Magnitude Of Heterosis Research Articles

Deciphering combining behaviour and magnitude of heterosis in bread wheat cross combinations under sub-tropical region

Deciphering combining behaviour and magnitude of heterosis in bread wheat cross combinations under sub-tropical region

Line×Tester Analysis for Heterosis and Combining Ability for Seed Yield and its Component Traits in Indian Mustard

Twelve advanced lines/varieties of Indian mustard (Brassica juncea L.) were selected for building the experimental material. It consisted of 8 lines and 4 testers, mated in Line × Tester design during rabi season 2018-19. These parents alongside with their 32 F1s were evaluated in RBD in rabi season 2019-20 for 13 traits including seed yield per plant (g), glucosinolate content (µmole/g) and oil content (%). Analysis of variance for combining ability showed that significant differences were present amid treatments for all the characters, except for siliqua length and seeds per siliqua. Line PAB 17-1 was identified as a good combiner on the basis of their GCA effect for seed yield, test weight; PAB 17-15 for number of primary branches, number of secondary branches, PAB 17-21 for plant height, length of main raceme, siliquae on main raceme, glucosinolate content and PAB 17-23 for oil content. Highest significant SCA effect was shown by cross-combination PAB 17-2×PHR-2 for seed yield per plant, PAB 17-23×NRCHB-101 for glucosinolate content and PAB 17-1×PAB-9511 for oil content. Cross combination PAB 17-2×PHR-2 showed highest heterobeltiosis (BP) for seed yield per plant followed by PAB 17-1 × PHR-2. The magnitude of heterosis over BP in the desired direction was quite high ranging from -36.18 to 160.14. Cross PAB 17-23×PHR-1 for oil content showed highest heterosis over BP. Cross combination PAB 17-15×PAB-9511 showed highest relative heterosis for seed yield per plant and PAB 17-20×PAB-9511 for oil content. Similarly PAB 17-2×PHR-2 showed highest economic heterosis for seed yield per plant.

Viability of simultaneously selecting for grain yield and seed physiological quality in maize

ABSTRACT: Currently, the demand is not only for more productive corn hybrids, but also for those with high physiological seed quality. Seed quality is considered the sum of genetic, physical, physiological and sanitary attributes that directly interfere in plant vigor. The objective of this study was to evaluate the physiological parameters of the seeds of parents and maize inter varietal hybrids obtained in a reciprocal recurrent selection program through physiological and image analysis techniques and either to study the feasibility of simultaneously selecting for seed physiological quality and grain yield. Two experiments were performed, one in the field and the other in the laboratory. The evaluated traits in the field were days of female flowering, days of male flowering, insertion of the 1st ear, plant height and grain yield. For the physiological quality, the attributes of germination at four days, germination at seven days, vigor by the cold test, emergence speed index, and the ratio of the root length to shoot length were obtained using GroundEye®. Heterosis was measured for the agronomic and physiological traits. Through the contrast between the inter varietal crosse hybrids and reciprocals we measured the maternal effect. The magnitudes of heterosis allowed us to infer that as greater as the number of selection and recombination cycles, on average, greater heterosis for the traits grain yield and seed germination. The correlated response indicated that, high yield intervarietal hybrids have better seed physiological quality.

Heterosis and heterobeltiosis in bell pepper (Capsicum annuum var. grossum) for growth and yield parameters

The magnitude of heterosis over commercial check and better parent was estimated to identify best crosses for growth and yield traits in bell pepper. Experimental material included 21 F1 hybrids developed by crossing seven diverse parents in half diallel mating design. The findings revealed that Arka Mohini X CW308 showed best heterotic cross combinations, recorded significantly higher heterosis and high per se value over commercial check with respect to number of primary branches, number of secondary branches, plant height, days to 50% flowering, days to first harvest, fruit length, fruit width, number of lobes per fruit, number of fruits per plant and average fruit weight. The cross Arka Mohini X CW308 also showed high heterobeltiosis for traits like fruit length, number of fruits per plant, average fruit weight and average yield per plant. Hence, this hybrid with high per se value and heterosis can be utilized to obtain desirable segregates for development of superior genotype for improvement of horticultural traits in bell pepper.

Heterosis Analysis Over Environments for Seed Yield and Its Attributing Traits in Linseed (Linum usitatissimum L.)

