Development of kelp rockfish, Sebastes atrovirens (Jordan and Gilbert 1880), and brown rockfish, S. auriculatus (Girard 1854), from birth to pelagic juvenile stage, with notes on early larval development of black-and-yellow rockfish, S. chrysomelas (Jordan and Gilbert 1880), reared in the laboratory (Pisces: Sebastidae).

Larval kelp (Sebastes atrovirens), brown (S. auriculatus), and blackand-yellow (S. chrysomelas) rockfish were reared from known adults, to preflexion stage, nine days after birth for S. chrysomelas, to late postflexion stage for S. atrovirens, and to pelagic juvenile stage for S. auriculatus. Larval S. atrovirens and S. chrysomelas were about 4.6 mm body length (BL) and S. auriculatus about 5.2 mm BL at birth. Both S. atrovirens and S. auriculatus underwent notochord flexion at about 6–9 mm BL. Sebastes atrovirens transform to the pelagic juvenile stage at about 14–16 mm BL and S. auriculatus transformed at ca. 25 mm BL. Early larvae of all three species were characterized by melanistic pigment dorsally on the head, on the gut, on most of the ventral margin of the tail, and in a long series on the dorsal margin of the tail. Larval S. atrovirens and S. auriculatus developed a posterior bar on the tail during the flexion or postflexion stage. In S. atrovirens xanthic pigment resembled the melanistic pattern throughout larval development. Larval S. auriculatus lacked xanthophores except on the head until late preflexion stage, when a pattern much like the melanophore pattern gradually developed. Larval S. chrysomelas had extensive xanthic pigmentation dorsally, but none ventrally, in preflexion stage. All members of the Sebastes subgenus Pteropodus (S. atrovirens, S. auriculatus, S. carnatus, S. caurinus, S. chrysomelas, S. dalli, S. maliger, S. nebulosus, S. rastrelliger) are morphologically similar and all share the basic melanistic pigment pattern described here. Although the three species reared in this study can be distinguished on the basis of xanthic pigmentation, it seems unlikely that it will be possible to reliably identify field-collected larvae to species using traditional morphological and melanistic pigmentation characters. (PDF file contains 36 pages.

Feasibility of hill plots for use in winter small grains research

Four plot types were evaluated for use with winter small grains research. The plot types evaluated were hill plot, hill row, rod row equivalent and drill strip. The objectives of this research were to study the feasibility of the two hill plot designs for use in winter small grains research and to compare these designs to standard rod rows and drill strips in the same experiment. The plot types were evaluated with Cumberland oats (Avena sativa L.), Volbar barley (Hordeum vulgare L.), and Arthur wheat (Triticum aestivum L.). The plot types were compared for measurment of spring stand, date headed, date ripe, plant height, percent lodging, yield, and 100 kernel weight. Ranges, coefficients of variation, correlations, analysis of variance, Duncan\u27s New Multiple Range Test, and Relative Efficiencies were used to evaluate the plot types. All correlations between plot types were positive and significant at the 0.05 probability level. Hill plots were much more variable with oats than rod rows and drill strips for measurement of spring stand by all by all measures of variability. Five replications of hill plots of oats were needed to equal one replication of rod equivalent. Yield evaluation in hill plots of oats was affected to a large extent by the erratic nature of winterkilling in the hill plots. For yield 3.5 replications of hill plots were needed to equal one replication of rod row equivalent. Date headed and date ripe evaluation in hill plots of oats was affected to a lesser extent than yield. Hill plots of barley and wheat where winter killing did not occur reacted more favorably than oats for yield, date headed, and date ripe evaluation. For yield 2.5 replications of hill plots would have been as or more efficient than one replication of rod row equivalent. Two replications of hill plots would have been as or more efficient as one replication of rod row equivalent for all the other characters. The hill row did not have enough advantage over the hill plot in reducing variability to justify its use. Although conducted at only one location for one year this study raises serious doubt on the feasibility of hill plots for use in winter small grains research when winterkilling occurs and is a factor to be evaluated

