Crop Science 42:2157-2160 (2002)
© 2002 Crop Science Society of America
PLANT GENETIC RESOURCES
Variation of Condensed Tannins in Roundhead Lespedeza Germplasm
T. L. Springer*,a,
R. L. McGrawb and
G. E. Aikenc
a USDA-ARS, Southern Plains Range Research Station, 2000 18th Street, Woodward, OK 73801
b Univ. of Missouri, Dep. of Agronomy, 208 Waters Hall, Columbia, Missouri 65211
c USDA-ARS, Dale Bumpers Small Farms Research Center, 6883 South State Highway 23, Booneville, AR 72927
* Corresponding author (tspringer{at}spa.ars.usda.gov)
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ABSTRACT
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Roundhead lespedeza, Lespedeza capitata Michx., is a deep-rooted, perennial legume native to the eastern and central USA and is relatively common on remnant upland prairies throughout the Midwest. Information on condensed tannin (CT) concentrations from different plant parts is needed for cultivar development and also to provide data for developing management and feeding strategies. The objectives of this study were to determine variation of CT concentrations in roundhead lespedeza leaves, stems, and inflorescences; evaluate genotype variation over environments; and select germplasm lines that could be used for breeding parents and/or bulked into a synthetic variety. Thirty-nine roundhead lespedeza plant introductions (PI) were sampled from replicated nurseries grown in two environments in 1996. Plant shoots were collected at flowering and seed filling. Each plant shoot sample was divided into leaf, stem, and inflorescence. Condensed tannin concentrations were determined by means of a modified vanillin–HCl method. We found that variation due to the environment was low, variation due to genotype was high, and variation due to genotype x environment interaction was high. Of these 39 plant introductions, we selected eight that were common to both environments and had low CT concentrations in leaves at flowering. The CT content of these plant introductions, however, was still relatively high when compared with sericea lespedeza [Lespedeza cuneata (Dumont) G. Don] that was bred for low tannin content. Collections should be made from a larger geographical region to look for germplasm with lower CT concentrations.
Abbreviations: CT, condensed tannin • PI, plant introduction
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INTRODUCTION
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ROUNDHEAD LESPEDEZA is a deep-rooted, perennial legume native to the eastern and central USA. Roundhead lespedeza is the most widely distributed of the 11 Lespedeza species native to North America (Clewell, 1966). It is relatively common on remnant upland prairies throughout the Midwest. Roundhead lespedeza has many uses. It is an excellent forage plant that is eaten by all classes of livestock and the seed and foliage are used by wildlife for food and habitat (Graham, 1941). Roundhead lespedeza is susceptible to overgrazing and is slow to reseed under natural conditions (Kneebone, 1959).
Condensed tannins are found in leaves, stems, and seeds of many plant species and are associated with reduced degradation of protein and dry matter digestibility by ruminant animals (Albrecht and Muck, 1991; Miller and Ehlke, 1994; Broderick and Albrecht, 1997). Tannin can increase resistance to insects (Feeny, 1968) and in low concentrations can be associated with high HCN concentrations in birdsfoot trefoil, Lotus corniculatus L. (Ross and Jones, 1983). Environmental variations, such as temperature and moisture, are known to affect the concentration of CTs in forages (Anuraga et al., 1993; Roberts et al., 1993; Lees et al., 1994). Condensed tannins are reported to occur in sericea lespedeza (Pieters, 1934), and it is assumed that tannins affect the palatability of forage (Clarke et al., 1939; Stitt and Clarke, 1941, Donnelly, 1954; Windham et al., 1988).
Breeding for low tannin content in sericea lespedeza is possible; however, lines bred for lower tannin have been less productive (Donnelly, 1981). Mosjidis (1988) determined the genotype x environment effects of 10 sericea lespedeza genotypes grown in 10 environments and found that "Low tannin sericeas were found to be proportionally less productive than high-tannin sericeas in high-yielding environments. However, it is possible to select low-tannin lines with an environmental response similar to high-tannin sericeas."
To develop roundhead lespedeza cultivars successfully, information is needed on the variation of CT concentration from different plant parts and the effect of environment on CT concentration for available germplasm. Our objectives were (i) to determine variation of CT in roundhead lespedeza leaves, stems, and inflorescences; (ii) evaluate genotype variation over environments; and (iii) select germplasm lines, common to both environments, with low CT concentrations that could be used for breeding parents and/or bulked into a synthetic variety.
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MATERIALS AND METHODS
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Roundhead lespedeza germplasm was evaluated at two locations (environments). The first was at the USDA-Agricultural Research Service, Dale Bumpers Small Farm Research Center near Booneville, AR, and the second was at the University of Missouri, Agricultural Experiment Station, Bradford Farm near Columbia, MO (Table 1)
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Table 1. Soil and climate information at two experimental sites for evaluation of condensed tannin in roundhead lespedeza.
