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Generation mean analysis study was carried out to estimate the gene action governing inheritance of yield and its components in blackgram using six parameter model. Six generations of a cross NUK-15-02 × NUK-15-09 was studied. Simple scaling test as well as joint scaling test were carried out to check the adequacy of additive-dominance model. Additive gene effect had lower magnitude than dominance gene effect in most of the characters. Additive × additive type of epistatis was found significance for days to first flower, plant height and branches per plant. Dominance × dominance gene interaction was registered significant by days to first flower, days to maturity and plant height. Hereby for the improvement of various characters studied in this cross, followed population improvement approach which takes in to account both additive and non-additive gene action.

The present study was carried out at Sakha farm, Sakha Agricultural Research Station (SARS), Kafr El-Sheikh, Egypt, during the three summer seasons of 2017, 2018 and 2019. Four crosses of soybean, each with six populations (P1, P2, F1, Bc1, Bc2 and F2) were tested for yield and some growth attributes. The results showed that: Over dominance was observed for flowering date in crosses I and II, for maturity date and plant height in cross II and seed yield per plant in all crosses, while partial dominance was observed for the remaining crosses for most traits. Significant negative heterosis were detected for flowering date for mid-parent in the first cross, significant positive heterotic effects were detected for other traits. The additive effect (a) was highly significant in positive or negative direction in all crosses for all traits, except in the four crosses for number of seeds per pod and 100 seed weight, crosses I and II for flowering date. Additive x additive types of gene action were found to be significant for most traits of all crosses, also additive x dominance and dominance x dominance types of gene effects were found to be significant for most traits. High narrow sense heritability values were obtained for plant height and number of seeds per pod in the first cross. While, the lowest estimates was resulted for number of seeds per pod in the second cross, number of branches per plant in the first cross and seed yield per plant in the fourth cross.

Heritability and Genetic advance are the direct selection parameters. Information on such parameters has great importance in enhancing the selection efficiency. Therefore, in the present investigation 77 maize genotypes including 54 F1s, 18 lines, 3 testers and 2 check varieties were evaluated in relation to direct selection parameters for different quantitative traits. All the genotypes showed significant variability for all the characters studied. High values (>20%) of genotypic coefficient of variance (GCV) and phenotypic coefficient of variance (PCV) were recorded for the traits, grain yield per plant, kernels per cob, cob weight and kernels per row. The traits such as seed vigour index, seedling length, cob length, cobs per plant 100-kernel weight, plant height and kernel rows per cob showed moderate values (10-20%) of GCV and PCV. For almost all the traits the values of GCV and PCV were almost similar but for cob diameter GCV was low while PCV was high indicated that all the traits had low environmental influence except cob diameter that had high environmental influence. High estimates of heritability coupled with high estimates of genetic advance as percent of mean were recorded for the traits grain yield per plant, kernels per cob, cob weight, kernels per row, seed vigour index, seedling length, 100-kernel weight, cob length, plant height, cobs per plant and kernel rows per cob. This indicated the role of additive gene effect in the inheritance of these traits; therefore, such traits could be improved through simple selection.

The study was conducted to investigate the body dimension, morphometric features and inheritance pattern of indigenous dwarf chicken (IDC) of Bangladesh under intensive management condition. The experiment was conducted at Bangladesh Agricultural University (BAU) poultry farm for a period of 28 months from March 2013 to June 2015 including a total of 979 birds. Body weight, shank length and circumference, chest girth, length of trunk, wing, keel and body, and body conformation indices were recorded at 8, 24 and 52 weeks of age. The average shank length, shank circumference and live weight at 24th week in adult dwarf males and females were 7.38 and 4.37 cm, 6.20 and 3.63 cm, and 1650 and 1067 g, respectively. The reduction of live weight for dwarf male and female chickens relative to their normal shank counterpart (NSC) at same age was 14.06 and 16.05%, respectively. Length of body, trunk, wing, shank and keel of IDC were also significantly shorter than NSC at all ages. The indices of shape, massiveness and long leggedness of NSC were significantly greater than IDC almost all ages. Shank lengths of day old chicks were measured within 1.4-1.6 cm. The ratio of non-dwarf and dwarf in indigenous chicken populations was found 9:7 for 1st generation where significant deviation observed in subsequent generations. Among the dwarf progeny, the male and female ratio was close to 1:1. Current hypothesis is in favor of autosomal dwarfism control by at least 2 pairs of genes where duplicate recessive gene interaction also known as complementary gene effect has probably been exerted between two pairs of genes. In conclusion, the present estimates give some insight information on morphometry and body conformational aspects between normal shanked and dwarf chickens which relate with lowered motoric activity, reduced metabolic rate and their body surface-mass makes the dwarf birds suitable for hot-humid climate like Bangladesh.

This study determined the gene effects involved in the inheritance of pod length and other yield-related traits and relationships among traits in crosses between two cowpea lines (TVu 2280 and TVu 2027) and a yard-long bean (TVu 6642) line with long pods. Plants of six generations (P1, P2, F1, F2, BC1P1, and BC1P2) derived from TVu 2280 × TVu 6642 and TVu 2027 × TVu 6642 were evaluated under field conditions. Data collected on 14 yield components of each cross were used for generation mean analysis. Gene effects and their magnitudes varied with the crosses, digenic epistatic gene effects were detected for 10 traits in TVu 2280 × TVu 6642 and 11 traits in TVu 2280 × TVu 6642. Only additive gene effect was significant for pod length in TVu 2280 × TVu 6642 while additive, dominant, and two of the three digenic epistatic gene effects were significant in TVu 2027 × TVu 6642. Models that incorporated only significant additive, dominant, and digenic epistasis were adequate for all 14 traits in TVu 2280 × TVu 6642 and eight of the 12 traits in TVu 2027 × TVu 6642 for which model-fitting was possible. Across segregating generation of the two crosses, pod length (PodLNT) was significantly (p &lt, 0.001) correlated with three major yield components viz. pod weight (0.84, 0.77), number of seeds per pod (0.41, 0.30) and seed weight per pod (0.61, 0.29). Significant correlation of PodLNT with seed yield per plant was moderate and significant (p &lt, 0.01–0.001) in the BC1P1 of the two crosses (0.31 and 0.41). An improvement in cowpea seed yield is feasible through selection for long pods in segregating generations involving crosses with yard-long bean.

Hybrid sterility is a major obstacle to the development of superior inter-subspecific hybrids between indica and japonica subspecies of Asian-cultivated rice. To overcome hybrid sterility, we introduced four japonica alleles (S-j) at Sa, Sc, f5, and S32 loci from Nipponbare into 9311 through marker-assisted backcross breeding, and four improved lines were obtained. Three wide-compatibility lines 9311(S5-n), 9311(f5-n), and 9311(S5-n+f5-n) previously constructed were used as control and parental line of hybridization. By crossing with 9311(S5-n+f5-n), two pyramiding lines 9311(Sa+S5-n+f5-n) and 9311(S32+Sa+S5-n+f5-n) were obtained. To evaluate the gene effect of pollen fertility and spikelet fertility, the near-isogenic lines (NILs) harboring S5-n, f5-n, Sa, Sc, f5, or S32 and three pyramiding lines with S5-n+f5-n, Sa+S5-n+f5-n, or S32+Sa+S5-n+f5-n were testcrossed to six japonica varieties. The results showed that single-gene f5, f5-n, S32, and S5-n could significantly improve spikelet fertility in majority of indica-japonica hybrids. Single-gene Sa and Sc could significantly improve spikelet fertility in part of indica-japonica hybrids. Moreover, the pyramiding lines exhibited significantly higher spikelet fertility than the control in indica-japonica hybrids. A significant increase in spikelet fertility (31.4–55%) was observed in three- or four-gene pyramiding lines. Our results provide an effective approach to exploiting heterosis between indica and japonica subspecies, which had a profound implication in rice breeding.

