Positive SCA Effects Research Articles

Gene action and combining analysis for kernel yield and its attributing traits in maize [zea mays (l.)

Eight maize (Zea mays L.) genotypes were crossed in a half diallel mating design.The analysis of variance for combining ability revealed that mean sum of squares due to general combining ability were found significant for all the traits except cob girth, whereas, the specific combining ability effects were found highly significant for all the characters except anthesis-silking interval. The low ratio (<1.0) of GCA to SCA variance for sixteen traits indicated that non-additive type of gene action was predominant in the expression of yield and component traits. Based on estimates of general combining ability effects revealed that four parents BLD-11 (5.19), CML-338 (4.28), VL-1032 (1.68) and VL-109178 (1.25) were found good general combiners because they registered significant and positive gca effects. The estimates of sca effects revealed that 23 hybrids were exhibited significant positive sca effects. The spectrum of differences in sca effects for this trait ranged from -2.70 (CBE-98 × CML-338) to 27.57 (CBE-98 × MRCN-3) and the top most three hybrids for kernel yield per plant on the basis of specific combining ability effects were CBE-98 × MRCN-3 (27.57), CBE-98 × BLD-11 (23.16) and CBE-26 × BLD-11 (21.20).

Estimation of Heterosis Combining and Ability in Faba Bean (Vicia faba L.) by Line X Tester Technique

The present study was conducted at Sakha Research Station during 2014/2015 and 2015/2016 growing seasons. Line x Tester analysis was used, five lines and four testers were crossed in all possible cross combination according to factorial mating design producing twenty hybrids of Faba Bean in the first season. All genetic materials were tested under two sowing dates, i.e. October 20 (early date) and November 20 (late date) each in one experiment arranged in a randomized complete block design with three replications in the second season. Results revealed highly significant variations within parents and F1 genotypes indicating a wide genetic variability for the studied characters and the possibility of genetic improvement using such genetic pools of faba bean. Regarding yield and its components traits, the most crosses exhibited significant positive heterosis values relative to better parent for total dry seed yield, three, six and four crosses exhibited significant positive heterotic effects relative to better parent for number of seeds/plant, seed yield/plant and 100-seed weight respectively, under the two sowing dates. Both general (GCA) and specific (SCA) combining ability were significant for the most studied characters revealing the important role of both additive and dominant components in the inheritance of the studied characters. The parental genotype (Giza716) was a good combiner for seed yield/plant and100-seed weight under the two sowing dates. Several crosses exhibited significantly positive SCA effects for the most studied characters especially the crosses (Sakha 4 x Qahera 4, Cross 957 x Giza 843 and Giza 716 x Qahera 4) and the crosses (Sakha1 x Misr 1, Sakha 4 x Misr 1 and Giza 40 x Giza 843) which exhibited highly significant and positive SCA effects for seed yield/plant and 100-seed weight respectively under the two sowing dates. Heritability in broad sense estimates (Hb %) were higher than their corresponding of narrow sense heritability (Hn %). The estimates of narrow sense heritability ranged were (37.7-40.4 %), (33.7-46.8 %) and (45.5-48.3 %) for number of seeds/plant, seed yield/plant and 100-seed weight, respectively under the two sowing dates.

Combining ability for some inbred lines in half-diallel crosses of maize under two different locations conditions

