Agricultural Experiment Station

A liquid chromatography/mass spectrometry (LC/MS) method with selected ion monitoring was developed and validated to analyze the contents of protodioscin and rutin in asparagus. The distribution of rutin and protodioscin within the shoots was found to vary by location, with the tissue closest to the rhizome found to be a rich source of protodioscin, at an average level of 0.025% tissue fresh weight in the three tested lines, while the upper youngest shoot tissue contained the highest amount of rutin at levels of 0.03-0.06% tissue fresh weight. The lower portions of the asparagus shoots that are discarded during grading and processing should instead be considered a promising source of a new value-added nutraceutical product.

Current models of parasite–host interactions generally emphasize considerations of parasite virulence and parasite transmission rather than host responses to attack. We describe a situation in which parasitism causes a host to change its feeding behavior and this change improves the expected fitness of the host and probably the fitness of its parasites. We have found that a tachinid parasitoid (Thelaira americana) often emerges from its caterpillar host (Platyprepia virginalis) without killing the host. Whether the host caterpillar survives its parasites depends in part on what it has been eating. Unparasitized caterpillars were more likely to survive to adulthood when feeding on lupine, whereas parasitized caterpillars were more likely to survive on poison hemlock. Development time and pupal masses of caterpillars (both parasitized and unparasitized) were not found to be affected by the host plants that they fed on. Survival of fly larvae in caterpillars that we determined were parasitized using ultrasound was not affected by host plant. However, fly pupae that emerged from caterpillars that had been reared on hemlock were heavier than those emerging from lupine-fed caterpillars. This was due primarily to the direct effect of diet on the flies and less so to the indirect benefit to flies whose host caterpillars survived their parasites by feeding on hemlock. Parasitized caterpillars were more likely to select hemlock, and unparasitized caterpillars were more likely to select lupine when offered both host plants in field tests. These results were consistent for the two years that the choice experiments were conducted. These results were also consistent with the hypothesis that caterpillars change their food plant choices so as to increase their conditional success. Conditional food choices that increase success depending upon parasite load are well accepted for humans, controversial for other primates, and unknown for insects. If caterpillars alter their host plant choices as a result of their parasite load, then this phenomenon could help to explain the evolution of host plant choices that have defied explanation in the past. Such a suggestion assumes that nonlethal parasitism is a common phenomenon. We believe that this may be the case since we did not detect the nonlethal nature of this interaction until we began the unconventional practice of rearing in the field. Other workers have described nonlethal parasitism for several tachinid–host systems, and many families of flies are similar to tachinids except that their hosts are vertebrates; these interactions are nonlethal. Future empirical work, as well as models of parasite–host interactions, should consider the possibility that hosts alter their plant choices depending upon their parasite loads.

The influence of pH on the type and concentration of metabolites produced from pyruvate by Lactobacillus plantarum ATCC 8014 was examined in pH-controlled fermentors at pH values of 4.5 to 6.5. Specific growth rates, cell dry weights, and diacetyl concentrations were highest at pH 5.5, with values of 0.78 h, 190 mg/liter, and 1.2 mM, respectively. While the conversion efficiency (millimoles of acetoin formed per millimoles of pyruvate utilized) was highest (94.6%) at pH 4.5, acetoin levels were similar (20 mM) between pH 4.5 and 5.5. Feeding stationary-phase cells exogenous pyruvate increased acetoin levels to 78 mM.

