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Genetic distance among six elite maize inbred lines was analyzed using SSR markers. Hybrid progeny obtained by crossing inbred lines according an incomplete diallel design was tested in field trials together with inbred lines per se.The objective of this study was to determine genetic distance of inbred maize lines and to examine if a significant correlation exist between the genetic distance of parental lines and the exhibited high parent heterosis (HPH) and specific combining abilities (SCA) for grain yield, ear lenght, kernel row numberand number of kernels per row. Twenty one SSR primers were used for genetic assesment of inbreds with detected 92 alleles. Genetically most distant lines were ZPL1 and ZPL5 and ZPL6 with the GD value of 0.549, while the closest one were ZPL2 and ZPL3 with GD value of 0.11. The dendrogram distinguished two main groups of inbreds: ZPL5 and ZPL6 grouped in a smaller cluster and ZPL1, ZPL2, ZPL3 and ZPL4 forming the second cluster. Values of the Spearman's rank correlation coefficient between genetic distance among inbred lines based on SSR markers and SCA for all analyzed traits were positive and significant with the exception of rows per ear. Highest correlation was exhibited between the genetic distance and SCA for number of kernels per row (0.643). Spearman's rank correlation coefficient between GD and high parent heterosis was positive and significant for ear length and kernel number in row with coefficient values of 0.554 and 0.611, respectively.

Genetic distance among six elite maize inbred lines was analyzed using SSR markers. Hybrid progeny obtained by crossing inbred lines according an incomplete diallel design was tested in field trials together with inbred lines per se.The objective of this study was to determine genetic distance of inbred maize lines and to examine if a significant correlation exist between the genetic distance of parental lines and the exhibited high parent heterosis (HPH) and specific combining abilities (SCA) for grain yield, ear lenght, kernel row numberand number of kernels per row. Twenty one SSR primers were used for genetic assesment of inbreds with detected 92 alleles. Genetically most distant lines were ZPL1 and ZPL5 and ZPL6 with the GD value of 0.549, while the closest one were ZPL2 and ZPL3 with GD value of 0.11. The dendrogram distinguished two main groups of inbreds: ZPL5 and ZPL6 grouped in a smaller cluster and ZPL1, ZPL2, ZPL3 and ZPL4 forming the second cluster. Values of the Spearman's rank correlation coefficient between genetic distance among inbred lines based on SSR markers and SCA for all analyzed traits were positive and significant with the exception of rows per ear. Highest correlation was exhibited between the genetic distance and SCA for number of kernels per row (0.643). Spearman's rank correlation coefficient between GD and high parent heterosis was positive and significant for ear length and kernel number in row with coefficient values of 0.554 and 0.611, respectively.

The objective of the present study was to observe differences among four sizes of the F2 populations (100, 200, 300 and 500 plants) on the basis of test-crosses for grain yield according to the average values of the populations, genetic and phenotypic variances, genotypic and phenotypic coefficients of variations and broad-sense heritability. The values of genetic variance did not significantly differ over population sizes according to all possible comparisons, including the comparison of values obtained for the phenotypic variance. Furthermore, the values of broadsense heritability (67.8%-69%) did not significantly vary over different F2 population sizes. Genetic variability of the observed progenies, as a principal prerequisite of successful selection, was at the satisfactory level in all population sizes., U radu su ispitivane razlike između četiri veličine F2 populacije od 100, 200, 300 i 500 biljaka na bazi test-ukrštanja, za prinos zrna, prema prosečnim vrednostima populacija, genetičkim i fenotipskim varijansama koeficijentima genetičke i fenotipske varijacije i vrednostima heritabilnosti u širem smislu. Vrednosti genetičke varijanse, nisu se značajno razlikovale između različitih veličina populacije u svim mogućim upoređenjima, što važi i za upoređenja dobijenih vrednosti fenotipske varijanse. Takođe, vrednosti heritabilnosti u širem smislu (67.8% do 69%) nisu značajno varirale sa promenom veličine F2 populacije. Genetička varijabilnost ispitivanih potomstava, kao glavni preduslov uspešne selekcije, je bila na zadovoljavajućem nivou u svim veličinama populacije.

The objective of the present study was to observe differences among four sizes of the F2 populations (100, 200, 300 and 500 plants) on the basis of test-crosses for grain yield according to the average values of the populations, genetic and phenotypic variances, genotypic and phenotypic coefficients of variations and broad-sense heritability. The values of genetic variance did not significantly differ over population sizes according to all possible comparisons, including the comparison of values obtained for the phenotypic variance. Furthermore, the values of broadsense heritability (67.8%-69%) did not significantly vary over different F2 population sizes. Genetic variability of the observed progenies, as a principal prerequisite of successful selection, was at the satisfactory level in all population sizes., U radu su ispitivane razlike između četiri veličine F2 populacije od 100, 200, 300 i 500 biljaka na bazi test-ukrštanja, za prinos zrna, prema prosečnim vrednostima populacija, genetičkim i fenotipskim varijansama koeficijentima genetičke i fenotipske varijacije i vrednostima heritabilnosti u širem smislu. Vrednosti genetičke varijanse, nisu se značajno razlikovale između različitih veličina populacije u svim mogućim upoređenjima, što važi i za upoređenja dobijenih vrednosti fenotipske varijanse. Takođe, vrednosti heritabilnosti u širem smislu (67.8% do 69%) nisu značajno varirale sa promenom veličine F2 populacije. Genetička varijabilnost ispitivanih potomstava, kao glavni preduslov uspešne selekcije, je bila na zadovoljavajućem nivou u svim veličinama populacije.

Six maize inbred lines for which we assumed that have a similar genetic background were selected for the study. Inbred lines were crossed according to incomplete diallel design and fifteen hybrid combinations were obtained. Hybrid combinations and their parental lines were used in our study. The objective of the study was to examine genetic polymorphism of parental lines, as well as to determine relationships between SSR genetic distance and values of high parent heterosis and specific combining abilities for grain yield. By using 19 SSR primers we classified inbred lines in two groups. First cluster consists of inbred lines L1, L2, L3, L4 and L5, while inbred line L6 formed second cluster, indicating different heterotic background in comparison to the other five inbred lines. The Spearman's correlation coefficients between SSR based genetic distance and specific combining abilities for grain yield had a value of (r=0,53*), while positive correlation were also found between genetic distance and high parent heterosis (r=0,57*).

