2-L3-P1-L1-P1. A/BTx644, tested as A/B803, was originally selected from an F 2 population at Halfway, TX. BTx645 was derived from the cross (BTx623*(BTx625*B35))-B37-BBK-BHBK-P3-L1-P2-L1-P1. A/BTx644, tested as A/B807, was originally selected from an F 2 population at Lubbock, TX. BTx625 is derived from the cross BTx3197*SC170-6 and released by the Texas Agricultural Experiment Station in BTx3197, also known as Combine Kafir-60, was developed and released by the Texas Agricultural Experiment Station in SC170-6 is a BC 1 F 2 selection of the cross [(BTx406*IS12661 F3 )*IS12661]. IS is a zera zera (Murty and Govil, 1967) sorghum originally from Ethiopia. BTx623 is derived from the cross BTx3197*SC170-6 and released by the Texas Agricultural Experiment Station in B35, released as BTx642 by the Texas Agricultural Experiment Station in 2002, was derived from the intentional cross [BTx406*IS12555 F3 )*IS12555]-6. BTx3042 is a Redbine type sorghum released by the Texas Agricultural Experiment Station in The male sterile (A-line) counterpart of

2 each line was created using ATx623 as the A 1 cytoplasm source. ATx623 is the sterile counterpart to BTx623, released by the Texas Agricultural Experiment Station in The pedigree of BTx623 is BTx3197*SC Selection in the F 3 to F 10 generation was practiced at one or more of the following locations: Lubbock, Halfway, Beeville, Corpus Christi, Orange Grove and Chillicothe, TX, and Mayaguez and Isabella, PR. In the final generation of selection 20 individual panicles were self-pollinated and bulked to create the experimental lines which have been maintained by self-pollination. Selected agronomic traits are presented in Table 1. Characteristics All lines are three dwarf (dw 1 Dw 2 dw 3 dw 4 ) in height and have no testa (b 1 b 1 B 2 B 2 ). The B-lines restore fertility in A 1 cytoplasm. Fertility restoration in other cytoplasms has not been tested but none of the lines carry any know genes for fertility restoration in other cytoplasms. All lines are three dwarf (dw 1 Dw 2 dw 3 dw 4 ) in height and have no testa (b 1 b 1 B 2 B 2 ) (Schertz and Stephens, 1966). BTx643 has a white (RRyy) translucent (ZZ) pericarp, purple-red (PPqq) plant, no awns (AA), red glumes that cover approximately 30% of the grain, and a juicy leaf midrib. The panicle is semi-loose, long, and rectangular in shape. Rachis branches are moderately long and erect. The grain is slightly oval and turtle shaped with glabrous glumes. It possesses good post-flowering drought tolerance, charcoal rot resistance, and lodging resistance, and moderate tolerance to pre-flowering drought stress. The staygreen in Tx643 is not as dominant as in Tx642 and in some combinations is completely recessive. It is very susceptible to head smut and head blight, and susceptible to anthracnose. It is moderately resistant to downy mildew, tolerant to MDMV, and highly resistant to head blight. It has moderate resistance to grain mold/weathering. BTx644 has a light red (RRYY) moderately translucent (ZZ) pericarp with a slight orange tint, purple (PP ) plant, no awns (AA), purple glumes that cover approximately 35% of the grain, and a juicy leaf midrib. The panicle is rectangular to slightly oval and long (8-12 in length) and moderately open with moderately long and not stiff rachis branches that are somewhat drooping at maturity. The grain is nearly round but slightly pointed with glabrous glumes. It possesses excellent pre-flowering drought tolerance and a slight degree of stay-green with some lodging resistance. It is moderately resistant to head smut, downy mildew and most leaf diseases, and is tolerant to MDMV. BTx645 has a dark red (RRYY) translucent (ZZ) pericarp, purple-red (PPqq) plant, no awns (AA), purple-red glumes that cover approximately 35% of the grain, and a juicy leaf midrib. The semi-loose panicle is rectangular to slightly oval and long (10-13 in length). The rachis branches are moderately long, erect, and not stiff. Glumes are slightly pointed and slightly hairy. The grain is moderately large, somewhat oval and pointed, and threshes easily and clean from the glumes. The dark red grain has a moderately high level of grain mold/weathering resistance that transfers well into F 1 hybrids resulting in attractive appearance. The line and its hybrids possess moderate lodging resistance and excellent pre-flowering drought tolerance but with no stay-green. It is very susceptible to head smut, moderately resistant to downy mildew, moderately resistant to leaf diseases, and tolerant to MDMV. The line has excellent general combining ability. Reaction for selected stresses are presented in Table 2.