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Seeds of 39 roundhead lespedeza PIs were obtained from the USDA-Agricultural Research Service, Plant Genetic Resources Conservation Unit, Griffin, GA (Table 2)
. Seeds of each PI were scarified with sandpaper and inoculated with Rhizobium specific for Lespedeza spp. before germination. Seedlings were grown in a greenhouse before transplanting into field plots. In April 1993 at Booneville, plants were transplanted into single-row plots of five plants on 1-m spacings with 1 m between rows in each replicate. In August 1994, plants were similarly transplanted on the same row and plant spacings at Columbia. Both field plots were randomized complete block designs replicated three times. Plots were weeded by hand during the establishment year. Once plants were established, weedy grasses and forbs were allowed to establish around the plants. Spaces between rows were mowed two to three times a year to minimize weed competition.
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Table 2. Plant introduction numbers and origin of plant materials used to study condensed tannin in roundhead lespedeza.
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In 1996, each PI was sampled at flowering and during seed filling at both locations. At Booneville, one or two plants of each PI in each replicate were harvested when approximately 25% of the flowers had opened (approximately 25% bloom). Plants were harvested in bloom from 17 June to 29 July with 73% harvested on 17 June. Plants were harvested during seed filling from 17 June to 16 September with 65% of the samples harvested on 16 July and another 24% on 29 July. At Columbia, a single harvest of two or three plants of each PI in each replicate was made on 5 July when the majority of the flowers had opened (approximately 90% bloom). At seeding, a single harvest was made on 5 August.
Samples were hand harvested approximately 5 cm above the ground. One shoot was selected from each plant sampled and divided into leaves, stems, and inflorescences. Samples were lyophilized and weighed, then stored at -10°C. Samples were ground to pass through a 1-mm screen. Condensed tannin concentrations, on a dry weight basis, were determined for each 0.1-g sample by means of a modified vanillin–HCl method (Price et al., 1978). Whole stalk CT concentration was calculated by a weighted average on a dry weight basis of the inflorescence, leaf, and stem values.
Separate analyses of variances (PROC GLM, SAS Institute, 1988) were used to analyze the data by stage of growth (flowering and seed filling) and plant part (leaves, stems, and inflorescences). The model was environment (E), replication in E, genotype (G), G x E interactions, replication in G x E interactions (experimental error), and the residual (sampling error). Upon analysis of the data, we found that the sampling error was less than or equal to the experimental error and that the experimental error when tested against the sampling error was not significant. Therefore, we averaged leaf, stem, and inflorescence CT values within a PI and replicate and the data were reanalyzed using the model environment (E), replication in E, genotype (G), G x E interactions, and residual (experimental error). Replication in E was the error term used to test environment and the residual was used to test G, and G x E interactions. Variance components were calculated (PROC VARCOMP, SAS Institute, 1988) and used to estimate the broad sense heritability as it applies to mass selection with self-pollinated species (Frey, 1983).
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RESULTS AND DISCUSSION
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Average weights of leaf, stem, inflorescence and total shoot were greater at Columbia for both flowering and seed filling stages of growth than at Booneville (Table 3)
. All but seven introductions were collected from Iowa, Illinois, Nebraska, Massachusetts, Michigan, Minnesota, and Wisconsin (Table 2). Hence, this collection of roundhead lespedeza may be better adapted at Columbia than at Booneville.
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Table 3. Condensed tannin concentrations and sample weights for roundhead lespedeza inflorescences, leaf and stem tissues, and whole shoot for two growth stages and two environments.
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When averaged over PIs, significant differences were observed between environments for inflorescences and whole shoot CT concentrations at flowering (Table 3). Condensed tannin concentration of inflorescences was greater at Columbia (150 g kg-1) than at Booneville (120 g kg-1). This difference can likely be explained by growth stage of the plants at sampling. At Booneville, plants were sampled at approximately 25% bloom with the majority (73%) of the samples collected on 17 June. At Missouri, all plants were sampled on 5 July when the plants were at approximately 90% bloom. Roundhead lespedeza plants contains both cleistogamous (self-pollinated) and chasmogamous (cross-pollinated) flowers with most seed set occurring thought cleistogamy (Cole and Biesboer, 1992). The data from Columbia suggest that CT may have been translocated from the stems and leaves into the inflorescences. This may have occurred with the transport of photosynthates in the early development of the seed. Mosjidis et al. (1990) speculated that CT in sericea lespedeza might be involved in photosynthetic transport and in other physiological processes of the plant. Further research, however, is needed to verify if CT is actively transported to inflorescences of roundhead lespedeza during early seed development.
