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The article evaluated the genetics of six cucumbers (Cucumis sativus L.) cultivars and 30 hybrids based on morpho-yield traits. The dominant and epistatic gene effects managed the fruit weight in three cucumber hybrids (C-25/1, A-6, and A-9), while additive gene effects in three other hybrids were supreme. For productivity per plant, dominant genes with epistatic effects controlled these in three accessions, while additive effects played a special role in manifesting the trait in three other hybrid (C-25/1, A-6, and A-9) genes. Likewise, dominant genes with epistatic effects controlled the yield per plant trait in three accessions, while additive effects influenced the attribute in three other hybrids (C-25/1, A-6, and A-9). According to these traits, the promising hybrids were С-25/1 х С25/2, С-26 х С-25/2, С-26 х С25/1, А-9 х С-26, and А-6 х С-25/1. The cucumber F1 hybrids C-26 x C29, A-9 x A-6, and A-9 x C-25/2 showed characteristics of large fruits weighing 108.2 to 113.1 g. In the accessions, C-25/1, A-6, and A-9, the additive gene effects dominated the studied trait (σ2ĝi > σ2si). The superior-in-yield hybrid combinations were C-26 x C-29, A-9 x A-6, and A-6 x A-9, with a total fruit yield of 691 to 769 g per plant. [ABSTRACT FROM AUTHOR]

In Ecuador, introduced coffee cultivars were selected, but there is no history of new cultivars having been developed through conventional genetic improvement. The objective of this research was to obtain improved coffee genotypes for the southern area of Manabí, for this the coffee germplasm bank of the State University of Manabí, located at the Andil Farm, was used in the 2021 campaign, where they were obtained F1 hybrid families using nine parental accessions (Acawa, Arara, Yellow Burbon, Catimor CIFC, Yellow Catuai, Catucai 25L, Catucai 78515, Red Caturra and Geisha), which were recombined in a Griffin diallelic design, obtaining 1477 genotypes. On the same Farm, in the nursery in the 2022 - 2023 campaigns, the materials were planted in a completely randomized experimental design. The general combinatorial aptitude (GCA) and the specific combinatorial aptitude (SCA) were determined for plant height (PH), stem diameter (SD), number of pairs of leaves (NPL), leaf area (LA), heterosis and heterobeltiosis of parents and progenies. The results showed that the Typica parent was salient and significant for PH. SD and LA. The 021-105 family was outstanding for PH, NPL and LA. The GCA for PH, SD, NPL and LA of the parents was good. There was heterosis for PH, SD and LA, in families 021-101 and 021-104; and, heterobeltiosis for PH in families 021-105, 021-106, 021-, 021-108 and 021-109; and, for LA in families 021-105 and 021-109. Genotypes with potential to be future cultivars were identified. [ABSTRACT FROM AUTHOR]

Introduction. The selection of pure lines followed by crosses to create superior hybrids is one of the oldest strategies in crop breeding. Combining ability studies provide reliable information for selection of parents for hybrid combination by revealing the nature and magnitude of gene actions involved in expression of quantitative traits. Objective. To estimate the general and specific combining ability (GCA and SCA) values for yield in cherry tomatoes and select F1 hybrids combining high yield and fruit quality traits. Materials and methods. The half-diallel design, following method 2 of Griffing was used to define the best breeding method. Five lines were crossed to produce ten hybrid combinations using a half diallel design involving the parents. Crosses and evaluations were conducted in a greenhouse in the Experimental Station at the University of Diyala, Baqubah, Iraq, in the winter of 2022-2023. Results. Based on GCA effects, lines LA353, LA3899 and IQ2 could be potential donor parents in breeding. Based on average performance, heterosis manifested and SCA effects, crosses IQ2•LA4013, LA3899•LA353 and IQ2•LA3899 were best in respect to yield and fruit quality. Conclusion. The general and specific combining ability values for most of the traits supported the material’s great variety. The magnitude of heterosis was improved compared to parental lines. The high-yielding parent lines LA3899 and IQ2 could be used for breeding cherry tomatoes under greenhouse conditions.

This present work aimed to evaluate the self-incompatibility and self-compatibility behaviour of the Brazilian Feijoa Active Germplasm Bank accessions. The presence or absence of the self-incompatibility of the accessions was accessed through hand self-pollination. Out of 210 accessions evaluated from 2001 to 2018, 53.3% were registered as self-incompatible, while 46.7% were self-compatible with different degrees of self-compatibility based on the number of formed fruits. Subsequently, the fruit set as a result of inter-crosses between five self-incompatible accessions were evaluated. Fifty per cent of the reciprocal crosses exhibited similar productive efficiency based on fruit set. Self-incompatible accessions, although compatible with each other, revealed differences in restoration, based on the number of fruit and seeds between reciprocal crosses. Using Spearman's correlation (rs), significant association between the number of seeds and fruit set in fruits from hand self-pollination were detected in two harvests (rs= 0.64, rs= 0.72, respectively). There was also a positive correlation between the number of seeds and yield of pulp (%) in hand self-pollination (rs= 0.30; rs= 0.39, P < 0.01), hand cross-pollination (rs= 0.35, rs= 0.64) and open pollination (rs= 0.58, rs= 0.72), respectively. These associations suggest that the number of seeds could be directly related to the pulp yield and the self-compatibility of feijoa. [ABSTRACT FROM AUTHOR]

The development of hybrid plants can increase the production and quality of blue corn, and, thus, satisfy its high demand. For this development, it is essential to understand the heterotic relationships of the germplasm. The objectives of this study were to determine the effects of general (GCA) and specific (SCA) combining ability, as well as the reciprocal effects (REs) on the yields of 10 blue corn lines, and to select the outstanding lines. Diallel crosses were generated with 10 lines and evaluated at the Valle de México Experimental Station in Chapingo, Mexico, and Calpulalpan, Tlaxcala, Mexico. There were differences (p ≤ 0.01) in the hybrids, Loc, effects of GCA, SCA, and REs, and in the following interactions: hybrids × Loc, GCA × Loc, SCA × Loc, and RE × Loc. For GCA, lines Ll, L4, L6, and L9 stood out, with significant values of 3.4, 2.9, 2.9, and 3.1, respectively. For SCA, the hybrids featured were L4 × L10, L2 × L10, L1 × L10, L7 × L8, and L2 × L6, with values of 3.0, 2.5, 2.3, 2.3, and 2.2, and yields of 11.2, 10.2, 10.4, 10.4, and 10.5 t ha−l, respectively. There were no significant REs in these lines. Considerable effects of GCA and SCA were detected; therefore, we concluded that native populations had favorable dominance and additive genetic effects that could be used to support the development of high-yielding lines and hybrids. [ABSTRACT FROM AUTHOR]

Summary: Gene expression variation, an essential step between genotype and phenotype, is collectively controlled by local (cis) and distant (trans) regulatory changes. Nevertheless, how these regulatory elements differentially influence gene expression variation remains unclear. Here, we bridge this gap by analyzing the transcriptomes of a large diallel panel consisting of 323 unique hybrids originating from genetically divergent Saccharomyces cerevisiae isolates. Our analysis across 5,087 transcript abundance traits showed that non-additive components account for 36% of the gene expression variance on average. By comparing allele-specific read counts in parent-hybrid trios, we found that trans-regulatory changes underlie the majority of gene expression variation in the population. Remarkably, most cis-regulatory variations are also exaggerated or attenuated by additional trans effects. Overall, we showed that the transcriptome is globally buffered at the genetic level mainly due to trans-regulatory variation in the population.

