Translocation of Coumarin Across a Graft Union m Sweetclover

Despite several recent investigations of the biosynthesis of coumarin and related compounds in sweetclover, little is known of the site or sites within the plant at which coumarin is formed. Weygand and Wendt reported coumarin formation in root cultures of Melilotus officinalis (L.) Lam. when suitable precursors were supplied. Mothes and Kala concluded that scopoletin and umbelliferone, compounds closely related to coumarin, can be synthesized by root cultures of Atropa belladonna L. The experiments cited gave no indication that the roots are the preferred site of synthesis or that synthesis takes place at all in the roots of intact plants. Neither of the studies excluded the possibility of synthesis in other organs

Inheritance of Leucoanthocyanidin Content in Sorghum Leaves

Leucoanthocyanidins (LAC) are structurally related to condensed tannins, a class of compounds having significant effects on the nutritional value of sorghum [Sorghum bicolor (L.) Moench) grain. Little is known of LAC inheritance in sorghum. Mature leaves of \u27Colman\u27 and \u27White Collier\u27 forage sorghum are high and low, respectively, in LAC content. The objective of the present study was to determine the inheritance of LAC content in reciprocal crosses between these two cultivars, Leaves of field-grown plants were assayed for LAC by a procedure that involved treating methanolic leaf extracts with acid at 50°C to convert the colorless LAC to an anthocyanidin having an absorbance maximum near 540 nm, Parental, F1 and F2 plants were grown and assayed in 1983. In 1984, F3 progenies from selected F2 plants representing various LAC levels were grown and assayed along with additional F2 and parental plants. Results from both years supported the conclusion that a single allelic pair with incomplete dominance was primarily responsible for the difference in LAC content between Colman and White Collier plants. Other genes with minor effects may also be involved but maternal or cytoplasmic effects were not important in determining LAC level. The LAC of Colman was not identified, but based on the work of other researchers with other sorghums, it is probably apiforol

Genetic Blocks in the Synthesis of Coumarin in \u3ci\u3eMelilotus alba\u3c/i\u3e

The influence of the two genes, cu and b upon the level and form of coumarin in sweetclover leaf tissue was determined by assaying 25 sweetclover plants of each of the four homozygous genotypes, CuCuBB, CuCubb, cucuBB, and cucubb. An assay of alfalfa leaves provided an indication of the magnitude of fluorescence not ascribable to coumarin. Approximately 0.2 percent total coumarin (dry weight basis) was found in plants homozygous for cu, which is 11.5 times the amount found in alfalfa, but only about 1/20 of the level found in CuCu plants. Thus, the cu-effected block in coumarin synthesis is partial rather than complete. However. the action of the b gene in blocking the formation of free coumarin is virtually complete, as shown by the extremely low levels of free coumarin in bb plants. The probable relationship of bound coumarin, free coumarin and the cu and b genes is shown. Important implications in sweetclover breeding, and in other studies are indicated

Translocation of Coumarin Across a Graft Union m Sweetclover

Despite several recent investigations of the biosynthesis of coumarin and related compounds in sweetclover, little is known of the site or sites within the plant at which coumarin is formed. Weygand and Wendt reported coumarin formation in root cultures of Melilotus officinalis (L.) Lam. when suitable precursors were supplied. Mothes and Kala concluded that scopoletin and umbelliferone, compounds closely related to coumarin, can be synthesized by root cultures of Atropa belladonna L. The experiments cited gave no indication that the roots are the preferred site of synthesis or that synthesis takes place at all in the roots of intact plants. Neither of the studies excluded the possibility of synthesis in other organs

Influence of Seed Size, Planting Depth, and Companion Crop on Emergence and Vigor of Seedlings in Sweetclover

Seed size has been shown to have an important influence on the emergence and early growth of seedlings of several forage legumes, but only fragmentary information on seed size effects in sweetclover (Melilotus spp.) has been published. Therefore, a 2-year study was conducted in which spring and fall seedings of small, medium, and large seeds of \u27Madrid\u27 and \u27N13\u27 sweetclover (Melilotus officinalis (L.) Lam.) were made at depths of 19, 38, and 57 mm. The spring seeding also included a comparison of a companion crop (oats) with no companion crop. Data on emergence score and plant height were collected for the spring seeding only; stand count and dry matter yield of tops and roots were measured for both spring and fall seedings. The companion crop had little effect on emergence score, but it reduced stand count and plant height, and was highly detrimental to dry matter yield. The performance of Madrid was poorer in all respects than that of N13, an experimental cultivar with relatively large seeds. As planting depth was increased, stand counts decreased, but the performance of plants that emerged from the greater depths was relatively good. The most striking results of increased seed size appeared to be improved emergence score and increased dry matter production