A complete set of 79 entries comprising of twelve parents, their 66 F1s and one check RLC-92 were evaluated during rabi 2020-21 at two locations i.e., ARS, Dahod, and BTRS, Anand, under two dates of sowing i.e., 2nd fortnight of October and 1st fortnight of November. The present study aimed to investigate the Heterosis analysis over environments for seed yield and its attributing traits in linseed (Linum usitatissimum L.). Among the all four environments, E1 had higher mean value for seed yield per plant and all other important yield contributing traits indicating sowing in second fortnight at Dahod conditions best for linseed cultivation. The hybrids viz., Indira × ILS 264, RLC 133 × Kartika, H 45 × Kartika, IPI 10 × H 45 and IPI 10 × Kartika depicted higher better parent heterosis (HB) and Shekhar × GS 384 and Shekhar × H 45 noted significant standard heterosis for seed yield per plant and other traits. Parental lines, Shekhar, GS 384, H 45, KB 961, IPI 10 and Kartika yielded superior heterotic crosses for seed yield and its component characters. The heterotic effect for seed yield per plant was found to be associated with heterosis for its related traits in the majority of the crosses. High standard heterosis and heterobeltiosis for seed yield per plant and its component characters suggested ample scope of exploiting heterosis commercially. The magnitude of heterosis provides information on the extent of genetic diversity in parents of a cross and helps in choosing the parents for superior Fl’s, and to exploit hybrid vigour.

Estimation of Heterosis and Combining Ability for Improving Yield, Sweetness, Carotenoid and Antioxidant Qualities in Pumpkin Hybrids (Cucurbita moschata Duch. Ex Poir.)

A full diallel mating design was used to hybridize seven pumpkin inbred parental lines, yielding 42 F1 hybrids, including reciprocals. The generated F1 hybrids, parental lines and commercial check hybrid were evaluated in two environments to investigate the per se performances, combining ability effects and magnitude of heterosis over mid-parent, better-parent and commercial check hybrids for yield, yield attributed, sweetness, total carotenoid and antioxidant traits, using a randomized complete block design with three replications. The analysis of variance for most of the examined traits revealed highly significant differences (p ≤ 0.01) for GCA, SCA, reciprocal, maternal and non-maternal variances and their interaction with the environment. Since the inheritance of yield and its contributing fruit quality, and antioxidant traits is governed by non-additive gene action, it suggests heterosis breeding would be useful in obtaining further improvements in pumpkin. From the experiment, it was found that the paternal lines P1 (Gold Butter 315) for dry matter content and DPPH (%), P4 (Asian pumpkin) for total carotenoid content, P6 (Sarawak) for fruit number per plant and P7 (Australia-1) for single fruit weight, fruit flesh thickness, yield per plant and total soluble solid were shown to be good general combiners. In respect to per se performance, combining ability effects and magnitude of heterosis over mid-parent, better-parent and commercial check, the cross P2 (928 Fuxiang) × P1 (Gold Butter 315) and P4 (Asian pumpkin) × P5 (Sarawak) for single fruit weight and yield per plant, the cross P5 (Sarawak) × P2 (928 Fuxiang) for fruits number per plant, P1 (Gold Butter 315) × P7 (Australia-1) and P1 (Gold Butter 315) × P6 (Sarawak) for total soluble solid and dry matter content, P7 (Australia-1) × P2 (928 Fuxiang) for total carotenoid content and P3 (Ser Bajadi) × P1 (Gold Butter 315) for DPPH (antioxidant) were identified to be highly significant positive specific combiners and the highest performers, and these crosses may be exploited as commercial hybrids.

Combining Ability Analysis and Marker-Based Prediction of Heterosis in Yield Reveal Prominent Heterotic Combinations from Diallel Population of Rice