The aim was to study the genetic control of the agronomic efficiency at low N availability in maize. Experiments were conducted in seven environments in a square lattice design with 49 hybrids, consisting of 48 crosses and one commercial hybrid, evaluated with and without application of N in top dressing. Grain yields with (GYHN) and without (GYLN) application of nitrogen in top dressing were assessed, and these traits were used to calculate the agronomic efficiency at low N availability (AELN) and the harmonic mean of the relative performance (HMRP). According to the joint analysis of variance of the diallel crosses and the estimates of the general and specific combining abilities, these traits were highly significant. Note that in general AELN was controlled by non-additive genetic effects and the hybrids H7, H3, H47 and H10 and the lines IG3-2, IG3-1, IG4-5, IG4-1 and IG4-6 show higher grain yield without top dressing. [ABSTRACT FROM AUTHOR]

The development of hybrid plants can increase the production and quality of blue corn, and, thus, satisfy its high demand. For this development, it is essential to understand the heterotic relationships of the germplasm. The objectives of this study were to determine the effects of general (GCA) and specific (SCA) combining ability, as well as the reciprocal effects (REs) on the yields of 10 blue corn lines, and to select the outstanding lines. Diallel crosses were generated with 10 lines and evaluated at the Valle de México Experimental Station in Chapingo, Mexico, and Calpulalpan, Tlaxcala, Mexico. There were differences (p ≤ 0.01) in the hybrids, Loc, effects of GCA, SCA, and REs, and in the following interactions: hybrids × Loc, GCA × Loc, SCA × Loc, and RE × Loc. For GCA, lines Ll, L4, L6, and L9 stood out, with significant values of 3.4, 2.9, 2.9, and 3.1, respectively. For SCA, the hybrids featured were L4 × L10, L2 × L10, L1 × L10, L7 × L8, and L2 × L6, with values of 3.0, 2.5, 2.3, 2.3, and 2.2, and yields of 11.2, 10.2, 10.4, 10.4, and 10.5 t ha−l, respectively. There were no significant REs in these lines. Considerable effects of GCA and SCA were detected; therefore, we concluded that native populations had favorable dominance and additive genetic effects that could be used to support the development of high-yielding lines and hybrids.

This study estimated the general and specific combining abilities and mean heterosis of tobacco lines of the varietal groups Flue-Cured Virginia (FCV) and Air-Cured Burley (BY). In addition, possible advantages and an improved strategy of using hybrids in tobacco breeding in the tropics were discussed. Ten BY and 13 FCV lines were crossed in a diallel mating design. The hybrids and parental lines were evaluated at two locations in Southern Brazil. The mean heterosis was 5.37% for FCV and zero for BY lines, although higher than 15% in some combinations. The occurrence of heterosis indicates dominance in the control of tobacco yield. Tobacco breeding programs must focus primarily on improving the performance of lines per se and then on the identification of the best hybrid by testing combinations. [ABSTRACT FROM AUTHOR]

Pearl millet (pennisetum glaucum l.) Considered a main warm-season cereal crop for grain and fodder in the arid and semi-arid tropical regions. The present research was carried out to assess combining ability and heterosis through a complete 5x5 diallel experiment for grain yield and related parameters in pearl millet. General combining ability (gca) effects were highly significant for days to 50% flowering, panicle length and plant height while nonsignificant for grain yield per plant, no. Of productive tillers and panicle girth. Specific combining ability (sca) effects were highly significant for grain yield and non-significant for rest of the characters. These studies suggested that non-additive gene action was more important regarding the inheritance of grain yield while additive gene action had major role in the inheritance of days to 50% flowering, no. Of productive tillers, panicle girth, panicle length and plant height. The parent mgp-84 was good general combiner for the parameters studied. 15rbs-01 was good general combiner for all the characters except days to flowering. The crosses, mgp-84 x 13rbs-09, mgp-304 x 15rbs-01, mgp-84 x 13rbs-10, 13rbs-10 x 15rbs-01, 13rbs-09 x 15rbs-01, mgp-84 x 15rbs-01 and mgp-84 x mgp-304 were the best combinations for grain yield which involved good x good and good x poor general combiners. Sca variance for grain yield was higher than gca variance indicating that non-additive gene action had major role in its inheritance. Gca variances for days to flowering, productive tillers, panicle girth, panicle length and plant height were higher than sca variances which suggested that additive gene action had played key role in the inheritance of these traits. The consistency in results of both the trials for all the parameters implies that the results could be of broader use to the genetic improvement of grain yield and growth parameters in pearl millet. [ABSTRACT FROM AUTHOR]

Abstract The objective of this work was to investigate the genetic control of black bean (Phaseolus vulgaris) and to select parents and segregating populations with high resistance to Fusarium wilt, high yield, and greater 100-seed weight (100SW), using a partial diallel cross. Twenty-five populations were obtained from two groups of parents – the first with five parents resistant to and the second with five parents susceptible to Fusarium wilt. The segregating populations were evaluated in experiments in three years/generations for reaction to Fusarium wilt, yield, and 100SW in an area naturally infested with the pathogen. The diallel analysis showed additive and nonadditive effects in control of the three studied traits, with predominance of additive effects. CNFP 15194, CNFP 15207, and 'BRS Esplendor' are the genotypes with high and negative general combining ability estimates (gi = -0.59, -0.76, and -0.13, respectively), being recommended for use as parents for resistance to Fusarium wilt. Among them, CNFP 15194 also forms populations with a greater 100SW (gi = 0.69). The BRS FP403 cultivar is recommended as a parent to increase yield (gi = 218) and 100SW (gi = 1.46). Six populations were selected to obtain black bean lines that combine resistance to Fusarium wilt, high yield, and high 100SW.