The present investigation was conducted to estimate the gene action effects in some traits of durum wheat by using crosses two generation of wheat (Albit-9 X omgenil-3) through generation mean analysis during growing season 2016-2017, at Field Crops Department, Collage of Agricultural Engineering Sciences, University of Duhok. The analysis of variance showed significant differences between generations mean for studied traits except spike length which did not significant. The mean value of F1 generation was higher than the respect parents (P1 and P2) F2, Bc1 and Bc2 for most of studied traits in wheat crosses. The results of gene effect shown that the dominance gene effects were significant and positive with all studied traits, whereas additive gene effect did not significant for all traits except plant height and number of grain per spike, also The results exhibited that the dominance and additive X additive variance was positive for all traits this mean complementary gene effect controlling these traits, regarding of broad and narrow sense heritability. The results indicate that broad sense value was more than the narrow sense heritability. Heterosis in F1 cross over mid parents was recorded a positive value (9.672, 8.112) for plant height and grain yield per plant, while inbreeding depression was measured as reduction in performance of F2 generation a positive results were obtained for all traits.

This study was carried out at Qlyasan location in Sulaimani region (Lat 35 º 34' 307''; N, long 45º 21' 992; E, 765 masl) for F3 generation of seven pea varieties (1-Avolla, 2-Americana, 3-Jeza, 4-Joneor, 5-Packland, 6-Arvena and 7-Samara). The seeds of 21 F3 crosses and their parents were sown in Completely Randomized Block Design (CRBD).With three replicates. The results showed that the mean squares of genotypes, gca and sca were highly significant for seed weight plant-1 and most its important components. The parents Americana and Jeza recorded maximum values for all studied characters. The cross AvollaxAmericana recorded the highest value for seed weight plant-1 and pod weight plant-1. The cross AvollaxPackland had the highest value for heterosis due to seed weight plant-1 122.114% and whole plant weight 147.111%. The parent Americana recorded maximum positive gca effect value for seed weight plant-1 and some its components pod length, pod weight plant-1 and 100-seed weight. The crosses JezaxArvena recorded maximum positive sca effect value for seed weight plant-1, while the cross AvollaxArvena showed maximum positive sca effect value for pod length and pod plant-1. The average degree of dominance was more than one for all characters indicating to the importance of non additive gene effect in controlling the inheritance of these characters. Heritability in broad sense was high for seed weight plant-1 and some its components pods number plant-1, pod weight plant-1 and 100-seed weight, while it was low in narrow sense for all characters.

Genetic information plays an important role in plant selection. This research was aimed to obtain genetic information on pattern inheritance of yield and yield component characters of two crosses population of birds chili. The research used biparental mating design consisted of 40 plants of parents population (P1 and P2), 40 plants of first generation (F1) and reciprocal (F1R) populations, 100 plants of backcross populations (BCP1 and BCP2), and 300 plants of second generation population (F2). Scaling test and joint scaling test indicated the presence of gene interaction (epistasis) in two crosses population. Estimates gene effect also showed that fruit weight character in crosses population of IPB C145 x IPB C174 was controlled by duplication epistasis, while yield per plant character in crosses population of IPB C145 x IPB C291 was controlled by complementary epistasis. All characters of both crosses populations had high broad sense heritability, but the characters in crosses population of IPB C145 x IPB C174 had medium to high narrow sense heritability, while the characters in crosses population of IPB C145 x IPB C291 had low to medium narrow sense heritability. Genetic difference between parents seemed to affect gene action of a character, in which yield per plant, number of fruits per plant, fruit weight, and fruit length characters in crosses population of IPB C145 x IPB C291 with small genetic difference were more controlled by the action of non additive gene than crosses population of IPB C145 x IPB C291 with large genetic difference.Keywords: epistasis, gene action, genetic difference, heritability, yield

The present investigation was carried out during 2015/2016 and 2016/2017 seasons at the Experimental Research Station, Faculty of Agriculture, Assiut University. The objectives of this investigation were to obtain information about the performance and genetic components of parental wheat genotypes and their F1s under normal and water stress conditions. The performance of all genotypes under water stress condition was lower than its performance under normal condition. The parent 6 (P6) was the earliest flowering under both conditions and the parent P5 under water stress condition (85.70 day), while the parents P1, P2,P4 andP6 gave the tallest spike under both of normal and water stress conditions. While, P1 and P2 gave the tallest spike under water stress condition. The hybrids (P4 × P5) and (P1 × P6) were the earliest among F1- hybrids under normal and water stress conditions, respectively. Furthermore, the hybrids (P1 × P3) and (P1× P4) gave the tallest spike under normal and water stress conditions, respectively. The mean of grain yield /plant for all genotypes was 32.70 g and 24.96 g under normal and water stress condition, respectively. The P6 gave the highest grain yield/ plant compared with other parental genotypes under both conditions. On the other hand, the highest grain yield /plant was obtained from the hybrids (P4 × P5) under both conditions. The results showed that the magnitude of SCA exceeded GCA ones for days from planting to 50 % heading trait, which indicating that the major portion of genetic variance was due to the non-additive gene effects. The ratio of GCA/SCA was noticed to be low for days from planting to 50 % heading trait, indicated the specific combining ability was more important than general combining ability variance. The ratio of GCA/SCA was low for Plant height except SCA under irrigation in the F1- hybrids. The ratio of GCA/SCA was 1.08 and 0.80 in the F1-hybrids under normal and water stress conditions, respectively. The good genotypes for plant height in the F1- hybrid under both environments were Entry 21 and Entry 20. While, the ratio of GCA/SCA was noticed to be low for spike length, indicated the specific combining ability was more important than general combining ability variance, which indicating that the major portion of genetic variance was due to the non-additive gene effects. The results showed that the magnitude GCA/SCA ratio for number of kernel/spike was 0.31 and 0.20 in the F1-hybrids under normal and water stress conditions, respectively, indicating that the non-additive were larger than additive effects in the inheritance of number of kernel/spike and both were highly significant. The ratios of GCA/SCA were less than the unity for grain yield/plant under both environments indicating that the non-additive gene action controlled the inheritance of grain yield/plant. The GCA/SCA ratio was 0.14 and 0.48 for 100-grain weight in the F1-hybrids under normal and water stress conditions, respectively, indicating predominance of non-additive gene effect in the inheritance of 100- grain weight

Analysis of variability carried out for ten characters in sixteen diverse genotypes of nigella ( Nigella sativa L.) revealed high genotypic and phenotypic co-efficient of variations for secondary branches per plant, number of grains per fruit, number of fruits per plant, length of fruit (cm) and width of fruit (cm). Heritability estimates were high for number of grains per fruit (0.86), number of fruit per plant (0.78), length of fruit (0.64), days to maturity (0.59), number of secondary branches per plant (0.56) and yield per plant (0.47). Higher genetic advance as percentage of mean was recorded for number of grains per fruit (46.11%), number of secondary branches per plant (43.99%), number of fruits per plant (39.65%), yield per plant (24.49%), length of fruit (24.12%) and indicating additive gene effect. Quantitative traits like days to maturity, number of secondary branches per plant, number of grains per fruit and number of grains per fruit exhibited wide range of variability (134.33-143.00) maximum genotypic co-efficient of variability (29.53), maximum phenotypic co-efficient of variability (22.18), broad sense heritability (0.86) and gene gain (46.11).