Agrobacterium tumefaciens biovar 3 causes both crown gall and root decay of grape. Twenty-two Agrobacterium strains representing biovars 1, 2, and 3 were analyzed for tumorigenicity, presence of a Ti plasmid, ability to cause grape seedling root decay, and pectolytic activity. All of the biovar 3 strains, regardless of their tumorigenicity or presence of a Ti plasmid, caused root decay and were pectolytic, whereas none of the biovar 1 and 2 strains had these capacities. Isoelectrically focused gels that were activity stained with differentially buffered polygalacturonate-agarose overlays revealed that all of the biovar 3 strains produced a single polygalacturonase with a pH optimum of 4.5 and pIs ranging from 4.8 to 5.2. The enzyme was largely extracellular and was produced constitutively in basal medium supplemented with a variety of carbon sources including polygalacturonic acid. Lesions on grape seedling roots inoculated with A. tumefaciens biovar 3 strain CG49 yielded polygalacturonase activity with a pI similar to that of the enzyme produced by the bacterium in culture. These observations support the hypothesis that the polygalacturonase produced by A. tumefaciens biovar 3 has a role in grape root decay.

Interactions among three tropic levels were investigated to determine host plant influences on insect susceptibility to fungal infection. Colorado potato beetle, Leptinotarsa decemlineata (Say), larvae were reared on six Solanum hosts( S. chacoense PI 414143 & 189220, S. hjertingii PI 251065, S. hougasii PI 161726, S. kurtzianum PI 472925, and S. tuberosum L. cv. Lenape) and inoculated topically with Beauveria bassiana (Balsamo) Vuillemin conidia. Larval susceptibility to fungal infection was similar, even though the host plants used for rearing differed ( P ≤ 0.05) in total glycoalkaloid content. The Solanum hosts also had little effect on fitnessof larvae. Applying B. bassiana topically presumably mitigates any direct negative influence that glycoalkaloids may have on the fungus when Colorado potato beetles are inoculated by mouth.

Tumorigenic (CG49) and nontumorigenic (CG484) strains of Agrobacterium tumefaciens bv. 3 attached to grape roots at a higher level than did a nonpectinolytic mutant of CG49 (CG50) or a tumorigenic strain of A. tumefaciens bv. 1 (CG628). Strains attached equally well to wounded and unwounded grape roots. Strains responded differently to pea plants in that biovar 3 strains consistently attached to unwounded roots at a lower level than they did to wounded roots, whereas CG628 attached equally well regardless of wounding. The lowest levels of attachment to pea roots were consistently observed for CG50. Population curves were calculated for the strains inoculated into wound sites on grape and pea roots. A. tumefaciens bv. 3 wild-type strains developed greater populations at wound sites on grape roots after 100 h (resulting in root decay) than did CG50 or CG628. Population curves for strains at wound sites on pea roots were different from those on grape roots. There were no significant differences in populations after 100 h, and no strains caused root decay. No differences in the chemotaxis of wild-type and mutant A. tumefaciens bv. 3 strains towards grape roots, crown pieces, or root extracts were observed, but the biovar 1 strain, CG628, always migrated the greatest distance towards all substrates. Polygalacturonase production may affect attachment to grape roots and multiplication of A. tumefaciens bv. 3 at wound sites and thus be associated with the specificity of the bacterium for grape.

The distribution and diversity of grapevine red blotch virus (GRBV) and wild Vitis virus 1 (WVV1) (genus Grablovirus; family Geminiviridae) were determined in free-living Vitis spp. in northern California and New York from 2013 to 2017. Grabloviruses were detected by polymerase chain reaction in 28% (57 of 203) of samples from California but in none of the 163 samples from New York. The incidence of GRBV in free-living vines was significantly higher in samples from California counties with high compared with low grape production (χ 2 = 83.09; P < 0.001), and in samples near (<5 km) to compared with far (>5 km) from vineyards (χ 2 = 57.58; P < 0.001). These results suggested a directional spread of GRBV inoculum predominantly from vineyards to free-living Vitis spp. WVV1 incidence was also significantly higher in areas with higher grape production acreage (χ 2 = 16.02; P < 0.001). However, in contrast to GRBV, no differential distribution of WVV1 incidence was observed with regard to distance from vineyards (χ 2 = 0.88; P = 0.3513). Two distinct phylogenetic clades were identified for both GRBV and WVV1 isolates from free-living Vitis spp., although the nucleotide sequence variability of the genomic diversity fragment was higher for WWV1 (94.3 to 99.8% sequence identity within clade 1 isolates and 90.1 to 100% within clade 2 isolates) than GRBV (98.3% between clade 1 isolates and 96.9 to 100% within clade 2 isolates). Additionally, evidence for intraspecific recombination events was found in WVV1 isolates and confirmed in GRBV isolates. The prevalence of grabloviruses in California free-living vines highlights the need for vigilance regarding potential grablovirus inoculum sources in order to protect new vineyard plantings and foundation stock vineyards in California.