Cytoplasmic effects for quantitative traits in interspecific Avena crosses

Recently, the incorporation of exotic germplasm from Avena sterilis L. into cultivated oats (A. sativa L.) has become a part of several oat improvement programs. To date, this research has involved only nuclear genes; yet, variation among cytoplasms in Avena may provide much opportunity for improving oats as an agricultural crop. The objectives of this study were (a) to determine if cytoplasmic effects occurred in reciprocal interspecific matings, (b) to assess whether backcrossing to the cultivated parent influenced cytoplasm effects, and (c) to determine if there were specific nuclear x cytoplasmic interactions;Sixty populations of 20 oat lines each, representing the BC(,0), BC(,1), and BC(,2) of the matings among five A. sterilis accessions and two A. sativa cultivars with reciprocals, were evaluated in a field-grown experiment for grain yield, straw yield, harvest index, heading date, plant height, unit straw weight, and vegetative growth rate. The data from this experiment were analyzed in such a way that the effects of nuclear genes, of cytoplasms, and of nuclear genes x cytoplasms could be assessed;A. sterilis nuclear effects on grain yield, straw yield, and plant height were large, even in the BC(,2), indicating much genetic variability was present in A. sterilis for these traits. The importance of the A. sativa parents to differences among matings increased with backcrossing to the A. sativa parent for all traits except plant height and grain yield. With random backcrossing, specific nicking ability of A. sterilis and A. sativa was lost, with the result that parental performance per se was a good indicator of the performance of a mating;Generally, the values for straw yield, plant height, unit straw weight, and vegetative growth rate were increased by A. sterilis cytoplasm, but these advantages decreased with backcrossing and were lost by BC(,2). Probably, this relationship with level of backcrossing resulted because interactions between A. sterilis cytoplasms and A. sterilis nuclear genes were responsible for the improved performance. Harvest index showed an advantage for A. sterilis cytoplasm in the BC(,1) and BC(,2). Grain yield and heading date were significantly increased by A. sterilis cytoplasm and these effects were not diminished by backcrossing. The effect of A. sterilis cytoplasm on heading date showed no mating interactions of importance, an indication of a direct cytoplasmic effect. The grain yield increase due to A. sterilis cytoplasm was most likely due to specific favorable interactions with A. sativa nuclear genomes;These results suggest that plant breeders might improve crop performance by making use of diverse cytoplasms. An additional benefit would be the added cytoplasmic diversity which could be a stabilizing influence on production

Evidence of cryptic introgression in tomato (Solanum lycopersicum L.) based on wild tomato species alleles

Abstract Background Many highly beneficial traits (e.g. disease or abiotic stress resistance) have been transferred into crops through crosses with their wild relatives. The 13 recognized species of tomato (Solanum section Lycopersicon) are closely related to each other and wild species genes have been extensively used for improvement of the crop, Solanum lycopersicum L. In addition, the lack of geographical barriers has permitted natural hybridization between S. lycopersicum and its closest wild relative Solanum pimpinellifolium in Ecuador, Peru and northern Chile. In order to better understand patterns of S. lycopersicum diversity, we sequenced 47 markers ranging in length from 130 to 1200 bp (total of 24 kb) in genotypes of S. lycopersicum and wild tomato species S. pimpinellifolium, Solanum arcanum, Solanum peruvianum, Solanum pennellii and Solanum habrochaites. Between six and twelve genotypes were comparatively analyzed per marker. Several of the markers had previously been hypothesized as carrying wild species alleles within S. lycopersicum, i.e., cryptic introgressions. Results Each marker was mapped with high confidence (e-30) to a single genomic location using BLASTN against tomato whole genome shotgun chromosomes (SL2.40) database. Neighbor-joining trees showed high mean bootstrap support (86.8 ± 2.34%) for distinguishing red-fruited from green-fruited taxa for 38 of the markers. Hybridization and parsimony splits networks, genomic map positions of markers relative to documented introgressions, and historical origins of accessions were used to interpret evolutionary patterns at nine markers with putatively introgressed alleles. Conclusion Of the 47 genetic markers surveyed in this study, four were involved in linkage drag on chromosome 9 during introgression breeding, while alleles at five markers apparently originated from natural hybridization with S. pimpinellifolium and were associated with primitive genotypes of S. lycopersicum. The positive identification of introgressed genes within crop species such as S. lycopersicum will help inform conservation and utilization of crop germplasm diversity, for example, facilitating the purging of undesirable linkage drag or the exploitation of novel, favorable alleles.</p

