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Michael N. Dana and Ricky D. Kemery

Interest in direct-seeding establishment of wildflowers as a component of landscape planting has continued to increase. Seed may be very expensive. Information is needed on the quality of seed available to consumers and the landscape industry. The goal of this work was to assess the level and consistency of seed quality available from the wildflower seed production/marketing industry. Eleven species of native prairie forb wildflowers and eight species of “garden” wildflowers from seven companies were purchased in 1992 and 1993 and subjected to germination testing. Germination procedures were those of AOSA where available, or generalized from the literature when no guidelines existed. Results showed significant variation among wildflower species, among companies supplying the same species, and over the two seed years tested in the study. These data reinforce the need for seed quality testing and reporting as a part of the sales of wildflower seed.

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Richard W. Hartmann

F3 seeds from a cross of P. erosus (indeterminate, daylength sensitive) X P. ahipa (determinate, daylength insensitive) were received from M. Sorensen of the Royal Veterinary and Agricultural University in Copenhagen, Denmark and sown in Hawaii in April, 1989 to increase the seed. The F4 seed were planted in March, 1990 and in October, 1990 (the normal time). All F4 progeny included both bush and vine plants in the summer planting, with more bush plants in the progeny of F3 bushes than vines. Likewise, the progeny of earlier-flowering F3 plants had a higher percentage of plants in flower in June than progeny of later-flowering ones. Root sizes and shapes were variable. The F4 progenies of the lines with the highest percentage of bushes and early-flowering plants were regrown in the summer of 1991 and selected for summer-flowering bush plants with acceptable root size. The selections were then grown in the winter of 1991 to test for performance during the normal growing season.

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Alison R. Cutlan, John E. Erwin, and James E. Simon

Parthenolide, a biologically active sesquiterpene lactone found in feverfew [Tanacetum parthenium (L.) Schultz. Bip.], has been indirectly linked to the antimigraine action of feverfew preparations. Commercial products of feverfew leaves vary widely in parthenolide content (0-1.0%/g dwt). No comprehensive studies have quantified parthenolide variation among feverfew populations or cultivars, and whether morphological traits are correlated with this natural product. In this study, 30 feverfew accessions were examined for parthenolide content, morphological traits, and seed origin. Statistically significant differences in parthenolide levels were found among the populations studied. Parthenolide content ranged from (0.012% ± 0.017 to 2.0% ± 0.97 /g dwt) as determined by HPLC-UV-MS. Higher parthenolide levels tended to be in wild material (0.41% ± 0.27) as opposed to cultivated material (0.19% ± 0.09). Parthenolide levels correlated with flower morphology: disc flower (0.49% = B1 0.36), semi-double (0.38% ± 0.13), double (0.29% ± 0.16), and pompon-like flower (0.22 ± 0.14). Leaf color also appeared to be indicative of parthenolide levels, with the light-green/golden leafed accessions showing significantly higher parthenolide content than darker-leafed varieties, but whether this was due to inadvertent original selection of a high parthenolide-containing golden leaf selection is not yet known. This study does show that further selection for improved horticultural attributes and natural product content is promising to improve feverfew lines for the botanical/ medicinal plant industry.

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M.C. Posa, J.D. Kelly, G.L. Hosfield, and K.C. Grafton

Two recombinant inbred populations of kidney beans were developed and evaluated for canning quality. One population, composed of 75 recombinant inbred lines (RILs), was from a Montcalm/California Dark Red Kidney 82 cross. The second population, with 73 RILs, was from a Montcalm/California Early Light Red Kidney cross. RILs from both populations were planted in North Dakota in 1996 and Michigan in 1996 and 1997. Beans of each RIL were thermally processed using established procedures. Appearance and degree of splitting of each sample and the check varieties were scored subjectively on a 1-7 scale to represent the minimum and maximum acceptability levels of the traits, respectively. Genotypes and genotype × environment interactions were highly significant based on analyses of variance. In the 75 RIL population, seven lines, based on appearance, consistently appeared in the top 25% in all environments (mean = 4.5; range = 4.0-6.1), and four had consistently high acceptability scores (mean = 4.6; range = 4.0-6.3) for the degree of splitting trait. In the population with 73 RILs, nine lines consistently appeared in the top 25% in all environments based on appearance (mean = 4.6; range = 4.1-5.3). For degree of splitting, nine lines had consistently high acceptability scores (mean = 4.2; range = 3.7-5.1). Appearance and splitting of cooked dry bean are quantitatively inherited traits. The field experiments were useful to obtain RILs for screening to identify molecular markers associated with QTLs. Three primers—OQ11, ON186, and OF5—reported to be useful RAPD markers for processing quality in navy beans are of special interest in the current study.