The genetic parameters were studied to elucidate the genetic variability, correlation and path co-efficient analysis in thirty-nine genotypes of bottle gourd [Lagenaria siceraria (Mol.) Standl] in randomized complete block design with three replications. Observations were recorded for eleven quantitative characters viz., days to first male flower open, days to first female flower open, node number of first female flower, braches plant-1, days to harvest, number of fruits plant-1, fruit weight, fruit length, fruit girth, 100 seed weight and yield ton ha-1. The analysis of variance showed highly significant differences for all the characters studied indicating considerable variability among the genotypes. The highest GCV (35.57%) and PCV (35.62%) were observed for fruit length. The differences between GCV and PCV were high for fruit number plant-1 and days to first male flower open indicating environmental influences. High heritability associates with high estimates of genetic advance in percent of mean were noted for length of fruit, yield, girth of fruit and number of fruits plant-1. It indicated presence of additive gene effect and selection for these traits would be effective. Yield were positively and significantly correlated with fruit weight, 100 seed weight, branch plant-1 and number of fruits plant-1 .Negative associations of yield were noted with days to first male and female flower open, days to harvest and length of fruit. Path analysis revealed that fruits plant-1 (0.93) and weight of fruit (0.467) had very high positive effect on fruit yield ton ha-1 .Int. J. Agril. Res. Innov. & Tech. 8 (1): 14-17, June, 2018

An experiment was conducted to study genetic variability in forty-nine elite slender grain rice genotypes for thirteen component characters including grain yield.The experimental materials possessed a considerable amount of variability for all the traits. Majority of the traits showed the smaller difference between phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV). Both PCV and GCV were high for grain yield (gm) (PCV:27.14%, GCV:26.27%), and fertile grains per panicles(PCV:20.61%, GCV:20.52%), indicating less effect of environment on these characters. PCV and GCV were moderate for characters like harvest index (PCV:16.99%, GCV: 14.18%), 100 seed weight (gm) (PCV:14.57%, GCV:13.82%), fertility percentage (PCV:15.72%, GCV:15.05%), flag leaf area (cm2 ) (PCV:17.83%, GCV: 17.74%) and days to 50 % flowering (PCV:11.20%, GCV:11.17%) indicating that there is considerable amount of environmental effect on such characters. Moderate to a high degree of heritability estimates were observed for the majority of the traits under study except for a number of effective tillers/plant indicating the low or negligible influence of environment in the expression of these traits and may respond to selection for their improvement. High heritability (H2 )estimates were associated with moderate to high genetic gain over mean (GAM) for days to 50% flowering (H2 : 99.35%,GAM: 19.52%), plant height (H2 :93.89%,GAM:14.01%), panicle length (H2 :94.06%,GAM:14.04%), flag leaf area(H2 : 98.93%,GAM: 31.05%), fertile grains/panicle (H2 :99.20%,GAM: 35.98%), fertility percentage (H2 :91.57%,GAM:25.34%),100 seed weight (H2 :89.90%,GAM:23.06%)and grain yield per plant (H2 :93.71%,GAM:44.76%) indicating the presence of additive gene effect and hence selection based on phenotypic performance for these traits would be effective.

The safflower (Carthamus tinctorius L.) is an oil seed crop from which the flowers is used as medicine and food colorants. The present investigation was undertaken to explore gene effects for safflower’s pigments in flower including carthamin and carthamidin. Six generation including P $$_1$$ , P $$_2$$ , F $$_1$$ , F $$_2$$ , BC $$_1$$ and BC $$_2$$ that derived from two different crosses (Mex. 2-138 (P $$_2$$ ) $$\times $$ Wht–Esf (P $$_1$$ ) and C $$_{111}$$ (P $$_2$$ ) $$\times $$ Wht–Esf (P $$_1$$ ) were used for generation of mean analysis. The joint scaling test showed that additive [a], additive $$\times $$ additive [aa], and additive $$\times $$ dominance [ad] effects were significant for genetic control of carthamin and carthamidin in both crosses. The traits, including carthamidin and carthamin, had medium (48%) and low (17%) narrow-sense heritability, respectively. The results obtained here could be suitable for designing the breeding strategies based on selection to improve carthamin and carthamidin pigments in safflower.

Combining ability analysis of 10×10 diallel set of crosses in Indian mustard for ten quantative traits revealed preponderance of non-additive gene effects for plant height, number of primary branches per plant and seed yield per plant, whereas additive gene effect was found to be predominant for the inheritance of rest of the character. The parent Varuna, RH-3904 and RH-819 were the good general combiners for seed yield and oil content. Varuna and RH-819 also exhibited desirable general combining ability effect for earliness and dwarfness. Among the cross combination, cross Varuna×RH-819 exhibited superior specific combining ability effect for days to 50% flowering, number of secondary branches per plant and other yield attributing traits. Most of the cross involving high-low general combining parent, exhibited high sca effect for various traits. Seed yield was highly, significantly and positively correlated with days to 50 % flowering, plant height, number of primary branches per plant, length of siliqua, and test weight. Hence, selection for the higher values of these traits will be desirable to increase seed yield.

The rust disease resistance of groundnut has inherited pattern 9 : 7, indicating that was controlled by double resessive genes. From this fact needs an explanation of gene action, so it can be used as information in the breeding system and selection. The purpose of this research is to know the gene action control, if resistant the rust disease in groundnut. The design used in this experiment was randomized block design with three replications. There were 29 genotypes as treatments (5 genotypes parents, 6 genotypes F1, 6 genotypes F2, 6 genotypes BC1.1 and 6 genotypes BC1.2). The result of the experiment showed that there was a gene non-allelic interaction, mean effect (m) and a dominant gene effect (h) in progeny of Muneng x ICGV 87358 (Six Parameters Mode). However, the gene non-ellelic interaction did not occur in other progenies. Meanwhile progenies of Gajah x ICGV 92088, Gajah x ICGV 87358, Gajah x ICGV 91227 had a mean effect (m) and a aditive gene effect (d), and Muneng x ICGV 92088, Muneng x ICGV 91227 had only a mean effect (m).

In order to determine the heritability and combining ability of the parents and crosses, a complete diallel cross study of five wheat varieties was performed with parents and a total number of 20 F2 progenies under normal conditions in randomized complete block design (RCBD) with three replications at the Nuclear Agricultural Research Institute. The importance of additive and non-additive effects was determined in the present study that may have implications in plant breeding programmes. The general combining ability (GCA) and specific combining ability (SCA) were significant for all the features in this study, although reciprocal effects were significant only for the number of grains per spike. The GCA effect was more prevalent than the SCA effect in the studied traits. On the other hand, the SCA effect was only significant for yield, weight of grains per spike and peduncle length. Traits with high GCA can be improved by selecting valuable traits in progenies. In this study, Kealk parents were found to be suitable parents in the breeding programme to improve grain yield. Furthermore, the Brown Bolani × AS48 crosses were the best combination for improvement of yield and the number of grains per spike. Hayman analysis of variance showed the inheritance of all traits except yield and grain weight per spike which were mainly controlled by the additive gene effect. A high narrow sense heritability was detected for the length of the second and third internodes, peduncle diameter and plant height.

The assessment of nature of gene effect for yield and its contributing traits and detection of epistasis in wheat was studied in five crosses involving seven parents through generation mean analysis. Scaling test and joint scaling test were showed significant for almost traits all crosses. Additive gene effects (d) were positively significant for days to maturity and tillers per plant in cross II; for seed per plant in cross IV. Dominance gene effects (h) were highly significant for days to 75% heading in cross II, III and IV; for days to maturity and grains per spike in cross II, for grain yield per plant and grains per spike in cross I. Additive x additive type of gene (i) were positive significant effect for days to 75% heading in cross II, III and IV; for days to maturity in cross II and grains per spike in crosses I, II; for 1000 grain weight in cross II and IV; for grain yield per plant in cross I. Additive x dominance type of gene effect (j) was positive significant for days to 75% heading in cross III; for days to maturity in cross II and III; for plant height in cross III; tillers per plant in cross II; for grain per spike and seed per plant in cross III and grain yield in cross IV. Dominance x dominance effect (l) were positively significant for days to 75% heading, plant height in cross I; for plant height in cross III, IV and V; for tillers per plant in cross II and for grains per spike in cross IV and V; seed per plant, grain yield in cross IV. Therefore, it has been suggested that selection of studied characters based on different gene action of generation mean to be used further crop improvement through ideal breeding programme.