A half diallyl cross among eight new yellow maize inbred lines, i.e. Gm. 142, Gm. 224, Gm. 233, Gm. 152, Gm. 297, Gm. 330, Gm. 201, and Gm. 303, was made in 2015 summer season. Twenty eight F1 crosses along with two yellow commercial check hybrids, SC162 and SC168 were evaluated in randomized complete block design with four replications at two locations (Gemmeiza, Gharbia and Sids, Bani Sweif, Egypt) in 2016 summer season to study the combining ability to identify the most superior parental inbred lines that produce superior hybrids and develop high yielding new yellow single crosses. Results indicated that mean squares of crosses exhibited significant or highly significant for all studied traits. Mean squares due to GCA and SCA were significant or highly significant for all studied traits at combined over the two locations, except GCA for ear diameter trait and SCA for ear length trait, which were non-significant. The ratio of GCA/SCA was more than unity for all studied traits at combined over the two locations, except days to 50% silking and ear diameter traits, indicating that additive gene was more important than non-additive gene action. The interaction between GCA and SCA and locations were highly significant for all studied traits, except GCA x Loc. for ear diameter trait and SCA x Loc. for ear length trait. The magnitude of the interaction was highest for GCA × locations than the SCA × locations for plant height, ear height, ear length and grain yield, indicates that additive genetic variance was influenced by environment and the additive component interacted more with the environment than the non-additive and vice versa for days to 50% silking and ear diameter. According to analysis of GCA effects, the best general combiners were P3 (Gm.233) for earliness; P4 (Gm.152), P5 (Gm.297), P6 (Gm.330) and P7 (Gm.201) for plant height (shortness); P5 (Gm.297), P6 (Gm.330) and P7 (Gm.201) towards lower ear position; P4 (Gm.152) and P6 (Gm.330) for ear length; P1 (Gm.142) for ear diameter; and P1 (Gm.142), P5 (Gm.297) and P8 (Gm.303) for grain yield. Based on mean performance and SCA effects analysis, there were seven crosses No. 1, 2, 5, 7, 9, 25 and 26 (P1 x P2, P1 x P3, P1 x P6, P1 x P8, P2 x P4, P5 x P8 and P6 x P7) were the best combinations where they recorded significant or highly significant positive SCA effects for grain yield.

Biochemical, physiological and phenological genetic analysis in common bean (Phaseolus vulgaris L.) under salt stress

Salinity is one of the most important abiotic stresses affecting agricultural productivity. The present study investigated combining abilities, heterosis and heritability estimates of common bean under salinity conditions for biochemical, physiological and phenological traits using a half-diallel cross. The salinity stress treatments were applied during all the vegetative cycle. Genetic analysis revealed highly significant genotypic variations between the four parents and their six hybrids, indicating a genetic variability and possibility of genetic improvement using such genetic material of common bean for salinity tolerance. Both general (GCA) and specific (SCA) combining abilities were highly significant for all the studied traits under all conditions, revealing the important role of both additive and dominant gene effects in the inheritance of these traits. The ratio GCA/SCA indicated preponderance of the additive effects for all the studied characters. The parental genotypes Améliore Roza and Coco nain proved to be the best combiners for salinity tolerance; on the other hand the crosses namely Amina × Améliore Roza; MGT × Améliore Roza and Coco nain × Amina recorded significant heterosis percentage relative to mid-parent (MP) and better parent (BP) for almost all the traits, the same crosses recorded significantly positive SCA effects. Diallel analysis revealed high heritability in broad-sense for salinity tolerance, while moderate to high narrow-sense heritability suggests a large breeding population and possible selection for salt tolerance. The results of this study confirmed that salinity tolerance is expressed by a different set of genes that could be pyramided using different genotypes to enhance salinity tolerance.

Cytoplasmic male sterile and doubled haploid lines with desirable combining ability enhances the concentration of important antioxidant attributes in Brassica oleracea

The Brassica vegetable crops are rich source of important antioxidant compounds having anticancer and health promoting properties. Development of F1 hybrids with better nutritional traits is one of the main breeding objectives in different vegetable crops. Our study is the first report of determining heterotic combinations utilizing cytoplasmic male sterile (CMS) and doubled haploid (DH) inbred lines for antioxidant compounds in snowball cauliflower. Twenty genetically diverse Ogura CMS lines of cauliflower and six DH male fertile inbred lines were crossed to develop 120 F1 hybrids in line × tester mating design. The resulting 120 test cross progenies along with 26 parents and 4 standard checks were evaluated in 10 × 15 alpha lattice design with three replications during next cropping season. The CMS lines Ogu33-1A, Ogu122-5A and Ogu119-1A were good general combiner and CMS line Ogu118-6A was poor general combiner for majority of traits. Most of the heterotic hybrids were associated with high positive SCA effects. The proportions of σ2A/D and $$\upsigma^{2}_{\text{gca}} /\upsigma^{2}_{\text{sca}}$$ ratios were less than unity in all the cases indicating preponderance of non-additive gene action in the genetic control of all the traits. Highest number of heterotic hybrids with SCA effects in desired positive direction was recorded for ascorbic acid content and phenolic content followed by total carotenoid content. The F1 hybrids with better combining ability and better per se performance could be useful in accumulation of favourable allele for higher concentration of important anti-oxidant compounds.