Six maize inbred lines for which we assumed that have a similar genetic background were selected for the study. Inbred lines were crossed according to incomplete diallel design and fifteen hybrid combinations were obtained. Hybrid combinations and their parental lines were used in our study. The objective of the study was to examine genetic polymorphism of parental lines, as well as to determine relationships between SSR genetic distance and values of high parent heterosis and specific combining abilities for grain yield. By using 19 SSR primers we classified inbred lines in two groups. First cluster consists of inbred lines L1, L2, L3, L4 and L5, while inbred line L6 formed second cluster, indicating different heterotic background in comparison to the other five inbred lines. The Spearman's correlation coefficients between SSR based genetic distance and specific combining abilities for grain yield had a value of (r=0,53*), while positive correlation were also found between genetic distance and high parent heterosis (r=0,57*).

Six maize inbred lines for which we assumed that have a similar genetic BACKGROUND: were selected for the study. Inbred lines were crossed according to incomplete diallel design and fifteen hybrid combinations were obtained. Hybrid combinations and their parental lines were used in our study. The objective of the study was to examine genetic polymorphism of parental lines, as well as to determine relationships between SSR genetic distance and values of high parent heterosis and specific combining abilities for grain yield. By using 19 SSR primers we classified inbred lines in two groups. First cluster consists of inbred lines L1, L2, L3, L4 and L5, while inbred line L6 formed second cluster, indicating different heterotic BACKGROUND: in comparison to the other five inbred lines. The Spearman's correlation coefficients between SSR based genetic distance and specific combining abilities for grain yield had a value of (r=0,53*), while positive correlation were also found between genetic distance and high parent heterosis (r=0,57*).

Six inbred lines were crossed according to incomplete diallel method. In this way fifteen hybrid combinations were obtained. Hybrid combinations derived from these parental components were used in this work. The objective of study was to estimate direct and indirect effects of five morphological traits on grain yield by the application of the simple coefficient correlation and path coefficient analysis. The trait number of leaves above the top ear with the value of 0.736 has the strongest direct positive effect on grain yield. Positive direct effects on grain yield were also observed for height to tassel base and plant height, while negative direct effects were observed for ear height and total number of leaves. As far as indirect effects were considered, a positive effect of the ear position height on yield over the total plant height stands out. The evaluation of the proportion of mutual effects of five observed morphological traits on grain yield, expressed by the coefficient of multiple determination (R-y12345(2)) amounted to 0.7881.

Six inbred lines were crossed according to incomplete diallel method. In this way fifteen hybrid combinations were obtained. Hybrid combinations derived from these parental components were used in this work. The objective of study was to estimate direct and indirect effects of five morphological traits on grain yield by the application of the simple coefficient correlation and path coefficient analysis. The trait number of leaves above the top ear with the value of 0.736 has the strongest direct positive effect on grain yield. Positive direct effects on grain yield were also observed for height to tassel base and plant height, while negative direct effects were observed for ear height and total number of leaves. As far as indirect effects were considered, a positive effect of the ear position height on yield over the total plant height stands out. The evaluation of the proportion of mutual effects of five observed morphological traits on grain yield, expressed by the coefficient of multiple determination (R-y12345(2)) amounted to 0.7881.

In the process of plant breeding the application of relevant breeding criteria is very important. The Path analysis is broadly applied with the aim to define yield components that mostly determine the yield and that can be used as quality breeding criteria. However, the significance of revealed relationships between yield and yield components can be affected by various factors, such as diverse genetic material that is observed, traits included into analysis, environments in which the material is observed, as well as, the applied statistic approach to determine the nature of the relationships itself. The interrelationships of yield and yield components of 15 commercial maize hybrids were observed using the Path and factor analyses. According to results of Path analysis, plant height, ear diameter and grain moisture had highly significant genetic and phenotypic direct effects on grain yield. At the same time, factor analysis points out significant effects of two factors on grain yield. Factor 1 was mostly determined by ear length and number of kernels per row, while grain moisture content, ear and cob diameter mostly determined Factor 2.

In the process of plant breeding the application of relevant breeding criteria is very important. The Path analysis is broadly applied with the aim to define yield components that mostly determine the yield and that can be used as quality breeding criteria. However, the significance of revealed relationships between yield and yield components can be affected by various factors, such as diverse genetic material that is observed, traits included into analysis, environments in which the material is observed, as well as, the applied statistic approach to determine the nature of the relationships itself. The interrelationships of yield and yield components of 15 commercial maize hybrids were observed using the Path and factor analyses. According to results of Path analysis, plant height, ear diameter and grain moisture had highly significant genetic and phenotypic direct effects on grain yield. At the same time, factor analysis points out significant effects of two factors on grain yield. Factor 1 was mostly determined by ear length and number of kernels per row, while grain moisture content, ear and cob diameter mostly determined Factor 2.

Geneticists have been trying to explain adaptability and stability of a genotype in terms of a desirable combination of alleles expressed via epistasis. Stability determined in one set of data is very often stability of a genotype to a prevalent stress factor in a moment of carrying out the experiment. However, grain stability of a certain genotype can be a result of different factors, such as tolerance to drought, or to some important diseases and pests. Yield and yield stability of 15 maize hybrids were observed in 24 environments. The level of the interaction effect of studied maize hybrids was identified by the AMMI analysis, while a number of bands positively related to yield and stability of studied maize hybrids were identified by a genetic characterization by RAPD markers. Bands positively related to yields were present to a greater extent in parents originating from the BSSS population, while bands positively related to stability were more present in parents originating from the Lancaster population., Gentičari pokušavaju da objasne adaptabilnost i stabilnost genotipa u smislu poželjne kombinacije alela ispoljenih kroz epistazu. Međutim, stabinost definisana u jednom setu podataka je vrlo često zapravo stabilnost genotipa na dominantni stresni faktor u momentu izvođenja ogleda. Stoga, stabilnost rodnosti određenog genotipa može biti rezultat različitih faktora kao što su tolerantnost na sušu ili neku značajnu bolest ili štetočinu. U ovom radu ispitivan je nivo i stabilnost prinosa 15 hibrida kukuruza u 24 poljne sredine. Nivo interakcijskog efekta definisan je AMMI analizom. Genetička karakterizacija je urađena RAPD markerima. Trake pozitivno vezane za visok nivo prinosa su najčešće bile prisutne u roditeljima koji vode poreklo iz BSSS populacije dok su trake pozitivno vezane za stabilnost bile u značajnom procentu prisutne kod roditelja Lancaster populacije.