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Ann Marie Connor, James J. Luby, and Cindy B.S. Tong

Variation in antioxidant activity (AA), total phenolic content (TPH), and total anthocyanin content (ACY) was examined in 1998 and 1999 in fruit of 52 (49 blue-fruited and 3 pink-fruited) genotypes from a blueberry breeding population. The species ancestry included Vaccinium corymbosum L. (northern highbush blueberry), V. angustifolium Ait. (lowbush blueberry), V. constablaei Gray (mountain highbush blueberry), V. ashei Reade (rabbiteye blueberry), and V. myrtilloides Michx. (lowbush blueberry). Using a methyl linoleate oxidation assay (MeLO) on acidified methanolic extracts of the berries, a 5-fold variation was found in AA in 1998 and a 3-fold variation in 1999 among the blue-fruited genotypes. Analyses of variance (ANOVA) revealed variation among genotypes (P < 0.0001) in single and combined years, regardless of inclusion of pink-fruited selections and adjustment for berry size. While mean AA of all genotypes did not change between the 2 years, ranking of some genotypes for AA changed significantly between 1998 and 1999. Of the 10 genotypes that demonstrated the highest AA in 1998, four were among the 10 genotypes that demonstrated highest AA in 1999. Similarly, of the 15 genotypes with the highest AA, 10 were the same both years. As with AA, mean TPH of all genotypes did not change between years and ANOVA demonstrated genotypic variation regardless of adjustment for berry size/weight or exclusion of pink-fruited selections. Changes in genotype rank occurred between years. The difference in TPH between lowest- and highest-ranking blue-fruited genotypes was ≈2.6-fold in both 1998 and 1999. Seven of the 10 highest-ranking genotypes were the same both years and TPH correlated with AA (r = 0.92, P < 0.01) on a genotype mean basis for combined years. ACY correlated less well with AA (r = 0.73, P < 0.01 for combined years). When genotypes were categorized into six groups according to species ancestry, V. myrtilloides and V. constablaei × V. ashei crosses ranked highest and second highest, respectively, for AA in both years. The groups comprised of V. corymbosum genotypes, V. angustifolium genotypes, and those with both V. corymbosum and V. angustifolium in their lineage were indistinguishable from each other. Samples from some of the genotypes were analyzed for oxygen radical absorbance capacity and ferric-reducing antioxidant power, and these aqueous-based antioxidant assays correlated well with the lipid emulsion-based MeLO (all r ≥ 0.90, P < 0.01). The three antioxidant assays may be equally useful for screening in a blueberry breeding program and the choice of assay may depend on the goal of the program and the resources available.

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Chuhe Chen, J. Scott Cameron, and Stephen F. Klauer

Accumulated attendance and fourth-derivative spectra were measured using intact leaf samples at mom temperature for 80 genotypes of four Fragaria species. Attendance peak wavelength and amplitude data of all samples was pooled and yielded 25 common bands for Fragaria. Of these, 14 chlorophyll bands and two phototransformed bands were consistent with French's (1972) model.

Peak wavelengths and amplitudes which represent major bands in F. chiloensis and F. × ananassa spectra were also determined separately. While peak wavelengths of the two species were identical, variation was noted in peak amplitude. The signals of the bands at Cb640, Cb649, Ca670, Ca673, Ca675-676, Ca684 and Ca693 in F. chiloensis were significantly stronger than those in F. × ananassa. Ca677 and Ca695 were stronger in F. × ananassa.

The greatest difference among Fragaria species was found in the amplitude of Ca693. The amplitude of this peak was greatest in F. chi/oensis (0.0025) and smallest in F. virginiana (-0.0005), The cultivated hybrid of these two species, F. × ananassa, was intermediate (0.0008), Preliminary evidence suggests that certain genotype-specific spectral characteristics may relate directly to observed differences in photosynthetic biology among these species.