Line × Tester analysis for kernel yield and component traits in maize (Zea mays L.)

Line × Tester analysis performed using 10 female and 4 male parental lines and their 40 hybrids in yellow maize. The analysis of variance showed that the enormity of sca variance was higher than the gca variance for all the traits except for days to tasseling, days to silking and ASI. The ratio of σ2gca/σ2sca was less than unity for all the characters except days to silking, which indicated predominance of non-additive gene action in the inheritance of these traits. Based on general combining ability (gca) effects, none of the parents was good general combiners for all the characters. Parental line IMR-33 was good general combiner for cob yield per plant, kernel yield per plant, plant height, ear height and cob length, while it was average for rest of the traits except days to dry husk. The cross combination VL-1032 × WNC 40218 exhibited highest significant positive sca effects for cob yield per plant (63.08) and kernel yield per plant (49.09). The cross BLD-329 × BLD-270 exhibited highest heterobeltiosis and standard heterosis for both cob yield per plant and kernel yield plant.

Study on heterosis and combining ability through diallel mating analysis in F1 generation of Bread Wheat (Triticum aestivum L.)

Estimation of combining ability by half diallel analysis and magnitude of heterosis was conducted at Section of Rabi Cereals, C. S. A. University of Agriculture Science and Technology, Kanpur, UP, in a set of 10 parents received from Economic Botanist Region, Section of Rabi Cereals, Kanpur by making 45 cross combinations evaluated during winter and Rabi 2012-13 in RBD with three replications. The data on nine characters viz. days to 50 % flowering, Plant height, No. of tillers/plant, Spike length/plant, No. of grains/main spike, Days to maturity, 1000-grain weight and Grain yield/plant were utilized for present study. On the basis of GCA effects across eight charactersK9423 and K9533 (-0.76) are good and desirable for days to 75% flowering for crop improvement, grain yield per plant observed for PBW502 and PBW343. The most promising crosses showing significantly positive SCA effects for yield per plant K9423xHD2285and PBW502xPBW343, days to maturity is showing significantly negative SCA effect for NW2036xHD2285 (-9.68). Heterosis is estimated highest over better parent for yield per plant was HD2285xK9533 (16.15). These crosses should be exploited for further advancement in breeding programme for HYVs and early maturity, simultaneously.

Combining ability and gene action for yield traits in greengram [Vigna radiata (L.) wilczek

The combining ability analysis of 225 F3s in greengram developed from half diallel crosses among six parents revealed importance of both additive and non-additive gene actions in the inheritance of pods per plant, seeds per pod, 100-seed weight and yield per plant. There were significant differences in gca and sca effects for the characters studied. OGG-12 was the best general combiner for pods/ plant and grain yield per plant where as OGG-57 was for seeds/ pod, OGG-12 and LGG-460 for 100-seed weight. Among the 15 crosses, six crosses showed significant positive and seven crosses had significant negative SCA effects for seed yield/plant. Significant positive SCA effects were observed in two crosses for pods/plant, four crosses for seeds/ pod and three crosses for 100-seed weight. Although some crosses were showing positive SCA effect for yield and its components, the frequency of unfavorable cases were more. Only TARM-1 × OGG-12 exhibited favorable SCA effect for all characters. Considering all the characters simultaneously, OGG-12 was the best combiner followed by TARM-1 and LGG-460

Combining ability for seed yield and its components in sesame (Sesamum indicum L.)