Taste threshold tests of ferrous sulfate (FeSO4) solutions have been confounded by the presence of putative odorants. To detect the presence of odorants released from these solutions solid-phase microextraction (SPME) was used to collect volatiles in the headspace above FeSO4 solutions. Gas chromatography-olfactometry of samples collected over three time periods (1, 5, and 16 h) and at two temperatures (22 and 37 degrees C) revealed the presence of several metallic-smelling odorants in the headspace. Using authentic standards, two of the odorants were conclusively identified as 1-octen-3-one and 1-nonen-3-one. Trace levels of other odorants were also detected, but dilution experiments indicated that 1-nonen-3-one was at least 10 times more potent than anything else released from the solutions. 1-Octen-3-one and 1-nonen-3-one are excellent candidates for the metallic odor responses often observed in threshold testing of solutions of FeSO4.

Abstract Extrusion cooking is a high‐temperature/short‐time process which is ideal for the production of flavor volatiles. However, due to the nature of this process there are many opportunities for these volatiles to be lost. This has led many researchers to study the formation and retention of volatiles during extrusion. This review focuses on the flavor‐related reactions which may occur during extrusion, including their occurrence in various flours and due to the addition of reactive precursors.

The high level of resistance to pea mosaic virus in the pea cultivar Bonneville is conferred by a single recessive gene. This factor, tentatively designated Pmv, is closely linked to mo, cyv, and sbm-2, which confer resistance to bean yellow mosaic virus, clover yellow mosaic virus, and the lentil strain of pea seedborne mosaic virus, respectively. These four genes are part of a cluster situated in linkage group 2. In the heterozygous condition mo was influenced by temperature, but cyv, pmv, and sbm-2 were not.

ABSTRACT The energy inputs at different stages in the total food cycle of peas were estimated for the market modes: refrigerated, frozen, and canned. The energy accounting showed for refrigerated 3,368; for canned 3,637; and for frozen 3,281 Btu /2.8‐oz serving. Because the energy consumption for each market mode is of the same order of magnitude, there is little reason for the consumer to select on bases other than availability, taste preference, and convenience. It was also found that energy for packaging, marketing, shopping, and in the home can be high depending on the market mode. Measures to reduce energy consumption are discussed for several sectors.

From 1982 to 1984, impact of spray timing on apple aphid, Aphis pomi De Geer, accumulated aphid-days was investigated. Effect of aphid-days on color, diameter, sugar content, firmness of fruit, yield, and shoot growth was also determined. Percentage of infested shoots was regressed with mean densities to evaluate the current estimated economic threshold (50% infested shoots). Varying spray timings had significant effects on accumulated aphid-days. Spray applications made between 450 and 650 degree-days resulted in lower total aphid-days each year. The greatest effect was noted in 1984, when aphid-days were significantly related to yield, shoot growth, and sugar content of fruit on the variety ‘Golden Delicious’. Because no significant relationship between aphid-days, yield, fruit quality, and shoot growth was noted for ‘Red Delicious’, we concluded that the apple aphid did not reduce yield, affect apple quality, or vegetative growth. The current threshold derived from the model for density and percent infested shoots was unsatisfactory for four of six data sets when compared with aphid-day accumulations.