The concentration of CT in leaves and stems was not different for the two environments at flowering. For Lotus uliginosus Schkuhr, Lees et al. (1994) found higher CT concentrations in leaves was a function of time (days in growth chamber), position of leaf on stem, and temperature of the environment. They found a 4- to 5-fold increase in average CT concentration when plants were sampled after 14 d and again after 33 d of growth. After 33 d of growth, CT concentrations remained relatively stable until plants were harvested. On the basis of Lees et al. (1994) data, leaves older than 33 d showed relatively little change in CT content. Thus, leaf CT may have peaked at both locations by the first sampling date. Whole shoots, however, had a greater concentration of CT at Booneville (89 g kg-1) than at Columbia (73 g kg-1). Although the difference between environments was insignificant for leaf and stem tissues at flowering, the concentration of CT in whole shoots was greater at Booneville because of higher concentrations of CT in the leaves and stems. On average, leaf and stem tissues account for 73% of the shoot weight.
When averaged over PIs, the concentration of CT in leaves, stems, and inflorescences declined with plant senescence (flowering to seed filling) in both environments (Table 3). The greatest change was in the inflorescences. The decline in inflorescence CT is likely due to a dilution effect caused by the seed. At Booneville, the weight of CT at flowering (approximately 25% bloom) was 0.31 g and at seed filling was 0.51 g. At Columbia, the weight of CT at flowering (approximately 90% bloom) was 0.59 g and at seed filling was 0.64 g. When environments were analyzed separately for weight of CT, no significant difference was found between growth stages (P > 0.23) at Columbia. Significant differences were found between growth stages (P < 0.01) at Booneville. Because plants were sampled before seed development at Booneville, the transport of CT into the inflorescences from the leaves and stem, as discussed earlier, would not have occurred. Thus, a lower CT weight was found for inflorescences at Booneville.
High CT concentrations in inflorescences might deter animals from eating flowers, thus ensuring a seed crop. Once CT levels have declined at seeding, browsing or grazing animals might ingest seed heads, thus providing for natural scarification of the seeds as they pass through the animals' digestive tract. These PIs of roundhead lespedeza averaged greater than 90% hard seed, but upon scarification of the seed with sandpaper germinated in excess of 85% (Springer and McGraw, 1995). In comparison, roundhead lespedeza seeds recovered after passage through the digestive tract of sheep (Ovis aries L.) was 12% greater in average germination compared with the same seed lot without scarification (Springer, unpublished data, 1996).
With 39 PIs in this study, we expected to find genotype x environment interactions. One of our objectives was to find PIs common to both environments with low CT concentrations. Since leaves are the primary plant part grazed on this species, we selected eight PIs (approximately 20%) with low CT concentrations in the leaves at flowering in each environment. These PIs were 287114, 287115, 287117, 287118, 287119, 287123, 287126, and 303847 (Table 4)
. To verify that these introductions lacked a genotype by environment interaction, we statistically analyzed these PIs separately for CT concentration of leaves at flowering. The genotype x environment component of the analysis of variance was not significant (P = 0.26). Similarly, no significant difference was found for environment (P = 0.06). Significant differences were found, however, for plant introduction (genotype, P = 0.04). Averaged across environments, the CT concentration of leaves at flowering ranged from 72 g kg-1 for PI 287117 to 94 g kg-1 for PI 287123. The CT content of these plant introductions is still relatively high when compared with sericea lespedeza bred for low tannin content (Windham et al., 1988). Plant collections should be conducted from a larger geographical region to collect germplasm with lower CT concentrations. The agronomic potential of these eight PIs has yet to be determined; however, through breeding, they could be used to produce roundhead lespedeza cultivars with low tannin characteristics. The estimate of broad sense heritability as it applies to mass selection for this population of 39 plant introduction for CT concentrations of leaves at flowering was 0.60. Hence, selecting for low CT content in roundhead lespedeza is possible.
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Table 4. Condensed tannin concentrations for inflorescences, leaf, and stem tissues for two growth stages and two environments of eight roundhead lespedeza lines selected for low tannin.
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CONCLUSIONS
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We found that variation due to the environment was low, whereas variation due to genotype and variation due to genotype x environment interaction was high. Of these 39 PIs we selected eight that were common to both environments and had low CT concentration in leaves at flowering. The CT content of these PIs, however, is still relatively high when compared with sericea lespedeza that was bred for low tannin content. New germplasm acquisitions will be needed from a larger geographical region to select and/or breeding new low tannin cultivars of roundhead lespedeza that will be adapted to a larger geographic region.
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NOTES
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Mention of a trademark or a proprietary product does not constitute a guarantee or warranty of the product by USDA or University of Missouri and does not imply approval to the exclusion of other suitable products. All programs and services of the U.S. Department of Agriculture are offered on a nondiscriminatory basis without regard to race, color, national origin, religion, sex, age, marital status, or handicap. Partial funding for this project was provided by the Clover and Special Purpose Legume Crop Advisory Committee through a specific cooperative agreement with the USDA-ARS, Forage & Range Research Laboratory, Logan, UT.