Combining ability along with heterosis was elucidated in the 21 F1 hybrid population of rice derived from a 7 × 7 diallel mating design. Furthermore, to formulate a strategy for marker-based prediction of heterosis, the molecular genetic diversity (GD) was then surveyed among the seven parental lines with RAPD markers. Analysis of combining ability revealed significant GCA and SCA variances and the ratio between the aforesaid genetic parameter was more than unity for most of the traits signifying the preponderance of additive gene action. Hybrid combination Double Rice × Pokkali was the best specific combiner for the traits pollen fertility percentage (%), panicle length (cm), filled grains/panicle (no.) and grain yield/hill (g) while Muktagacha × BRRI dhan29 and Basmati × Double Rice were the best specific combiners for grain length (mm) and 1000-grain weight (g), respectively. Regarding the magnitude of heterosis, Double Rice × Pokkali exhibited maximum heterobeltiosis for panicle length (33.33%) and the number of filled grains/panicle (144.01%). Furthermore, Pokkali × Chinigura was verified for producing the highest heterobeltiosis for tillers/hill (173.17%), as well as grain yield/hill (71.05%). The heatmap relying on molecular genetic diversity exposed the highest genetic distance between Chinigura and Pokkali followed by Muktagacha and Pokkali. Unweighted neighbor-joining trees clustered the parental lines into three groups indicating the presence of considerable genetic diversity among those seven parental genotypes. A positive and significant correlation was explored between molecular GD with specific combining ability as well as heterosis for all of the traits revealing the huge potentiality of hybrid performance prediction using RAPD markers with the present set of individuals. Thus, exploration of definite genomic regions underlying the candidate genes for respective traits relying on such RAPD-generated data following an advanced molecular marker approach would pave the path of mining out yielder heterotic combinations.

AN INVESTIGATION ON HETEROSIS, GENERAL AND SPECIFIC COMBINING ABILITY FOR POD YIELD AND ITS CONTRIBUTING PARAMETERS IN OKRA [ABELMOSCHUS ESCULENTUS (L.) MOENCH

The heterosis and combining ability studies were conducted by utilizing modified Line X Tester mating design involving 6 Lines and 9 testers of Okra [Abelmoschus esculentus (L.) Moench]. The breeding material involving fifty four F1 hybrids along with 15 parents with one commercial check were evaluated during Kharif 2020 in a Randomized Block Design (R.B.D.) with three replications at Research Centre of Goldking Biogene Private Limited with an aim to estimate the magnitude of heterosis and to identify the good parents and good hybrid combinations for pod yield and other quantitative traits. Among the parents GKOF-1, GKOF-5 and GOM-7 were found to be good general combiners for pod yield per plot. Among the lines GKOF-3, GKOF-4 and GKOF-6 and testers GKOM-4, GKOM-5, GKOM-7 and GKOM-9 were found to be involved in exhibiting significant sca effects for almost all characters. Among the crosses GKOF-2 X GKOM-5, GKOF-1 X GKOM-8 and GKOF-6 X GKOM-7 exhibited high per se performance for pod yield per plot. Further the cross GKOF-1 X GKOM-7, GKOF-4 X GKOM-9 and GKOF-6 X GKOM-4 revealed highest positively significant sca effects for pod yield per plot.

Studies on Heterosis, Residual Heterosis and Inbreeding Depression for Yield and Related Traits in Sorghum (Sorghum bicolor L.)

Background: Selection of genotypically superior parents is most challenging task for the development of potential hybrids. In conventional plant breeding, magnitude of heterosis and inbreeding depression has been proved very effective in identifying vigorous parental combinations. Methods: The present investigation was carried out to study the heterosis, residual heterosis and inbreeding depression of forty sorghum crosses (F1s and F2s) obtained by crossing of eight restorer lines with five cytoplasmic male sterile lines in Line x Tester mating design in 2013 and 2014. Observations were recorded on morphological traits viz. days to 50% flowering, days to maturity, plant height, flag leaf length, flag leaf width, panicle length, panicle width, panicle weight,1000 seed weight and grain yield per plant. Result: Among all crosses, ICSA467 x UPC2 and MR750A2 x UPC2 were found to be best for most of the characters. Inbreeding depression was recorded as significantly positive for plant height for most of the crosses indicates the occurrence of transgressive segregants in F2 generation.