PCBs : exposures, effects, remediation, and regulation with special emphasis on PCBs in schools

Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Environmental Science and Pollution Research 23 (2016): 1971-1974, doi:10.1007/s11356-015-5774-y.The Eighth International PCB Workshop: PCBs in Schools was held in Woods Hole, MA, October 5-9, 2014, and was attended by more than 130 scientists and other interested persons, including citizen’s groups and concerned parents. The program included a wide range of thematic areas. Presentations addressed essential questions and progress toward understanding mechanisms of PCB toxication and risks of PCB exposure. Presentations were also held illuminating several key PCB contamination problems.2016-12-0

Evaluation of tomato accessions for flavour and flavour-contributing components

Flavour is one of the most highly demanded consumer traits of tomato at present; poor flavour is one of the most commonly heard complaints associated with modern varieties of tomato. In order to combine flavour with other desirable fruit traits in improved cultivars, it is important to determine how much variability exists in the crucial compounds that contribute most to flavour. The objective of the present study was to determine the variability of flavour-contributing components including total soluble solids (TSS) and total titratable acids (TTA) among other subjective traits related to flavour in a core collection of tomato accessions. The core collection was comprised of 173 tomato accessions with a wide genetic background from the United States Department of Agriculture (USDA), Agricultural Research Services (ARS) Plant Genetic Resources Unit repository. The TTA varied from 0.20 to 0.64%, whereas the TSS ranged from 3.4 to 9.0%, indicating the availability of broad variation for these traits. Rinon (PI 118783), Turrialba, Purple Calabash and LA2102 were among the high TTA (>0.45%) containing accessions, whereas those with high TSS (>7.0%) were AVRDC#6, Sponzillo and LA2102. A positive correlation of overall flavour with TTA (r=0.33; P<0.05) and TSS (r=0.37; P<0.05) indicated that these two components play an important role in determining the overall flavour in tomato. Subjectively measured other traits including fruity odour and fruity flavour had positive correlations with overall flavour. Overall flavour is discussed in the context of other traits including fruit firmness. Information obtained from this study may be useful for tomato breeders aiming to improve tomato flavou

Biphenyl-4-yl 2,2,2-trichloro­ethyl sulfate

The mol­ecular structure of the title compound, C14H11Cl3O4S, displays a biphenyl dihedral angle of 4.9 (2)° between the benzene rings, which is significantly smaller than the calculated dihedral angle of 41.2° of biphenyl derivatives without ortho substituents. The CAr—O bond length of 1.432 (4) Å is comparable with other sulfuric acid biphenyl-4-yl ester 2,2,2-trichloro­ether ester derivatives without electronegative substituents in the sulfated phenyl ring

AlleleCoder: a PERL script for coding co-dominant polymorphism data for PCA

A useful biological interpretation of diploid heterozygotes is in terms of the dose of the common allele (0, 1 or 2 copies). We have developed a PERL script that converts FASTA files into coded spreadsheets suitable for principal component analysis. In combination with R and R Commander, two- and three-dimensional plots can be generated for visualizing genetic relationships. Such plots are useful for characterizing plant genetic resources. This method nicely illustrated the spectrum of genetic diversity in tomato landraces and the varieties categorized according to human-mediated dispersa