Geneticists have been trying to explain adaptability and stability of a genotype in terms of a desirable combination of alleles expressed via epistasis. Stability determined in one set of data is very often stability of a genotype to a prevalent stress factor in a moment of carrying out the experiment. However, grain stability of a certain genotype can be a result of different factors, such as tolerance to drought, or to some important diseases and pests. Yield and yield stability of 15 maize hybrids were observed in 24 environments. The level of the interaction effect of studied maize hybrids was identified by the AMMI analysis, while a number of bands positively related to yield and stability of studied maize hybrids were identified by a genetic characterization by RAPD markers. Bands positively related to yields were present to a greater extent in parents originating from the BSSS population, while bands positively related to stability were more present in parents originating from the Lancaster population., Gentičari pokušavaju da objasne adaptabilnost i stabilnost genotipa u smislu poželjne kombinacije alela ispoljenih kroz epistazu. Međutim, stabinost definisana u jednom setu podataka je vrlo često zapravo stabilnost genotipa na dominantni stresni faktor u momentu izvođenja ogleda. Stoga, stabilnost rodnosti određenog genotipa može biti rezultat različitih faktora kao što su tolerantnost na sušu ili neku značajnu bolest ili štetočinu. U ovom radu ispitivan je nivo i stabilnost prinosa 15 hibrida kukuruza u 24 poljne sredine. Nivo interakcijskog efekta definisan je AMMI analizom. Genetička karakterizacija je urađena RAPD markerima. Trake pozitivno vezane za visok nivo prinosa su najčešće bile prisutne u roditeljima koji vode poreklo iz BSSS populacije dok su trake pozitivno vezane za stabilnost bile u značajnom procentu prisutne kod roditelja Lancaster populacije.

Geneticists have been trying to explain adaptability and stability of a genotype in terms of a desirable combination of alleles expressed via epistasis. Stability determined in one set of data is very often stability of a genotype to a prevalent stress factor in a moment of carrying out the experiment. However, grain stability of a certain genotype can be a result of different factors, such as tolerance to drought, or to some important diseases and pests. Yield and yield stability of 15 maize hybrids were observed in 24 environments. The level of the interaction effect of studied maize hybrids was identified by the AMMI analysis, while a number of bands positively related to yield and stability of studied maize hybrids were identified by a genetic characterization by RAPD markers. Bands positively related to yields were present to a greater extent in parents originating from the BSSS population, while bands positively related to stability were more present in parents originating from the Lancaster population., Gentičari pokušavaju da objasne adaptabilnost i stabilnost genotipa u smislu poželjne kombinacije alela ispoljenih kroz epistazu. Međutim, stabinost definisana u jednom setu podataka je vrlo često zapravo stabilnost genotipa na dominantni stresni faktor u momentu izvođenja ogleda. Stoga, stabilnost rodnosti određenog genotipa može biti rezultat različitih faktora kao što su tolerantnost na sušu ili neku značajnu bolest ili štetočinu. U ovom radu ispitivan je nivo i stabilnost prinosa 15 hibrida kukuruza u 24 poljne sredine. Nivo interakcijskog efekta definisan je AMMI analizom. Genetička karakterizacija je urađena RAPD markerima. Trake pozitivno vezane za visok nivo prinosa su najčešće bile prisutne u roditeljima koji vode poreklo iz BSSS populacije dok su trake pozitivno vezane za stabilnost bile u značajnom procentu prisutne kod roditelja Lancaster populacije.

Geneticists have been trying to explain adaptability and stability of a genotype in terms of a desirable combination of alleles expressed via epistasis. Stability determined in one set of data is very often stability of a genotype to a prevalent stress factor in a moment of carrying out the experiment. However, grain stability of a certain genotype can be a result of different factors, such as tolerance to drought, or to some important diseases and pests. Yield and yield stability of 15 maize hybrids were observed in 24 environments. The level of the interaction effect of studied maize hybrids was identified by the AMMI analysis, while a number of bands positively related to yield and stability of studied maize hybrids were identified by a genetic characterization by RAPD markers. Bands positively related to yields were present to a greater extent in parents originating from the BSSS population, while bands positively related to stability were more present in parents originating from the Lancaster population., Gentičari pokušavaju da objasne adaptabilnost i stabilnost genotipa u smislu poželjne kombinacije alela ispoljenih kroz epistazu. Međutim, stabinost definisana u jednom setu podataka je vrlo često zapravo stabilnost genotipa na dominantni stresni faktor u momentu izvođenja ogleda. Stoga, stabilnost rodnosti određenog genotipa može biti rezultat različitih faktora kao što su tolerantnost na sušu ili neku značajnu bolest ili štetočinu. U ovom radu ispitivan je nivo i stabilnost prinosa 15 hibrida kukuruza u 24 poljne sredine. Nivo interakcijskog efekta definisan je AMMI analizom. Genetička karakterizacija je urađena RAPD markerima. Trake pozitivno vezane za visok nivo prinosa su najčešće bile prisutne u roditeljima koji vode poreklo iz BSSS populacije dok su trake pozitivno vezane za stabilnost bile u značajnom procentu prisutne kod roditelja Lancaster populacije.

Herein, we present the combined S1-HS-RRS method using inbred testers (S1-TC-RRS) as a long-term maize breeding program, which increases the frequency of favorable alleles and maintains genetic variability in two genetically opposite populations. The method improves two different genetic sources simultaneously, where S1 families, developed by selfing phenotypically superior plants from both breeding populations are crossed with opposite inbred testers for specific combining ability selection, accompanied by selection of S1 families per se. A certain percentage of the evaluated S1 families is used for the next TC-RRS selection cycle. Maternal haploids from the selected S1 lines of each cycle of S1-TC-RRS can serve to produce elite 100% homozygous inbred lines (dihaploids) in a short time, which decreases the time and expenses of the selection cycle and influence the efficiency of seed production, as well as, variety protection rights. This elite lines than can be converted to CMS versions (paternal haploids), for the seed production, which lowers the costs of it., Prestavlja se kombinovani S1-HS-RRS metod uz korišćenje inbred testera (S1-TCRRS), kao dugoročni program u oplemenjivanju kukuruza, koji povećava frekvenciju poželjnih alela i održava genetičku varijabilnost dve genetički opozitne populacije. Metodom se u isto vreme popravljaju dva genetički opozitna izvora, gde se S1 familije, dobijene samooplodnjom fenotipski superiornih biljaka iz obe populacije, ukrštaju sa opozitnim inbred testerom radi selekcije na posebne kombinacione sposobnosti, uz istovremenu selekciju S1 familija per se. Određen procenat ispitivanih S1 familja se koristi za sledeći TC-RRS ciklus selekcije. Uz pomoć metode majčinskih haploida, iz odabranih S1 linija svakog S1-TC-RRS ciklusa mogu se dobiti 100% homozigotne elitne inbred linije (dihaploidi) za kratko vreme, što smanjuje vreme i troškove selekcionog ciklusa, a utiče na efikasnost semenske proizvodnje i zaštitu oplemenjivačkih prava. Ove elitne inbred linije mogu se prevesti na cms verziju (ocinski haploidi), što smanjuje troškove u semenskoj proizvodnji.