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.

Estimate of the genetic parameters, gene effects through generation mean analysis in two faba bean crosses were carried out at the Fac. Agric. Edu. Farm, Minia University, Egypt during three successive seasons 2015/18. Heritability values in broad sense were higher than heritability in narrow sense for all traits in both crosses. Heterosis over better parent, mid parents and inbreeding depression were positive for all traits in the two crosses. Degree of dominance was higher than one for all traits in both crosses. The significant positive additive gene effect for days to 50% flowering DF and plant height PH in cross I and biological yield BY/P and 100 seed weight 100 SW in cross II, indicates effective selection for these traits. Values of dominance effects were greater the additive effects for all traits. Complementary epistasis type for traits like PH and no. seeds/plant NS/P in cross I and DF, PH and 100 SW in cross II indicates that the two selected parents for crossing are different. For this reason, it is possible to achieve genetic advance in breeding programme of these traits. Duplicate epistasis type was predominant than complementary epistasis type in different traits in the two crosses. Hence, recurrent selection could be improved of these traits in advanced generations.

Availability of multiple-stress tolerant maize is critical for improvement in maize production in West and Central Africa (WCA). A study was carried out to (i) assess a set of inbred lines for combining ability under stressed and optimal conditions, (ii) determine the performance of the testcrosses under different conditions, and (iii) identify outstanding hybrids across the conditions. Two hundred and five testcrosses were planted with five hybrid checks under Striga-infested, low soil nitrogen, drought and optimal conditions between 2015 and 2016 in Nigeria. The grain yield inheritance under optimal condition was largely regulated by additive gene effect whereas non-additive gene effects largely regulated grain yield under the three stresses. Four of the inbreds had significant positive general combining ability effects each under low N and drought, and three under Striga infestation for grain yield. The inbreds could be vital sources of beneficial alleles for development and improvement of tropical yellow maize hybrids and populations. Hybrids TZEI 443 x ENT 13 and TZEI 462 x TZEI 10 were high yielding and stable; they out-performed the three early maturing released hybrids in WCA. The new hybrids should be extensively assessed and released in the sub-region to improve food security.

To improve brown planthopper (Nilaparvata lugens Stal; BPH) resistance of an elite indica cultivar of South China, Hemeizhan (HMZ), we applied marker-assisted backcross (MABC) to incorporate three BPH-resistance genes (Bph3, Bph14 and Bph15) into the genetic background of HMZ. In the third backcross (BC3) generation, we obtained near-isogenic lines (Bph3-NIL, Bph14-NIL, Bph15-NIL and Bph14 + Bph15-NIL) with more than 96% recovery of recurrent parent genome, and pyramided lines (Bph3 + Bph14-PYL, Bph3 + Bph15-PYL and Bph3 + Bph14 + Bph15-PYL) with more than 89% recovery of recurrent parent genome. These lines showed stronger resistance against BPH than HMZ at seedling and booting stages. The rank of resistance gene effect was Bph3 + Bph14 + Bph15 ≥ Bph3 + Bph15 ≥ Bph3 +Bph14 ≥ Bph14 + Bph15 ≥ Bph3 ≥ Bph15 ≥ Bph14 > none. Compared with HMZ, only Bph3 + Bph14 + Bph15-PYL had a significant difference in yield per plant, and the lines carrying Bph3 had higher amylose contents, indicating that Bph3 was tightly linked to Wxa allele. These improved lines are good intermediate sources of broad-spectrum and durable BPH resistance to improve other indica cultivars. Our results demonstrate that MABC is a very efficient approach to improve BPH resistance of elite rice cultivar.

Forage sorghum (FS; Sorghum bicolor (L.) Moench) is growing in popularity as an important forage crop replaced corn (Zea mays L.) in semi-arid regions of the world. FS can further be divided into white midrib (WMR), green midrib (GMR) and brown midrib (BMR) populations based on the color of leaf midrib. Understanding expression of nutritive values in different FS populations is essential to the breeding and utilization of the new FS varieties with high quality. A field experiment was conducted in 2012 and 2013 in order to analyze the change regulation of nutritive values and compare the differences in photosynthetic indexes and anatomy parameters among WMR, GMR, BMR-6 and BMR-12 forage sorghum populations. The results showed that there were significant (P 0.05) were observed in photosynthetic indexes. When compared with non-BMR populations (WMR and GMR), the mean ADL, NDF and ADF content of BMR populations (BMR-6 and BMR-12) were decreased respectively by 28.0%, 4.1% and 5.8% while the mean CP content was increased by 8.0% during the two years. Especially, BMR-12 populations had significantly (P BMR-6 > GMR > WMR. In conclusion, the BMR populations, particularly BMR-12, had exhibited consistently higher nutritive values since joint stage (the average plant height was about 130 cm). This result further reinforces the advantages of BMR gene effect in populations and also will provide scientific data for rational utilizing BMR forage sorghum resources in practice.

The present investigation was carried out to estimate the genetic parameters for ten traits in ricebean genotypes. Fourteen genotypes of ricebean (Vigna umbellata (Thunb.) were collected from different regions of country were evaluated for yield and its components. The study revealed that the phenotypic coefficient of variation (PCV) was higher than genotypic coefficient of variation (GCV) for all traits. The value of PCV and GCV was higher for seed yield/plant, 100 seed weight and number of pods/plant. Heritability values were high for all the traits except leaflet size and pod length. High genetic advance was observed for days to 50% flowering, number of pods and seeds /plant, days to maturity, suggest that scope for improvement of these characters through selection. High heritability coupled with high genetic advance was registered for 50% flowering, number of pods and seeds /plant indicate that the genetic variance for these traits are probably owing to their high additive gene effect and thus there is better scope for improvement of these traits through direct selection. Therefore selection based on these characters will bring the desired improvement in seed yield of ricebean. With respect to mean performance of genotype, PRR-2, PRR-1 and PRR-2011- 1 was found superior among all the genotypes.

The experiment was conducted to study general and specific combining ability (GCA and SCA) and to estimate heterosis estimation at experimental farm of Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur during T. Aman, 2006 and 2007 seasons. Eleven rice parental lines consisting of two quasi CMS lines in BC3 generation as lines and nine restorer lines as testers along with their eighteen F1s and a check variety (BRRI dhan37) were used for combining ability study in a line x tester mating design for eight characters. Ratio of general combining ability (GCA) to specific combining ability (SCA) variances above unity were observed for 1000-grain weight(g) indicating predominance of additive gene action for controlling the character. Among mother parents, CMS-1 appeared as good general combiner for panicle length, 1000-grain weight(g), and grain length–breadth ratio. Among male parents, Benaful, Oval Tapi and Sorukamini-1 were observed to be good general combiners for most of the characters studied. The cross combinations, CMS-1 × Kataribhog, CMS-2 × Maloti-1 and CMS-2 × Keora were found as good specific combiners for most of the characters under study. Good specific combiners were evolved from all kinds of combinations of general combiners indicating additive and non-additive types of gene effect for inheritance. Maximum hybrids showed desired significant standard heterosis for panicle length and 1000-grain weight. None of the hybrids showed desired and significant standard heterosis simultaneously for any three or more characters.

