You are looking at 1 - 10 of 45 items for
- Author or Editor: I.L. Goldman x
The use of cylindrically shaped red beet cultivars for production of processing beets has increased in recent years. Yield and shape of globe-shaped red beet cultivars are determined in part by population density and within-row spacing; thus, it is thought cylindrical cultivars are similarly affected by these factors. The objective of this investigation was to evaluate the effects of population density on shape and size of cylindrical red beet cultivars. Two F1 hybrids and two open-pollinated cultivars were planted in replicated trials consisting of three population densities during 1993 and 1994. Ten traits were measured on a randomly selected sample of beets from each plot. Averaged over genotypes, significant differences among densities were found for percent harvestable beets per plot, length × width, harvest weight, length, and mid-width. Average over genotypes, greater harvest weight, higher percentage of harvestable beets, and greater length, mid-width, and length × width values were found at low density. Average over densities, open-pollinated cultivars exhibited a greater degree of straightness along with lower yield, harvest weight, and percent harvestable beets than their hybrid counterparts. These data demonstrate population density has a differential effect on shape and size of cylindrical beet genotypes.
Pigments in orange carrot tissue, such alpha and beta carotene, are important vitamins in the human diet. Previously identified white or nonpigmented carrot roots, such as those from wild carrot and white derivatives of yellow or orange types, are dominant to the production of pigment, which is recessive. A nonpigmented carrot root was discovered during routine propagation of the inbred line W266 in 1992. Subsequent segregation analysis in the F2 and BC1 generations in three genetic backgrounds demonstrated the lack of pigmentation is due to a single recessive gene (reduced-pigment: rp). Total carotenoid content was reduced 92% in the roots of rprp genotypes compared to RPRP genotypes, however there were no differences in carotenoid content in leaves. Plants carrying rprp also exhibit white-speckled leaves during early stages of development, suggesting rp has an effect on leaf chlorophyll content. This character may prove useful in dissecting the complex inheritance of carotenoids in carrot.
Carrots contribute ≈14% of the total Vitamin A to the human diet in the United States due to the presence of the provitamin A carotenoids α- and β-carotene. We have described a recessive gene (rp) that inhibits carotenoid biosynthesis in carrot by 93%, resulting in whitish-yellow roots. The rp mutation is also associated with relatively high levels of a tocopherol (Vitamin E, 0.61±0.15 mg α-tocopherol/100 g FW). Vitamin E is a powerful antioxidant that must be obtained from the diet. The biosynthesis of a tocopherol in carrot has not been studied in any detail; however, the rp gene may provide clues as to its mechanism. The production of carotenoids and tocopherols is biosynthetically linked by their common precursor, geranylgeranyl diphosphate (GGDP). GGDP is converted into phytoene by phytoene desaturase to produce carotenoids and combined with homogentisic acid to produce tocopherols. Carotenoid and tocopherol profiles for various carrot genotypes are presented alongside a model describing the potential relationship between root carotenoids and tocopherols in carrot. The presence of significant amounts of tocopherols in carrot could significantly raise the nutritional profile of this vegetable.
The effects of population density on shape and size of cylindrical red beet genotypes were evaluated in a field experiment during 1994 and 1995. Two F1 hybrids and two open-pollinated genotypes were planted in replicated trials consisting of three population densities. Yield, harvest weight, percent harvestable beets per plot, length, middle width, top width, bottom width, length × width, length to width ratio, and a shape index (SI) were measured on a sample of beet plants from each plot. The density × genotype interaction was nonsignificant for all 10 traits. Averaged over genotypes, significant differences among densities were found for harvest weight, percent harvestable beets per plot, length, middle width, and length × width. In general, greater harvest weights, a higher percentage of harvestable beets, and greater length, middle width, and length × width values were found at low density. Averaged over densities, significant differences among genotypes were measured for all 10 traits. The open-pollinated genotypes Cyndor and Cylindra exhibited lower yield, lower harvest weight, greater SI, and a higher percentage of harvestable beets than their hybrid counterparts. These data demonstrate that population density has a differential and significant effect on the shape and size of cylindrical beet genotypes.
A fasciated flower stem character arose spontaneously during development of the red beet (Beta vulgaris L.) inbred line W411. The fasciated character is manifest by a flattened flower stem with petioles coalesced into a twisted, ribbonlike appearance. No fasciation is present in the vegetative stem or petioles. An inheritance study was conducted to determine the genetic control of flower stem fasciation. The inbred line W411 was used both as a male and female parent in crosses with four red beet inbred lines. Segregating progenies in both the BC1 and F2 generations were developed and scored for the fasciated flower stem character. Variable expression of the fasciated flower stem phenotype was observed in these progenies; however, the presence of flattened flower stems at the stem-hypocotyl junction was unequivocal. Chisquare goodness-of-fit tests in the BC1 and F2 generations did not deviate significantly from expected ratios for a monogenic recessive character for each genetic background. No reciprocal differences were detected for any cross in this group of four inbred lines, which suggests the lack of maternal effect for the fasciated character. The symbol ffs is proposed to describe the genetic control of the fasciated flower stem phenotype.
Much of the medicinal activity induced by vegetable Alliums is derived from a suite of organosulfur compounds formed following hydrolysis of the S-alk(en)yl-l-cysteine sulfoxides (ACSOs). One of these medicinal activities is the inhibition of blood platelet aggregation; a factor that may influence cardiovascular health. Concentrations of ACSOs in the onion bulb ebb-and-fl ow during the vegetative phase, suggesting they act as storage forms of sulfur. To examine whether medicinal efficacy paralleled these changes, I tracked bulb, leaf, and inflorescence-induced antiplatelet activity during reproductive growth of four onion genotypes. Levels of bulb-induced antiplatelet activity dropped sharply for the first 8 weeks following the end of vernalization. Leaf-induced antiplatelet activity also dropped rapidly for the first 4 weeks, but rose precipitously by week 6. The rapid loss in leaf-induced antiplatelet efficacy between week 6 and week 8 suggests a recycling of these organosulfur compounds from the leaves to the developing flower stalk and inflorescence, which would be needed for protection against insect pests. Overall, I found a dramatic decrease in bulb-induced antiplatelet activity concomitant with an initially similar decrease and subsequent increase in leaf-induced antiplatelet activity. These were complemented by the presence of high levels of antiplatelet activity induced by the inflorescence. These data indicate development mediates the medicinal activity induced by onion plants. Furthermore, the flux of antiplatelet activity induced by various plant organs suggests that this medicinal trait is serendipitously associated with the storage and cycling of sulfur in onion plants; perhaps in response to insect predation.