3 Availability Seed will be maintained and distributed by Texas AgriLife Research, Texas AgriLife Research and Extension Center, 1102 East FM1294, Lubbock, Texas Seed will be available with a Materials Transfer Agreement (MTA) from the Office of Technology Commercialization, Texas A&M University System, 1700 Research Parkway, Suite 250, College Station, TX Seed will be distributed with an MTA for a period of 12 years. Acknowledgement Development of these lines was supported in part by the International Sorghum/Millet (INTSORMIL) collaborative research support program funded by the United States Agency for International Development (USAID) under Grant No. LAG-G The significant contribution of L.E. Clark, R.A. Frederiksen, F.R. Miller, and A.J. Hamburger to the development and testing of these lines is sincerely acknowledged. References Murty, B.R. and J.N Govil Description of 70 groups in genus sorghum based on a modified Snowden s classification. Indian J. Genet. 27: Rosenow, D.T. 1993a. Breeding for drought resistance under field conditions. p In Proc. 18 th Biennial Grain Sorghum Research and Utilization Conference, Feb. 28 March 2, 1993, Lubbock, TX. Rosenow, D.T. 1993b. Screening plants for drought. Pp In Proc. of a Workshop on Adaptation of plants to soil stresses. August 1-4, 1993, Lincoln, NE. INTSORMIL Publication No Rosenow, D.T. and L.E. Clark Drought tolerance in sorghum. p In Proc. 36 th Annual Corn and Sorghum Res. Conf., Dec. 9-11, 1981, Chicago, IL. Rosenow, D.T., G. Ejeta, L.E. Clark, M.L. Gilbert, R.G. Henzell, A.K. Borrell and R.C. Muchow Breeding for pre- and post-flowering drought stress resistance in sorghum. In Proc. of the International Conference on Genetic Improvement of Sorghum and Pearl Millet, September 23-27, 1996, Lubbock, TX. Rosenow, D.T., J.E. Quisenberry, C.W. Wendt and L.E. Clark Drought tolerant sorghum and cotton germplasm. Agric. Water Manag. 7: Schertz, K. and J. C. Stephens Compilation of gene symbols, recommended revision and summary of linkages for inherited characters of Sorghum vulgare Pers. Texas Agric. Exp. Stn. Tech. Monograph 3, Texas A&M University, College Station, TX. Stephens, J. C. and R. F. Holland Cytoplasmic Male-Sterility for Hybrid Sorghum Seed Production. Agron. J. 46: Stephens, J.C., F.R. Miller, and D.T. Rosenow Conversion of alien sorghums to early combine genotypes. Crop Sci. 7:396.

4 Table 1. Agronomic characteristics of B.Tx643 - B.Tx645 sorghum parental lines at College Station and Lubbock, Texas. Designation/ Days to 50% Plant Panicle Agronomic desirability LPD Stalk Grain weight Location anthesis height exsertion rating rating lodging 1000 seed cm cm % g BTx LB BTx LB BTx LB BTx LB BTx LB = very good to 5 = very poor; =Leaf and plant death rating: 1 = all green, 3 = 50% of leaf area dead, 5 = entire plant dead # CS= College Station; = Corpus Christi; LB = Lubbock

5 Table 2. Disease and other ratings of B.Tx643 B.Tx645 sorghum parental lines at College Station, Corpus Christi, and Lubbock, Texas. Pre- flowering drought Post- flowering drought Designation/ Head Downy Anthracnose head phyto- Fusarium Chemical Location smut mildew blight toxicity rating rating % % BTx643 CS LB 1.0 BTx644 CS 3.0 LB 2.5 BTx645 CS 4.0 LB 3.0 BTx378 CS 1.0 LB 3.5 BTx623 CS 5.0 LB 2.5 Scored on a scale of scale of 1 = resistant to 5 = death Drought rating 1 = very good through 5 = very poor # CS= College Station; = Corpus Christi; LB = Lubbock