Herein, we present the combined S1-HS-RRS method using inbred testers (S1-TC-RRS) as a long-term maize breeding program, which increases the frequency of favorable alleles and maintains genetic variability in two genetically opposite populations. The method improves two different genetic sources simultaneously, where S1 families, developed by selfing phenotypically superior plants from both breeding populations are crossed with opposite inbred testers for specific combining ability selection, accompanied by selection of S1 families per se. A certain percentage of the evaluated S1 families is used for the next TC-RRS selection cycle. Maternal haploids from the selected S1 lines of each cycle of S1-TC-RRS can serve to produce elite 100% homozygous inbred lines (dihaploids) in a short time, which decreases the time and expenses of the selection cycle and influence the efficiency of seed production, as well as, variety protection rights. This elite lines than can be converted to CMS versions (paternal haploids), for the seed production, which lowers the costs of it., Prestavlja se kombinovani S1-HS-RRS metod uz korišćenje inbred testera (S1-TCRRS), kao dugoročni program u oplemenjivanju kukuruza, koji povećava frekvenciju poželjnih alela i održava genetičku varijabilnost dve genetički opozitne populacije. Metodom se u isto vreme popravljaju dva genetički opozitna izvora, gde se S1 familije, dobijene samooplodnjom fenotipski superiornih biljaka iz obe populacije, ukrštaju sa opozitnim inbred testerom radi selekcije na posebne kombinacione sposobnosti, uz istovremenu selekciju S1 familija per se. Određen procenat ispitivanih S1 familja se koristi za sledeći TC-RRS ciklus selekcije. Uz pomoć metode majčinskih haploida, iz odabranih S1 linija svakog S1-TC-RRS ciklusa mogu se dobiti 100% homozigotne elitne inbred linije (dihaploidi) za kratko vreme, što smanjuje vreme i troškove selekcionog ciklusa, a utiče na efikasnost semenske proizvodnje i zaštitu oplemenjivačkih prava. Ove elitne inbred linije mogu se prevesti na cms verziju (ocinski haploidi), što smanjuje troškove u semenskoj proizvodnji.

The combined effect of cytoplasmic male sterility and xenia on maize hybrid traits is referred to as the plus-hybrid effect. Two studied ZP hybrids differently responded to this effect for grain yield. All plus-hybrid combinations of the firstly observed hybrid had a higher yield than their fertile counterparts, but not significantly, while only one combination of the second hybrid positively responded, also without statistical significance. It seems that the observed effect mostly depended on the genotype of the female component., Plus-hibrid efekat odnosi se na kombinovani uticaj citoplazmaticne muške sterilnosti i ksenija na svojstva hibrida kukuruza. Dva ispitivana ZP hibrida različito su reagovala ovaj efekat za prinos zrna. Sve Plus-hibrid kombinacije prvog ispitivanog hibrida su imale veći prinos od svojih fertilnih analoga, ali ne značajno, dok je samo jedna kombinacija drugog hibrida pozitivno odreagovala, takođe bez statističke značajnosti. Ispitivani efekat izgleda zavisi najviše od genotipa majke.

The combined effect of cytoplasmic male sterility and xenia on maize hybrid traits is referred to as the plus-hybrid effect. Two studied ZP hybrids differently responded to this effect for grain yield. All plus-hybrid combinations of the firstly observed hybrid had a higher yield than their fertile counterparts, but not significantly, while only one combination of the second hybrid positively responded, also without statistical significance. It seems that the observed effect mostly depended on the genotype of the female component., Plus-hibrid efekat odnosi se na kombinovani uticaj citoplazmaticne muške sterilnosti i ksenija na svojstva hibrida kukuruza. Dva ispitivana ZP hibrida različito su reagovala ovaj efekat za prinos zrna. Sve Plus-hibrid kombinacije prvog ispitivanog hibrida su imale veći prinos od svojih fertilnih analoga, ali ne značajno, dok je samo jedna kombinacija drugog hibrida pozitivno odreagovala, takođe bez statističke značajnosti. Ispitivani efekat izgleda zavisi najviše od genotipa majke.

Analysis of 60 maize populations was conducted to identify genotypes that had either low or high concentration of phytate. Genetic variability in seed phytate content was observed, with values ranging from 1,147 to 4, 13 g kg-1. Inorganic phosphorus (Pi) concentrations were between 0, 35 and 1, 29 and averaged 0, 65 g kg-1. Three groups of populations were identified as having low, intermediate and high phytate content. The low phytate concentration was measured in eight, intermediate in 25 and high in 27 populations. Positive correlation was found between phytate and protein. Population 216 had the lowest phytate concentration of 1, 14 gkg-1, and a Pi concentration 40% greater than Pi mean but lower than average protein content. This population will be used for further breeding genotypes with low phytate content and good agronomic traits., Analizirano je 60 populacija kukuruza u cilju identifikacije genotipova koji imaju nizak ili visok sadržaj fitina. Utvrđena je genetička varijabilnost u sadržaju fitina u opsegu od 1,147 do 4,13 g kg-1. Sadržaj neorganskog fosfora je bila između 0,35 i 1,29, prosečno 0,65 g kg-1. Tri grupe populacija su identifikovane koje sadrže nizak, srednji i visok sadržaj fitina. U osam populacija izmerena je niska koncentracija fitina, u 25 srednja i u 27 visoka. Pozitivna korelacija je utvrđena između sadržaja fitina i proteina. Populacija 216 ima najnižu koncetraciju fitina 1,14 gkg-1, i Pi koncetraciju 40% veću nego prosek Pi ali niži od proseka sadržaj proteina. Ova populacija će se koristiti za dalju selekciju genotipova sa niskim sadržajem fitina i dobrim agronomskim osobinama.

