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REGISTRATION OF GERMPLASM

Registration of TEM-SLC and TEM-SEC Switchgrass Germplasms

^a USDA-ARS, Grassland, Soil, and Water Research Lab., 808 E. Blackland Rd., Temple, TX 76502
^b ATO-DLO, Bornsesteeg 59, Postbus 17, 6700AA Wageningen, The Netherlands
^c Texas A&M Univ., College Station, TX 77843-2474
^d Texas Ag. Exp. Sta., 3507 HWY 59-E, Beeville, TX 78102-9410
^e Angelo State Univ., Box 10888, ASU Station, San Angelo, TX 76909
^f USDA-ARS, Pasture Systems and Watershed Manage. Res. Lab., Curtin Rd., University Park, PA 16802-3702

* Corresponding author (tischler{at}brc.tamus.edu)

TEM-SLC and TEM-SEC switchgrass (Panicum virgatum L.) germplasms (Reg. no. GP-77, PI 607837, and Reg. no. GP-78, PI 607838, respectively) were developed at the Grassland, Soil, and Water Research Laboratory, Temple, TX, and were released by the USDA-ARS and the Texas Agricultural Experiment Station on 24 Feb. 2000. These germplasms resulted from three cycles of recurrent phenotypic selection for reduced and enhanced seedling crown node elevation when grown under dim, continuous light. TEM-SLC and TEM-SEC were derived from ‘Alamo’ switchgrass.

Cell division at the base of the crown node normally stops when the coleoptile tip intercepts an adequate amount of red light (van Overbeek, 1936). When the amount of light is inadequate, continued elongation of the subcoleoptile internode (below the crown node) can push the crown node above the soil surface. Because adventitious roots are required for successful seedling establishment, seedlings with elevated crown (EC) nodes would need to initiate these roots above the soil surface. This seldom happens, and these seedlings often perish.

For the first cycle of selection, Alamo switchgrass seedlings were grown in dim light (Photosynthetic photon flux density 1.5 umol m^-2 s^-1) at 30°C (Tischler and Voigt, 1993), and seedlings having crown nodes in the highest and lowest 10% of values were saved to give rise to populations with EC and low crown (LC) node placement, respectively. These two populations were planted in separate isolation blocks in the field and allowed to intermate. Following seed harvest, seed of the EC and LC populations was planted, and seedlings were again grown in dim light. Individuals having the highest and lowest 10% of values for crown node placement were saved from the respective populations to give rise to cycle-2 plants. The process was repeated again to produce cycle-3 plants, seed of which constitute TEM-SEC and TEM-SLC.

When seed of TEM-SLC, Alamo, and TEM-SEC were evaluated in the low-light system, crown node elevations of the resulting seedlings were 0, 0.065, and 0.285 cm, respectively (F-test significant, P = 0.001) (Elberson et al., 1998). Considerable variability in crown node elevation was observed in TEM-SEC, indicating that continued selection for higher crown node placement should be successful. Little variability remained for crown node placement in TEM-SLC. When grown in field nurseries, mature plants of TEM-SLC and TEM-SEC were similar to Alamo switchgrass in height, leafiness, and flowering behavior.

Both TEM-SLC and TEM-SEC should be useful in photobiology and physiology studies to investigate factors regulating crown node placement and their genetic control (Elberson et al., 1998, 1999). In addition, TEM-SLC may have better establishment characteristics in field plantings when competition or atmospheric conditions limit incident light at the time of seedling emergence.

Seed of TEM-SLC and TEM-SEC will be maintained at the USDA Grassland, Soil, and Water Research Laboratory at Temple, TX. Limited samples of seed are available upon request from the corresponding author for at least 5 yr.

NOTES

Registration by CSSA.

Accepted for publication March 31, 2001.

REFERENCES

• Elberson, H.W., W.R. Ocumpaugh, M.A. Hussey, M.A. Sanderson, and C.R. Tischler. 1998. Crown node elevation of switchgrass and kleingrass under low light. Crop Sci. 38:712–716.[Abstract/Free Full Text]
• Elberson, H.W., W.R. Ocumpaugh, M.A. Hussey, M.A. Sanderson, and C.R. Tischler. 1999. Field evaluation of switchgrass seedlings divergently selected for crown node placement. Crop Sci. 39:475– 479.[Abstract/Free Full Text]
• Tischler, C.R., and P.W. Voigt. 1993. Characterization of crown node elevation in Panicoid grasses. J. Range Manage. 46:436–439.
• van Overbeek, J. 1936. Growth hormone and mesocotyl growth. Rec. Trav. Bot. Neerl. 33:333–340.

This Article Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Tischler, C.R. Articles by Sanderson, M.A. Search for Related Content PubMed Articles by Tischler, C.R. Articles by Sanderson, M.A. Agricola Articles by Tischler, C.R. Articles by Sanderson, M.A.