The understanding of the generated hybrids’ breeding value gives a measure of probable advances in a breeding program. Four cocoa genotypes (testers) were crossed with two distinct lines (T65/7 and T86/2). The parents and the hybrids were separately established in randomized complete block design with six replications. The fourteen genotypes were evaluated for pod length (PL), weight (PW), beans/pod (NoB), bean length (BL), width (Bwi) and thickness (BT). The treatment, parent, crosses and Line x Tester sources of variation were significant (P ≤ 0.05). Hybrids from the same maternal parent differed significantly (P < 0.05) for the six traits. Contribution to the total variance of PL, PW and Bwi were in the following order: Tester > Line x Tester > Lines. The highest general combining ability (0.42) occurred in T65/7 for PW; the least (-0.081) occurred in T86/2 for PL. Cross combination T65/7xT57/22 produced the highest specific ability of combination (4.33) for NoB. Variance of GCA and SCA were significant (P < 0.05) for the six traits. The GCA/SCA ratios revealed the inheritance of PL, PW, Bwi and BT to be additive. Non-additive gene effect controlled NoB and BL. Heterosis for the six traits ranged between -17.82% for BT (T65/7xT57/22) to 52.40% for PW (T65/7xT53/8). Increased productivity in cocoa is possible through hybrid breeding programs.

Five two-row winter barley (Hordeum vulgare L.) cultivars divergent in spike traits were crossed in all possible combinations excluding reciprocals to produce 10 F1 and F2 hybrids for analysis of combining abilities. The analysis of variance of combining abilities showed significant differences for GCA and SCA in F1 hybrids and F2 generation, suggesting additive and non-additive gene action. The GCA/SCA ratio in F1 and F2 indicated the prevalence of the additive component of genetic variance for spike length, grain weight per spike and spike harvest index. By contrast, the SCA variance for grain weight per spike was higher than the GCA variance, indicating the dominance of non-additive gene action. Good GCAs were found in parents having high values for spike length (Djerdap, NS-293), grain number per spike (Vada, Jagodinac), grain weight per spike (Vada, NS-293) and spike harvest index (Djerdap, Jagodinac). None of the parents had good GCA for all traits, suggesting a potential increase in combining abilities for spike traits. The best SCA were obtained mostly from crosses between parents having high x low, high x high or average x low GCA values. Parents having high GCA values may be used to produce improved lines in hybridisation programmes. Combinations with high SCA values may yield good segregating lines in further selection programmes.

We sought the novel concept, transcript capacity (TC) and analyzed TC. Our approach to estimate TC was through an in silico method. TC refers to the capacity that a transcript exerts in a cell as enzyme or protein function after translation. We used the genome-wide association study (GWAS) beta effect and transcription level in RNA-sequencing to estimate TC. The trait was body fat percent and the transcript reads were obtained from the human protein atlas. The assumption was that the GWAS beta effect is the gene's effect and TC was related to the corresponding gene effect and transcript reads. Further, we surveyed gene ontology (GO) in the highest TC and the lowest TC genes. The most frequent GOs with the highest TC were neuronal-related and cell projection organization related. The most frequent GOs with the lowest TC were wound-healing related and embryo development related. We expect that our analysis contributes to estimating TC in the diverse species and playing a benevolent role to the new bioinformatic analysis.

Amylose content (AC) and grain appearance traits of rice (Oryza sativa L.) represent a major problem of rice marketing in many rice producing areas in the world. In Uganda, cooking, eating and appearance qualities remain undefined in the rice breeding programme. The objective this study was to determine amylose content of rice genotypes, and its relationship with grain appearance traits; and mode of its inheritance in selected rice genotypes. Forty genotypes were planted in two seasons (2015B and 2016A), in alpha lattice design at National Crop Resource Research Institute in Uganda. Seven parents, involving 3 low and 4 intermediate amylose content genotypes selected in 2015B season,were crossed in a half diallel,and the F1 were advanced to F2 generation, which together with parents were planted in the field. Amylose content (AC), kernel width (KW) and kernel length (K/L) to width ratio were affected by both genetic effects and genotype by season (G x S) interactions; while kernel length was mainly affected by genetic factors. Genotypes were grouped into low, intermediate and high amylose content categories depending on the environment where the genotypes were grown. Three genotypes (Namche 1, P62H17 and 1190) had no significant responsesin amylose content in different growing seasons, suggesting that these genotypes were stable. Amylose content correlated weakly and negatively with physical appearance quality traits of the grain; implying that improvement in amylose content would not affect grain size and shape.There were significant differences (P

The aim of this study was to determine the gene effect of Growth Hormone (GH) on divergent selection of Japanese quail. Quails were grouped into high weight (Q-H), low weight (Q-L) and random weight (Q- R) females as a treatment for divergent selection. Parameter phenotype observed in each generation is the weight at four weeks of age and egg production at ten weeks of age for five generations. The results showed that the dominance level on body weight of Q-L was incomplete dominance, Q-R was over dominance and Q-H was lack of dominance. While the dominance level on egg production of Q-L and Q-H were over dominance and Q-R was lack of dominance. The gene effect of GH on body weight of Q-H is 1.53 times greater than the Q-L and 12.37 times greater when compared with Q-R. Whereas the gene effect of GH on egg production of Q-H is 1.53 times greater than the Q-L but only 4 times greater when compared with Q-R. Should be developed that to increase the low-weight (Q-L) is in the BB genotype and the high weight (Q-H) is in the AA genotype groups. Otherwise, to increase the low-weight (Q-L) and high-egg production are in the AA and BB genotypes and the high weight (Q-H) and low-egg production are in the AA and AB genotypes groups

Leptin, the product of the ob gene, is secreted mainly in adipose tissue. Due to the associations between plasma leptin concentrations and body fat, leptin could be used as an indicator for the in vivo evaluation of carcass composition in breeding programs. Previous studies showed relation between leptin concentrations and some trace elements, suggesting that they might be mediators of leptin production. The present study was designed to evaluate the effect of single nucleotide polymorphism of the leptin gene on concentration of trace elements in the serum of 58 Czech Pied bulls. Three experimental groups of bulls were formed depending on different leptin genotypes: group CC (n = 28), group CT (n = 21) and group TT (n = 9). In all groups, the age (at a mean age of 240 days) and the body weight (mean 291 ± 11 kg) difference among the chosen animals was non-significant. Blood samples of all bulls in experimental groups were collected from vena jugularis externa between 8.00 and 9.30 h. Concentrations of copper, zinc and iron in the serum of animals were measured. Significantly lower (P < 0.05) zinc concentrations were recorded in bulls of TT group (13.21 ± 1.81 µmol·l-1) compared to CC (20.09 ± 1.11 µmol·l-1) and CT group (19.67 ± 1.45 µmol·l-1). In case of copper and iron concentrations in serum of animals, no differences were recorded between the tested groups. This is the first study of its kind in Czech Pied cattle. Based on our results, we may assume that zinc plays some role in the metabolism of adipose tissue, havings an effect on beef quality.