Fifty sesame crosses generated in line x tester (10 lines x 5 testers) mating method were studied to estimate combining ability for fourteen characters in sesame. Analysis of variance for combining ability revealed that the mean squares due to lines, testers and line x testers were significant for all the characters except mean squares due to lines for days to maturity. The results indicated the importance of both additive and non-additive genetic variances in the expression of these characters. The estimated ratio of σ2gca/σ2sca from analysis of combining ability revealed that non-additive gene action was predominant in the genetic control of all the characters studied except plant height. Among female parents, ES-246 was found to be good general combiner for eleven characters followed by Lalavadar-6 for five characters and Borda-2 for four characters. Among the testers, G. Til-4 was good general combiner for seven characters followed by G. Til-1-9-4, which gave desirable gca for five traits. The estimates of sca effects of the crosses indicated that twelve hybrids manifested significant and positive sca effects for seed yield per plant. Among these, the best three specific cross combinations were RMT-180 x G. Til-3, Borda-2 x G. Til-1-9-4 and Lalavadar-6 x J-68-3., which had high sca effects for seed yield per plant along with per se performance and other yield traits.

Studies on combining ability and heterosis in rice (Oryza sativa L.)

Combining ability analysis was carried out in rice involving seven lines, four testers and 28 cross combinations. The combining ability variances revealed that SCA was greater than GCA indicating the preponderance of non-additive gene action for all the traits viz., days to 50 per cent flowering, plant height, number of productive tillers per plant, panicle length, number of grains per panicle, hundred grain weight, grain yield per plant, kernel length, kernel breadth and kernel L/B ratio. From standard heterosis, hybrids viz., STBN 4/ADT 45, STBN 3/ADT 45 and ADT 43/PMK 3 recorded significant standard heterosis for most of the traits. Among the parents ADT 43, STBN 3, STBN 4 among lines and ADT 45 among testers were good general combiners for grain yield per plant and other component traits. Among hybrids, STBN 3 x ATD 45, STBN 4 x ADT 45 and ADT 43 x PY 3 recorded significant and positive sca effects for grain yield per plant which indicated the involvement of additive type of epistasis for grain yield and other characters.

Heterosis and combining ability studies for yield and its component traits in Maize (Zea mays L.)

Heterosis and combining ability was studied in F1 hybrids of maize with respect to grain yield and yield attributing traits using twenty-two hybrids which were developed through Line × Tester mating design. The parents and their hybrids were subjected to assess the combining ability and nature of gene action governing the quantitative traits. The results inferred that the predominance of non-additive gene action was observed for all the traits. Among the parents, the overall study of gca effects suggested that parent UMI 1200-7-26-1-6-1, N 14, N 107 and N 285 were significant general combiner for yield, these can be used to improve hybrids with desirable traits in future. Significant positive SCA effects were found for all the studied traits. Among the hybrids, N 14 × UMI 1200-7-26-1-6-1 showed desirable standard heterosis percentage over the checks CO 6 and NK 6240 along with good sca effects and per se performance for grain yield and other important yield contributing traits over different locations thus it can be used for commercial seed production programme.

Combining ability and breeding potential of oilseed rape advanced lines for some of important quantitative traits

AbstractInformation on estimates of combining ability of the promising lines of breeding material is important for evolving higher yielding varieties of oilseed rape (Brassica napus L.). An experiment was conducted to quantitatively examine the genetic parameters of phenological traits, plant height, pods on main raceme, pods per plant and seed yield for eight oilseed rape genotypes using a half-diallel crosses. The result of the diallel analysis revealed significant mean squares of general and specific combining abilities (GCA and SCA) for all studied traits, indicating the importance of additive and non-additive genetic effects for these traits. On the other hand estimation of high narrow-sense heritability estimates for days to flowering, duration of flowering and pods on main raceme, indicated the prime importance of additive genetic effects for these traits. L420 and L401 with significant negative GCA effects for days to flowering and days to maturity were suitable for yielding early maturity combinations. L41, Zafar and L22 with significant positive GCA effects for seed yield were superior parents for increasing seed yield. The crosses with significant positive SCA effects for seed yield had at least one parent with significant positive GCA effects for this trait. The crosses including L41×L22, L41×LF2, Zafar×L22 and Zafar×L420 with seed yield of 3421.7, 3400, 3348.1 and 3311.3 kg ha-1 could be promising for determination of superior recombinants for high seed yield coupled with other growth characters in advanced generations of segregation.

