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In diallel crosses of four genetically divergent wheat cultivars (Jugoslavija, Osječanka, Žitnica, and NS Rana 2) the variability and inheritance of grain protein content (GPC) were studied. The mode of inheritance, gene effect, combining ability of parent cultivars and F1 hybrids plant for protein content were investigated. The different mode of inheritance: intermediate, partial dominance, dominance and over-dominance for analyzed trait were established. The highest protein contents among parent cultivars had Novosadska Rana 2. The combination Žitnica/NS Rana 2 in F1 generation was the best for protein content.

A study was conducted for estimating combining ability and standard heterosis for grain yield and various agromorphological traits involving 10 parents and their 45 F1s (half diallel) during 2012-13 and 2013-14. The results of present investigation revealed that additive gene action played a predominant role in the inheritance of most of the traits under study. On the basis of general combining ability (GCA) effects and specific combining ability (SCA) effects, three parents (Vallabh Basmati 21, Pusa Basmati 1, CSR 13) and three crosses (Vallabh Basmati 21 x Pusa 1121, Pusa 1121 x CSR 13 and Pusa Basmati 1 x CSR 13) were found good general and specific combiners. The best combinations mostly involved good x good and good x poor parental GCA effects suggesting that there is addi-tive x additive and additive x dominance type of gene action for yield and other component traits. The cross showing additive gene action can be improved by pedigree breeding and selection can be postponed to later generations. The most appropriate breeding method for the exploitation of non additive gene action will be heterosis breeding. The six best cross combinations (Vallabh Basmati 21 x CSR 30, CSR 30 x CSR 13, Vallabh Basmati 21 x CSR 13, CSR 30 x Pusa basmati 1, Pusa basmati 1 x CSR 13 and Vallabh Basmati 21 x Pusa basmati 1) had significant standard heterosis for grain yield and other component traits. The crosses which showed significant standard heter-osis is highly suitable for commercial exploitation of heterosis in rice crop.

Line x tester analysis using a set of four females, ten males and their forty hybrids was carried out to esti-mate the general combining ability of parents and specific combining ability of hybrids for yield and ten other associ-ated components in rice (Oryza sativa L.) in a Randomized Block Design during Kharif 2011. GCA variances for females (s2f) were significant at 0.1% level of significance for plant height (40.8), no. of grains per panicle (505.9), grain yield per plant (29.1), test weight(17.9), straw yield per plant (61.3) and kernel L/B ratio (0.2) whereas specific combining ability (SCA) variances for f x m interactions were highly significant for all the characters. Non-additive gene action was prevalent in all characters (Range: 0.03 in amylose content to 0.88 in kernel length breadth ratio) except plant height (1.33) as evident by low GCA to SCA ratio. None of the parents were good general combiner for all traits, however, female IR-28 and male AMT-119 and PNR-546 were good general combiners for a maximum number of traits i.e. five traits out of eleven.. The general combining ability for grain yield per plant for female parent Gurjari (6.19) and NVSR-178 (5.29); and male parents AMT 119 (2.73) and PNR 546 (2.44) makes them a good choice for improving yields in a hybridization programme as these female and male parents are also having signifi-cant GCA effects for maximum number of yield associated traits i.e. four and five traits out of eleven for female and male parents respectively. A vis-à-vis comparison of top three specific combining ability crosses with their mean performance showed correlation and these crosses were having at least one good general combining ability parent.

The development of sunflower hybrids with high genetic potential for seed and oil yields requires information on the general combining ability (GCA) and specific combining ability (SCA) for plant height and head diameter in the F-1 generation. Used in this study were thirteen new divergent cms inbred lines (A), three Rf restorers utilized as testers, and their F-1 hybrids. The inbred A-lines, Rf-testers and F-1 hybrids differed significantly in the mean values for plant height and head diameter. The mode of inheritance for plant height was superdominance of the better parent and for head diameter it was dominance and superdominance of the better parent. Highly significant positive values of GCA for both traits were found in cms inbred line NS-G-7 and restorer line RHA-N-49. Based on the GCA values chosen were lines with the best GCA for plant height (NS-G-9, NS-G-7) originating from PRA-RUN and head diameter (NS-G-13, NS-G-12) originating from DES. The greatest highly significant positive SCA value was found in NS-G-1xRHA-N-49 for plant height and in NS-G-8xRUS-RF-OL-168 for head diameter. Non-additive genetic variance played the main role in the inheritance of both traits as confirmed by the GCA/SCA ratios in the F-1 generation, which were invariably smaller than unit. The female A lines had the highest contribution to the expression of head diameter and plant height.

