Population structure, phenotypic information and association studies in long-generation crops

Poster presented at Generation Challenge Program Annual Research Meeting. Sao Paulo (Brazil), 12-16 Sep. 200

Envelope Factorization with Partial Elimination and Recombination, EF-PER, a New Linear RF Architecture

In this paper, a new architecture for efficient linear radio frequency transmitters is proposed; it includes envelope-tracking (ET) and envelope-elimination-and-restoration (EER) architectures as special instances. The proposed technique is referred to as Envelope Factorization with Partial Elimination and Recombination (EF-PER). It relies on a decomposition of the RF signal before power amplification as a product of two signals, one of them being the envelope signal elevated to an exponent “α”. Compared to ET or EER architectures, the parameter “α” constitutes a new degree of freedom. This allows one to realize good tradeoffs between different performance criteria such as spectrum use, power efficiency, and transmitter linearity. An intuitive aggregate cost function is introduced to capture the desired tradeoff and turns out to be maximized in α=0.5. The full relevance of EF-PER is sustained both by analytical results and realistic simulations performed for OFDM signals. The EF-PER architecture (with α=0.5) has been simulated under Agilent-ADS with a non-linear transistor model from Avago (E-PHEMT) and compared with ET and EER

Barrières pré-zygotiques chez les hybrides entre formes sauvages du niébé, Vigna unguilata (L.) Walp.

Hybrids pre-zygotic barriers between wild forms of cowpea. The wild forms of cowpea, Vigna unguiculata, constitute an important gene pool insufficiently exploited for the improvement of the cultivated form. In order to promote the use of these wild forms in the genetic improvement programmes, we undertook to understand the various incompatibility reactions which appear in the crosses between wild forms. Efforts were concentrated to understand the incompatibility barriers in the hybridizations between subsp. baoulensis NI 933 and the other wild forms of V. unguiculata. Thanks to the use of the aniline blue fluorescence, we observed a high frequency of pre-zygotic barriers. They appear in three sites, i.e. the higher and lower third of the style, and within the ovary. However, these incompatibility barriers are not absolute. Indeed, in our hybridizations, more than 4% of the ovules were fertilized in the various studied combinations

Analysis of incompatibility barriers during cross-pollinations among Phaseolus L. and other leguminous plants

Plant breeding is intended to seek for ways of realizing a genetic structure adapted to criteria and population needs. In this context, cross-pollinations are for great interest. They offer the means of creating a wide genotypic variability. However, a limited number of species are able to undergo hybridization studies. In Phaseolus L., improvement can be envisioned by either exploiting the primary genetic pool of the species, or the genetic variability of other species. In fact, there are wild or wild-like species more resistant to stresses or diseases than the cultivated ones. The methods of embryo rescues facilitate the interspecific crosses and contribute to exploiting the available genetic diversity within plant germplasm. Difficulties related to obtaining hybrids in grain legumes, and Phaseolus L. in particular, are reported in this research. It is possible to avoid the incompatibility barriers based on their appearance time. When they are pre-zygotic, the use of growth regulators during pollination is recommended. The in vitro explants culture is the most usual method to overcome the post-zygotic barriers. The mechanisms leading to abortion of hybrid embryos, as well as adequate methods to overcome the interspecific incompatibilities should be subjected to further studies.Keywords: Abortion, hybridization, interspecific barriers, Phaseolus L., plant embryos

Amélioration du taux de multiplication in vitro de Jatropha curcas L

Improvement of the Rate of in vitro Multiplication of Jatropha curcas L. In order to improve the in vitro multiplication rate (number of shoots/explant/subculture) of Jatropha curcas L. axillary nodes taken from young plants of two accessions of this species (originating from Cameroon and Senegal) have been cultivated for three weeks on a MS medium supplemented with 8.87 μM BAP, 4.92 μM IBA, and 30 g/l sucrose at pH 5.7 ± 0.1, and solidified with 0.7% agar. The shoots obtained from each original explant were then transferred to proliferation media (PM) consisting of MS medium supplemented with 2.21 to 8.9 μM BA or 2.21 to 8.9 μM kinetin in combination with 2.46 μM IBA. Each combination was completed with 33.12 μM adenine sulfate, 82.92 μM of glutamine and 30 g / L sucrose. The best multiplication rate was obtained for the PM medium containing 6.65 μM BA and 2.46 μM AIB. On this medium 42.72 ± 3.22 and 38.15 ± 4.7 shoots/explant were obtained respectively for the accessions from Cameroon and Senegal after 6 weeks of culture, and the mean multiplication rates were 8.27 ± 1.27 (accession from Cameroon) and 7.89 ± 1.13 (accession from Senegal) shoots per explant during the 7 following subcultures (3 weeks/subculture). This medium was also the one that allowed the best overall growth in shoot height. Leafy shoots obtained have been rooted in a medium containing half of the major mineral components of MS supplemented with 5.7 μM IBA, 1.5% sucrose and solidified with 0.7% agar, then acclimated with a survival rate of 97%. These results allow considering the establishment of industrial units of plantlet multiplication from elite clones of Jatropha curcas

Effect of floral debris removal from fruit clusters on botrytis bunch rot of Chardonnay grapes

The relationship between senescent floral debris retained in fruit clusters and the incidence and severity of botrytis bunch rot was examined in Chardonnay grapevines over three seasons. Floral debris was removed from clusters at either early or late fruit set using compressed air or a back-pack leaf blower. Additional treatments were included to determine if a commercial sticker spray adjuvant (Nu-Film 17) increased debris retention in clusters. Physical removal of floral debris generally reduced botrytis bunch rot; however, reductions in botrytis bunch rot were only significant in some vineyards. The sticker spray adjuvant had no effect on retention of debris or on botrytis bunch rot. The incidence and severity of botrytis bunch rot were not affected by timing of debris removal, but late removal by compressed air, when berries were as much as 8 mm in diameter, did cause berry bruising. The data demonstrate that senescent floral debris and aborted berries can contribute to increased botrytis bunch rot, and that practical measures to reduce debris retention may aid disease control

Codex Corpus y la revancha final de la memoria

Decir que Codex Corpus es una cavilación sobre el cuerpo es cierto, pero insuficiente para describir este libro. Añadir que se trata de un poemario en el cual el cuerpo de la escritura es tan importante como la carne que lo sostiene, completa esa idea pero todavía no alcanza para dar cuenta de su complejidad. El último trabajo de la boliviana Paola Senseve, merecedor en el 2019 del Premio Nacional de Poesía Yolanda Bedregal -el mayor galardón de su país para este género-, es también o cómo mínimo una elaboración sobre el duelo y la materialidad del amor ante la ausencia fáctica que produce la muerte