Copyright of Revista Mexicana de Ciencias Agrícolas is the property of Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Agronomía & Ambiente is the property of Universidad de Buenos Aires. Facultad de Agronomia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Our objectives were to evaluate general and specific combining ability (SCA) and genetic divergence among tropical maize inbred lines using single sequence repeat (SSR) markers. Thirteen inbred lines were crossed based on a complete diallel scheme. Hybrids and three checks were evaluated in a lattice experimental design. Silk and anthesis flowering, average plant height, average ear height, white spot (Pantoea ananatis) and gray leaf spot (Cercospora zeae-maydis) severity, and grain yield were evaluated. Significant differences (p < 0.05) for general and specific combining abilities were observed for all traits. Based on additive effects, inbred lines 1 (Flash) and 12 (SG 6015) were selected to reduce the flowering period and plant and ear height. Inbred lines 2 (CD 303) and 3 (AG 8080) were selected to reduce disease severity. For the simultaneous increase in grain yield and reduced severity of diseases, line 11 (AG 9090) as a parent or tester in topcross schemes is recommended. According to non-additive effects, crosses 2 (CD 303) × 13 (DKB 747) and 11 (AG 9090) × 12 (SG 6015) were selected for grain yield and future breeding programs. Six groups were identified using SSR markers; a major group contained six inbred lines. Because of the minor relationship between genetic divergence and SCA effects on grain yield limits, the use of the groups for future divergent crosses is recommended.

A set of diallel crosses involving 10 diverse parents (excluding reciprocals) of barlay (Hordeum vulgare L.) was made and its F2’s were evaluated under three different date of sowings during rabi 2015-16 and 2016-17 at RARI, Durgapura, Jaipur, Rajasthan, India. Heterosis for grain yield per plant ranged from -20.75 to 41.86 %; -21.95 to 39.65 %and -48.13 to 64.34 % under early (E1), normal (E2) and late (E3) sowing conditions, respectively. Out of 45 crosses, nine crosses in E1 and fifteen crosses in each E2 and E3 exhibited positive significant heterosis while, seven crosses in E1 and E3 and nine crosses in E2 exhibited positive significant heterobeltiosis. Negative significant inbreeding depression for grain yield per plant was reported. Overall, crosses BHS 400 × PL 426, PL 426 × RD 2552 and BH 959 × RD 2552 exhibited positive significant heterosis and heterobeltiosis. Hence, these crosses considered to be most desirable for grain yield per plant. 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.

Twenty one wheat hybrids and their seven parental genotypes were evaluated in the research farm of the Faculty of Agriculture, Ain shams University, Shoubra El-khema, Cairo, Egypt, in 2016/2017 growing season. The genetic analysis was conducted using Griffing (1956), Method 2, model 1). Significant differences among parent genotypes and their 21 crosses for all the studied traits (days to 50% heading, days to maturity, flag leaf area, plant height, number of spikes/ plant, spike length, number of spikelets/ spike, number of kernels/ spike, 1000-kernel weight and grain yield/ plant) were detected. This indicated that, variability exists among these populations may increase the chance appearance of good new combination that can be isolated in the succeeding generations. Parents versus crosses mean squares as an indication for average heterosis over all crosses were significant for all studied traits. Mean squares of general (GCA) and specific (SCA) combining abilities were significant for all studied traits except spike length trait for SCA which was insignificant. GCA/SCA ratios were more than unity for all studied traits, which indicating that the additive type of gene action is of great importance in the inheritance of these traits. Heterosis over the better parents showed that, the best hybrids were Gemmiza 9xGiza 168, Sakha 93x Giza, 168, Sakha 94x Jawahir-14, Sakha 94x Bob white, Giza 168xAcsad 925 and Jawahir-14x Bob white for grain yield/ plant trait and some of the other studied traits. The best general combiner parents were Sakha 94, Jawahir-14 and Bob white for grain yield/ plant trait and some of the other studied traits. The best SCA hybrids were Gemmiza 9x Sakha 93, Gemmiza 9x Giza 168, Sakha 93x Jawahir-14, Sakha 94xJawahir-14, Sakha 94x Acsad 925, Sakha 94xBob white, Giza 168x Jawahir-14, Giza 168x Acsad 925, Jawahir-14x Bob white and Acsad 925x Bob white for grain yield/ plant trait and some of the other studied traits. These result could be used in wheat breeding programs.

Мета. Виявити селекційно-генетичні особливості сортів ячменю багаторядного озимого за довжиною колоса та виділити ефективні джерела підвищеної комбінаційної здатності в умовах Лісостепу України. Методи. Дослідження виконано в Миронівському інституті пшениці у 2012/13–2014/15 рр. з сортами ячменю багаторядного озимого ‘Паладін Миронівський’, ‘Жерар’, ‘Селена стар’, ‘Стрімкий’, ‘Cartel’, ‘Existens’, ‘Cinderella’ та F1 від їх схрещування за повною діалельною схемою (7´7). Дисперсійний аналіз, розрахунки комбінаційної здатності і генетичних параметрів проводили відповідно до загальноприйнятих методик (Доспехов Б. А., 1985; Федин М. А. та ін., 1980). Результати. У генотипів виявлено достовірні відмінності за рівнем прояву довжини колоса, що дало змогу оцінити комбінаційну здатність та розрахувати параметри генетичної варіації. Високі ефекти загальної комбінаційної здатності (ЗКЗ) в усі роки досліджень відмічено у сортів ‘Стрімкий’ (gi = 0,64–0,76), ‘Паладін Миронівський’ (gi = 0,34–0,53). Ефекти ЗКЗ від середнього до високого рівня виявлено в сорту ‘Existens’ (gi = 0,07–0,23). Графічний аналіз та розрахунок параметрів генетичної варіації свідчать про наявність внутрішньолокусного наддомінування в 2012/13 ( = 1,16) та неповне домінування в 2013/14 р. ( = 0,69) і 2014/15 р. ( = 0,82). Значного прояву епістазу не виявлено. В усі роки домінування було спрямоване на збільшення ознаки і зумовлене домінантними алелями (ефектами). Висновки. Вперше в умовах Лісостепу України виявлено селекційно-генетичні особливості сортів ячменю озимого за довжиною колоса в системі повних діалельних схрещувань. Встановлено варіювання генетичного контролю ознаки від наддомінування в посушливому 2012/13 р. до неповного домінування у зволожених 2013/14 і 2014/15 рр. Виділено сорти ‘Стрімкий’, ‘Паладін Миронівський’, ‘Existens’ з підвищеними ефектами ЗКЗ, які є цінними у селекції на збільшення ознаки.