Two-year grain yield and 1000-grains mass data of 24 maize hybrids of FAO maturity groups 400, 500, 600, 700 were analyzed. Investigations were performed at the two environments in two years. Nonparametric methods of the Kubinger and the van der Laan-de Kroon showed genotype x environment interaction for both investigated features, and method of Hildebrand showed interaction for 1000-grains mass. Maize hybrids stability was estimated with stability parameters: Si(1)- the mean of the absolute rank differences over environments, Si(2)- the common variance of the ranks, Si(3).and Si(6): the sum of the absolute deviations and sum of squares of rank for each genotype relative to the mean of ranks, respectively. On the basis of the stability parametar values, the most stable and the most unstable hybrids were estimated for each FAO maturity group, for both investigated features. Correlation coefficients between both investigated features and stability parameters and for all pairs of stability parameters were computed. In spite of the positive correlations estimated between all four stability parameters, we can make two groups: the first group formed: Si(1)- the mean of the absolute rank differences over environments and Si(2)- the common variance of the ranks and the second group formed: Si(3) and Si(6)- the sum of the absolute deviations and sum of squares of rank for each genotype relative to the mean of ranks respectively., Analizirani su dvogodišnji podaci prinosa i mase 1000 semena kod 24 hibrida kukuruza FAO grupe zrenja 400, 500, 600 i 700. Istraživanja su izvršena na dva lokaliteta tokom dvogodišnjeg perioda. Primenom neparametrijskih metoda: Kubingerove i van der Laana i de Kroona, utvrđeno je postojanje interakcije genotip × spoljašnja sredina za obe ispitivane osobine a metoda Hildebranda je utvrdila postojanje interakcije za masu 1000 zrna. Stabilnost hibrida procenjena je pomoću neparametrijskih parametara stabilnosti: Si(1)- prosečne razlike rangova u različitim sredinama; Si(2)- varijanse rangova; Si(3) i Si(6)- relativnog odstupanja u odnosu na prosečan rang. Na osnovu izračunatih vrednosti parametara stabilnosti utvrđeni su najstabilniji i najnestabilniji hibridi za svaku FAO grupu zrenja, kod obe ispitivane osobine. Izračunati su koeficijenti korelacije između obe ispitivane osobine i parametara stabilnosti kao i između samih parametara stabilnosti. Iako je između sva četiri parametra stabilnosti utvrđena jaka povezanost, ipak se može govoriti o dve grupe parametara stabilnosti: u prvu grupu spadaju prosečna razlika rangova u različitim sredinama i varijansa rangova, a u drugu grupu relativno odstupanje u odnosu na prosečan rang.

Analysis of 60 maize populations was conducted to identify genotypes that had either low or high concentration of phytate. Genetic variability in seed phytate content was observed, with values ranging from 1,147 to 4, 13 g kg-1. Inorganic phosphorus (Pi) concentrations were between 0, 35 and 1, 29 and averaged 0, 65 g kg-1. Three groups of populations were identified as having low, intermediate and high phytate content. The low phytate concentration was measured in eight, intermediate in 25 and high in 27 populations. Positive correlation was found between phytate and protein. Population 216 had the lowest phytate concentration of 1, 14 gkg-1, and a Pi concentration 40% greater than Pi mean but lower than average protein content. This population will be used for further breeding genotypes with low phytate content and good agronomic traits., Analizirano je 60 populacija kukuruza u cilju identifikacije genotipova koji imaju nizak ili visok sadržaj fitina. Utvrđena je genetička varijabilnost u sadržaju fitina u opsegu od 1,147 do 4,13 g kg-1. Sadržaj neorganskog fosfora je bila između 0,35 i 1,29, prosečno 0,65 g kg-1. Tri grupe populacija su identifikovane koje sadrže nizak, srednji i visok sadržaj fitina. U osam populacija izmerena je niska koncentracija fitina, u 25 srednja i u 27 visoka. Pozitivna korelacija je utvrđena između sadržaja fitina i proteina. Populacija 216 ima najnižu koncetraciju fitina 1,14 gkg-1, i Pi koncetraciju 40% veću nego prosek Pi ali niži od proseka sadržaj proteina. Ova populacija će se koristiti za dalju selekciju genotipova sa niskim sadržajem fitina i dobrim agronomskim osobinama.

Two-year grain yield and 1000-grains mass data of 24 maize hybrids of FAO maturity groups 400, 500, 600, 700 were analyzed. Investigations were performed at the two environments in two years. Nonparametric methods of the Kubinger and the van der Laan-de Kroon showed genotype x environment interaction for both investigated features, and method of Hildebrand showed interaction for 1000-grains mass. Maize hybrids stability was estimated with stability parameters: Si(1)- the mean of the absolute rank differences over environments, Si(2)- the common variance of the ranks, Si(3).and Si(6): the sum of the absolute deviations and sum of squares of rank for each genotype relative to the mean of ranks, respectively. On the basis of the stability parametar values, the most stable and the most unstable hybrids were estimated for each FAO maturity group, for both investigated features. Correlation coefficients between both investigated features and stability parameters and for all pairs of stability parameters were computed. In spite of the positive correlations estimated between all four stability parameters, we can make two groups: the first group formed: Si(1)- the mean of the absolute rank differences over environments and Si(2)- the common variance of the ranks and the second group formed: Si(3) and Si(6)- the sum of the absolute deviations and sum of squares of rank for each genotype relative to the mean of ranks respectively., Analizirani su dvogodišnji podaci prinosa i mase 1000 semena kod 24 hibrida kukuruza FAO grupe zrenja 400, 500, 600 i 700. Istraživanja su izvršena na dva lokaliteta tokom dvogodišnjeg perioda. Primenom neparametrijskih metoda: Kubingerove i van der Laana i de Kroona, utvrđeno je postojanje interakcije genotip × spoljašnja sredina za obe ispitivane osobine a metoda Hildebranda je utvrdila postojanje interakcije za masu 1000 zrna. Stabilnost hibrida procenjena je pomoću neparametrijskih parametara stabilnosti: Si(1)- prosečne razlike rangova u različitim sredinama; Si(2)- varijanse rangova; Si(3) i Si(6)- relativnog odstupanja u odnosu na prosečan rang. Na osnovu izračunatih vrednosti parametara stabilnosti utvrđeni su najstabilniji i najnestabilniji hibridi za svaku FAO grupu zrenja, kod obe ispitivane osobine. Izračunati su koeficijenti korelacije između obe ispitivane osobine i parametara stabilnosti kao i između samih parametara stabilnosti. Iako je između sva četiri parametra stabilnosti utvrđena jaka povezanost, ipak se može govoriti o dve grupe parametara stabilnosti: u prvu grupu spadaju prosečna razlika rangova u različitim sredinama i varijansa rangova, a u drugu grupu relativno odstupanje u odnosu na prosečan rang.