Days to flowering, plant height and head diameter are significant parameters which are directly or indirectly correlated with yield, main trait of sunflower. Eight CMS lines, three testers and their twenty four hybrids were examined by line x tester method. Significant differences were found between lines, testers and hybrids. Results showed that lines PD-3 and PD-25 had good combining abilities for the trait of days to flowering (58 days and 65 days, respectively). In the expression of plant height best combiners were PD-2 (107.5 cm) and PD-3 (108.7 cm). For head diameter lines PD-52 (24.5 cm) and MA-57 (23.2 cm) were marked as good combiners. Variance of SCA was greater than variance of GCA for all the traits. CMS lines had the greatest part in the expression of the analyzed traits. Non-additive type of gene effect was reported for all examined traits, which implies that they could be improved through heterosis breeding. Broj dana do cvetanja biljke, visina biljke i prečnik glave su značajni parametri koji su direktno ili indirektno povezani sa prinosom, glavnim svojstvom suncokreta. Osam CMS linija, tri testera i njihovih dvadeset četiri hibrida ispitivano je metodom linija x tester. Značajne razlike su nađene između linija, testera i F1 hibrida. Rezultati su pokazali da dobre kombinacione sposobnosti za svojstvo broj dana do cvetanja poseduju linije PD-3 (58 dana) i PD-25 (65 dana). U ispoljavanju visine biljke kao najbolji kombinatori su se pokazale linije PD-2 (107,5 cm) i PD-3 (108,7 cm). Za prečnik glave linije PD-52 (24,5 cm) i MA-57 (23,2 cm) su označene kao dobri kombinatori. Najveći značaj u ispoljavanju navedenih svojstava imale su CMS linije. Varijansa uzrokovana PKS je bila veća od varijanse uzrokovane OKS za sva svojstva. Neaditivan efekat gena je zapažen u ispoljavanju svih ispitivanih osobina, što pokazuje da one mogu biti poboljšane metodom oplemenjivanja na heterozis.

Half diallele analysis was used to identify the high heterotic crosses and their relationship in terms of general combinig ability (GCA) and specific combining ability (SCA) of 6 roselle cultivars evaluated in two locations Yola and Mubi, located within latitude 7 0 14' North, Longitude 12 0 38' East and Latitude 10 0 03' North, Longitude 13 0 07' East respectively in Adamawa State, Nigeria. The results showed significant entries, parents and crosses for all the traits studied in the individual and also in the poolled analysis, suggesting that roselle populations were highly variable for all the traits and therefore would most likely respond to selection. Significant GCA and SCA variances were also obtained in all the traits implying that both the additive and non- additive gene effects were operating in the genetic expression of the traits. The non-additive gene effect was however greater in magnitude as shown by the δ 2 GCA/δ 2 SCA ratios, which were all less than unity. The combining ability analysis of parents also revealed that Gerio-AB3, Bazza-AB2 and Bazza-AB1 yielded consistently higher general combining ability effect for most of the traits, indicating that their crosses should produce desirable segregates for the improvement of calyx yield of roselle. SCA effects identified Bazza-AB2 x Gerio-AB2, Bazza-AB1 x Gerio-AB3 and Bazza-AB1 x Michika-AB1 as the best crosses. The hybrid Bazza-AB2 x Gerio-AB2 exhibited heterosis of up to 46.01 % over the higher yielding parent.

Rapeseed ( Brassica napus L.) with purple-red leaf is a valuable resource for plant breeder. It was utilized in breeding program as a morphological marker, and the source of resistance gene to biotic or abiotic stress due to its anthocyanin content (AC). However, the inheritance of AC and the correlation with chlorophyll content (CC) in rapeseed leaf are still unknown. This study aimed to investigate the gene action and heritability of AC and CC in a 10-Zi006 × 10-4438 rapeseed cross using generation mean analysis. The results indicated that AC and CC were controlled by main gene effect and non-allelic interactions. The AC was mainly controlled by genetic effect. However, the genetic effect and non-genetic effect were both important for CC. In addition, the total fixable gene effects was higher than unfixable gene effects for AC, but opposite results was found for CC. Both negative and positive correlations between AC and CC were obtained in different generations. RESUMO: Colza ( Brassica napus L.) de folhas vermelho-púrpura é um recurso valioso para os produtores. Foi utilizada em programas de melhoramento como um marcador morfológico ao gene de resistência a estresses abióticos, bióticos ou devido ao seu teor de antocianinas (AC). No entanto, a herança da AC e a correlação com o teor de clorofila (CC) na folha de colza ainda são desconhecidos. Este estudo teve como objetivo investigar a ação dos genes e hereditariedade da CA e CC em 10 Zi006 × 10-4438 colza, usando geração de análise. Os resultados indicaram que CA e CC foram controladas por efeito do gene principal e interacções não-alélicas. O AC foi controlado principalmente por efeito genético. No entanto, os efeitos genético e não genético foram ambos importantes para CC. Além disso, o total de efeitos gênicos solucionáveis foi maior do que os efeitos de genes para AC, mas os resultados opostos foram encontrados para CC. Correlações negativas e positivas entre CA e CC foram obtidas em diferentes gerações.

espanolLos efectos del gen BMP15, localizado en el cromosoma X, sobre la media y la variabilidad de la prolificidad fueron estimados en la poblacion Rasa Aragonesa, donde se analizaron 918.956 partos de ovejas de distintos genotipos (heterocigotas para el alelo FecXR o ROA®; y no portadoras). En primer lugar, se utilizaron modelos umbral que incluian o no el efecto del gen para estimar el efecto del genotipo BMP15 y su contribucion a la variabilidad genetica de la prolificidad en esta poblacion. Tambien se utilizaron otros dos modelos para estimar las interacciones entre el genotipo y los poligenes, asi como el efecto del genotipo sobre la variabilidad de la prolificidad. Todos los analisis se hicieron con el programa ASReml. El efecto del genotipo sobre la media fue de 0,32 corderos adicionales por parto cuando el alelo ROA® se encontraba presente. Debido a que durante muchos anos la seleccion por prolificidad en esta poblacion se ha llevado a cabo desconociendo la presencia de esta mutacion, los animales selectos portadores tienen un valor genetico poligenico residual mas bajo que los no portadores. No se encontro interaccion significativa entre el genotipo y los efectos poligenicos sobre el valor genetico. Aunque la interaccion entre el genotipo y el conjunto de umbrales fue significativa, la diferencia entre ambos genotipos en la varianza de la prolificidad sobre la escala observada a una prolificidad media dada es escasa y muy poco relevante EnglishThe effects of the BMP15 gene, located on the X chromosome, on mean prolificacy and its variability, were estimated in the Rasa Aragonesa sheep population through the analysis of 918,956 lambing records from ewes of different genotypes (FecXR or ROA® heterozygous ewes; and non-carrier ewes). Threshold models including or not the gene effect were first run to determine the effect of the BMP15 genotype and its importance in the total genetic variability of prolificacy. Two other models were also run to estimate the interaction between the BMP15 genotype and the polygenic background, as well as the effect of the genotype on the variability of prolificacy. All the models were run using the ASReml software. The effect of the presence of the ROA® allele of the BMP15 gene on the mean prolificacy was 0.32 extra lambs per lambing. Due to the selection on prolificacy performed during many years in this population ignoring the presence of this major gene, animals carrying the mutation were found to have lower remaining polygenic estimated breeding values than non-carrier animals, and there was no interaction between the BMP15 genotype and the polygenic background. Although the interaction between the genotype and the set of thresholds was significant, the resulting between-genotypes difference of variance of prolificacy on the observed scale, at a similar mean litter size, was very low and not relevant

Mode of inheritance and genetic variance components for spike length, grain number per spike and grain weight per spike were evaluated in four parental genotypes and their F1 and F2 hybrids obtained through incomplete diallel crossing. Multi-rowed barley genotypes HVW-247 and Partizan and two-rowed barley genotypes KG-15 and NS-293 were selected for the crossing based on the trait concept with the parents being divergent for spike length, grain number per spike and grain weight per spike. The average values for spike length in F1 and F2 generations were intermediate or close to those of the parent having longer spikes, with the mode of inheritance being partial dominance, dominance or overdominance, depending on the crossing combination. The six-rowed x six-rowed and two-rowed x two-rowed crossing combinations showed dominance of increased grain number per spike and increased grain weight per spike in the inheritance of grain number per spike and grain weight per spike, respectively, whereas the six-rowed x two-rowed cross was predominated by partial dominance. [Projekat Ministarstva nauke Republike Srbije, br. 031092: A study of the genetic basis of yield and quality improvements in cereals under different agro-environmental conditions]