Journal Article Inheritance of susceptibility to powdery mildew in the watermelon Get access R. W. ROBINSON, R. W. ROBINSON New York State Agricultural Experiment StationGeneva, New York 14456 Search for other works by this author on: Oxford Academic PubMed Google Scholar R. PROVVIDENTI, R. PROVVIDENTI New York State Agricultural Experiment StationGeneva, New York 14456 Search for other works by this author on: Oxford Academic PubMed Google Scholar J. W. SHAIL J. W. SHAIL New York State Agricultural Experiment StationGeneva, New York 14456 Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Heredity, Volume 66, Issue 5, September 1975, Pages 310–311, https://doi.org/10.1093/oxfordjournals.jhered.a108636 Published: 01 September 1975

Current models of parasite–host interactions generally emphasize considerations of parasite virulence and parasite transmission rather than host responses to attack. We describe a situation in which parasitism causes a host to change its feeding behavior and this change improves the expected fitness of the host and probably the fitness of its parasites. We have found that a tachinid parasitoid (Thelaira americana) often emerges from its caterpillar host (Platyprepia virginalis) without killing the host. Whether the host caterpillar survives its parasites depends in part on what it has been eating. Unparasitized caterpillars were more likely to survive to adulthood when feeding on lupine, whereas parasitized caterpillars were more likely to survive on poison hemlock. Development time and pupal masses of caterpillars (both parasitized and unparasitized) were not found to be affected by the host plants that they fed on. Survival of fly larvae in caterpillars that we determined were parasitized using ultrasound was not affected by host plant. However, fly pupae that emerged from caterpillars that had been reared on hemlock were heavier than those emerging from lupine-fed caterpillars. This was due primarily to the direct effect of diet on the flies and less so to the indirect benefit to flies whose host caterpillars survived their parasites by feeding on hemlock. Parasitized caterpillars were more likely to select hemlock, and unparasitized caterpillars were more likely to select lupine when offered both host plants in field tests. These results were consistent for the two years that the choice experiments were conducted. These results were also consistent with the hypothesis that caterpillars change their food plant choices so as to increase their conditional success. Conditional food choices that increase success depending upon parasite load are well accepted for humans, controversial for other primates, and unknown for insects. If caterpillars alter their host plant choices as a result of their parasite load, then this phenomenon could help to explain the evolution of host plant choices that have defied explanation in the past. Such a suggestion assumes that nonlethal parasitism is a common phenomenon. We believe that this may be the case since we did not detect the nonlethal nature of this interaction until we began the unconventional practice of rearing in the field. Other workers have described nonlethal parasitism for several tachinid–host systems, and many families of flies are similar to tachinids except that their hosts are vertebrates; these interactions are nonlethal. Future empirical work, as well as models of parasite–host interactions, should consider the possibility that hosts alter their plant choices depending upon their parasite loads.

The accumulation of a polychlorinated biphenyl (PCB) mixture (Aroclor 1242) in the process of detritus formation by a shredded marshgrass (Spartina alterniflora) under aerobic conditions was monitored in percolators for 4 months at 20 degrees C. Dissolved PCB in the influent solution was 14 to 16 mug/liter. Parameters monitored in addition to PCB accumulation were CO(2) evolution, NH(4) uptake, NO(3) production, and total organic nitrogen and carbon in the effluent. An NaN(3-) poisoned control served to assess nonbiological PCB absorption. Up to 90% of the PCB dissolved in the influent water was removed by the biologically active detritus. Biomagnification resulted in three to four times higher PCB concentrations in the active detritus than in the abiotic control. Evolution of CO(2) was slightly depressed by PCB, but the overall quality (C:N ratio) of the detritus was not affected. The results indicate that bioaccumulation of PCB in detritus is an important means of entry for this pollutant into estuarine food webs.

Abstract Traps were used to monitor the emergence and seasonal activity of apple maggot flies, Rhagoletis pomonella (Walsh), in unsprayed habitats, and in selected commercial blocks and farms in the New York apple pest management program to determine the need and timing of control sprays. An average of 69, 43, and 43% fewer sprays and 71, 47, and 57% less insecticides were applied for apple maggot control, respectively, in single blocks monitored in 1976, 1977, and farms monitored in 1977, than in representative orchards in the same areas using regular commercial control schedules.