Combining ability and gene action for fruit yield and its attributes in brinjal (Solanum Melongena L.)

Gentic studies for fruit yield per plant and its attributing traits in brinjal was conducted by following line x tester mating design comprising of seven lines and four testers at Instructional Farm, Junagadh Agricultural University, Junagadh, Gujarat. The analysis of combining ability revealed the predominant role of both additive and non-additive gene effects in the inheritance of fruit yield and its component traits. The genotypes NSR-1, JBG-10-208 and Pant Rituraj displayed high gca effect for fruit yield per plant and some desirable traits like days to 50 % flowering, days to first picking, fruit girth, fruit weight, numbers of primary branches per plant, plant spread and total soluble solids. The estimates of sca effect of the crosses indicated that five hybrids manifested significant and positive sca effect for fruit yield per plant. The crosses JBG-10-208 x GJB-2, ABR-2-23 x GBL-1 and AB-09-1 x GOB-1 were emerged as best specific combinations. The cross JBG-10-208 x GJB-2 was also found good specific combiner for plant height, fruit weight, fruit girth and number of primary branches per plant and also showed maximum per se performance. These hybrids may be exploited for obtaining transgressive segregants toward developing hybrid varieties in brinjal.

PREDICTION OF COMBINING ABILITY AND HETEROSIS IN THE SELECTED PARENTS AND HYBRIDS IN RICE (Oryza Sativa.L)

&lt;p&gt;Selection of parents based on their combining ability is an effective approach in hybrid breeding. Four CMS and four restorer lines were crossed in line x tester mating design to obtain 16 F1 hybrids rice. The 8 parental lines and 16 hybrids rice were planted in randomized complete block design with three replications at Kuningan and Muara field station of ICRR during 2012-2013. The results revealed that mean squares for GCA were significant for number of fertile spikelet per panicle, a thousand-grains weight, and 50% days of flowering. Mean squares for SCA were significant for plant height and grain yield. Parental lines exhibited the highest GCA effects for GMJ12A (line) and CRS703 (tester) for grain yield trait and revealed good potential to be used as parents for hybrid rice. Among all the crosses, GMJ6A/CRS707 and GMJ12A/CRS707 showed the greatest positive SCA effects for grain yield and had heterosis over better parent and midparent.&lt;/p&gt;

Combining ability and gene action estimates for some yield attributes in durum wheat (&lt;i&gt;Triticum turgidum L. var. durum)&lt;/i&gt;

Combining ability and gene action of a set of durum wheat characters were studied using 6 x 6 half diallel crosses. Results revealed that general (GCA) and specific (SCA) combining ability mean squares were significant for all studied traits, suggesting the importance of both additive and non additive components in the inheritance of these traits. Baker ratio indicated the predominance of additive gene effects for majority of traits studied except grain yield. From the GCA effect it was observed that, none of the six parents was good general combiner for all yield components. Among the fifteen crosses, Zenati-Bouteille/Flamengo x Gta/durum followed by Waha x Ofanto, Waha x Mexicali 75 and Ofanto x Guemgoum Rkhem expressed the greatest positive SCA effects for grain yield. Days to heading and spikes number index could be used as an indirect selection criterion for better grain yield. Therefore, selecting early heading genotypes having high fertile tillers number could improve grain yield.