Two-year grain yield and 1000-grains mass data of 24 maize hybrids of FAO maturity groups 400, 500, 600, 700 were analyzed. Investigations were performed at the two environments in two years. Nonparametric methods of the Kubinger and the van der Laan-de Kroon showed genotype x environment interaction for both investigated features, and method of Hildebrand showed interaction for 1000-grains mass. Maize hybrids stability was estimated with stability parameters: Si(1)- the mean of the absolute rank differences over environments, Si(2)- the common variance of the ranks, Si(3).and Si(6): the sum of the absolute deviations and sum of squares of rank for each genotype relative to the mean of ranks, respectively. On the basis of the stability parametar values, the most stable and the most unstable hybrids were estimated for each FAO maturity group, for both investigated features. Correlation coefficients between both investigated features and stability parameters and for all pairs of stability parameters were computed. In spite of the positive correlations estimated between all four stability parameters, we can make two groups: the first group formed: Si(1)- the mean of the absolute rank differences over environments and Si(2)- the common variance of the ranks and the second group formed: Si(3) and Si(6)- the sum of the absolute deviations and sum of squares of rank for each genotype relative to the mean of ranks respectively., Analizirani su dvogodišnji podaci prinosa i mase 1000 semena kod 24 hibrida kukuruza FAO grupe zrenja 400, 500, 600 i 700. Istraživanja su izvršena na dva lokaliteta tokom dvogodišnjeg perioda. Primenom neparametrijskih metoda: Kubingerove i van der Laana i de Kroona, utvrđeno je postojanje interakcije genotip × spoljašnja sredina za obe ispitivane osobine a metoda Hildebranda je utvrdila postojanje interakcije za masu 1000 zrna. Stabilnost hibrida procenjena je pomoću neparametrijskih parametara stabilnosti: Si(1)- prosečne razlike rangova u različitim sredinama; Si(2)- varijanse rangova; Si(3) i Si(6)- relativnog odstupanja u odnosu na prosečan rang. Na osnovu izračunatih vrednosti parametara stabilnosti utvrđeni su najstabilniji i najnestabilniji hibridi za svaku FAO grupu zrenja, kod obe ispitivane osobine. Izračunati su koeficijenti korelacije između obe ispitivane osobine i parametara stabilnosti kao i između samih parametara stabilnosti. Iako je između sva četiri parametra stabilnosti utvrđena jaka povezanost, ipak se može govoriti o dve grupe parametara stabilnosti: u prvu grupu spadaju prosečna razlika rangova u različitim sredinama i varijansa rangova, a u drugu grupu relativno odstupanje u odnosu na prosečan rang.

Clear description of maze is useful in planning crosses for hybrids, in classifying inbreds to heterotic groups, and in the plant variety protection. The objection to visual assessment of morphological traits is its subjectivity. But it can be very useful for plant breeders especially when they work with a material of unknown genetic origin. The phenotypic characterization (30 traits) of 45 inbred lines according to the UPOV Descriptor, with a known pedigree, is used with the main goal to investigate a possibility of exploiting such a kind of information for the classification of inbred lines in homogenous groups according to their relatedness. Ward's method of cluster analysis had the best concordance with pedigree data. This method divided 45 inbreds into two large clusters, each of them containing two subclusters. Quality of the cluster analysis with four groups was tested by the discrimination analysis. All of the tree discrimination functions were significant and enclosed 64%, 20% and 16% of variance, respectively. In plant breeding such information can be useful for a more precise description of existing heterotic groups, as well as, for grouping lines of unknown genetic origin. On the basis of obtained grouping, the decision on their crossing can be made. Hence they either should be crossed to related (F2 populations for a new selection) or unrelated materials (testing of combining abilities)., Precizan opis varijeteta je važan za oplemenjivanje biljaka. Vizuelnim ocenama se često zamera na subjektivnosti ocenjivača. Međutim, takođe je nekada bolje degradirati mernu skalu (od skalnog na ordinarni nivo merenja) iz više razloga. Jeftinije je i brže ocenjivati ekspresiju nekog svojstva svrstavanjem u određenu kategoriju, nego vršiti obimna merenja većeg broja biljaka u više ponavljanja i spoljnih sredina. Ordinarni nivo merenja je i pod manjim uticajem spoljašnje sredine. Postojanje baze podataka o fenotipskim ocenama omogućava i poređenje genotipova koji su ispitivani u različitim vremenskim periodima i u situacijama kada su korišćeni različiti kontrolni varijeteti. Za istraživanje je uzet fenotipski opis (upotrebljeno je 30 karakteristika) po principima UPOV deskriptora 45 linija kukuruza poznatog pedigrea. Urađena je klaster analiza sa ciljem da se utvrdi da li se može iskoristiti fenotipska karakterizacija genotipova po principima UPVOG deskriptora za formiranje homogenih grupa i koliko su rezultati u saglasnosti sa poznatim informacijama o pedigreu. Klaster analiza Wardsov metod je dala najbolje slaganje sa pedigreom ispitivanog materijala. Formiraju se dva velika klastera koji se dalje razlažu na dva podklastera. Kvalitet klaster analize testiran je diskriminacionom analizom pri čemu je prva diskriminaciona funkcija obuhvatila 64% varijanse, druga 20% a treća 16% i sve su statistički značajne. U oplemenjivanju biljaka ovakve informacije mogu biti od koristi za jasniju deskripciju postojećih heterotičnih grupa kao i za grupisanje linija nepoznatog genetičkog izvora i time definisanje poželjnog testera. Ove informacije bi bile korisne i za odabir genotipova za zasnivanje F2 populacija. Ukoliko se unosi neko poželjno svojstvo ili otpornost na sušu ili bolesti iz materijala nepoznatog porekla važno je izvršiti ukrštanja u okviru heterotične grupe da bi se zadržao što veći broj poželjnih svojstava.