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Jo-Ann Bentz

This study quantified how different shading levels alter the foliar nutrient, C:N ratio, chlorophyll content and key leaf characters in azalea `Delaware Valley White' Rhododendron mucronatum (Blume) (Ericales: Ericaceae), which influenced, in turn, feeding, oviposition, survival and development of the azalea lace bug, Stephanitis pyrioides (Scott) (Heteroptera: Tingidae). The mean contents of N, Ca, Fe, and Zn increased linearly with increases in the shading level, whereas P, K, B, Mn, and the C:N ratio of leaves were significantly decreased. Although injured leaves contained significantly less chlorophyll than uninjured leaves, the mean relative chlorophyll content of leaves increased linearly with the level of shading. Mean leaf area and moisture content of leaves increased linearly with increased degree of shading, while the mean trichome density decreased. The mean number of oviposited eggs and the percent of nymphs reaching adulthood increased linearly with the degree of shading. Azalea shoots suffered increased feeding injury as the season progressed, yet unshaded plants suffered more feeding injury than shaded plants. While the mean number of eggs laid, and the mean number of reared adults, were significantly and positively correlated with the mean leaf N, the mean feeding injury was negatively correlated with leaf N. Although these dependent variables were not correlated with K nor Ca, the mean number of eggs laid, and the mean number of reared adults were negatively correlated with the mean leaf P and with the mean C:N ratio. Mean feeding injury was positively correlated with leaf P and with the C:N ratio, but negatively correlated with N. This study shows that shaded plants are of better quality as hosts and that these plants can tolerate infestations by the lace bug.

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Michael J. Havey

Restriction fragment length polymorphisms (RFLPs) in the chloroplast and nuclear genome are useful for estimation of phylogenetic relationships. Fifteen mutations at restriction enzyme sites in the chloroplast DNA were discovered. The wild species A. oschaninii and A. vavilovii were identical to A. cepa for all mutations. These species represent sources of wild germplasm closely related to the bulb onion. Nuclear RFLPs are now being used to estimate the genetic distances between accessions of A. oschaninii A. vavilovii, and open-pollinated populations of the cultivated bulb onion.

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Yuefang Wang, S. Kristine Braman, Carol D. Robacker, Joyce G. Latimer, and Karl E. Espelie

Epicuticular lipids were extracted from the foliage of six deciduous and one evergreen azalea genotypes (Rhododendron sp.) and identified by gas chromatography-mass spectrometry. The relationship of leaf-surface lipid composition with measures of resistance to azalea lace bug, Stephanitis pyrioides Scott, was evaluated. Each genotype had a distinct epicuticular lipid composition. The major surface lipid components from all test taxa were n-alkanes and triterpenoids. In the most resistant genotypes [R. canescens Michaux and R. periclymenoides (Michaux) Shinners] ursolic acid, n-hentriacontane, and n-nonacosane were the most abundant epicuticular lipids. The lipids present in largest proportion among all susceptible deciduous genotypes tested were α-amyrin, β-amyrin, and n-nonacosane. The proportions of the lipid components from the same plant of each genotype varied between spring and fall samples. Among classes of lipids, n-alkanes, n-1-alkanols, and triterpenoids had significant correlations with azalea lace bug behavior on host plants. Among individual components, heptadecanoic acid, n-hentriacontane, oleanolic acid, ursolic acid and one unknown compound (with major mass spectra 73/179/192/284/311) were significantly negatively correlated with host plant susceptibility to azalea lace bug, as measured by oviposition, leaf area damaged, egg and nymphal development, and nymphal survivorship. Triacontanol, α-amyrin, β-amyrin, and three unknowns were significantly positively correlated with host plant susceptibility. Acceptance or rejection by azalea lace bug to a particular plant may be mediated by a balance of positively and negatively interpreted sensory signals evoked by plant chemicals. This study indicated that the high levels of resistance observed in R. canescens and R. periclymenoides may be due to the lesser amount or the absence of attractants and stimulants for feeding or oviposition.

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Vicky W. Lee, H.P. Vasantha Rupasinghe*, and Chung-Ja Jackson

Apples are excellent sources of dietary phenolics, in particular flavonoids and chlorogenic acid, which are potent antioxidants that may play important roles in the prevention of chronic diseases. This study investigated the major phenolics profiles of apple fruit in relation to (1) the distribution among 8 Ontario-grown cultivars, (2) the different fruit parts, and (3) the effect of processing of fresh-cuts. In addition, total antioxidant capacity (TAC) and total phenols content (TPC) were measured in apples by spectrophotometric assays. Flavonoids and chlorogenic acid were quantified using HPLC/PDA. Vitamin C was quantified using HPLC/Fluorescence. TAC, TPC and flavonoids levels were the highest in Honey Crisp and Delicious, moderate in Idared, Spartan, Granny Smith, and Cortland, and the lowest in Crispin and Empire. Apple peel contained 2 to 10-fold higher TAC, TPC and total of 10 major phenolics than that of core and flesh indicating peeling of apples during processing could reduced significantly the nutritional quality of fresh-cut apples. Dihydrochalcone (phloridzin) and chlorogenic acid levels were 2 to 21-fold higher in apple core than skin and flesh. TAC levels and vitamin C contents could be increased up to 3-fold and 14 to 20-fold, respectively by the post-cut dipping treatment with an ascorbic acid-based antioxidant formula. The phenolic profiles of sliced apples were stable up to 21 days at 4°C.