Combining ability analysis for yield and quality traits in single cross hybrids of quality protein maize (Zea mays L.) using diallel mating design

Forty-five single-cross hybrids developed (in rabi 2014) from ten inbred lines of quality protein maize through diallel mating design along with four checks viz., Pratap QPM Hybrid- 1, Vivek QPM- 9, HQPM- 1 and HQPM-5 were evaluated in randomized block design with three replications for yield and quality traits during kharif-2014, to estimate the gca (general combining ability) of the parents and sca (specific combining ability) of hybrids considered for the development of high yielding varieties. The analysis of variance for combining ability revealed significant mean sum of squares due to gca and sca for all the traits, except mean sum of square due to gca for num-ber of grain rows per ear. Ratio of ?2 sca / ? 2 gca was greater than one for all the traits, thereby indicating the preponderance of non-additive gene effects in the expression of these traits. Inbred line P8 and P5 has been found good general combiner with highest magnitude of gca effects 10.46 and 8.89, respectively and high per se i.e. 52.33 g and 44.67 g, respectively for grain yield per plant and majority of traits. Hybrids P6xP8, P5xP8, P3xP5, P5xP7 and P1xP8 showed higher significant positive sca effects ranged from 25.66 to 34.59 along with good per se ranged from 98.00 to 107.67 g for grain yield per plant. These hybrids also exhibited significant positive sca effects for most of the yield and quality traits under study, indicating potential and may be used for exploiting hybrid vigour in in QPM hybrid breeding programmes.

Heterosis and combining ability in pearl millet

Among the 48 hybrids produced by (4) x tester (12) crossing programme, maximum positive standard heterosis for grain yield per plant over hybrid check, Aadishakti was observed in DHLB-16A x S-16/08 (36.88%) followed by DHLB-14A x S-16/06 (34.74%) and DHLB-16A x S-16/07 (26.29%). The range of standard heterosis over check Aadishakti was-49.28 per cent (DHLB-14A x S-16/10) to 36.88 per cent (DHLB-16A x S-16/08). Among the hybrids with positive significant SCA effects for grain yield, the frequency of good x average combiner was more. Among the top ten hybrids one parent of five hybrids viz., DHLB-16A x S-16/08, DHLB-16A x S-16/07, DHLB-8A x S-16/01, DHLB-8A x S-16/05 and DHLB-16A x S-16/12 found to be good general combiners. Among four females three lines DHLB-16A, DHLB-8A and DHLB-14A and among males S-16/07, S-16/08 and S-16/05 gave top yielding hybrid combinations. Among ten top performing hybrids, three hybrids viz., DHLB-16A x S-16/08, DHLB-14A x S-16/06 and DHLB-16A x S-16/07 exhibited significant favorable heterobeltiosis, standard heterosis, GCA and SCA effects for yield and most of the related traits could be utilized for commercial cultivation after extensive testing in state and national trails.

Isolation and half-diallel analysis of earliness in five (vicia faba l.) Genotypes

The present investigation was carried out at Genetic Resources Department, Bahtim, Egypt, to evaluate five faba bean cultivars in Half-diallel crosses set. Ten crosses were constituted in 2014/2015 winter season, whereas, parents and crosses were evaluated in 2015/2016 winter season, in a randomized complete block design, with three replications. Results revealed highly significant variations within parents and F1 genotypes, indicating a wide genetic variability for the studied characters and the possibility of genetic improvement, using such genetic pools of faba bean. Some crosses recorded significant desired heterotic percentages relative to mid parent and better parents for all studied traits, except for plant height and numbe of branches per plant. Both general (GCA) and specific (SCA) combining abilities were significant for all studied traits, revealing the important role of both additive and dominant earliness in the inheritance of the studied characters. The ratio of general and specific combining abilities (GCA/SCA) indicated great additive effects for the majority of the studied characters. P1 and P5 were proved to be good combiners for all studied traits except for number of pods per nod and number of pods per plant. Several crosses exhibited highly significant positive SCA effects for the studied traits, especially P2×P3 and P4×P5 for number of seeds per plant, with high seed weight and number of pods per plant. Heritability, in the broad sense (H2bs%) estimates generally was, high for all studied traits, except for number of branches per plant and number of pods per nod. However, heritability, in the narrow sense, was high for 100-seed weight (72.25%) and pod length (51.03%), while, it was low for the majority of traits. High heritability values indicated that such traits would respond to selection.

