Laboratory of Plant Breeding

São José dos Campos, Brazil

Laboratory of Plant Breeding

São José dos Campos, Brazil
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Vivas M.,Darcy Ribeiro North Fluminense State University | Silveira S.F.,Darcy Ribeiro North Fluminense State University | Pio-Viana A.,Laboratory of Plant Breeding | Amaral-Junior A.T.,Laboratory of Plant Breeding | And 2 more authors.
Crop Protection | Year: 2015

The absence of cultivars with satisfactory levels of genetic resistance justifies the search for genotypes incorporating disease-resistance genes in the papaya-breeding program. In this study, two field-plot experiments were carried out in the municipality of Linhares, Espirito Santo State, Brazil, to evaluate resistance to foliar diseases in a papaya germplasm collection. The variables incidence and severity of leaf diseases and black spot incidence and severity on fruits were considered for uni- and multivariate variance analyses. The Mahalanobis distance was calculated for each pair of genotypes, and the distance matrix was used for clustering methods. Papaya genotypes were grouped by the Tocher method and the hierarchical method of Un-weighted Pair Group with Arithmetic Mean (UPGMA) was used for dendrogram construction. Although no immune reaction was observed among the genotypes for any of the leaf diseases, the data analyses highlight the following genotypes as potential sources of resistance genes for use in a papaya breeding program: 'STZ 23 PL', 'Maradol', 'Maradol GL', 'JS 11', 'Americano', 'Caliman SG', 'Sekati', 'Sekati FLM', 'Waimanalo', 'Caliman AM', 'Papaya 46', 'Tailândia' and 'SH 12-06'. This is the first time multivariate analyses were employed to evaluate multiple disease resistance in a papaya crop. © 2015 Elsevier Ltd.


Grant
Agency: Narcis | Branch: Project | Program: Completed | Phase: Social Sciences | Award Amount: | Year: 2007

None


Cheng F.,Chinese Academy of Agricultural Sciences | Wu J.,Chinese Academy of Agricultural Sciences | Fang L.,Chinese Academy of Agricultural Sciences | Sun S.,Chinese Academy of Agricultural Sciences | And 4 more authors.
PLoS ONE | Year: 2012

Polyploidization, both ancient and recent, is frequent among plants. A "two-step theory" was proposed to explain the meso-triplication of the Brassica "A" genome: Brassica rapa. By accurately partitioning of this genome, we observed that genes in the less fractioned subgenome (LF) were dominantly expressed over the genes in more fractioned subgenomes (MFs: MF1 and MF2), while the genes in MF1 were slightly dominantly expressed over the genes in MF2. The results indicated that the dominantly expressed genes tended to be resistant against gene fractionation. By re-sequencing two B. rapa accessions: a vegetable turnip (VT117) and a Rapid Cycling line (L144), we found that genes in LF had less non-synonymous or frameshift mutations than genes in MFs; however mutation rates were not significantly different between MF1 and MF2. The differences in gene expression patterns and on-going gene death among the three subgenomes suggest that "two-step" genome triplication and differential subgenome methylation played important roles in the genome evolution of B. rapa. © 2012 Cheng et al.


Grant
Agency: Narcis | Branch: Project | Program: Completed | Phase: Physics, Chemistry and Medicine | Award Amount: | Year: 2007

This project aims to identify existing, or to create new mutant alleles in genes involved in quality traits of potato. Laborious phenotypic screening methods would be required to identify mutants with new properties. However, with (Eco-) TILLING as method, it is possible to efficiently screen allelic variation which may already be present in existing potato cultivars. In addition new material will be developed with the mutagen EMS, to expand the spectrum of DNA polymorphisms.

A set of candidate genes will be screened in a large number of potato cultivars and EMS treated clones. Deviating alleles that are expected to affect gene function and thus change quality traits will be bred to homozygosity. Homozygous material will be phenotyped for altered properties for quality traits for consumption and processing industry.


Win K.T.,Laboratory of Agricultural Ecology | Win K.T.,Laboratory of Plant Breeding | Mochizuki T.,Laboratory of Agricultural Ecology
Journal of the Faculty of Agriculture, Kyushu University | Year: 2010

Rice genotypes with improved N-use efficiency are becoming a prerequisite for optimizing grain yield, reducing production cost, and developing environmentally friendly cropping systems. The physiological efficiency of grain (PE-grain) and biomass (PE-biomass), photosynthetic N-use efficiency (PNUE), and in vivo carboxylation efficiency of Rubisco (Pn/Rubisco) under varying N nutrition conditions were investigated in two Myanmar varieties (Bawgyi and Sawbwa), an indica variety (IR24), and a japonica control variety (Nipponbare). Nipponbare and IR24 had significantly higher grain yield and PE-grain at both soil N and standard N supply, Bawgyi exhibited moderately high grain yield and PE-grain, and Sawbwa had a low grain yield and PE-grain at both N levels. Nipponbare and IR24 had significantly higher PE-biomass at all N levels; while Bawgyi had lower PE-biomass than Nipponbare and IR24 at all N levels, its PE-biomass was significantly higher than that of Sawbwa at the low N level. Net photosynthesis (Pn) of Bawgyi was not significantly different from that of Nipponbare and IR24, but was higher than that of Sawbwa, even with no significant difference in leaf N content. Nipponbare, IR24, and Bawgyi showed no significant difference in PNUE, but had significantly higher PNUE than Sawbwa, especially at low and standard N levels. There was no significant difference in Pn/Rubisco among Bawgyi, Nipponbare, and IR24, but Pn/Rubisco was significantly higher in these varieties than in Sawbwa at low and standard N levels. PE-biomass corresponded well to PE-grain and showed significant positive correlations with PNUE and Pn/Rubisco, indicating that rice genotypes with high physiological efficiency have high Pn with low leaf N and low Rubisco content with high Rubisco efficiency. These results suggest that, of the two Myanmar rice varieties, Bawgyi is the more desirable genotype, with considerably higher physiological efficiency and high photosynthetic activity through the highly efficient use of Rubisco.


Grant
Agency: Narcis | Branch: Project | Program: Completed | Phase: Agriculture | Award Amount: | Year: 2007

None


Grant
Agency: Narcis | Branch: Project | Program: Completed | Phase: Agriculture | Award Amount: | Year: 2007

None


Grant
Agency: Narcis | Branch: Project | Program: Completed | Phase: Agriculture | Award Amount: | Year: 2007

None


Grant
Agency: Narcis | Branch: Project | Program: Completed | Phase: Agriculture | Award Amount: | Year: 2007

None


Grant
Agency: Narcis | Branch: Project | Program: Completed | Phase: Agriculture | Award Amount: | Year: 2007

None

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