This investigation was carried out at Etay El- Barod research station. Five populations (P1, P2, F1, F2 and F3) for three cross namely Sakha 93 x Line32, Giza 168 x Line 42 and Sakha 93 x Giza 168 were used in this investigation to study the genetic behavior of yield and its components. Significant positive heterotic effects were obtained for most of the characters studied in the F 1 generations. However, significant negative heterotic effects were found for all other characters except for no.of spikes/plant in the first and third crosses, and no.of spikes/plant ,and grain yield/plant, in the second cross. Inbreeding depression estimates were found for kernels weight in the first cross, no.of kernels/spikes and kernels weight in the second cross, no.of spike/plant and grain yield/plant in the third one. The (additive, and additive x dominance )gene effects were significant for number of spikes/plant, number of kernels/spike and grain yield/plant in the second cross. Dominance gene effect (h) was significantly positive for number of kernels/spike and grain yield/plant in the three crosses. Significance of these components indicated that, both additive and dominance gene effects are important in the inheritance of these characters. In addition, dominance and epistasis were found to be significant for most of the studied attributes. Moreover, high to medium values of heritability estimates were associated with high and moderate expected and actual gain in most studied characters. These obtained results prove that selection for the studied characters could be used in the early generations but would be more effective if postponed to late ones.

With 1 figure and 6 tables Abstract Heritability and gene effect estimates for components of partial resistance to grey leaf spot were evaluated in Eastern Tanzania, using three populations derived from grey leaf spot partial-resistant maize inbred lines K36 and P103 and susceptible inbred lines CML 395-5 and L37 by generation mean analysis. Populations included the resistant parents (P1), susceptible parents (P2), F1 and F2 generations and backcross BC1 and BC2 generations. Significant differences between generations, crosses and generation × cross and generation × location interactions were detected. Measurements for components conferring partial resistance to grey leaf spot behaved in a quantitative manner. The magnitude of additive, dominance and epistatic effects varied between crosses and components. Broad- and narrow-sense heritability estimates were high for disease severity, lesion length and lesion size but lower for incubation period. Results have shown that lesion size, lesion length, lesion numbers and disease severity could be used for selection of partial resistance to grey leaf spot based on field measurements.

Technological meat quality is a significant economic factor in pork production, and numerous publications have shown that it is strongly influenced both by genetic status and by rearing and slaughter conditions. The quality of meat is often described by meat pH at different times postmortem, as well as by color and drip loss, whereas carcass quality is often characterized by lean percentage. A meta-analysis of findings relating to 3,530 pigs reported in 23 publications was carried out to assess the effects of the halothane gene, sex, breed, and slaughter weight of animals on 7 selected variables: pH at 45 min postmortem, ultimate pH, reflectance (L*-value), redness (a*-value), yellowness (b*-value), drip loss, and lean percentage. Two statistical methods were used in the meta-analysis: the method of effect size and the better known random effects model. The method of effect size was associated with Markov chain Monte Carlo techniques for implementing Bayesian hierarchical models to avoid the problems of limited data and publication bias. The results of our meta-analysis showed that the halothane genotype had a significant effect on all analyzed pork quality variables. Between-study variance was evaluated with the Cochran (1954) Q-test of heterogeneity. Meta-regression was used to explain this variance, with covariates such as breed, sex, slaughter weight, and fasting duration being integrated into different regression models. The halothane gene effect was associated with the breed effect only for the following variables: L*-value, b*-value, and drip loss. Slaughter weight contributed significantly only to the explanation of differences in ultimate pH between homozygous genotypes. In response to inconsistencies reported in the literature regarding the difference between the genotypes NN and Nn, results of the meta-analysis showed that the difference between these 2 genotypes was significant for all the analyzed variables except the a*-value.

Field trials were carried out at the Experimental Research Station of Desert Research Center at Ras Sudr , South Sinai Governorate during 2003 and 2004 seasons . This investigation aimed to improve tomato genotypes for salinity tolerance in SuperMarmand and CastleRock and marketable characters in exotic genotypes LA1673 and LA1963 and Edkawy the results indicated that Edkawy genotypes was superior than the other tomato genotypes in plant height, number of fruits/ plant, number of locules / fruit and total soluble solids in fruit under saline condition. While, the two local genotypes of tomato SuperMarmand and Castle Rock were earlier and heavier than the other studied genotypes in early yield, average weight / fruit and total yield / plant . The crosses Edkawy × LA 1673 , SuperMarmand × LA 1963 and LA 1673 × LA 1963 recorded positive and significantly heterosis for average fruit weight . Both additive and non-additive gene actions were involved in the genetic control of each plant height, number of fruits/ plant, early yield , number of locules/ fruit, average fruit weight , total soluble of solids ( TSS ) and total yield/plant. Non-additive gene effects were more important than additive ones for all studied characters except average fruit weight and total yield/ plant, where additive gene effect was more important in the inheritance of both characters . Heritability in broad sense for all the studied characters were high and ranged from (64.55%) for total soluble of sugar in fruit to (88.4%) for average of fruit weight. Whereas, heritability in narrow sense was moderate (39.51%) for total soluble of solids (TSS) and high ( < 50 % ) for the remaining characters under study . Positive and highly significant GCA effects were recorded for plant height and number of locules / plant in Edkawy and LA1673 ; number of fruits / plant , early yield and TSS in Edkawy and castle Rock as well as average fruit weight and total yield / plant in castle Rock and SuperMarmand. The cross Castle Rock × LA 1963 was the heaviest average fruit weight and the followed that cross Edkawy × LA 1673 and Edkawy × Castle Rock were positive and significantly SCA effects. While, the crosses SuperMarMand with each of LA 1673 and LA1963 respectively were positive and significantly SCA effects for total soluble of sugar (TSS). The crosses Castle Rock × SuperMarmand and Castle Rock × LA 1673 were the heaviest grain yield/ plant and highly significant positive for combing ability SCA effect under saline condition in irrigation water at Ras Sudr region.