Heterosis and combining ability estimates through line × tester analysis in inter-specific hybrids of cotton (G. hirsutum L. × G. barbadense L.)

The present investigation comprised of seventy two inter-specific hybrids obtained by mating twelve diverse lines of G. hirsutum and five testers of G. barbadense in line × tester fashion and were evaluated to study standard heterosis and combining ability for seed cotton yield and its component traits. Combining ability analysis indicated the preponderance of non-additive gene action for all the traits. The lines, L 762, MR 786, BS 37, NDLH 1938 and H 1442 and the testers, DB 16, DB 11 and GSB 41were found to be good general combiners for seed cotton yield plant -1 and its component characters. The hybrid, L 1058 × TCB 37 exhibited high and significant positive sca effect for seed cotton yield plant -1 and its contributing traits viz ., number of bolls plant -1 , boll weight and seed index. The cross combinations, L 762 × TCB 37, H 1442 × DB 16 and H 1442 × GSB 41 registered high and significant positive heterosis over both the standard checks for seed cotton yield plant -1 . The cross combinations which are showing high standard heterosis and sca effects may be recommended for commercial cultivation after testing their stable performance for seed cotton yield.

Estimation of combining ability and gene action for yield contributing traits in spring barley under normal and salinity conditions

Large proportion of the total land area in the world is salt-affected. Breeding for high yielding-varieties under normal and salinity conditions present an important solution for increasing the production and reduce the gap between production and consumption of cereal crops. Half diallel analysis among eight diverse spring barley genotypes was performed to provide information on general and specific combining ability, gene action and heritability for different agronomic traits under normal and salinity conditions. The used genotypes were four commercially cultivars (Giza 123, Giza 126, Giza 132 and Giza 2000) and the other four were introduced from ICARDA (Australian, CHK 38, CHK 2 and CHK 53). The parents were grown and crossed during 2014-2015 in the Experimental Farm of Faculty of Agriculture (Ghazala), Zagazig University, Egypt. In second season the derived seeds from crosses and parents were sown at two distinct locations. The first was in Ghazala as normal condition and the other was under salinity condition in the Experimental Farm of Desert Research Center, Ras-Sudr Research Station, South Sinai, Egypt, with salinity in irrigation water and soil containing 4500 ppm and 5535 ppm, respectively. Both experiments were in randomized complete block design with three replications. The measured traits were; plant height (cm), spike length (cm), number of spikes per plant, number of grains per spike, grain weight per spike (g), 100 grain weight (g) and grain yield per plant (g). Diallel analysis was performed for each environment separately. Analysis of variance indicated that there were highly significant differences between parental genotypes and theirs F1 crosses for all studied traits. General (GCA) and specific (SCA) combining ability effects were highly significant under both conditions for all traits. The genotypes; P3 (Australian) and P6 (CHK 53) showed good performance as well as good GCA effects under salinity condition, while P4 (CHK 38) and P8 (Giza 2000) under normal one and P2 (Giza 126), P5 (CHK 2) and P7 (Giza 132) under both conditions. The cross combinations; P3×P5, P3×P8 and P5×P8 exhibited good performance and significant positive SCA effects for grain yield and its attributes under salinity, while P2×P7, P3×P4, P4×P7, P5×P7 P6×P7 and P7×P8 under both conditions. The variance due to SCA was higher than that of GCA for all the traits except plant height and number of spikes per plant under salinity condition and 100 grain weight under normal condition. The components of genetic variance suggested more contribution of the dominance effects in the inheritance of the studied traits compared to additive ones. Narrow sense heritability values changed from environment to another, it ranged from low to moderate (4.62% to 31.96). The low values due to excess of dominance effect as well as great effect of the environmental factors in the genetic control of the studied traits. Wr-Vr graphs showed high degree of genetic diversity for parents with different degrees of dominance and different distribution of dominant and recessive alleles in the parental material for all traits under both conditions.