Clear description of maze is useful in planning crosses for hybrids, in classifying inbreds to heterotic groups, and in the plant variety protection. The objection to visual assessment of morphological traits is its subjectivity. But it can be very useful for plant breeders especially when they work with a material of unknown genetic origin. The phenotypic characterization (30 traits) of 45 inbred lines according to the UPOV Descriptor, with a known pedigree, is used with the main goal to investigate a possibility of exploiting such a kind of information for the classification of inbred lines in homogenous groups according to their relatedness. Ward's method of cluster analysis had the best concordance with pedigree data. This method divided 45 inbreds into two large clusters, each of them containing two subclusters. Quality of the cluster analysis with four groups was tested by the discrimination analysis. All of the tree discrimination functions were significant and enclosed 64%, 20% and 16% of variance, respectively. In plant breeding such information can be useful for a more precise description of existing heterotic groups, as well as, for grouping lines of unknown genetic origin. On the basis of obtained grouping, the decision on their crossing can be made. Hence they either should be crossed to related (F2 populations for a new selection) or unrelated materials (testing of combining abilities)., Precizan opis varijeteta je važan za oplemenjivanje biljaka. Vizuelnim ocenama se često zamera na subjektivnosti ocenjivača. Međutim, takođe je nekada bolje degradirati mernu skalu (od skalnog na ordinarni nivo merenja) iz više razloga. Jeftinije je i brže ocenjivati ekspresiju nekog svojstva svrstavanjem u određenu kategoriju, nego vršiti obimna merenja većeg broja biljaka u više ponavljanja i spoljnih sredina. Ordinarni nivo merenja je i pod manjim uticajem spoljašnje sredine. Postojanje baze podataka o fenotipskim ocenama omogućava i poređenje genotipova koji su ispitivani u različitim vremenskim periodima i u situacijama kada su korišćeni različiti kontrolni varijeteti. Za istraživanje je uzet fenotipski opis (upotrebljeno je 30 karakteristika) po principima UPOV deskriptora 45 linija kukuruza poznatog pedigrea. Urađena je klaster analiza sa ciljem da se utvrdi da li se može iskoristiti fenotipska karakterizacija genotipova po principima UPVOG deskriptora za formiranje homogenih grupa i koliko su rezultati u saglasnosti sa poznatim informacijama o pedigreu. Klaster analiza Wardsov metod je dala najbolje slaganje sa pedigreom ispitivanog materijala. Formiraju se dva velika klastera koji se dalje razlažu na dva podklastera. Kvalitet klaster analize testiran je diskriminacionom analizom pri čemu je prva diskriminaciona funkcija obuhvatila 64% varijanse, druga 20% a treća 16% i sve su statistički značajne. U oplemenjivanju biljaka ovakve informacije mogu biti od koristi za jasniju deskripciju postojećih heterotičnih grupa kao i za grupisanje linija nepoznatog genetičkog izvora i time definisanje poželjnog testera. Ove informacije bi bile korisne i za odabir genotipova za zasnivanje F2 populacija. Ukoliko se unosi neko poželjno svojstvo ili otpornost na sušu ili bolesti iz materijala nepoznatog porekla važno je izvršiti ukrštanja u okviru heterotične grupe da bi se zadržao što veći broj poželjnih svojstava.

Many authors showed the possibility of developing highly yielding and stable hybrids. The assumption was that commercial maize hybrids were characterized not only by the level of average yield bat also by their stability. Fifteen commercial maize hybrids of medium late and late FAO maturity groups (400-700) were used in the present study. The two-year four-replicate trials were set up in six locations according to the randomized complete-block design. Stability parameters were determined after the method of EBERHART and RUSSEL (1966), in which the genotype was considered stable if it had a high average yield, a coefficient of regression of approximately 1.0 and deviation from regression as small as possible. The obtained results show that early maturity hybrids responded better to more modest growing condition and had a greater deviation from regression, while late maturity hybrids had a coefficient of regression closer to unity and they generally better responded to improved growing conditions., Mnogi autori su pokazali mogućnost stvaranja prinosnih, a istovremeno stabilnih hibrida. Pretpostavljeno je da se komercijalni hibridi kukuruza razlikuju ne samo po prosečnom prinosu već i po stabilnosti. Petnaest komercijalnih ZP hibrida kukuruza, srednje ranih, srednje kasnih i kasnih FAO grupa zrenja (400-700) je bilo uključeno u ovo ispitivanje. Ogled je bio postavljen u šest lokacija, dve godine i četiri ponavljanja po kompletno randomiziranom blok dizajnu. Parametri stabilnosti su određeni po metodu EBERHART I RUSSEL (1966), po kojem se genotip smatra stabilnim ako ima visok prosečan prinos, koeficijent regresije oko jedinice i devijaciju od regresije što je moguće manju. Dobijeni rezultati pokazuju da srednje rani I srednje kasni hibridi imaju veću devijaciju od regresije i daju bolji odgovor u lošijim sredinama, dok kasni hibridi imaju koeficijent regresije blizu jedinice i generalno daju bolji odgovor na poboljšanje uslova gajenja.

Many authors showed the possibility of developing highly yielding and stable hybrids. The assumption was that commercial maize hybrids were characterized not only by the level of average yield bat also by their stability. Fifteen commercial maize hybrids of medium late and late FAO maturity groups (400-700) were used in the present study. The two-year four-replicate trials were set up in six locations according to the randomized complete-block design. Stability parameters were determined after the method of EBERHART and RUSSEL (1966), in which the genotype was considered stable if it had a high average yield, a coefficient of regression of approximately 1.0 and deviation from regression as small as possible. The obtained results show that early maturity hybrids responded better to more modest growing condition and had a greater deviation from regression, while late maturity hybrids had a coefficient of regression closer to unity and they generally better responded to improved growing conditions., Mnogi autori su pokazali mogućnost stvaranja prinosnih, a istovremeno stabilnih hibrida. Pretpostavljeno je da se komercijalni hibridi kukuruza razlikuju ne samo po prosečnom prinosu već i po stabilnosti. Petnaest komercijalnih ZP hibrida kukuruza, srednje ranih, srednje kasnih i kasnih FAO grupa zrenja (400-700) je bilo uključeno u ovo ispitivanje. Ogled je bio postavljen u šest lokacija, dve godine i četiri ponavljanja po kompletno randomiziranom blok dizajnu. Parametri stabilnosti su određeni po metodu EBERHART I RUSSEL (1966), po kojem se genotip smatra stabilnim ako ima visok prosečan prinos, koeficijent regresije oko jedinice i devijaciju od regresije što je moguće manju. Dobijeni rezultati pokazuju da srednje rani I srednje kasni hibridi imaju veću devijaciju od regresije i daju bolji odgovor u lošijim sredinama, dok kasni hibridi imaju koeficijent regresije blizu jedinice i generalno daju bolji odgovor na poboljšanje uslova gajenja.

