RESUMEN
Crop improvement is a continuous effort, since some 10,000 years ago when primitive man made the transitionfrom hunting and foraging to domestication and crop cultivation. Since then, man-made interventions havechanged the entire scenario of crop evolution, by means of genetic alterations of plants and animals made tosatisfy man’s needs. The process of domestication has led to dramatic changes in their appearance, quality andproductivity that have contributed substantially to global food security. The tremendous decline in cultivableland, freshwater, and increasing risk of biotic and abiotic stress demand immediate attention on cropimprovement to cope with the higher demand of *40% of the food by 2020. Therefore, plant genetic variationplays a key role in plant breeding for its improvement. Most of the genetic variations useful for cropimprovement have been deposited and maintained in seed gene banks across the world; they need to be broughtinto the mainstream of breeding lines. Recent advances and progress made in molecular markers have beensubstantial tools for deeper insights of genetics, and greatly complemented breeding strategies. Integration of thenext-generation sequencing (NGS) technologies with precise phenotyping, association mapping, proteome andmetabolome studies has increased the chances of finding candidate genes and their allelic variants controlling atrait of interest. Further, these functional markers (FMMs), genotype-by-sequencing and association mappingmethodologies have opened new avenues for identification of novel genetic resources (lines) that can facilitateaccelerated crop breeding programs for increased yield, high nutritional quality, and tolerance to a variety ofabiotic and biotic stresses. The details of popular molecular markers, advancement in the technologies andstrategies for crop diversity studies and their application in crop breeding programs are presented here.
RESUMEN
The purpose of this study was to investigate food habits, nutrients intakes and nutritional quality of the preschool children living in Seoul. The study was performed by analyzing a questionnaire answered by the mothers of 233 subjects aged 2 to 6 years old. A three-day dietary intakes survey, using a 24 hour recall method was used by both the mothers and teachers of the children in day care centers. Twenty eight, 65.9 and 21.8% of preschool children were underweight, normal and overweight or obese, respectively. It was found that 19.8% of preschool children replied that they skipped breakfast sometimes. The major reasons for skipping breakfast were 'snacks'(38.3%) and 'no appetite' (32.6%). The proportion of subjects having unbalanced meals was 61.6%. From the 24-recall survey, it was found that all nutrients intakes were higher than those of the Korean RDA except zinc. The proportions of carbohydrate, protein and fat from total calories were 56,1, 17.2 and 30.7%. The P/M/S ratio was 0.62 : 0.86 : 1. Nutrient adquacy (NAR), mean of nutrient adequacy ratio (MAR) and index of nutritional quality (INQ) were considered adequate. In conclusion, the dietary intakes of children aged 2 to 6 were assumed adequate judging from nutrient intakes, although some attention should be paid to fat intake in this age group.