Diallel Cross Analysis Research Articles

High-Throughput Yield Prediction of Diallele Crossed Sugar Beet in a Breeding Field Using UAV-Derived Growth Dynamics.

Data-driven techniques could be used to enhance decision-making capacity of breeders and farmers. We used an RGB camera on an unmanned aerial vehicle (UAV) to collect time series data on sugar beet canopy coverage (CC) and canopy height (CH) from small-plot breeding fields including 20 genotypes per season over 3 seasons. Digital orthomosaic and digital surface models were created from each flight and were converted to individual plot-level data. Plot-level data including CC and CH were calculated on a per-plot basis. A multiple regression model was fitted, which predicts root weight (RW) (r = 0.89, 0.89, and 0.92 in the 3 seasons, respectively) and sugar content (SC) (r = 0.79, 0.83, and 0.77 in the 3 seasons, respectively) using individual time point CC and CH data. Individual CC and CH values in late June tended to be strong predictors of RW and SC, suggesting that early season growth is critical for obtaining high RW and SC. Coefficient of parentage was not a strong factor influencing SC. Integrals of CC and CH time series data were calculated for genetic analysis purposes since they are more stable over multiple growing seasons. Calculations of general combining ability and specific combining ability in F1 offspring demonstrate how growth curve quantification can be used in diallel cross analysis and yield prediction. Our simple yet robust solution demonstrates how state-of-the-art remote sensing tools and basic analysis methods can be applied to small-plot breeder fields for selection purpose.

Combining ability analysis of Cucurbita moschata D. in Côte d'Ivoire and classification of promising lines based on their gca effects.

Cucurbita moschata varieties grown in Africa have very low yield. They have been neglected, and totally ignored in agricultural research programs. However, interest in their fruits, seeds, flowers and leaves is growing nowadays due to their nutritional and medicinal potentials. That growing interest has prompted plant breeders and agronomists to develop research programs for their improvement. A complete diallel cross analysis of four parental lines, Long, Zouan-H, Oval, and Soubre and their twelve F1 hybrids, was carried out in a farming environment at the University Nangui Abrogoua, Abidjan, Côte d'Ivoire. The four parental lines and the F1 hybrids were evaluated for their general performances, combining abilities, potency ratio and heterosis effects. The investigated traits included plant height, and eleven fruit- and seed-related characters. The analysis of variance showed significant differences for all traits studied. In addition, the diallel model yielded highly significant gca effects of the female parents. The gca effects of the male parents were significant for all traits except plant height, length of the fruit, width of the fruit and length of the seed. Highly significant sca effects were observed in the crosses for all the traits. Strong maternal effects were observed for the weight and diameter of the fruit, weight of the pulp, number of seeds per fruit, weight of the fresh seeds and 100-seed weight. The general predictive ratio approached the value 1 for all the traits except weight of the fresh seed and width of the dry seed. Most of the characters under this study are predominantly determined by the effects of additive genes. But, weight of the fresh seed and width of the dry seed may be controlled by non-additive genes. Mid-parent heterosis was significant for all measured traits in the crosses, except the length of the fruit. And better-parent heterosis was significant for all traits except plant height, number of fruits per plant and length of the fruit. Gene expression is described by a super-dominance for many traits, and partial dominance for some other traits in all twelve F1 hybrids. Classification of the parental lines based on the effects of their general combining ability grouped the Soubre lines as promising contributors to fruit yield. The parental lines Long and Oval formed another group likely on the basis of the small size of their fruits, the small pulps, the smaller number of fruits per plant and the large number of seeds per fruit. However, Long would be a candidate parent for the development of cultivars with longer vegetative growth. The parental line Zouan-H formed the third group and it was mostly characterized by its large number of seeds per fruit and relatively large fruits.

Genetic Analysis of Diallel Crosses of Rapeseed (B. rapa) for Screening High Temperature Tolerant Genotypes under Phytotron Facility and Late Field Sown Condition

High temperature tolerance is assuming importance in breeding rapeseed-mustard. In the present investigation attempt was made to study genetic variation for traits in response to high temperature and screened during flowering to pod formation stage. Populations of diallel crosses involving three yellow sarson and two toria varieties were used in this study. The diallel populations were exposed to high temperature at National Phytotron Facility, IARI, New Delhi and also grown in late sown field conditions which generally experience high temperature terminal stress. The temperature treatment was given only to the crosses as the parents did not come to flowering in the normal growth chamber. B9 x Jeuti, B9 x TS46, YSH401 x Jeuti and NRCYS05-03 x Jeuti were found to be promising for yield attributes under phytotron facility. In field experiments, Jeuti, B9 x NRCYS05-03, B9 x YSH401, B9 x Jeuti, NRCYS05-03 x Jeuti, YSH401 x Jeuti and YSH401 x NRCYS05-03 were found promising for seed yield and its attributes. Main shoot length, siliquae on main shoot, seeds per siliqua, percent flower drop, siliqua density and biological yield per plant showed high to moderate heritability with high genetic advance.