Our objectives were to evaluate general and specific combining ability (SCA) and genetic divergence among tropical maize inbred lines using single sequence repeat (SSR) markers. Thirteen inbred lines were crossed based on a complete diallel scheme. Hybrids and three checks were evaluated in a lattice experimental design. Silk and anthesis flowering, average plant height, average ear height, white spot (Pantoea ananatis) and gray leaf spot (Cercospora zeae-maydis) severity, and grain yield were evaluated. Significant differences (p < 0.05) for general and specific combining abilities were observed for all traits. Based on additive effects, inbred lines 1 (Flash) and 12 (SG 6015) were selected to reduce the flowering period and plant and ear height. Inbred lines 2 (CD 303) and 3 (AG 8080) were selected to reduce disease severity. For the simultaneous increase in grain yield and reduced severity of diseases, line 11 (AG 9090) as a parent or tester in topcross schemes is recommended. According to non-additive effects, crosses 2 (CD 303) x 13 (DKB 747) and 11 (AG 9090) x 12 (SG 6015) were selected for grain yield and future breeding programs. Six groups were identified using SSR markers; a major group contained six inbred lines. Because of the minor relationship between genetic divergence and SCA effects on grain yield limits, the use of the groups for future divergent crosses is recommended. [ABSTRACT FROM AUTHOR]

In different crop plants, combining ability and heterosis are used as important diagnostic tools for assessing the performance of parental genotypes and their hybrids. This research aimed to evaluate heterotic and combining ability effects in the diallel crosses of melon (Cucumis melo L.) for yield- and quality-related traits. Seven melon (C. melo L.) genotypes were grown and crossed in a complete diallel fashion to produce F1 hybrids. During the 2019 crop season, 49 melon genotypes (7 parents + 42 F1 hybrids) were grown in a randomized complete block design with three replications. Observations were made for seven characters. Analysis of variance revealed significant (P = 0.01) differences among the melon genotypes for harvest age, fruit flesh thickness, fruit total soluble solids, fruit length, and fruit diameter and merely significant differences (P = 0.05) for fruit weight. Combining ability analysis revealed that mean squares due to general combining ability (GCA) were significant for fruit diameter but were nonsignificant for all other traits. However, mean squares due to specific combining ability (SCA) were significant for all traits. The parental genotypes PK-165, PK-464, and PK-669 exhibited the highest and desirable GCA effects for yield and quality traits. Hence, these genotypes could be used to generate high-yielding hybrid/open-pollinated cultivars. GCA:SCA ratios further revealed that the traits of harvest age, fruit flesh thickness, fruit total soluble solids, fruit length, and fruit weight were controlled by dominant gene action, whereas fruit diameter was managed by additive and dominant genes. The majority of the traits were controlled by nonadditive gene action, verifying that the said breeding material could be efficiently used for the production of hybrid cultivars on the basis of heterotic effects. [ABSTRACT FROM AUTHOR]

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Southern Agriculture is the property of Journal of Southern Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

It is necessary to know the combining ability of starting material for effective breeding to create varieties. The research aim was to determine the peculiarities of the general combining ability (GCA) and specific combining ability (SCA) and the ratio of their variances for awned and awnless varieties and their parental forms in F1. The study was conducted in 2014–2015. Spring barley varieties and their parental forms were used in direct diallel crosses. In 2014–2015, peculiarities of the combining ability of awned and awnless spring barley varieties and their parental forms were determined in F1. We highlighted varieties with strong GCA effects: ‘Badioryy’ for plant productivity; ‘Dzherelo’, ‘Badioryy’, ‘Vitrazh’ and ‘Maliovnychyy’ for grain number per spike; ‘Dzherelo’, ‘Badioryy’, ‘Etiket’, ‘Granal’, ‘Modern’, ‘Vitrazh’, and ‘Tolar’ for 1000-grain weight; ‘Dzherelo’, ‘Granal’, and ‘Vitrazh’ for spike length; ‘Dzherelo’ and ‘Maliovnychyy’ for spikelet number per spike; ‘Dzherelo’, ‘Badioryy’ and ‘Granal’ for plant height; ‘Zvershennya’ and ‘Badioryy’ for productive tillering; ‘Zvershennya’ and ‘Badioryy’ for total tillering; and ‘Badioryy’ for straw weight. These varieties had the largest numbers of genes that positively determine these traits. The level of combining ability of parental forms may be manifested differently in varieties created via hybridization of them. GCA variances exceeded SCA variances in ‘Zvershennya’ in 2014–2015 for the trait “1000-grain weight” (GCA – 4.20 and 4.03, respectively; SCA – 3.78 and 3.84, respectively), therefore, it is determined mainly by additive gene effects. Strong and weak SCA effects were observed for plant productivity (grain weight) and its structural components (productive tillering, grain number per spike, 1000-grain weight). Strong SCA effects were the most numerous for the trait “1000-grain weight.”

Increasing incidence of heat stress (HS) is appearing as an important abiotic stress, limiting chickpea (Cicer arietinum L.) yield globally. Therefore, understanding of the nature of gene action of yield- related traits could help in breeding heat tolerant chickpea genotype for its sustainable production under HS. In the present investigation a total of six chickpea genotypes, viz. ICC 4958, ICC 92944, ICC 1205, DCP 92-3, ICC 96030 and KWR 108 were used as parents for 6 × 6 diallel analysis (excluding reciprocal crosses) to estimate gene action for various phenological and yield-related traits by growing them under normal sown (NS) and late sown (LS) conditions. Genetic analysis revealed the presence of both additive and non-additive genetic variances. However, higher magnitude of general combining ability (GCA) variance than specific combining ability (SCA) variance, with predictability ratio > 0.5 for most of the traits studied under both NS and LS conditions indicated preponderance of additive gene action. The estimates of GCA effects revealed that the parents ICC 92944 and KWR 108 were better general combiners for yield and yield- related traits, under both NS and LS conditions. Likewise, ICC 4958 × ICC 92944 (under both conditions) and DCP 92-3× KWR 108 (under LS) F1 crosses were the most suitable cross combinations for yield and yield-related traits. High estimates of broad sense heritability for most of the traits, and low to medium estimates of narrow sense heritability for the studied traits were noted under both conditions. Therefore, inclusion of parent with high GCA effect in crossbreeding programme could be a potential strategy for improving HS tolerance in chickpea.

Background and aims: Although the races of maize native to the Northeast of Argentina (Misiones) have been described and a work on phenetic relations has been published, nevertheless little is known about genetic relationships, this being the main objective of this work. M&M: A group of 6 races of maize and the "F," offspring of crosses derived from a diallel scheme have been evaluated on the basis of 21 morphological vegetative, reproductive and phenological quantitative traits using ANOVA and multivariate statistical methods (discriminant canonic analysis and cluster analysis). Results: The ANOVA showed highly significant differences among parental races and progeny for almost all the variables. The first two canonical variables (CV) explain almost 67% of overall variation. The most important discriminating characters associated with the first CV correspond to dimensions of ears and grains, while the traits contributing to the second CV are related mainly to vegetative and reproductive morphology. Racial groups defined by cluster analysis were described. Conclusions: Cluster analysis allowed distinguishing related racial groups. The genetic relationships observed from diallel crosses are different according to the parameter considered for regrouping. The results obtained are important from the taxonomic and evolutionary point of view and facilitate the choice of material to be used in breeding programs. [ABSTRACT FROM AUTHOR]

