Estimation of genetic variance components for yield and protein content for some new genotypes in maize [electronic resource].

Includes references.

Increasing grain protein concentration in maize (Zea mays L.) has not been a major focus of most breeding programs, which mainly focus on yield, maturity, and resistance to stress. The objectives of this research work are: (1) Evaluation of the non selected and selected H.S familles(the origina/100 H.S tested and the 20 " H.S selected) in two locations i.e., Gemmeiza and Sids Agricultural Research Stations, three maize population's i. e., Pool¬ 15 - 67 CIMMYT, Composite - 45 and Gemmeiza yellow. (2) Evaluation of the original populations and the first cycles of selection (CO and C1) of all studied populations in two sowing dates (early and late) at University of Menoufiya Agriculturally Research Farm. (3) Determine the efficiency of the modified ear - to - row method for improving the yielding ability and protein content of the three maize populations. Considerable amount of genetic variations existed between all maize families within each studied population. At the same time, the mean squares of Genotype x location Interaction were highly significant for all studied traits of each population separate. It indicated that the behavior of all traits were obviously differing from location to another. For all studied maize populations, the estimates of genotypic variances for grain yieldl plant and protein content traits represented in the main and major partition of the phenotypic variances which reflected high estimates of heritability in broad senses. Increasing an/or decreasing rates of all studied traits due to selection showed that the Ear _ to _ row seiection method was effective in this concern. The data showed that the improved one cycle in 1st sowing date (C1D1) had the highest mean values of all studied traits such as protein content and grain yield/plant traits except the days of 50 " silk trait for all studied maize populations. Generally, the improved half-sib maize families of Gemmeiza Yellow population had the higher mean value of protein content" (13.925 ), while Composite-45 population during the 111 sowing date had the highest mean value of grain yield I plant compared to the other studied maize populations (232 gm). Key words: Maize (Zea Mays L.), Genetic Variance, Genotypes, Phenotypes, Heritability.

Summary in Arabic.

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