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  • Author or Editor: C. E. Peterson x
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Abstract

One cannot review the history of vegetable breeding without being impressed by the extent to which some of our crops are dependent on a relatively few characteristics originally derived from introduced material. Several important vegetable crops would not exist as they do today without the introduction of disease resistance and horticultural characteristics from distant parts of the world.

Open Access

Abstract

The inability to achieve adequate pollination of seed parents has slowed the development of hybrid carrots (Daucus carota L.) and dampened industry acceptance. Thus, cytoplasmically male-sterile inbreds and F1 seed parents were compared with their fertile counterparts for synchrony of floral events and character of pollinator foraging stimuli. Usually, but not always, male-sterile plants were visually different, bloomed later, and exhibited delayed nectar and aroma production compared to male-fertiles. The quality and quantity of nectar and aroma were also different, with male-sterile flowers often inferior to fertile flowers in amounts of nectar produced. Successful use of any cross-pollinated entomophilous hybrid crop system should involve selection for similar floral characteristics early in the breeding program to insure maximum transfer by insects of pollen from male-fertile to male-sterile parents.

Open Access

Abstract

Silver nitrate and gibberellin A4/A7 (GA4/7) were compared for induction of staminate flower production on an inbred gynoecious cucumber (Cucumis sativus L.) line grown in the field at Madison, Wisconsin. Foliar sprays of silver nitrate at 100, 200, and 400 ppm induced significantly more staminate flowers per plant than did GA4/7 at the standard, widely-used rate of 50 ppm, making gynoecious x gynoecious hybrid seed production commercially feasible. The strong induction all plants treated with silver nitrate should minimize the genetic shift toward maleness observed from one generation to the next when GA is used to increase seed of gynoecious parental lines.

Open Access

Abstract

Four sets of nearly isogenic bacterial wilt [Erwinia tracheiphila (E.F. Smith)] Holland resistant and susceptible gynoecious cucumber (Cucumis sativus L.) lines, along with their companion segregating generations were evaluated under replicated field conditions for flowering date, fruit quality, fruit number, and length : diameter ratio (L:D). In addition to flowering earlier, susceptible lines were higher-yielding and had longer fruits than their resistant counterparts. Although differences in fruit quality were not significant, susceptible lines were preferred by a panel of seven judges. Compared to susceptible lines, hybrid progeny were later-flowering and in some instances lower-yielding.

Open Access

Abstract

Quercetin-4’-glucoside, quercetin-4’,7-diglucoside, and quercetin-3,4’-diglucoside were identified by paper chromatography as the major flavonols in the fleshy scales of yellow onion bulbs. Absorbance readings at 357 nm on crude alcoholic extracts were highly correlated (r=.96) to spectrophotometric measurements of quercetin at 373 nm following acid hydrolysis. This relationship was used to estimate total flavonol concentration in terms of quercetin from crude extracts. Concentrations on a fresh weight basis ranged from 276 ppm for the inbred MSU 826 to 1,285 ppm for MSU 4535. The pigments were found to be most concentrated in the upper and outer portions of the bulb. Approximately 90% of the total pigment was found to be confined to epidermal tissue.

Open Access
Authors: and

Abstract

Allium cepa L. bulbs of different genetic constitution were examined for free and bound gibberellin-like substances (GA) by conventional extraction, bioassay, and chromatographic procedures. Both free and bound GA were found in these bulbs. Based on the dwarf-pea bioassay, it was shown that free and bound GA in the extracts varied depending on the source of the bulbs. The total GA of dormant bulbs was greater than that of non-dormant bulbs.

Open Access

Abstract

A strong linkage (~ 1 crossover unit) was detected between the gene Bw for resistance to bacterial wilt incited by Erwinia tracheiphila (E. F. Smith) Holland and the gene M for pistillate vs. perfect flowers in cucumber (Cucumis sativus L.).

Open Access

Abstract

A consistent preference by the meadow vole, Microtus pennsylvanicus, for the roots of certain inbred carrot lines and hybrids observed in field plantings suggested the possibility of using these animals to evaluate carrot breeding material for nutritive value and culinary quality. In a preliminary field test, 50 carrot lines representing the full range of feeding damage were planted in a confined feeding experiment. Lines showing no damage and severe damage were selected for controlled feeding trials and further evaluation.

In laboratory ad libitum feeding tests, all carrot diets were inferior to control diets. There was no relationship between vole preference and the nutritive value of the carrots as measured by the growth response of weanling voles. However, vole preference showed a significant positive correlation with the sucrose content of the roots while a significant negative correlation was found between preference and total reducing sugars. Neither growth response nor vole preference was correlated with crude fiber, protein, or total carbohydrates. No correlation was found between taste panel scores for overall rating of carrot samples and ad lib. feeding indexes by the voles.

Open Access

Abstract

Sensory analysis was performed on 4 carrot (Daucus carota L.) entries (inbred lines B6274 and B3615 and open-pollinated cultivars ‘Imperator 58’ and ‘Nantes’) grown in Florida, Texas, and California. Variation from entries and locations was observed for 5 sensory attributes. Significant differences were found among entries for harsh flavor (burning, turpentine-like flavor) and among locations for overall carrot flavor. Florida-grown roots elicited low sweetness and low overall carrot flavor responses, Texas-grown carrots expressed distinct differences in harsh flavor, and California-grown carrots had less harsh flavor with more sweetness and more overall carrot flavor. Significant inter-line differences were observed for different attributes at each location. Sensory analysis over all locations indicated that B3615 was more harsh, less sweet, and less preferred than the other entries. Harsh flavor and sweetness were used as independent variables in regression analyses and were found to account for much variation in overall preference and intensity of flavor differences. Harsh flavor could not be masked by dipping B3615 roots in 30% fructose. Phloem is harsher, sweeter, more flavorful, and preferred to xylem while a comparison of crown, midsection, and tip displays a significant acropetal reduction in carrot flavor.

Open Access

Abstract

The flavor of raw carrots (Daucus carota L.) was largely influenced by genetic variation, with dominance for desirable flavor attributes (high sweetness, low harsh flavor). Quality characteristics of plants grown under controlled temperature, relative humidity, daylength, and light intensity were comparable to those of plants grown in the simulated natural climate. Climate had a major influence on carotenoid levels. Terpinolene was the most abundant volatile terpenoid, and it affected harsh flavor, sweetness, and preference. Total sugar levels also influenced sweetness.

Open Access