Estimation of Magnitude of Heterosis and Heritability in Sunflower in 8X8 Half Diallel Population

Selected eight inbreed line were used in crossing as half diallel fashion to find out different genetic parameter as well as targeting superior combination for hybrid vigour. Sunflower first introduce in Bangladesh 1980 by Bangladesh Agricultural Research Institute and Mennonite Central Committee. BARI Sunflower-1(Kironi) and BARI Sunflower-2 is only two released variety. But major obstacles for sunflower cultivation are both varieties are more than 1.50m height and require > 100 days for maturity. As this country is facing climate change unfavorable weather, sunflower cannot withstand in stormy weather. Specially at the time of prematurity stormy weather causes lodging due to over height, it is essential to develop dwarf stature plant. Due to strong crop competition in winter it cannot fit in major cropping pattern T-Aman-Mustard-Boro due to it long duration. Bangladesh has accessible land of 0.85 million hectares in saline areas (Banik et al., 2011). These lands can be used for sunflower cultivation as it is moderately saline tolerant (Rahman et. al. 2018). On the other hand in different part of Bangladesh (e.g. Cumilla, Manikgonj, Sherpur, Jamalpur, Netrokina, Tangail, Dinajpur, etc.), a huge amount of lands are kept fellow after T. Aman harvest. These current fellow lands can be easily used by sunflower cultivation if short duration varieties are available. Both plant height and days to maturity were considered as favorable for negative heterosis to obtain dwarf plant stature and short duration plant to fit in existing cropping pattern in Bangladesh. Positive heterosis is considered desirable for other yield contributing traits. The hybrid HE15, HE17 and HE16 showed significant negative heterosis both for mid parent and better parent. Negative heterosis for plant height is desirable to adopt hybrid in unfavorable weather condition. The Hybrid HE15 showed both for significant negative mid parent and better parent heterosis. High heritability along with significant mid parent and better parent heterosis indicate scope of utilization of hybrid as commercial and further use in breeding programmes. Several outstanding cross combinations, HE17, HE16, HE14, HE15, and HE18 showed significant and desirable heterosis for seed yield per plant over mid parent and better parent. The hybrid combinations HE17, HE16 and HE14 could be utilized to exploit the heterosis as well as commercial multiplication of seed to get direct benefit by the farmers.

Estimation of heterosis for yield and it’s components in chickpea (Cicer arietinum L.)

Chickpea is highly self-pollinated crop and the scope for exploitation of hybrid vigour will depend on the direction and magnitude of heterosis, biological feasibility and the type of gene action involved. Also study of heterosis will have the direct bearing on the breeding methodology to be employed for varietal improvement. The experiment was conducted at Pulses Research Unit, Dr. P.D.K.V. Akola, during rabi season of 2018-19. In this study, four lines were crossed with six male parents by using line x tester design and twenty four hybrids were developed along with the variety JAKI-9218 as standard check have been evaluated in RBD with two replication. The highest mean performance was recorded in PDKV Kanchan x GJG-0814 (27.65g) and significant standard heterosis (15.45% over check JAKI-9218), heterobeltiosis (20.22) and average heterosis (25.68). Another cross Phule Vikram x C-1821 revealed high mean performance for (26.50 g) for seed yield per plant also recoded high magnitude of useful heterosis (10.65 over check JAKI-9218).

Heterosis studies for seed cotton yield and yield contributing traits in desi cotton (Gossypium arboreum L.) over the environments

Fifty six hybrid combinations developed by crossing 7 lines and 8 testers were tested along with their parents including 4 checks in Line X Tester design for seed cotton yield and yield contributing characters during kharif, 2016 at three locations viz., Cotton Research Station, Nanded (L-1), Experimental farm of Department of Agricultural Botany, VNMKV, Parbhani (L-2) and Experimental farm, Agricultural Research Station, Badnapur (L-3). The magnitude of heterosis was estimated in relation to better parent and standard checks. The magnitude of heterosis, heterobeltiosis and standard heterosis for all the characters in the present study was highly appreciable. Out of fifty six crosses, the crosses showed highest and desirable significant standard heterosis for various traits viz., cross PA 801 x AKA 8 for days to 50 per cent flowering, days to 50 per cent boll bursting and days to maturity; PA 809 x CNA 449 for plant height ; PAIG 346 x DWDa 1402 for number of sympodia per plant ; PAIG 346 x DWDa 1402 for number of bolls per plant; PA 740 x DIgvijay for boll weight; PAIG 346 x JLA 797 for seed cotton yield per plant and seed index; PA 812 x HD 514 for lint index and PA 809 x AKA 8 for harvest index over standard check PKVDH 1,PKV Suvarna, NACH 12 and PA 255, respectively. The crosses PAIG 346 X JLA 794, PAIG 346 X DWDa 1402, PA 809 X AKA 8, PA 785 X CNA 449, PAIG 346 X CNA 449 and PAIG 346 X HD 514 hold promise for further evaluation and commercial exploitation of heterosis for seed cotton yield and yield contributing traits.