Mode of inheritance and effect of genes for leaf petiole angle and plant height have been analyzed in the F1 and F2 generations of a 6x6 partial diallel cross. The tested genotypes differed significantly in mean value of the analyzed characteristics. The expected regression line intersected the Wr axis above the origin indicating preponderance of partial dominance in the inheritance of leaf petiole angle and plant height in both generations. Among the tested inbred lines, NS-204B contained the largest number of dominant genes, NS-22B had equal number of dominant and recessive genes and NS-BD contained the largest number of recessive genes for the two characteristics. Results of this study may find application in developing models of hybrids with modified architecture, suitable for high stand densities that may bring direct increases in seed yield and oil content., U 6x6 dialelnom ukrštanju, isključujući recipročna, ispitivan je način nasleđivanja i efekat gena za ugao lisne drške i visinu biljke u F1 i F2 generaciji. Između ispitivanih genotipova postojale su značajne razlike u srednjim vrednostima za sva ispitivana svojstva. Očekivana linija regresije seče Wr osu iznad koordinatnog početka pokazujući parcijalnu dominaciju u nasleđivanju ugla lisne drške i visine biljke u obe generacije. Među proučavanim inbred linijama linija NS-204B je posedovala naveći broj dominantnih gena, linija NS-22B je imala podjednak broj dominantnih i recesivnih gena, dok je linija NS-BD imala najviše recesivnih gena za svojstvo ugao lisne drške i visinu biljke. Ova istraživanja će naći primenu za stvaranje modela hibrida izmenjene arhitekture biljke pogodnog za gajenje većeg broja biljaka po jedinici površine, što će se direktno odraziti na povećanje prinosa semena i sadržaja ulja.

Sunflower is the main crop species for the production of edible oil in many countries of the world, including ours. Plant height and head size, form and position on the stem as well as the number of leaves, their size, duration and distribution on the plant all play an important role in defining optimal plant architecture in sunflower hybrids (Škorić, 1975, 1989, 2002). In order to monitor the mode of inheritance and gene effects for head diameter in the F1 and F2 generations, half diallel crosses were made in six genetically divergent sunflower inbreds. The mean values of the trait in question differed significantly. The mode of inheritance of head diameter in the F1 generation was superdominance in all but four crosses, which had dominance instead. In the F2 generation, on the other hand, the prevailing mode was dominance, while superdominance was recorded in four cases. The dominant component accounted for the bulk of genetic variance, and the mode of inheritance of head diameter taking into account both the F1 and F2 generations was superdominance. These findings may prove valuable for developing high-yielding sunflower genotypes., Suncokret je u mnogim zemljama u svetu i kod nas osnovna biljka za proizvodnju jestivog ulja. Visina biljke, veličina, forma i položaj glave na stablu, broj listova, njihova veličina, trajanje i raspored na biljci imaju važnu ulogu u definisanju optimalne arhitekture hibrida suncokreta (Škorić 1975; 1989; 2002). U cilju praćenja načina nasleđivanja i efekta gena prečnika glave suncokreta u F1 i F2 generaciji izvršena su dialelna ukrštanja isključujući recipročna sa šest genetski divergentnim inbred linijama suncokreta. Dobijene su značajne razlike u srednjim vrednostima za ispitivano svojstvo. Prečnik glave se u F1 generaciji nasleđivao superdominantno jedino se u četiri ukrštanja javila dominacija, dok se u F2 generaciji nasleđivao dominantno, a superdominacija se zadržala u četiri kombinacije. Glavni deo genetske varijanse čini dominantna komponenta, a način nasleđivanja prečnika glave je superdominacija uzevši u obzir sve kombinacije ukrštanja u obe generacije (F1 i F2). Ova istraživanja mogu biti od značaja u stvaranju visoko prinosnih genotipova suncokreta.