Estimation of gene action through partioning of genetic variance was carried out, using the parents, F1, F2 and F3 populations in the cross Giza 90 x Pima S62 (24202). Results showed that the heterotic effects relative to better parent (useful heterosis) were positive and highly significant or significant for all studied characters except for First Fruiting Node (FFN), boll weight (BW), micronair value (Mic), Fiber strength (St) and Fiber elongation (Elon %), while days to first flower (DFF) recorded highly significant better parent heterosis value. Mid-parent heterosis values were highly significant and negative for days to first flower (DFF) and boll weight (BW). On the other hand, the remaining traits revealed positive and highly significant or significant heterotic effects except for First Fruiting Node (FFN), lint percentage (L %), micronair value (Mic) and Fiber elongating (Elon %) which showed insignificant heterotic effects. Inbreeding depression was positively significant and highly significant for all traits except for boll weight (BW), micronair value (Mic) and Fiber elongation (Elon %). On the other hand First Fruiting Node (FFN) and days to first flower (DFF) recorded negatively significant inbreeding depression. Regarding potence ratio, partial dominance values were obtained for all studied traits except for days to first flower (DFF), seed cotton yield/plant (SCY/P), lint yield/plant (LY/P), Fiber strength (St) and upper half mean length (UHM) which recorded over dominance. Concerning the type of gene effects, the additive gene effects were negative and highly significant for days to first flower (DFF), Fiber strength (St) and upper half mean length (UHM), while lint yield/plant (LY/P), lint percentage (L%) and Fiber elongation (Elon %) showed positive significant and highly significant for additive gene effect. Dominance gene effects were positive and highly significant or significant for days to first flower (DFF), seed cotton yield/plant (SCY/P), lint yield/plant (LY/P), Fiber strength (St) and upper half mean length (UHM) and boll weight (BW), respectively. On other hand, Fiber elongation (Elon %) trait showed highly significant negative dominance gene effect. Additive x additive gene type of epistasis effects were highly significant for seed cotton yield/plant (SCY/P), lint yield/plant (LY/P) and lint percentage (L%), while first fruiting node (FFN), days to first flower (DFF), boll weight (BW), micronair value (Mic), Fiber strength (St), uniformity index (UI), upper half mean length (UHM), seed index (SI) and lint index (LI) recorded negatively highly significant and significant epistatic of gene effects. With regarded to the dominance x dominance interaction, the values were positive and highly significant for all studied traits except for seed index (SI), lint index (LI) and uniformity index (UI). High values of broad sense heritability (over 50%) were detected for first fruiting node (FFN), boll weight (BW) and Fiber elongation (Elon %). Moderate heritability estimates (between 30% and 50%) were found for seed cotton yield/plant (SCY/P), lint yield/plant (LY/P), seed index (SI), lint index (LI), micronair value (Mic), uniformity index (UI) and upper half mean length (UHM). Low broad sense heritability values (less than 30%) were obtained for days to first flower (DFF), lint percentage (L %) and Fiber strength (St). Narrow sense heritability estimates were calculated for lint index (LI), Fiber strength (St), uniformity index (UI) and upper half mean length (UHM), which exceeded 50% value. Moderate heritability estimates were observed for first fruiting node (FFN), seed cotton yield/plant (SCY/P) and lint percentage (L %). On the other hand low heritability values in narrow sense were obtained for days to first flower (DFF), boll weight (BW), lint yield/plant (LY/P), seed index (SI), micronaire value (Mic) and Fiber elongation (Elon %). The expected genetic advance from selecting the desired 5% of F2 population was 56.098, 71.687, 29.399 and 48.12 for first fruiting node (FFN), days to first flower (DFF), lint yield/plant (LY/P) Fiber elongation (Elon %) and upper half mean length (UHM), respectively. Regression of F2/F3 results exhibited high values for first fruiting node (FFN), seed cotton yield (SCY/P), lint yield/plant (LY/P), lint percentage (L %), uniformity index (UI) and upper half mean length (UHM), indicating that the higher values due to the additive genetic variance. Positively highly significant or significant correlation coefficient was observed between days to first flower (DFF) with first fruiting node (FFN), seed cotton yield/plant (SCY/P) with boll weight (BW), lint yield/plant (LY/P) with seed cotton yield/plant (SCY/P), lint percentage (L%) with lint yield/plant (LY/P), lint index (LI) with lint percentage (L%) and Fiber strength (St), micronair value (Mic) with lint index (LI), Fiber elongation (Elon%) with Fiber strength (St) and upper half mean length (UHM) with days to first flower (DFF), lint percentage (L%) and uniformity index (UI). Negative significant or highly significant correlation coefficient were recorded between seed cotton yield/plant (SCY/P) with days to first flower (DFF), seed index (SI) with seed cotton yield/plant (SCY/P) and lint yield/plant (LY/P). It could be concluded that the selection improvement of first fruiting node (FFN), seed cotton yield (SCY/P), lint percentage (L%), seed index (SI), uniformity index (UI) and upper half mean length (UHM) traits could be achieved in early segregating generations, but the other traits need intensive selection in later generations.

O objetivo deste trabalho foi estudar o controle genético do caráter comprimento do pedúnculo em feijão-caupi (Vigna unguiculata). Para isso, foi realizado um cruzamento entre os parentais TVx-5058-09C, de pedúnculo curto, e TE96-282-22G, de pedúnculo longo. Os parentais e as gerações F1, F2, RC1 (P1xF1) e RC2 (P2xF1) foram avaliados em delineamento de blocos ao acaso, com quatro repetições. Foram estimados: variâncias fenotípica, genotípica, ambiental, aditiva e de dominância; herdabilidades no sentido amplo e restrito; grau médio de dominância e número mínimo de genes que determinam o caráter. O modelo aditivo-dominante foi adequado para explicar a variação observada. O efeito gênico aditivo foi o mais importante no controle do comprimento do pedúnculo, que é, aparentemente, controlado por cinco genes. The objective of this work was to investigate the genetic control of peduncle length in cowpea (Vigna unguiculata L.). A short peduncle cowpea line (TVx-5058-09C) was crossed with a long peduncle line (TE 96-282-22G). The parents and the F1, F2, RC1 (P1xF1), and RC2 (P2xF1) generations were evaluated in randomized block design with four replications. Genotypic, phenotypic, environmental, additive, and dominance variances for peduncle length were determined. Narrow and broad sense heritability, the degree of dominance, and the minimum number of genes determining peduncle length were estimated. The additive-dominant model was adequate to explain the observed variation. The additive gene effect was the most important in controlling peduncle length, which appeared to be controlled by five genes.

International audience; The basic principle of Marker-Assisted Selection (MAS) is to exploit Linkage Disequilibrium (LD) between markers and QTLs. With strong enough LD, MAS should in theory be easier, faster, cheaper, or more efficient than classical (phenotypic) selection. I briefly review the major MAS methods, describing some ‘success stories’ where MAS was applied successfully in the context of plant breeding, and detailing other cases where efficiency was not as high as expected. I discuss the possible causes explaining the difference between theoretical expectations and practical observations. Finally, I review the principal challenges and issues that must be tackled to make marker-assisted selection in plants more effective in the future, namely: managing and controlling QTL stability to apply MAS to complex traits, and integrating MAS in traditional breeding practices to make it more economically attractive and applicable in developing countries.

QTLs for salt-tolerance (ST) related traits at the seedling and tillering stages were identified using 99 BC(2)F(8) introgression lines (IL) derived from a cross between IR64 (indica) as a recurrent parent and Binam (japonica) from Iran as the donor parent. Thirteen QTLs affecting survival days of seedlings (SDS), score of salt toxicity of leaves (SST), shoot K(+) concentration (SKC) and shoot Na(+) concentration (SNC) at the seedling stage and 22 QTLs underlying fresh weight of shoots (FW), tiller number per plant (TN) and plant height (PH) at the tillering stage were identified. Most QTLs detected at the tillering stage showed obvious differential expression to salt stress and were classified into three types based on their differential behaviors. Type I included 11 QTLs which were expressed only under the non-stress condition. Type II included five QTLs expressed in the control and the salt stress conditions, and three of them (QPh5, QPh8 and QTn9) had similar quantity and the same direction of gene effect, suggesting their expression was less influenced by salt stress. Type III included six QTLs which were detectable only under salt stress, suggesting that these QTLs were apparently induced by the stress. Thirteen QTLs affecting trait difference or trait stability of ILs between the stress and non-stress conditions were identified and the Binam alleles at all loci except QPh4, QTn2 and QFw2a decreased trait difference. The three QTLs less influenced by the stress and 13 QTLs affecting trait stability were considered as ST QTLs which contributed to ST. Comparing the distribution of QTLs detected at the seedling and tillering stages, most (69%) of them were genetically independent. Only four were the same or adjacent regions on chromosomes 1, 2, 8 and 11 harboring ST QTLs detected at the two stages, suggesting that partial genetic overlap of ST across the two stages occurs. It is likely, therefore, to develop ST rice variety for both stages by pyramiding of ST QTLs of different stages or selection against the overlapping QTLs between the two stages via marker-assisted selection (MAS).