Registration of RTx437 sorghum parental line. (Parental Line).
RTx437 was developed using pedigree breeding methodology and has a pedigree of (77CS4 x RTx430)-B1-B2-B1-B1-B4-B1-CBK. 77CS4 is an unreleased line in the sorghum breeding program which was a selection from the partially converted version of SC120-14E (IS 2816C)(Rosenow et al., 1997). IS 2816C is a white, tan zerazera (Murty and Govil, 1967) from Sudan that was converted and released by the TAES/USDA in 1970 (Rosenow et al., 1997). RTx430 was developed and released in 1976 by the Texas Agricultural Experiment Station (Miller, 1984). The initial [F.sub.1] was made in a greenhouse in College Station by hand emasculation. [F.sub.2] progeny were selected at College Station, TX. Selections in the [F.sub.3] through [F.sub.8] generations were made at Beeville or Corpus Christi, TX. In most generations, selections were made in nurseries that were rainfed, and encountered significant disease pressure. Final selection and initial increases of RTx437 were made at College Station in 1990.
Grain from RTx437 has a white pericarp (rrYY), thick mesocarp (zz), and no testa ([b.sub.1][b.sub.1][B.sub.2][B.sub.2]). The line has tan plant color (ppqq), light brown glume color, and is awnless (AA). The line has moderate resistance to insecticide phytotoxicity, but the reaction is difficult to detect because of the tan plant color. The panicles are semicompact, glumes cover approximately 20% of the seed, and the grain is easily threshed from the panicle. Seed and/or grain of RTx437 are medium in size. Thousand seed weight of RTx437 averaged 27.6 g over four environments. RTx437 fully restores fertility in the A1 cytolasmic sterility system, but it is does not restore fertility to the A2 and A3 cytoplasmic sterility system.
Days to 50% anthesis for RTx437 range from 58 to 90 d (Table 1). RTx437 is genetically a three dwarf inbred (d[w.sub.1]D[w.sub.2] d[w.sub.3]d[w.sub.4]) in plant height, and phenotypically, the plant height of RTx437 ranges from 79 to 115 cm (Table 1). Panicle exsertion of RTx437 ranged from 0 to 17 cm (Table 1). Leaf and plant death ratings for RTx437 are similar to those of RTx436 (Miller et al., 1992), RTx430 and Tx2783 (Peterson et al., 1984), but the line will express higher levels of stress susceptibility than the checks under extremely dry conditions. On average, desirability ratings for RTx437 were similar to ratings for RTx430, RTx436, and Tx2783 (Table 1).
RTx437 is resistant to systemic and local lesion downy mildew pathotype 1 infection [caused by Peronosclerospora sorghi (W.Weston & Uppal) C.G. Shaw]. RTx437 is resistant to head smut [caused by Sporisorium reilianum (Kuhn) Langdon & Fullerton]. RTx437 shows moderate tolerance to Maize dwarf mosaic virus (MDMV) and it is susceptible to anthracnose [caused by Colletotrichum graminicola (Ces.) G.W. Wilson] when evaluated in College Station, TX. RTx437 is susceptible to grain mold, but has moderate levels of resistance to rust (caused by Puccinia purpurea Cooke), and zonate leaf spot (caused by Gloeocercospora sorghi D. Bain & Edgerton). The line has not been evaluted for reaction to any insect pests.
In hybrid combinations, RTx437 has good general combining ability. Hybrids of RTx437 with three different inbred lines in over 30 environments yielded 110% of RTx436 hybrids with the same females. Grain quality parameters for hybrids of RTx437 are similar to those of RTx436 hybrids. Performance of RTx437 hybrids was consistent across a wide range of environments, and there was no specific environment in which RTx437 hybrids performed consistently better or worse than the checks.
Seed of RTx437 will be maintained by the Dep. of Soil & Crop Sciences, Texas A&M University, College Station, TX 77843-2474. Small samples of RTx437 are available for distribution upon written request to the corresponding author. We request that appropriate recognition of the source be given if this germplasm contributes to the development of new germplasms or parental lines.
Table 1. Agronomic characteristics of RTx437 and checks from a total of 16 environments across Texas and Kansas. Days to 50% anthesis Plant height Genotype Mean Range Mean Range cm cm RTx437 71 58-90 102 79-119 RTx436 73 57-90 106 86-125 Tx2783 77 64-99 106 84-117 RTx430 72 60-90 109 86-124 Desirability Exsertion ([dagger]) Genotype Mean Range Mean Range cm cm RTx437 7 0-17 2.8 1.4-3.5 RTx436 7 0-17 2.8 1.3-3.7 Tx2783 1 0-3 3.0 1.3-4.4 RTx430 3 0-10 2.9 1.4-4.1 ([dagger]) Desirability ratings are a subjective rating based on a scale of 1 (best) to 10 (worst).
This research was supported in part by the International Sorghum/Millet Collaborative Research Support Program (INTSORMIL), which is funded by the United States Agency for International Development (USAID), and the Texas Grain Sorghum Producers Board. We acknowledge the support of the Sorghum Improvement Program staff involved in testing these lines.
Miller, F.R. 1984. Registration of RTx430 sorghum parental line. Crop Sci. 24:1224.
Miller, F.R., T.F. Dusek, K.L. Prihoda, and L.W. Rooney. 1992. Registration of RTx436 sorghum parental line. Crop Sci. 32:1518.
Murty, B.R., and J.N. Govil. 1967. Description of 70 groups in genus Sorghum based on a modified Snowden's classification. Indian J. Gen. Plant Breed. 27:75-90.
Peterson, G.C., J.W. Johnson, G.L. Teetes, D.T. Rosenow, and R.E. Schaffert. 1984. Registration of Tx2783 greenbug resistant soghum germplasm line. Crop Sci. 24:390.
Rosenow, D.T., J.A. Dahlberg, G.C. Peterson, L.E. Clark, F.R. Miller, A. Sotomayor-Rios, A.J. Hamburger, P. Madera-Torres, A. Quiles-Belen, and C.A. Woodfin. 1997. Registration of fifty converted sorghums from the sorghum conversion program. Crop Sci. 37: 1397-1398.
W.L. ROONEY, * F.R. MILLER, AND L.W. ROONEY
W.L. Rooney and L.W. Rooney, Associate Professor and Professor, respectively, Dep. of Soil & Crop Sciences, Texas A&M University, College Station, TX 77843-2474; F.R. Miller, Professor (retired), Dep. of Soil & Crop Sciences, Texas A&M University, College Station, TX 77843-2474; Registration by CSSA. Accepted 31 July 2002. * Corresponding author (email@example.com)
|Printer friendly Cite/link Email Feedback|
|Author:||Rooney, W.L.; Miller, F.R.; Rooney, L.W.|
|Date:||Jan 1, 2003|
|Previous Article:||Registration of the maize population Zapalote Chico 2451F. (Registrations Of Germplasms).|
|Next Article:||Environmental Effects of Transgenic Plants: the Scope and Adequacy of Regulation.|