Rapid Detection of o-Hydroxycinnamic Acid and Beta-Glucosidase in \u3ci\u3eMelilotus alba\u3c/i\u3e

The tests utilize small samples of leaf tissue crushed on sheets of filter paper. For detection of o-hydroxycinnamic acid (o-HCA), a crude preparation containing sweetclover β-glucosidase is added to a spot of crushed tissue to insure hydrolysis of glucosidically bound o-HCA. An extract containing cis-o-HCA glucoside is added to another tissue spot to serve as the substrate for the detection of β-glucosidase activity. Finally, all spots are moistened with NaOH and are scored for fluorescence under ultraviolet light. Results of qualitative and quantitative tests on plants representing various genotypes are compared. The importance of exposing plants to sunlight before testing for o-HCA is discussed. The tests are particularly useful in genetic studies, in the development and maintenance of breeding lines, and in testing for contamination in low-o-HCA sweetclover varieties

Range and forage research needs for red meat production in the north central region

The 12 contiguous states of the North Central Region constitute one of the most productive agricultural areas in the world. Before the region was settled, vegetation consisted primarily of forest in the east, grasses in the west, and an intermingling of grass and forest in the central portions. Although the region contains a high proportion of productive soils, there are great differences within the region in soils, as well as in climate, vegetation, and geology. The short-grass soils in the western areas are higher in pH, lighter in color, and thinner than the tail-grass soils in the central and west-central areas, which have thick, dark surface horizons. The more strongly leached soils of the eastern humid forested areas are more acid and have thin, dark surface (A) horizons and light-colored subsurface horizons, which are mixed when cultivated. Approximately 75% of all soils in the region is derived from glacial till and loess. A large proportion of the deposits of glacial origin was derived locally from underlying bedrock or from material laid down during previous glaciations. Most of these deposits range from a few to tens of feet thick, but occasionally are several hundred feet thick. Loess deposits deeper than 4 feet cover large areas of Illinois, Iowa, Missouri, Kansas, and Nebraska. There also are extensive areas where shallow loess deposits cover the land surface

Registration of N30-N56, N741, N743, N745, N747, U362, U363, U367, U369-U374, U389-U394, U396-U398, and U500 Sweetclover Genetic Stocks

Forty-nine white-flowered sweetclover (Melilotus alba Medik.) genetic stocks [N30-N45 (Reg. GS-1–16, PI 549120–549135); N46-N53 (Reg. GS-17–24, PI 557503–PI 557510); N54-N55 (Reg. GS-25–Reg. GS-26, PI 629289–PI 629290); N741, N743, N745, N747 (Reg. GS-27–GS-30, PI 557511–PI 557514); U362, U363, U367 (Reg. GS-31, Reg. GS-32, Reg. GS-33, PI 557515–PI 557517); U369-U374 (Reg. GS-34–GS 39, PI 557518–PI 557523); U389-U394 (Reg. GS-40–GS 45, PI 557524–PI 557529); U396- U398 (Reg. GS-46–GS 48, PI 557530–PI 557532); U500 (Reg. GS-49, PI 557533)] (Table 1); and N56 (Reg. no. GS-50, PI 634019), a yellow-flowered sweetclover [Melilotus officinalis (L.) Lam.] genetic stock, were developed jointly by USDA- ARS and the Agricultural Research Division, Institute of Agriculture and Natural Resources, University of Nebraska-Lincoln and were jointly released in May 2004. The genetic stocks, which contain unique combinations of genes and traits, were developed over more than three decades of cooperative sweet- clover genetic research

Genetic Studies of Induced Mutants in \u3ci\u3eMelilotus alba\u3c/i\u3e III. Folded Leaflet, Elongatyed Stem, and Short-Petiole Dwarf

Observations of the F1, F2, and F3 progenies of crosses between normal annual Melilotus alba Desr. and three mutants, folded leaflet, elongated stem, and short-petiole dwarf, indicate that each of the mutant characters is controlled by a single recessive gene. Proposed symbols for the three mutant genes are f, el, and dsp, respectively. In limited tests for linkage, el appeared to be linked (12% recombination) to a gene for multifoliolate leaves (Mf). No linkage was detected between f and Mf, cu (low o-hydroxycinnamic acid), or b (low β-glucosidase activity)