Heterosis, heterobeltiosis and inbreeding depression for grain yield and its components were studied through 6 crosses in F1 and F2 generations. These crosses were resulted from half diallel mating design between 4 different parents in 2014/2015. In 2017/2018 season, an experiment was conducted in randomized complete block design with three replications at Faculty of Agriculture, Cairo University, Giza, Egypt to evaluate the 16 genotypes (4 parental lines and their 6 crosses in F1 and 6 crosses in F2). Moreover, simple phenotypic correlation and path analysis were performed to study the nature of associations between grain yield and its components. The results showed that, for grain yield plant-1, the cross combination (P2 × P3) depicted the highest significant and positive heterosis (88.12%) and heterobeltiosis (81.9%) followed by cross combination (P1 xP2) which exhibited a high positive significant heterosis (83.43%) and high positive significant heterobeltiosis (60.35%). Concerning inbreeding depression, highly significant and positive values of inbreeding depression were detected for total dry matter, spike dry matter, grain yield plant-1 and 1000-kernels weight for all crosses. On the other hand, significant and negative values of inbreeding depression were detected in plant height, No. of spikes plant-1, spike length, harvest index and No. of kernels spike-1. Respect to the correlation analysis. The results showed that, highly significant and positive correlation was observed between grain yield plant-1 and each of No. of spikes plant-1 (r=0.64**), biological yield (r=0.94**), spike dry matter (r=0.98**) and 1000-kernels weight (r=0.76**). Concerning path-analysis technique, the spike number plant-1 exhibited the highest direct effect value (0.61) towards grain yield plant-1 followed by number of kernels spike-1 which exhibited a high degree of direct effect (0.547). The greatest indirect effect on grain yield plant-1 was achieved by total dry matter via number of spikes plant-1. It could be concluded that, plant height, number of spikes plant-1, spike length, No. of kernels spike-1 and 1000-kernels weight are major components of wheat yield and could be used as selection criteria in the breeding programs. [ABSTRACT FROM AUTHOR]

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Common bean parents and populations resistant to white mold (WM, caused by Sclerotinia sclerotiorum) were selected based on estimates of general combining ability (GCA) and specific combining ability (SCA) for WM severity in three field nurseries in Brazil. Twenty-seven populations were obtained by partial diallel crosses between parents from two groups: GI) three sources of partial resistance identified abroad and GII) nine Brazilian cultivars and elite lines. Populations were advanced in bulk up to the F6 generation. The overall mean of WM severity from combined analysis ranged from 2.83 to 5.03 (scale of 1 to 9 scores) in the F6 population. The score of the susceptible control BRS Requinte was 7.21. The GI parents K-59, in Oratórios, MG, and Viçosa, MG, and K-407 and PI204717, in Goianira, GO, contributed to increase resistance to WM. The most promising populations for obtaining elite lines resistant to WM were K-59/BRS Executivo, PI204717/BRS Campeiro, PI204717/Jalo Precoce, K-59/BRS Radiante, and K-407/BRS Cometa. [ABSTRACT FROM AUTHOR]

Twenty one wheat hybrids and their seven parental genotypes were evaluated in the research farm of the Faculty of Agriculture ,Ain shams University, Shoubra El-khema, Cairo, Egypt, in 2016/2017 growing season. The genetic analysis was conducted using Griffing( 1956 ,)Method 2, model 1). Significant differences among parent genotypes and their 21 crosses for all the studied traits (days to 50% heading, days to maturity, flag leaf area, plant height, number of spikes/ plant, spike length, number of spikelets/ spike, number of kernels/ spike, 1000-kernel weight and grain yield/ plant) were detected. This indicated that, variability exists among these populations may increase the chance appearance of good new combination that can be isolated in the succeeding generations. Parents versus crosses mean squares as an indication for average heterosis over all crosses were significant for all studied traits. Mean squares of general (GCA) and specific (SCA) combining abilities were significant for all studied traits except spike length trait for SCA which was insignificant. GCA/SCA ratios were more than unity for all studied traits, which indicating that the additive type of gene action is of great importance in the inheritance of these traits. Heterosis over the better parents showed that, the best hybrids were Gemmiza 9xGiza 168, Sakha 93x Giza, 168, Sakha 94x Jawahir-14, Sakha 94x Bob white, Giza 168xAcsad 925 and Jawahir-14x Bob white for grain yield/ plant trait and some of the other studied traits. The best general combiner parents were Sakha 94, Jawahir-14 and Bob white for grain yield/ plant trait and some of the other studied traits. The best SCA hybrids were Gemmiza 9x Sakha 93, Gemmiza 9x Giza 168, Sakha 93x Jawahir-14, Sakha 94xJawahir-14, Sakha 94x Acsad 925, Sakha 94xBob white, Giza 168x Jawahir- 14, Giza 168x Acsad 925, Jawahir-14x Bob white and Acsad 925x Bob white for grain yield/ plant trait and some of the other studied traits. These result could be used in wheat breeding programs. Wheat (Triticum aestivum L.) is one of the leading cereals and staple food in many countries of the world including Egypt. It plays a remarkable role in meeting the food requirements of the country [Barutcular et al 2017; Ljubičić et al 2017; Singh, S.P. and V. Sharma, 2017; Thomas et al 2017 and Tiwari et al 2017]. In Egypt, wheat is the main winter cereal crop used as a staple food for urban and rural societies and the major source of straw for animal feeding [Ismail 2015, Hamda and Ibrahim 2016 and Kandil et al 2016]. However, total wheat consumption has increased drastically due to over population growth by about 2.5 % per year. Egypt imports about 45 % of its wheat requirements. This reflects the size of the problem and the efforts needed to increase wheat production. Thus, increasing production per unit area appears to be one of the important factors for narrowing the gap between wheat production and consumption. Information regarding general and specific combining ability of wheat genotypes is a prerequisite to launch a successful wheat-breeding programs. Diallel mating design has been extensively used to analyze the combining ability effects of wheat genotypes and also to provide information regarding genetic mechanisms controlling grain yield and other traits. Knowledge of general and specific combining ability. influencing yield and its components has become increasingly important for plant breeders in the choice of suitable parents for developing potential possessing varieties in wheat. Many researchers gave reviews, which revealed that both general and specific combining ability were involved in the improvement of yield and its contributing traits in wheat such as [Tiwari et al 2017; Patel, 2017; Ljubičić et al 2017; Kumar et al 2017 and Ahmad et al 2017]. [ABSTRACT FROM AUTHOR]

Half F2 diallel crosses of eight spring cultivars of rapeseed were used in partial circulant diallel analyses to estimate biometric genetic parameters for phenological traits, yield components and seed yield. The greatest variation in the GCA-to-SCA mean square ratio was related to days to flowering, and its lowest variation to days to maturity. A high coefficient of variation of the narrow-sense heritability estimate was obtained for days to maturity, followed by plant height and seed yield. For diallel analysis with a low number of parents, the differences of the heritability estimates of the traits were small; therefore, for precise estimation of heritability, a high number of diallel crosses will be preferred. [ABSTRACT FROM AUTHOR]

Corn (Zea mays L.) crop that is grown on large areas - over 140 million hectares worldwide, and 400-500 thousand ha in Moldova due to production potential broad diversity of use as food for humans, animals, birds raw material for industrial processing. The upward trend in average yields achieved is largely attributed to the improvement of scientific programs. Select the line with the characters and traits that are transmitted hereditary hybrids and contribute to their performance, ensure progress in improvement. Therefore, the process of creating inbred lines associated with combining ability testing as a measure of productivity conferred hybrids, is significant research programs. Orientation purpose of improved maize hybrids to formulas and simple change to a superior capitalization heterosis effect and perfect uniformity of plant requires changes in methodology for the creation, evaluation and classification of inbred lines.