Identification of superior parents and hybrids for yield improvement in castor (Ricinus communis L.)

An experiment was conducted to determine the nature and magnitude of heterosis in castor for seed yield and its yield attributing traits. Forty hybrids were synthesized involving five lines and eight testers through line x tester(L×T) mating design and were evaluated for yield and its components. Among 13 parental lines, JP-96, VP-1, DPC-9, RG-2661-1, RG-109 and RG-3160 were identified as good general combiners for seed yield and its components, which can be directly exploited in heterosis breeding. The cross combination, DPC-18 × RG-2661-1 was good specific combiner for early maturity. High seed yield per plant was recorded for hybrids: VP-1×RG-109(105.04 g), DPC-18×RG-1771 (98.26g) and DPC-18×RG-2661-1 (97.97 g). These promising crosses involved parents with high × high and high × low GCA effects and were found promising for high yield potential in castor.

Study on heterosis for yield and quality traits in rice (Oryza sativa L.)

To know the extent of heterosis among the selected 21 crosses derived from the diallel mating system using seven parents regarding yield and quality traits. The magnitude of heterosis was high for grain yield and protein content and moderate to high for plant height, ear bearing tillers per plant, number of primaries per panicle, L/B ratio, head rice recovery and GT score. The best heterotic crosses for grain yield were erramallelux NLR 33637 and IR 72 x NLR 33637. The high heterotic effects in the hybrids may be due to predominant role of non additive component in the inheritance of the characters studied.

Heterosis and inbreeding depression for yield and its components traits in barley (Hordeum vulgare)

Heterosis and inbreeding depression was analysed using a set of diallel crosses involving 10 diverse parents (excluding reciprocals). Heterosis over standard parent for grain yield per plant ranged from -9.65–45.45 (%) and -14.78–12.05 (%) under normal and late sown conditions, respectively and heterosis over better-parent for grain yield per plant ranged from -26.43–70.77(%) and -32.16–12.05(%) respectively. Nature and magnitude of heterosis and inbreeding depression varied across crosses, characters as well as environments. Considering the very high degree of heterosis in desirable direction, the importance of non-additive components of genetic variance was observed for yield and most of the yield contributing components. Cross II (K 603 × Azad) and cross IV (RD 2618 × PL 708) revealed better specific cross combinations to be used for heterosis. The study revealed good scope for commercial exploitation of heterosis as well as isolation of pure lines among the progenies of heterotic F1 for improvement of yield levels in barley.

Combining Ability and Heterosis of Sorghum (<i>Sorghum bicolor</i> L. Moench) Hybrids for Grain and Biomass Yield

This study was carried out to estimate the magnitude of heterosis and combining abilities (general & specific) for forage and over all grain yield performance of sorghum hybrids. Even though, information on heterotic performance and combining ability of Ethiopian elite sorghum lines for biomass, yield, and overall performance is too insufficient, there is ample amount of sorghum elite lines developed through pedigree breeding. The result of ANOVA found out that mean squares had to indicate a considerable amount of variability among the tested genotypes for most traits. Parents and hybrids are drastically unique for all traits besides thousand-grain weight, number of green leaves, and panicle width. This found out that hybrids have a higher yield than Open pollinated types (OPVs) parents. Hybrids, 106 × 94 (123.5%), 106 × 87 (80.4%), 106 × 78 (72.5%), 107 × 92 (74.5%) 107 × 99 (56.9%), and 107 × 104 (60.8%) have been discovered maximum heterotic hybrids for yield in comparison to check. The estimations of parental GCA effects confirmed that female 106 and males 79, 96, 94, and 81 had been excellent general combiners for biomass, yield and associated traits. Primarily based on perse overall performance, heterotic response, and combining ability, female parent 106 and male parents 94, 102, and 90 were observed maximum performed. Those parental lines could be used for hybrid and germplasm improvement.

An elucidation of over a century old enigma in genetics-Heterosis.

