1,721,002 research outputs found
Inheritance of Fusarium wilt resistance introgfressed from Solanum aethiopicum Gilo and Aculeatum groups into cultivated eggplant (S. melongena) and development of assiciated PCR-based markers
No full textThe two eggplant relatives Solanum
aethiopicum gr. Gilo and Solanum aethiopicum gr.
Aculeatum (=Solanum integrifolium) carry resistance
to the fungal wilt disease caused by Fusarium
oxysporum f. sp. melongenae, a worldwide soil-borne
disease of eggplant. To introgress the resistance
trait into cultivated eggplant, the tetraploid
somatic hybrids S. melongena + S. aethiopicum and
S. melongena + S. integrifolium were used. An
inheritance study of the resistance was performed
on advanced anther culture-derived androgenetic
backcross progenies from the two somatic hybrids.
The segregation fitted a 3 resistant (R): 1 susceptible
(S) ratio in the selfed populations and a 1R:1S ratio in
the backcross progenies for the trait derived from
S. aethiopicum and S. integrifolium. These ratios are
consistent with a single gene, which we designated as
Rfo-sa1, controlling the resistance to Fusarium
oxysporum f. sp. melongenae. The allelic relationship
between the resistance genes from S. aethiopicum and
S. integrifolium indicate that these two genes are
alleles of the same locus. Bulked Segregant Analysis
(BSA) was performed with RAPD markers on the
BC3/BC5 resistant advanced backcross progenies, and
three RAPD markers associated with the resistance
trait were identified. Cleaved Amplified Polymorphic
Sequences (CAPSs) were subsequently obtained on
the basis of the amplicon sequences. The evaluation
of the efficiency of these markers in predicting the
resistant phenotype in segregating progenies revealed
that they represent useful tools for indirect selection
of Fusarium resistance in eggplant
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Introgression of resistance to Fusarium oxysporum f.sp. melongenae into cultivated eggplant and characterization of linked molecular markers for development of a markers assisted selection system
No full textVariations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Utilizzo del sistema CRISPR/Cas9 per ottenere partenocarpia in pomodoro
No full textCon genome editing s’intende l’introduzione di una modifica in un punto preciso del genoma della cellula attraverso l’utilizzo di nucleasi artificiali che operano sul gene bersaglio una rottura, la cui riparazione può generare mutazioni ed annullare la funzione del gene. Il sistema più diffuso è quello CRISPR/Cas9 di Streptococcus pyogenes, e prevede che una DNA nucleasi (Cas9) venga guidata ad una sequenza di DNA da modificare, grazie alla sua associazione con una piccola molecola di RNA (RNA guida) in grado di appaiarsi alla sequenza bersaglio. L’allegagione, l’inizio della crescita dell’ovario a seguito della fecondazione, è un processo coordinato da segnali endogeni, soprattutto ormonali, ma che risente di fattori ambientali, che se sfavorevoli, possono avere effetti negativi sulla fecondazione e sulla produttività. Numerosi geni che controllano l’allegagione sono stati individuati. La partenocarpia è un processo alternativo in cui lo sviluppo del frutto avviene in assenza di fecondazione ed indipendentemente dalle condizioni ambientali. La manipolazione genetica del metabolismo e della trasduzione del segnale dell’auxina e delle gibberelline ha permesso di identificare i geni che controllano la partenocarpia. Nel presente studio, il sistema CRISPR è stato usato per indurre mutazioni nel gene SlARF7, noto per essere un regolatore dello sviluppo partenocarpico del frutto di pomodoro. Tre sequenze nucleotidiche corrispondenti a 3 RNA guida aventi come bersaglio 3 regioni diverse del gene SlARF7 sono state clonate nel T-DNA di un vettore binario pFGC-pcoCAS9 (https://www.addgene.org; Li et al., 2013). L’efficacia dei tre RNA del costrutto nell’indurre il taglio nel gene ARF7- RNA guida mediato, è stata testata in vitro attraverso l’impiego del kit commerciale “Guide-it sgRNA in vitro Transcription and Screening Systems” (Clontech). Il vettore binario è stato poi inserito in Agrobacterium tumefaciens (ceppo GV2260) ed impiegato per indurre mutazioni nella cv. UC8
Segregation distortion and linkage analysis in eggplant (Solanum melongena L.)
No full textAn anther-derived doubled haploid (DH) and an F2 mapping population were developed from an intraspecific hybrid between the eggplant breeding lines ‘305E40’ and ‘67/3’. The former incorporates an introgressed segment from S. aethiopicum gr. gilo carrying the Rfo-sa1 gene which confers resistance to Fusarium oxysporum; the latter is a selection from an intraspecific cross involving two conventional eggplant varieties and lacks Rfo-sa1.
Initially, 28 AFLP primer combination (PCs) were applied to a sample of 93 F2 individuals and 93 DH individuals, from which 170 polymorphic AFLP fragments were identified. In the DH population, the segregation of 117 of these AFLPs, as well as that of markers closely linked to Rfo-sa1 were substantially distorted, while in the F2 population, segregation distortion was restricted to just ten markers, thus the latter was chosen for map development.
A set of 141 F2 individuals was genotyped with 73 AFLP PCs (generating 406 informative markers), 32 SSRs, four tomato RFLPs and three CAPS markers linked to Rfo-sa1. This resulted in the assigning of 348 markers to 12 major linkage groups. The framework map covered 718.7 cM, comprising 238 markers (212 AFLPs, 22 SSRs, one RFLP and the Rfo-sa1 CAPS).
Marker order and inter-marker distances in this eggplant map were largely consistent with those reported in a recently published SSR-based map. From an eggplant breeding perspective, DH populations produced by anther culture appear to be subject to massive segregation distortion, and thus may not be very efficient in capturing the full range of genetic variation present in the parental lines
- …