To date, no studies on the inheritance of Fusarium spp. ear rot resistance in popcorn are available. The purpose of this paper was to investigate the additive-dominance model to estimate the genetic components of variance, heritability and the inheritance pattern in a diallel for popcorn, by Hayman's approach. The experiment was carried out in two environments, using eight parent lines. The following traits were measured: grain yield (GY), popping expansion (PE), incidence of ears infected by Fusarium (FusIE), total number of kernels infected by fungi (FunIK) and total number of kernels infected by Fusarium spp. (FusIK). The results indicated that the incidence of FusIK (Fusarium-infected kernels), FunIK (fungus-infected kernels), and FusIE (Fusarium-infected ears) is controlled by dominant genes. Parent L77 had a high number of favorable alleles for all resistance-related traits, as well as for PE. The strategy recommended for reduction of FunIK, FusIK, and FusIE consists of exploiting hetorosis using inbred lines with favorable alleles. [ABSTRACT FROM AUTHOR]

The aim of this work was to estimate the combinatory aptitude, genetic variance and heterosis of eight creole corn varieties. The research work was carried in Irapuato, Guanajuato, México, during 2008 and 2009. A randomized complete block design with three replications was used to evaluate the twenty-eight crosses under method 4 Griffing (1956). Each experimental plot included four rows five meters long with a separation of 0,75 m. The general combing ability and specific (ACG and ACE) were highly significant (P<0.01) for all traits except flowering days. The dominance variance (s2D) was larger and more important than additive variance (s2A) for most of the traits, indicating that non-additive genetic genes were important on the expression of those traits on crosses. It was observed that varieties P6 (creole #5), P7 (creole #2) and P8 (creole San Antonio) had larger variance effects (s2ACE) for long cob, number of rows per cob, total cob number, and grain yield. Some outstanding crosses were identified for their high grain yield as well as heterosis, mainly those that included germoplasm of creole #5, #2 and San Antonio. According to the aforementioned we recommend to draw lines from the above populations and cross them to produce hybrids. [ABSTRACT FROM AUTHOR]

Fusarium oxysporum f. sp. phaseoli ( Fop) is a soil pathogen that causes wilt in common bean ( Phaseolus vulgaris L.) and is one of the most important diseases of this crop. The use of resistant cultivars is the most effective method of controlling losses from this pathogen, and studying the inheritance of Fop resistance could provide useful insights for developing cultivars with resistance. Thus, the aim of this study was to determine the inheritance of resistance to fusarium wilt in common bean. The parents, F and F plants from seven crosses between resistant and susceptible parents of a partial diallel scheme 3 × 5 were inoculated with the isolate FOP UFV 01. During each generation, the plants were individually evaluated to determine disease severity. Among the eight parents, five were resistant, and three were susceptible to fusarium wilt. Only two phenotypic classes were observed in the parents (resistant and susceptible). Based on the performance of the F generation, all the individuals were resistant, indicating that resistance is dominant over susceptibility. Different results were obtained for the segregation of plants from the F generation based on the methods applied to determine the inheritance of resistance. However, the maximum likelihood estimator method, which was the most suitable methodology, showed that Fop resistance in common bean is a dominant trait governed by few major genes plus polygenes. These findings can support breeding programs in obtaining Fop-resistant cultivars. [ABSTRACT FROM AUTHOR]

Foi avaliada a capacidade combinatória de oito cultivares de trigo, por meio de um esquema dialélico analisado segundo o modelo quatro da metodologia de Griffing. Paralelamente, foi realizada uma análise de dissimilaridade com marcadores SSR, a partir de estimativas de distância genética baseadas em pedigree. Oito características foram avaliadas num experimento delineado em blocos ao acaso, com duas repetições. O agrupamento das cultivares a partir das distâncias genéticas foi efetuado com os métodos UPGMA e Tocher. Ficou evidenciada a variabilidade entre os genótipos de trigo. As cultivares 'CD 108', 'CD 0542' e 'CD 104' apresentaram grande capacidade geral de combinação para vários caracteres. Os maiores valores de capacidade específica de combinação foram detectados nos híbridos mais heterozigotos, formados pelo cruzamento de parentais integrantes de grupos diferentes. Os agrupamentos indicados pelo pedigree não coincidiram com os indicados a partir dos marcadores moleculares. As distâncias dos marcadores SSR provavelmente refletem melhor as relações entre as cultivares de trigo do que as distâncias medidas com base na genealogia. A falta de associação entre os padrões de agrupamento foi provavelmente devida às propriedades intrínsecas de cada forma de estimação das distâncias genéticas, as quais podem modificar a interpretação e a distribuição da variabilidade genética entre os genótipos avaliados.The combining ability of eight wheat varieties was evaluated according to the fourth model of the Griffing's diallelic methodology. Studies on genetic dissimilarity based on microsatellite markers and genetic distance among genotypes from pedigree data were also performed. The experiment was carried out in a randomized block design with two replications. Eight traits were evaluated in the diallel. Genotypes were grouped according to the UPGMA and Tocher methods. Genetic variability among genotypes was evident. Varieties 'CD 108', 'CD 0542' and 'CD 104' were those who showed high values for general combining ability in several traits. Since the effects of specific combining ability were more important in those particularly heterozygous combinations obtained from varieties allocated in different clusters, field and molecular results coincided in a certain way. There was no a good coincidence between the dendrogram based on parentage coefficient and the one based on microssatellite markers. The very small association between standards of grouping was probably related to the intrinsic properties of each way of estimating the genetic distance, which can modify the interpretation and the distribution of the genetic variability in the evaluated genotypes.