In order to enable progress in sunflower breeding, an increasing amount of attention has to be paid to the morpho-physiological traits (petiole angle and length) of this crop that have a significant effect on its seed yield and oil concentration. In the inheritance of petiole angle and petiole length the additive component of genetic variance had the predominant role in the F1 and F2 generation. The mean degree of dominance (H1/D)1/2 and the intersection of the expected regression line with the Wr axis indicated partial dominance in the inheritance of petiole angle and petiole length. Broad sense heritability for petiole angle was 88% and for petiole length 85%., Da bi se obezbedio napredak u selekciji suncokreta potrebno je obratiti veću pažnju na morfo-fiziološke osobine (ugao lisne drške i dužinu lisne drške) koje značajno utiču na prinos semena i sadržaj ulja. Radi proučavanja nasleđivanja, efekta gena, komponenti genetske varijanse i heritabilnosti ugla i dužine lisne drške šest genetski divergentnih inbred linija suncokreta u F1 i F2 generaciji primenjena analiza dialelenih ukrštanja za kombinacione sposobnosti, Griffing, 1956 metod 2, model I. Za ocenu komponenti genetske varijanse i regresionu analizu korišćen je metod MATHER and Jinks (1982). Ocena heritabilnosti u užem smislu je rađena po formuli MATHER and Jinks (1971). U nasleđivanju ugla i dužine lisne drške aditivna komponenta genetske varijanse je bila predominantna u F1 i F2 generaciji. Prosečan stepen dominacije (H1/D)1/2 i presek očekivane linije regresije sa Wr osom ukazuje na parcijalnu dominaciju u nasleđivanju ugla i dužine lisne drške. Heritabilnost u užem smislu za ugao lisne drške iznosi 88%, a za dužinu lisne drške 85%.

The mode of inheritance, gene effect, combining ability and genetic components of variance for length of spike, number of spikelets per spike and number of kernelsper spike in 4 divergent cultivars (Srbijanka, Partizanka, KG-56 and PK&111) were studied in diallel crosses (without reciprocals). Cultivars and F2 hybrids showed great differences for the analyzed traits. This study showed that the mode of inheritance for all analyzed yield components was different with preponderance of partial dominance. The best general combiner for length of spike was Partizanka cultivar, while for number of spikelets per spike and number of kernels per spike it was Srbijanka cultivar. Key words: wheat, cultivar, length of spike, number of spikelets/spike, number of kernels/spike, combining ability, inheritance, U radu je proučavan način nasleđivanja, efekat gena, kombinacione sposobnosti i komponente genetičke varijanse za dužinu klasa, broj klasica po klasu i broj zrna po klasu kod četiri sorte ozime pšenice (Srbijanka, Partizanka, KG-56 i PKB-111), koje su ukrštene po metodu nepotpunog dialela (bez recipročnih). Analize su urađene za roditelje i F2 hibride. Sorte i F2 hibridi su pokazali značajne razlike za ispitivana svojstva. Ustanovljeno je da u nasleđivanju ispitivanih komponenti prinosa učestvuju geni sa aditivnim i neaditivnim efektima, s' tim što veći značaj imaju aditivni geni. Kod svih proučavanih osobina preovlađje parcijalna dominacija. Najbolje opšte kombinacione sposobnosti za dužinu klasa ispoljila je sorta Partizanka, a za broj klasića po klasu i broj zrna po klasu sorta Srbijanka. Najveća vrednost posebnih kombinacionih sposobnosti za dužinu klasa i broj zrna po klasu ustanovljena je kod kombinacije KG-56 x PKB-111, a za broj klasića po klasu kod kombinacije Partizanka x PKB-111.