FR 06. Doe rabbit performances in Martinique

The purpose of this study was to analyse the litter size performance and to estimate the effect of farms, month of weaning and litter size on the reproductive performances of doe rabbits reared under semi-intensive conditions in Martinique. Data were collected from 5 farms units in Martinique between February 1994 and September 1995. Rabbitries were populated with locally adapted stock of mixed breeding, including contributions from several breeds - New Zealand White, Californian and local breed. The percentage of stillborn and the percentage of kits dead between kindling and weaning were significantly different between litter sizes at birth. The percentage of mortinatality was significantly smaller in litter size including between 6-9 (6.95 %) than the other groups: respectively 10.75 % and 10.69 %. Preweaning mortality was higher in litter sizes > 10 than others groups (39.53 % vs 28.29 % and 25.96 %). This result showed that the optimum litter size was included between 6-9 kits total bom by litter. The doe performance traits reported in this study were comparable with those reviewed and reported by different authors in Caribbean island, but were inferior to those observed in temperate climate. Beyong the unfavorable effect of the month of weaning, some of these differences in performances were connected with high frequency of “small” litter size and quit high general mortality. The improvement in management of mating and reproductive replacement and the satisfaction of nutrient requirements for nursing does could certainly increase the doe performances in Martinique. Besides, the generalization of cross-fostering to equilize the litter size between 6-9 kits, could to enable to control the mortality between kindling and weaning

DNA marker-assisted selection to pyramid rust resistance genes in “carioca” seeded common bean lines

This work reports a gene pyramiding approach assisted by DNA markers used to develop “carioca” seeded common bean (Phaseolus vulgaris L.) elite lines harboring three different rust resistance genes. Rust is among the most destructive diseases that attack P. vulgaris and cause serious damage worldwide. The rust resistance genes Ur-5 (from ‘Mexico 309’), Ur-11 (from ‘BelMiDak RR-3’), and Ur-14 (from ‘BRS Pioneiro’, a “carioca” seeded cultivar derived from the resistance source ‘Ouro Negro’) were combined in the “carioca” seeded bean cultivar ‘Rudá’. Firstly, two different backcross programs were conducted separately to produce progenies harboring individually the Ur-5 and Ur-11 genes. Molecular fingerprinting analysis was used to select plants genetically similar to ‘Rudá’ in the backcross cycles to accelerate the recurrent-background recovery. The obtained progenies were initially intercrossed and then crossed with ‘BRSMG Pioneiro’ (Ur-14). The final F1 plants derived from these crosses were screened with DNA markers linked to the three rust resistance genes: SI19 (Ur-5), SAE19 (Ur-11) and OPX11 (Ur-14). The plants selected as harboring all the alleles of interest were used to obtain the next generations. The selection based on DNA markers was conducted up to the F4:5 generation. We were able to select F4:7 progenies showing all the DNA markers associated to the genes of interest and resistant to all specific races of U. appendiculatus used for phenotypically detecting each one of the rust resistance genes. Yield evaluations show that these selected lines are as productive as the recurrent parent ‘Rudá’ and high-performing control cultivars grown in Brazil