The initial idea of this study was a hypothesis that erect leaf maize inbred lines were characterized by properties of an efficient photo-model and that as such were very desirable in increasing the number of plants per area unit (plant density) in the process of contemporary selection and seed production. The application of a non-invasive bioluminescence-photosynthetic method, suitable for the efficiency estimation of the photo-model, verified the hypothesis. Obtained photosynthetic properties of observed erect leaf maize inbred lines were based on the effects and characteristics of thermal processes of delayed chlorophyll fluorescence occurring in their thylakoid membranes. The temperature dependence of the delayed chlorophyll fluorescence intensity phase transitions (critical temperatures) in the thylakoid membranes and activation energy are the principal parameters of the thermal processes. Based on obtained photosynthetic properties it is possible to select erect leaf maize inbred lines that are resistant and tolerant to high and very high temperatures, as well as, to drought. They could be good and efficient photo-models wherewith., Početna ideja za ovaj rad je bila hipoteza da su uspravni listovi samooplodnih linija kukuruza karakteristični za efikasan foto-model i da su kao takvi veoma poželjni u povećanju broja biljaka po jedinici površine (gustina biljaka) u procesima savremenog oplemenjivanja i semenske proizvodnje. Primena neinvazivne bioluminiscencne fotosintetičke metode pogodne za efikasnu ocenu modela, potvrdila je hipotezu. Dobijene fotositetičke karakteristike posmatranih uspravnih listova samooplodnih linija kukuruza su zasnovane na efektu i karakteristikama termalnih procesa odložene fluorescencije hlorofila, koji se pojavljuje na njihovim tilakoidnim membranama. Temperaturna zavisnost intenziteta odložene hlorofilne fluorescencije, fazni prelaz (kritična temperatura) u tilakoidnim membranama i aktivaciona energija su glavni parametri termalnih procesa. Na osnovu dobijenih fotosintetičkih karakteristika, moguće je izabrati samooplodne linije kukuruza uspravnih listova, koje su otporne i tolerantne na visoke i vrlo visoke temperature, kao i na sušu. One mogu biti efikasan fotomodel, za postizanje poboljšanja modernog oplemenjivanja i semenske proizvodnje.

New high-throughput techniques, together with advances in analytical and computational technologies are enabling systemic investigations of molecular processes of biological systems. Clustering is widely applied by biologists in genome sequencing projects and phylogenetic studies. In the microarray expression analysis, the aim of cluster is to better organize but not to alter primary data: genes are visually organized according to the statistical transformation and calculation, due to the expression pattern in maize kernel during heat and water stress. Besides grouping together genes with similar patterns of expression, genes are represented by increased intensity of red, dig. green color, according to their up- or down-regulation in stress condition, compared to control., Nove tehnike, zajedno sa dostignućima u analitičkoj i kompjuterskoj tehnologiji omogućile su sistematsko ispitivanje molekularnih procesa u biološkim sistemima. Klaster analiza se široko primenjuje od strane biologa u programima sekvencioniranja genoma i filogenteskim proučavanjima. U proučavanju ekspresije gena korišćenjem "microarray" tehnike, cilj klaster analize je da se bolje organizuju, ali ne i zamene izvorni podaci: geni su vizuelno organizovani na osnovu statističkih transformacija i proračuna, a prema načinu ekspresije u uslovima toplotnog i vodnog stresa u zrnu kukuruza. Pored grupisanja gena sa sličnim načinom ekspresije, svaki gen je predstavljen različitim intenzitetom crvene, tj.zelene boje u zavisnosti od toga da li je utvrđeno povećanje ili smanjenje ekspresije gena u uslovima stresa u odnosu na kontrolu.

The initial idea of this study was a hypothesis that erect leaf maize inbred lines were characterized by properties of an efficient photo-model and that as such were very desirable in increasing the number of plants per area unit (plant density) in the process of contemporary selection and seed production. The application of a non-invasive bioluminescence-photosynthetic method, suitable for the efficiency estimation of the photo-model, verified the hypothesis. Obtained photosynthetic properties of observed erect leaf maize inbred lines were based on the effects and characteristics of thermal processes of delayed chlorophyll fluorescence occurring in their thylakoid membranes. The temperature dependence of the delayed chlorophyll fluorescence intensity phase transitions (critical temperatures) in the thylakoid membranes and activation energy are the principal parameters of the thermal processes. Based on obtained photosynthetic properties it is possible to select erect leaf maize inbred lines that are resistant and tolerant to high and very high temperatures, as well as, to drought. They could be good and efficient photo-models wherewith., Početna ideja za ovaj rad je bila hipoteza da su uspravni listovi samooplodnih linija kukuruza karakteristični za efikasan foto-model i da su kao takvi veoma poželjni u povećanju broja biljaka po jedinici površine (gustina biljaka) u procesima savremenog oplemenjivanja i semenske proizvodnje. Primena neinvazivne bioluminiscencne fotosintetičke metode pogodne za efikasnu ocenu modela, potvrdila je hipotezu. Dobijene fotositetičke karakteristike posmatranih uspravnih listova samooplodnih linija kukuruza su zasnovane na efektu i karakteristikama termalnih procesa odložene fluorescencije hlorofila, koji se pojavljuje na njihovim tilakoidnim membranama. Temperaturna zavisnost intenziteta odložene hlorofilne fluorescencije, fazni prelaz (kritična temperatura) u tilakoidnim membranama i aktivaciona energija su glavni parametri termalnih procesa. Na osnovu dobijenih fotosintetičkih karakteristika, moguće je izabrati samooplodne linije kukuruza uspravnih listova, koje su otporne i tolerantne na visoke i vrlo visoke temperature, kao i na sušu. One mogu biti efikasan fotomodel, za postizanje poboljšanja modernog oplemenjivanja i semenske proizvodnje.

New high-throughput techniques, together with advances in analytical and computational technologies are enabling systemic investigations of molecular processes of biological systems. Clustering is widely applied by biologists in genome sequencing projects and phylogenetic studies. In the microarray expression analysis, the aim of cluster is to better organize but not to alter primary data: genes are visually organized according to the statistical transformation and calculation, due to the expression pattern in maize kernel during heat and water stress. Besides grouping together genes with similar patterns of expression, genes are represented by increased intensity of red, dig. green color, according to their up- or down-regulation in stress condition, compared to control., Nove tehnike, zajedno sa dostignućima u analitičkoj i kompjuterskoj tehnologiji omogućile su sistematsko ispitivanje molekularnih procesa u biološkim sistemima. Klaster analiza se široko primenjuje od strane biologa u programima sekvencioniranja genoma i filogenteskim proučavanjima. U proučavanju ekspresije gena korišćenjem "microarray" tehnike, cilj klaster analize je da se bolje organizuju, ali ne i zamene izvorni podaci: geni su vizuelno organizovani na osnovu statističkih transformacija i proračuna, a prema načinu ekspresije u uslovima toplotnog i vodnog stresa u zrnu kukuruza. Pored grupisanja gena sa sličnim načinom ekspresije, svaki gen je predstavljen različitim intenzitetom crvene, tj.zelene boje u zavisnosti od toga da li je utvrđeno povećanje ili smanjenje ekspresije gena u uslovima stresa u odnosu na kontrolu.