We examined the heterotic parameterizations of diallel crosses among10 popcorn inbred lines in two different environments (municipalities of Campos dos Goytacazes and Itaocara, Rio de Janeiro State) and originating from tropical, temperate and subtropical germoplasm. Traits, including grain yield (GY), plant height (PH), ear height (EH), days to silking (FL) and popping expansion (PE), were measured. The inbred lines and the hybrids were evaluated in a randomized complete block design with three replications. The sources of genotypic variation, inbred lines and heterosis had significant effects on all traits. When the sources of heterotic variation were compared separately, estimated mean heterosis was found to be significant for all traits. When inbred lines and specific heterosis was investigated, only popping expansion was not significantly different, demonstrating that heterotic effects are favorable for developing superior hybrids. A direct relation between .i and i V. was made clear, especially for traits that were slightly influenced by the effects of dominance. Additivity was determined to have the best effect for improving popping expansion. The hybrid combinationshad positive estimates of heterosis for the GY but not for PE. The hybrids P1 x P3 and P2 x P4 had the best responses for the GY and PE. The superiority of the combination P1 x P3 shows that the addition of genomes with different edaphoclimatic adaptations is an important factor in obtaining superior hybrids.O presente trabalho teve com objetivo averiguar as parametrizacoes heteroticas de cruzamentos dialelicos entre dez linhagens de milho pipoca oriundas de genotipos tropicais, temperados e semi-temperados, em dois ambientes (municipios de Campos dos Goytacazes e Itaocara, Estado do Rio de Janeiro), em relacao as caracteristicas rendimento de graos; altura media de planta e da insercao da primeira espiga; numero medio de dias para florescimento e capacidade expansao. As linhagens e os hibridos foram avaliados em delineamento em blocos ao acaso, com tres repeticoes. Para as fontes de variacao linhagens eheterose houve significancia, pelo teste F, para todas as caracteristicas. No desdobramento da fonte de variacao heterose, estimativas de heterose media foram significativas para todas ascaracteristicas. Em relacao a heterose de linhagens e especifica, apenas a caracteristica capacidade de expansao nao expressou diferenca significativa, o que confirma que os efeitos heteroticos naosao favoraveis para sintese de hibridos com superioridade. A relacao direta entre .i e i V. ficou claro, especialmente para as caracteristicas pouco influenciadas pelos efeitos de dominancia. O efeito genico aditivo foi confirmado para capacidade de expansao. As combinacoes hibridas revelaram estimativas positivas de heterose para GY, mas nao para PE. Os hibridos P1 x P2 e P3 x P4 tiveram as melhores respostas para GY e PE. A superioridade da combinacao P1 x P3, demonstra que a adicao de genomas com adaptacao edafoclimaticas diferentes e importante para a obtencao de hibridos superiores.

Eight tropical maize populations were crossed in a diallel system. Parent and their 28 crosses were evaluated for grain yield in two plantations in 2006. The objective was to estimate the general combining ability (GCA) of the parental populations and the specific combining ability (SCA) of the crosses for grain yield. The populations were: 21, 22, 23, 25, 32, 43, 49 and the commercial variety VS-536. The Griffing method 2 design was utilized to estimate GCA and SCA effects, on a complete randomized block design with three replications, at two planting dates. The diallel analysis showed significant differences (P ≤ 0.01 y 0.05) among planting dates (PD), crosses (C), GCA, PD × C and PD × SCA interaction. Populations 23 and 43 showed the highest significant (P ≤ 0,01)  GCA, and the crosses VS 536 × Pob 32, Pob 22 × Pob 43, Pob 25 × Pob 49 y Pob 43 × Pob 49 showed the highest significant (P ≤ 0,01) SCA effects. Both high parent positive heterosis were observed for the crosses Pob 25 × Pob 49, Pob 43 × Pob 49 and Pob 22 × Pob 43. Populations 23 and 43 revealed potential to be used in maize breeding programs.

Combining ability was determined in an 8 × 8 diallel intra specific F1 crosses in rapeseed (Brassica napus L.) during 2011-2013 to scrutinized potential lines, hybrids, and nature of gene action involved in the inheritance of maturity and plant architecture traits. Analyzed data revealed highly significant differences among the genotypes for days to flowering, maturity, plant height, primary branches plant-1 and main raceme length. Analysis of combining ability revealed highly significant GCA (general combining ability), SCA (specific combining ability) and RCA (reciprocal combining ability) effects for the studied traits. Based on GCA, best general combiners were AUP-7 for earlier flowering and maturity, AUP-2 for plant height, AUP- 14 for primary branches plant-1 and AUP-9 for main raceme length. Based on SCA effects, best F1 hybrids were AUP-7 × AUP-14 (days to flowering), AUP-8 × AUP-9 (days to maturity), AUP-17 × AUP-18 (plant height), AUP-14 × AUP-20 (primary branches plant-1) and AUP-14 × AUP-20 (main raceme length) and could be utilize in future rapeseed breeding programs. The estimates of variances of combining ability (σ2GCA, σ2SCA) and predictability ratio (σ2GCA/σ2SCA>1.00) indicated that gene action was predominantly additive for days to flowering while, for the rest of the traits non additive gene action was responsible as the predictability ratio was less than unity which was further confirmed by higher values of variances of SCA than GCA. In present study for all the traits except days to flowering, non-additive gene action was prominent therefore selection should be delayed to late segregation generation. [ABSTRACT FROM AUTHOR]

Vitamin A deficiency (VAD) is of public health significance in the developing world. In spite of extensive promotion of orange-fleshed sweetpotato(Ipomoea batatas)varieties (OFSPs), they are poorly utilized in Ghana because of their low dry matter and high sugar content. The objective of this study was to develop farmer- and consumer-preferred beta-carotene-rich varieties to increase OFSP utilization in Ghana and beyond. One released variety in Ghana (Apomuden) and four other varieties which are introductions (Beauregard, Resisto, CIP 442850, and CIP 443035) were used as parents. They were crossed using the full diallel mating design. There was significant genetic variation for the traits and among the F1hybrids. Significant positive and negative heterosis was found, but the levels were not adequate for the development of non-sweet, high dry matter, and high beta-carotene-rich varieties. Twenty-one F1hybrids that had comparable beta-carotene content and storage root yield but lower sugar content than the only released high-beta-carotene variety in Ghana were identified for further testing for potential release. [ABSTRACT FROM PUBLISHER]

The number of branches per tree was analysed on F1 individuals originated in several crosses between apple cultivars with different architectural ideotypes: spur (Starkrimson, Golden spur), semispur (Liberty), weeping (Florina). The number of branches per tree in F1 hybrid apple, in their third year of vegetation, was different in six combinations, depending on the genotype of genitors, respectively on their architectural ideotype. There have been noticed significant differences among the tested cultivars used as genitors, the average of trait on hybrid combination being comprised between 4.28 in Goldenspur x Liberty and 7.14 in Starkrimson x Florina. A small number of branches per seedling were registered in Starkrimson x Goldenspur combination (4.32), where the both genitors are spur ideotypes. The variability of analysed characters was high, with s% between 33.9 at Liberty x Florina and 56.8 at Starkrimson x Liberty. These values suggest that seedlings with very different number of branches are likely to be identified in each combination. The analysis of variance for GCA and SCA has emphasised the fact that, in the studied apple combinations, both effects of general and specific combining ability contributed to the phenotypic expression of number of branches per tree. Goldenspur showed negative value for GCA, thus this could produce descendents with low vigour and number of branches, if they are used as genitors in apple breeding. Based on the values of general combining ability (GCA) and specific combining ability (SCA) selection of genitors can be very efficient for desirable characters of growth in apple breeding.