Analyses of proximity soundings and upper-air fields for 37–51 Utah severe wind cases (WIND), reported in the months of May–September and occurring within 3 h after upper-air observation time, are presented. In addition, a comparison of sample mean values between the WIND cases and a climatological sample (CLIM) is made using a standard t test to determine which variables are significantly different between the two samples. This study seeks to determine if the synoptic-scale-derived fields play a significant role in producing severe wind for a region in which subsynoptic effects, attributed to uneven terrain, are important. The WIND sample environment had the following important differences when compared to CLIM: more convergent wind in the lower troposphere (700-mb moisture and wind convergence), greater moisture at 500 mb (dewpoint, mixing ratio), greater positive vorticity advection (500 mb) and differential vorticity advection (700–500 mb), a larger lapse rate based on various stability indices, more southerly component flow at levels from 500 to 200 mb, higher absolute vorticity at levels from 300 to 200 mb, greater 500-mb wind speeds, and larger thermal advection (warm) at 200 mb. Taken together, the statistical results combined with examination of individual cases and composite maps, suggest that severe wind events in Utah are commonly associated with an approaching upper-level trough system that provides enhanced lift, increased thermal instability, and increased midlevel moisture. These changes to the environment, when added to the normally dry, well-mixed, neutrally stratified boundary layer of the afternoon–evening hours, likely promotes high-based convection with severe downbursts at times. Discriminating effects on the subsynoptic scale cannot be determined in this study since only the standard upper-air station network of observations is employed and no surface data is used. Sample mean differences are small and intrasample variability is large, so results must be used with considerable caution in forecasting applications.

Chalcone synthase (CHS), a key enzyme of flavonoid synthesis, was localized in shoot apices of Fagopyrum, Brassica and Pisum. The enzyme was detected in initial cells of the shoot apex, which gives rise to the whole plant body. In Fagopyrum and Brassica CHS was located in the rib and flank meristems, whereas in the Argenteum mutant of Pisum this enzyme was localized at an earlier stage in the ontogenesis of the shoot. It occurs in a few cells of the tunica, which gives rise to the protoderm, and then to the epidermis which contains anthocyanins in these plants.

Summary Carotene analyses and vitamin A bioassays have been carried out on 9 samples of silage, including regular corn silage, crops ensiled with molasses, and by the A.I.V. procedure. In every case the bioassays showed a higher vitamin A potency per unit of carotene than was obtained on a sample of International Standard Carotene, but the differences were of such magnitude that the carotene analysis may be taken as a reliable index of vitamin A potency. One International Unit (0.6 microgm.) of carotene in silage was found to be equivalent to 1.8 U.S.P. units of vitamin A.

Semen frozen at-79 C. in a diluter of egg yolk, sodium citrate, glycerol, streptomycin, and water had a mean fertility after 7-14 days of 66.7%, after 6 months of 70.1%, and after 12 months of 65.7%. The fresh semen had a fertility of 68%. Editor. There are few data indicating in what manner fertility of bull semen frozen and stored at about-79 C. is influenced by length of storage period. Rowson and Polge (6) found that a storage period of from one to 12 months at --79 C. and stored at about -79 C. is influenced by length of storage period. Rowson et al. (1) found that the fertility of three bulls' semen, frozen and stored at --79 C. for 103 days, showed no decline when compared to frozen semen stored at --79 C. for one day only. Snyder et al. ( Hendrikse et al. (3) found no evidence of a decline in fertility of frozen semen from 22 bulls tested at interval~ of one month for five months and from five of these bulls tested at monthly intervals up to 12 months. Madden (~) obtained a fertility rate of 60.5% on 17,4:33 breedings to frozen semen stored less than two months, and a fertility rate of 58.0% on 13,352 breedings to frozen semen stored over two months--a highly significant difference statistically.