Received for publication October 9, 2001.
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REFERENCES
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- Albrecht, K.A., and R.E. Muck. 1991. Proteolysis in ensiled forage legumes that vary in tannin concentration. Crop. Sci. 31: 464–469.[Abstract/Free Full Text]
- Anuraga, M., P. Duarsa, M.J. Hill, and J.V. Lovett. 1993. Soil moisture and temperature affect condensed tannin concentrations and growth in Lotus corniculatus and Lotus pedunculatus. Aust. J. Agric. Res. 44:1667–1681.
- Broderick, G.A., and K.A. Albrecht. 1997. Ruminal in vitro degradation of protein in tannin-free and tannin-containing forage legume species. Crop. Sci. 37:1884–1891.[Abstract/Free Full Text]
- Clarke, I.D., R.W. Frey, and H.L. Hyland. 1939. Seasonal variation in tannin content of Lespedeza sericea. J. Agric. Res. 58:131–139.
- Clewell, A.F. 1966. Natural history, cytology and isolating mechanisms of the native North American lespedezas. Bull. Tall Timbers Res. Stn. 6:1–39.
- Cole, C.T., and D.D. Biesboer. 1992. Monomophism, reduced gene flow, and cliestogamy in rare and common species of Lespedeza (Fabaceae). Am. J. Bot. 79:567–575.[ISI]
- Donnelly, E.D. 1954. Some factors that affect palatability in sericea lespedeza. Agron. J. 46:96–97.[Free Full Text]
- Donnelly, E.D. 1981. Registration of AU-Lotan sericea lespedeza. Crop Sci. 21:474.[Free Full Text]
- Feeny, P.P. 1968. Effect of oak leaf tannins on larval growth of the winter moth Operophtera brumata. J. Insect Physiol. 14:805–817.
- Frey, K.J. 1983. Plant population management and breeding. p. 55–88. In D.R. Wood (ed.) Crop breeding. ASA, CSSA, and SSSA, Madison, WI.
- Graham, E.H. 1941. Legumes for erosion control and wildlife. USDA Misc. Publ. 412. U.S. Gov. Print. Office, Washington, DC.
- Kneebone, W.R. 1959. An evaluation of legumes for western Oklahoma rangelands. Bull. B–539. Okla. Agric. Exp. Stn., Stillwater.
- Lees, G.L., C.F. Hinks, and N.H. Suttill. 1994. Effect of high temperature on condensed tannin accumulation in leaf tissues of big trefoil. J. Sci. Food Agric. 65:415–421.
- Miller, P.R., and N.J. Ehlke. 1994. Condensed tannin relationships with in vitro forage quality analyses for birdsfoot trefoil. Crop Sci. 34:1074–1079.[Abstract/Free Full Text]
- Mosjidis, C.O'H., C.M. Peterson, and J.A. Mosjidis. 1990. Developmental differences in the location of polyphenols and condensed tannins in leaves and stems of sericea lespedeza, Lespedeza cuneata. Ann. Bot. (London) 65:355–360.[Abstract/Free Full Text]
- Mosjidis, J.A. 1988. Response of sericea lespedeza genotypes low in tannins to different environments. Plant Breed. 101:302–306.
- Pieters, A.J. 1934. The little book of lespedeza. The Colonial Press, Washington, DC.
- Price, M.L., S. Van Scoyoc, and L.G. Butler. 1978. A critical evaluation of the vanillin reaction as an assay for tannin in sorghum grain. J. Agric. Food Chem. 26:1214–1218.
- Roberts, C.A., P.R. Beuselinck, M.R. Ellersieck, D.K. Davis, and R.L. McGraw. 1993. Quantification of tannins in birdsfoot trefoil germplasm. Crop Sci. 33:675–679.[Abstract/Free Full Text]
- Ross, M.D., and W.T. Jones. 1983. A genetic polymorphism for tannin production in Lotus corniculatus and its relationship to cyanide polymorphism. Theor. Appl. Genet. 64:263–268.
- SAS Inst. Inc. 1988. SAS/STAT user's guide, Release 6.03 Edition. Cary, NC.
- Springer, T.L., and R.L. McGraw. 1995. Seed germination of roundhead lespedeza. p. 180. In Agronomy abstracts. ASA, Madison, WI.
- Stitt, R.E., and I.D. Clarke. 1941. The relation of tannin content of sericea lespedeza to season. J. Am. Soc. Agron. 33:739–742.
- Windham, W.R., S.L. Fales, and C.S. Hoveland. 1988. Analysis for tannin concentration in sericea lespedeza by near infrared reflectance spectroscopy. Crop Sci. 28:705–708.[Abstract/Free Full Text]
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ABSTRACT
INTRODUCTION