Recognition and exploitation of hybrid vigor or heterosis among individual crosses of plants and animals has a long and distinguished history. Its manifestation is influenced by a combination of genetic, epigenetic, phenotypic, and environmental factors. Although heterosis is known to be governed by both dominant and epistatic gene action, its expression is greatly influenced by nonlinear interaction among epigenetic and phenotypic (phenomic) components. The magnitude of heterosis is generally inferred post hoc by the phenotypic performance of hybrids among laboriously made individual crosses. The expression of dominance, however, is nonlinear at the cellular level and obeys the principles underlying metabolic flux. Then, is it possible to exploit these relationships to predict heterosis? Vasseur and colleagues have indeed demonstrated the feasibility of such an approach in a series of experiments taking integrated biochemical and computational approaches, as well as testing these results on large samples of model organisms. The results offer promise toward phenomic prediction of heterosis across a wide array of organisms.

Heterosis for growth, yield and fruit quality traits in papaya

An experiment was conducted during 2016–2017 to determine the magnitude of heterosis in papaya for growth, yield and fruit quality traits. A total of eight genotypes consisting three hybrids along with their five parents were evaluated in a Randomized Block Design with three replications. Appreciable heterosis was found over better over mid parent in traits like days to fruit maturity, number of fruits per plant, fruit yield, fruit shelf life, fruit firmness, antioxidant activity of fruit, total carotenoid content and lycopene content in desirable direction. A hybrid, of progeny of Red Lady (Self) × Pusa Nanha (14.57%) showed significant relative heterosis for yield, whereas none of the hybrids were recorded with better parent heterosis. Two hybrids, Red Lady (Self) × Pusa Nanha (2.93%) and Pune Selection 3 × P-7-9 (22.13%) was observed with high heterosis for number of fruits per plant. All three hybrids exhibited heterosis in negative direction for days to fruit maturity. For fruit shelf life at ambient temperature, hybrid Red Lady (Self) × P-9-5 (3.12%) exhibited better parent heterosis, whereas all three hybrids showed positive mid parent heterosis for the same trait. All three hybrids showed positive mid-parent heterosis for traits like number of fruits per plant, shelf-life, total phenolic content and antioxidant activity. The hybrid Red Lady (Self) × Pusa Nanha exhibited better parent and mid parent heterosis for total carotenoid and lycopene content along with total phenolic content and antioxidant activity. Moreover, none of the hybrids showed positive heterosis for TSS, leaf length, fruit weight, fruit diameter and fruit length. However, hybrid Red Lady (Self) × Pusa Nanha has shown moderate heterosis for important economic traits and same may be exploited further to develop a commercial hybrid of papaya.

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.

Genetic Behavior of Some Agronomic Characters in Three Bread Wheat Crosses under Different Environmental Conditions

This investigation was carried out at the Experimental Farm of Gemmeiza Agriculture Research Station, Egyptduring the three successive seasons,i.e., 2015/2016, 2016/2017 and 2017/2018 to study nature of gene action for yield andits components, heterosis expression, heritability and expected genetic advance under normal and water stress conditions.Six populations model (P1, P2, F1, F2, BC1 and BC2) was used in this study for three crosses; (I) Gemmeiza 11× Giza168, (II) Giza 171× Shandawel 1 and (III) Gemmeiza 9× Misr1. Means of the six generations were recorded for eightcharacters, i.e. number of spikes per plant, plant height, main spike length, number of spikelets per main spike, number ofkernels per main spike, main spike yield, grain yield per plant and 1000- kernels weight. Results revealed that thecoincidence of sign and magnitude of heterosis and inbreeding depression was also detected for most characters in thethree crosses under both conditions. Study of generation means analysis revealed that additive, dominance and epistasiceffects were involved in the inheritance of yield and its components. Additive (a) and dominance (d) genes effects weresignificant for most studied characters under both conditions. High heritability estimates in broad sense were detected forall studied characters in the three crosses under both conditions, except, main spike yield in the first cross under stress.Narrow sense heritability estimates were found to be high for most characters under both conditions. Moderate to highgenetic advance (Δg%) was detected for all characters of the three crosses under the two environments, except, plantheight for the three crosses under normal condition and first and second cross under stress condition. The highestestimates of narrow sense heritability associated with highest genetic advance for most of the studied characters in most ofcrosses under both conditions indicated sufficient improvement of the variable characters. These results indicated thepossibility of practicing selection in early generations for these characters.