In order to study the genetic control of soybean resistance to sudden death syndrome (SDS), a 5 x 5 diallel with the F2 generation, without the reciprocals, was carried out in a greenhouse. The following parents were used: Forrest, MG/BR-46 (Conquista), IAC-4, FT-Cristalina, and FT-Estrela. The first two cultivars are more resistant to SDS than IAC-4, which is considered to be moderately resistant to SDS, and the last two cultivars are highly susceptible. The fungus was inoculated with three colonized sorghum grains placed at the bottom of the holes with two soybean seeds. Single plants were evaluated between 14 and 37 days after emergency based on foliar severity symptoms (1-5) of SDS. The disease incidence and a disease index were also calculated for each plot (clay pots with five plants each). The analysis for severity and disease index was performed only with the data of the 37th day after emergence. Additive and dominant genetic effects were detected by Jinks-Hayman's analysis, but the dominant genetic effects were higher. The genetic parameters estimated indicated that the average degree of dominance showed the presence of overdominance; at least three loci or genic blocks that exhibited dominance were responsible for the genetic control of SDS resistance; the estimates of narrow-sense heritabilities were moderate (0.48 to 0.62), but in the broad-sense they were higher (0.90 to 0.95), thus reinforcing the presence of dominance effects; and the resistance to SDS was controlled mostly by dominant alleles. Five microsatellite markers (Satt163, Satt309, Satt354, Satt371 and Satt570), reported as linked to five QRLs of the SDS, were used to genotype the parents and showed the possibility of occurrence of multiallelism in those loci, but this evidence did not invalidate the fitting of the data to the Jinks-Hayman's model.

The utilization of diallel crosses for identification of superior combinations is a common practice in maize (Zea mays L.) breeding programs. This methodology allows the estimation of the combining ability of genotypes being evaluated. In this work, five inbred lines were evaluated as to their general (GCA) and specific (SCA) combining abilities, by using a complete diallel scheme. The single-crosses produced between these inbred lines were evaluated in seven environments, along with two checks, by using a randomized complete block design. Traits analized were: grain yield, plant height, ear height, ear placement, and prolificacy. A diallel analysis was carried out, following an adaptation of Griffing's method IV, in addition to hybrid stability and adaptability analyses. Significant differences were detected for entries and environments for all traits. The interaction genotype vs. environment was significant for all traits. GCA's were significant for all traits, while SCA's were non-significant only for ear placement. For grain yield, both additive (GCA) and non-additive (SCA) effects were important, while for the remaining traits additive effects were more important. The high yielding single-cross was obtained from the cross of lines L-08-05F and L-38-05D. Those inbred lines showed higher GCA's and their cross also had high SCA; also, it is responsive to environment improvements and reasonably stable. The second in rank high yielding single-cross, L-46-10D x L-08-05F, showed wide adaptability and stability.

Six white maize (Zea mays L.) inbred lines were crossed in a half diallel mating scheme at Gemmeiza Agric. Res. Stn. in 2009 season. In 2010 season, the resulting lS crosses along with three check hybrids.; SC 10, SC 128 and SC 129 were evaluated at Gemmeiza and Mallawy Agric. Res. Stations. General combining ability (GCA) and specific combining ability (SCA) effects were estimated according to Griffing (19S6) model 1, method 4. Location mean squares were highly significant for ear diameter and 100-Kernel weight, while crosses and cross x location interaction mean squares were highly significant for all traits. Mean squares due to GCA and SCA were significant revealing that both additive and non-additive types of gene effect were involved in the inheritance of the studied traits. GCA/SCA mean square exceeded the unity for no. of rows ear-1 at Mallawy and combined data, no. of kernels row-1 at Gemmeiza and grain yield at Gemmeiza and combined data, indicated the predominance of additive (a) and (aa) gene effects in the genetic variance of these cases, while the same ratio mean squares were less than unity for the rest of the cases indicating that non-additive genes played an important role in the inheritance of these traits. 'P3' was considered as a good general combiner for 100-kernel weight at Gemmeiza. The cross; P2 x PS had significant inter-and intra-allelic interactions for no. of kernels row-1, 100-kernel weight and grain yield at both locations. The crosses; P2 x PS, P3 x P4 and P3 x P6 were superior to the three check hybridS'for 100-kernel weight and grain yield. [ABSTRACT FROM AUTHOR]

The aim of the present research was to study the combining ability and heterosis effect for seed yield and its components in sesame under Shandaweel (Upper Egypt) conditions, usirlg half diallel ,crosses during the summer seasons of 2012 and 2013. Eight genotypes were crossed to produce 28 hybrids However, results indicated that genotype variance was significant for all the studied traits. The general (GCA) and specific combining ability (SCA) effects were highly significant for all the studied traits, indicating that additive and non-additive gene actions were involved in the inheritance of all traits. Both additive and dominance components were important for all traits. Among genotypes, Giza 32 proved itself as a good combiner for all the studied traits. 820 proved to be a good combiner for all the studied traits except for oil percentage. Shandaweel 3 also proved itself as a good combiner for the studied traits except for plant height and fruiting zone. Hence, these three local pare nts could be used as donor parents in hybridization programs for transferring desirable traits. With respect to SCA, the crosses (Giza32xline107-2) had significant SCA for all the studied traits; (Giza32xline102f7) had significant SCA for the studied traits except for 1000-seed weight, while (Line102f7xB20) had significant SCA for all studied traits except for oil perce?tage. Meanwhile, the crosses (Shandaweel3xLine87) and (Line107-2xline109f7) had significant SCA for the studied traits except for oil percentage and 1000-seed weight. However, cross (Shandaweel3xlinelllfll) had significant SCA for the studied traits except for seed yield plot-1 and seed weightplant-1, while cross (Line102f7xline87) for all the studied traits except for 1000-seed weight and capsule number. Some crosses showed the maximum desirable heterotic effects over mid and better parents as cross (Line102f7xB20) for seed yield plot-1, seed weight plant-1 and number of capsules plant-1, and cross (Line87xlinelllfll) for oil percentage, cross (Shandaweel3xGiza32) for 1000-seed weight, cross (Shandaweel3xline87) for plant height and fruiting zone. Heritability estimates in broad sense ranged from 77.4 for 1000-seed weight to 97.9 for number of capsulesplant-1. The general and specific combining abilities were highly significant for all traits, indicating that additive and non-additiye gene action were involved in the inheritance of those traits. [ABSTRACT FROM AUTHOR]