The flowering locus Hr colocalizes with a major QTL affecting winter frost tolerance in Pisum sativum L.

An understanding of the genetic determinism of frost tolerance is a prerequisite for the development of frost tolerant cultivars for cold northern areas. In legumes, it is not known to which extent vernalization requirement or photoperiod responsiveness are necessary for the development of frost tolerance. In pea (Pisum sativum L.) however, the flowering locus Hr is suspected to influence winter frost tolerance by delaying floral initiation until after the main winter freezing periods have passed. The objective of this study was to dissect the genetic determinism of frost tolerance in pea by QTL analysis and to assess the genetic linkage between winter frost tolerance and the Hr locus. A population of 164 recombinant inbred lines (RILs), derived from the cross Champagne x Terese was evaluated both in the greenhouse and in field conditions to characterize the photoperiod response from which the allele at the Hr locus was inferred. In addition, the population was also assessed for winter frost tolerance in 11 field conditions. Six QTL were detected, among which three were consistent among the different experimental conditions, confirming an oligogenic determinism of frost tolerance in pea. The Hr locus was found to be the peak marker for the highest explanatory QTL of this study. This result supports the hypothesis of the prominent part played by the photoperiod responsiveness in the determinism of frost tolerance for this species. The consistency of three QTL makes these positions interesting targets for marker-assisted selection.

[Nutritional evaluation of health shift workers from the Canary Islands]. / Valoración nutricional de trabajadores sanitarios expuestos a turnicidad en Canarias.

OBJECTIVE: Shift workers are known to have increased morbidity associated to wrong habits. In this study we have evaluated the nutritional status, food habits and physical activity in health shift workers. SUBJECTS: 207 permanent morning-shift workers and 210 shift workers (3-shift system) were randomized selected from the 2,100 workers of the North Area of the Canary Island Sanitary Health System. METHODS: Dietary intake was assessed by a self-registered food frequency questionnaire. We also assessed Body Mass Index, blood lipid levels (total cholesterol, HDL cholesterol, LDL cholesterol and triglycerides), physical activity, age and sex. RESULTS: Shift workers shown higher intake of red meat, eggs, fruit juices and pasta. No differences were observed in lipid levels, weight status and physical activity in relation to the shift working status. 62% of men and 37.2% of women were overweight or obese. 46% of the subjects were sedentary. CONCLUSIONS: Shift work system seems to have little influence on the food habits of health workers.