Summary During the years 2000 to 2005, field trials were conducted in different locations of the Province of Buenos Aires and Santa Fe and also laboratory analysis were carried out. The data collected from the field trials and lab made possible to study and analyze the morphology, agronomic performance and chemical traits of the kernels of twenty-eight new inbreds and twelve single-crosses derived from them that carry recessive genes of commercial interest. The new inbreds CIG and the single-crosses HC stand out for having 11 to 15 leaves and up to 2 productive ears per plant, the last reveals and excellent performance of the materials under the field trials conditions. The single-crosses stand out because of their modern architecture, stated through a reduced plant height and ear insertion height and a lower number of leaves which are erect in relation to the stem. The degree of prolificity achieved in the single-crosses HC is similar to that observed in the best maize hybrids commercially grown in Argentina. It is remarkable, the high degree of precocity to silking (R1) in the materials developed, as this phase is raised after storing less than 680,0 growing degree days in the 64,3% of the inbreds and 50% of the single-crosses, so that these ultra precocious materials belong to the classes FAO 100 and 200. The rest genotypes need to gather 680,0 to 720,0 growing degree days to the same phenological stage and are classified as precocious (class FAO 300-400). The precocity degree of the single-crosses HC will facilitate their culture in areas with short summers and humid autumns as for example the Western and Southern Pampaīs regions and also will make possible to proceed with late sowings in the Northern Pampa region and the Corn region VI. The new inbreds CIG produce from 2.371,4 Kg kernels/ha to a maximum of 6.482,7 Kg. kernels/ha, exceeding the least economic threshold that any inbred must reach to be used in the production of single-crosses seed. Otherwise, the specialty corn single-crosses HC equalled and even exceeded the national average yield (6,4 to 7,4 ton/ha) obtained during the seasons 2002/03 to 2004/05. The waxy hybrid HC1 showed the highest productivity level with an average of 11.137,1 Kg. kernel/ha whilst the high quality protein hybrid termed HC6 was the less yielding one with an average production of 7.246,1 Kg. kernels/ha. The effect of heterosis increased up to four folds the yield of the least productive parent of the crossing. The parent inbreds CIG7 and CIG28 strongly contributed to the yielding of the most heterotic single-crosses. The results obtained show that 15% of the new inbreds CIG and the 41,7% of the single-crosses HC have a high oil content (similar or lightly higher than 6,0%). Likewise, the inbreds and their single-crosses have a fatty acids profile analogous to that of the argentine maize hybrids commercially grown. Near infrared analysis revealed that the kernel protein level exceeds 11% in twenty-four of the new CIG inbreds, reaching the extreme value of 13,3% in case of the genotype CIG21. The single-crosses HC have a protein content of 10,7% to 12,2% in their grains and in this aspect the materials HC6 and HC8 stand out. Half of the single-crosses have a protein content similar or higher than that observed in commercial hybrids grown in Argentina. The quality protein inbreds CIG and the single-crosses HC have up to 4,7 mg lysine/100 mg protein and 1,3 mg triptophan/100 mg protein. The genotypes HC2, HC4 and HC10 particularly stand out amongst the single-crosses for this reason. The results prove that those genotypes with quality proteins increase two or three folds the lysine and triptophan content found in the waxy and vitreous materials. The high quality protein single-crosses, except HC5, have kernels with 50 to 75% of vitreous endosperm, reason by which they could be considered as modified opaque-2 materials. The near infrared transmission spectroscopy analysis (NIRT) uncovered that the total carbohydrates level of the CIG inbreds kernels varied between 68,0% to 72,9% whilst for the single-crosses HC it ranges from 69,0% to 71,5% and fits within the values usually reported for commercial maize hybrids in our country. The whole starch of some of the new CIG inbreds and single-crosses HC is constituted by 97,5% to 99,0% of amylopectin and stains light violet or orchid in presence of the Krismanīs reagent. This fact suggests the presence of up to three doses of the wxa allele in these materials whose genetic backgroung includes genetic information of the synthetics V1 and V2 from Argentina. The content and quality of the protein, oil and starch held within the kernels of the single-crosses HC together with their outstanding productivity implies that these materials may produce large amounts of these components per area unit and consequently be very competitive and give potential comparative advantages in the field of human and animal nutrition as well as in the transformation industries. Keywords: Zea mays L, waxy, opaque-2, NIR, HPLC, gas chromatography, starch, oil, protein, thermal time, yield, parametric, multivariate analysis