The launch of a successful quality-oriented breeding program requires both mining the residual diversity in grain quality parameters contained in the elite, high-yielding breeding material with good agronomic performance and introgression of new germplasm, such as local landraces, with a high level of targeted quality parameters per se. This study analyzed the combining abilities of 31 maize landraces and two divergent inbred lines–testers (ZPL217 and ZPL-255/75-5) regarding the yield and protein, starch, and lipid content, assessed by Near Infrared Reflectance (NIR) spectroscopy as a fast, non-destructive, and cost-effective method. The general combining ability (GCA) defines the average behavior of genotype in hybrid combination, resulting from additive gene action, so positive GCA values of landraces AN13 and AN197 for protein, AN632 for lipids, and AN594 for starch content indicate that they can be valuable sources of the mentioned properties in quality-oriented maize breeding programs. The obtained correlation between starch content and protein and yield (−0.948 **; 0.587 **) pointed out that an increase in the protein content during breeding will be accompanied by a decrease in the starch content and yield. The specific combining ability (SCA) of the testers used, suggests their possible application in establishing and improving quality breeding programs’ initial material.

High and stabile yield in different production environments is priority in maize breeding. New statistical methods are constantly being sought to accompany analysis of variance, in order to achieve more reliable hybrid assessment. In this study nonparametric stability analysis is applied in order to assess GxE interaction for yield of 36 commercial maize hybrids. The experiment was set up at five locations in Serbia for three years according to the Randomised complete block design in three replications. Yield stability of investigated genotypes was analysed by stability parameters Si (1), Si (2), Si (3), Si (6) TOP and RS. Analysis of variance identified highly significant F values for all experimental factors. Bredenkamp method confirmed the existence of non-crossover GxE interaction, for maize yield. Hybrid ZPH15 achieved the most stable yield based on parameters Si (1) and Si (2). According to parameter Si (3) it was ZPH5, while based on parameter Si (6) it was ZPH34. The highest overall yield achieved ZPH36 (11.18 t ha-1), which was quite unstable (rank 24 in parameters Si (1) and Si (2)), and very unstable (rank 34 in parameters Si (3) and Si (6)). The most stable hybrids had average yields. In total, the hybrid ZPH23 had the best average rank (15.93). Based on TOP parameter, ZPH36 had the best rank (yield), followed by ZPH11, ZPH20, ZPH21 and ZPH9. However, RS parameter revealed that ZPH21 was the most stable hybrid, so taking into account both TOP and RS parameters this is the most productive and the most stable hybrid. Based on this research, TOP and RS are the best parameters for selecting new maize hybrids for production in particular environment. In case of identical TOP value, the genotype with the lowest RS value should be selected. The parameters Si (1), Si (2), Si (3) and Si (6) can be used as alternative methods for the selection of genotypes with moderate yield and high stability.

In this study 36 maize hybrids of different FAO maturity groups were observed in three successive years (2011, 2012 and 2013), on 8 locations. The main objective of this experiment was to observe the GxE interaction concerning yield, grain moisture, grain yield per ear and test weight. The experiment was set up according to the RCBD. Based on the obtained results average estimates, CV and overall ranking of hybrids were calculated. ANOVA was applied in order to estimate the effect of factors: genotype, environment and interaction. Thus the significance of all these factors was observed. Results of this research indicate the importance and necessity of performing multilocation and multiyear trials with the aim of observation and understanding the intensity of GxE interaction, as well as its influence on the grain yield and it components.

Differences in the seed testing rules for domestic trade (Regulation on the quality of seeds of agricultural plants Sl. SFRJ 47/1987) and export (International rules for seed testing - ISTA rules) are the reason for the lack of consistency in the seed testing and the interpretation of the obtained results. For certain species, there are even different test methods, which can additionally lead to inconsistent test results of the same seed lot. Therefore, the objective of this paper is to highlight the differences that exist and point out the need to harmonize national and international rules for seed testing. Through this review, the main differences during sampling and the most common methods of seed testing are shown: purity, germination, 1000 seed weight and moisture content. Differences in the quality control of test conditions are also shown, which laboratories that have both, national and international accreditation, must pay attention to. International rules (ISTA) are changed every year, at the initiative of member laboratories, based on new research and experiences from laboratories around the world. Harmonization of national and international rules for seed testing would greatly facilitate work in laboratories and contribute to uniform criteria for seed testing and reporting of test results.

Cold test (CT) is the oldest vigour test, which is widely used for testing maize seed. CT has not been validated and it is not included in the ISTA Rules, due to the variations in the soil used as a substrate and differences in test procedures. The objective of this study was to compare two CT procedures by evaluation the seed vigour of 12 maize seed lots. Soil was used in both cases with differences in chilling temperature (10 °C in standard and 7.5 °C in severe CT). Also duration of low temperatures was prolonged from 7 (standard CT) to 10 days (severe CT). Germination at optimal conditions were the same (7 days at 20<=>30°C). Statistical analysis showed that seed lots differed significantly in seed vigour. The application of severe CT created larger differences between lots, but they maintained similar rank positions in both CT procedures, leading to a very high rank correlation. Results of this research show that standard CT is a good indicator of maize seed vigour, but severe CT is useful for clearer differentiation of maize seed lots.