Combining ability estimates and gene action studies from full diallel mating design in maize (Zea mays L.)

A study was under taken during kharif season of 2016 at College of Agriculture, Bheemarayanagudi and UAS, GKVK, Bengaluru to estimate the combining ability and investigate gene action involved in inheritance of yield and its components traits of maize inbreds through 20×20 full diallel cross analysis. 380 SCHs synthesized through full diallel mating design were evaluated in simple lattice square lattice design at two locations. Analysis of variance revealed significant differences among the hybrids, parents vs. hybrids and straight crosses for all the characters and among the parents for all the characters except ASI, ear circumference and shelling %. Significant differences were also recorded in reciprocal crosses for all the characters except ear circumference and shelling %. Significant GCA variance for grain yield revealed the role of additive components of genetic variance. SCA variance was also highly significant for all characters except ear circumference and test weight indicating the importance of both additive and non additive components of genetic variance. However, there was predominance of additive gene action recorded for all the characters. GCA: SCA variance ratio was less than unity for all the traits, suggesting the predominance of non-additive gene action. Inbreds MAI 283 and VL 109252 were identified as good general combiners as they registered significant gca effects in positive direction for grain yield and its component traits. Straight cross MAI-283×KDMI-16 and reciprocal cross M 04×KDMI 16 registered highest significant sca effects in positive direction for grain yield along with high and significant sca effects in negative direction for ASI.

Combining ability estimates and gene action studies from full diallel mating design in maize (Zea mays L.)

A study was under taken during kharif season of 2016 at College of Agriculture, Bheemarayanagudi and UAS, GKVK, Bengaluru to estimate the combining ability and investigate gene action involved in inheritance of yield and its components traits of maize inbreds through 20×20 full diallel cross analysis. 380 SCHs synthesized through full diallel mating design were evaluated in simple lattice square lattice design at two locations. Analysis of variance revealed significant differences among the hybrids, parents vs. hybrids and straight crosses for all the characters and among the parents for all the characters except ASI, ear circumference and shelling %. Significant differences were also recorded in reciprocal crosses for all the characters except ear circumference and shelling %. Significant GCA variance for grain yield revealed the role of additive components of genetic variance. SCA variance was also highly significant for all characters except ear circumference and test weight indicating the importance of both additive and non additive components of genetic variance. However, there was predominance of additive gene action recorded for all the characters. GCA: SCA variance ratio was less than unity for all the traits, suggesting the predominance of non-additive gene action. Inbreds MAI 283 and VL 109252 were identified as good general combiners as they registered significant gca effects in positive direction for grain yield and its component traits. Straight cross MAI-283×KDMI-16 and reciprocal cross M 04×KDMI 16 registered highest significant sca effects in positive direction for grain yield along with high and significant sca effects in negative direction for ASI.

Response to selection for yield and quality traits under salt affected soil in brinjal (Solanum melongena L.)

A field experiment was conducted to assess the genetic components such as heritability in narrow sense (h2 ns) and genetic advance for nineteen yield,its attributes and biochemical traits of forty five crosses and their ten parents by using the diallel cross analysis (excluding reciprocal) at the Main Experiment Station (MES), Department of Vegetable Science, Acharya Narendra Deva University of Agriculture and Technology, Narendra Nagar, Kumarganj, Ayodhya (U.P.) India during 2020-2021 (Y1 ) and 2021-2022 (Y2 ). High heritabilityin narrow sense (h2 ns) coupled with high genetic advance in percent of mean were observed for fruit length, fruit equatorial circumference, number of fruits per plant, average fruit weight, reducing sugars, non-reducing sugar, total sugar,chlorophyll content, total phenol content and total fruit yield per plant in the pooled indicating thereby these traits were less influenced by environment and were mainly under control of additive genes.

Genetic Analysis of Polygenic Traits for Seed, Fibre and Dual Purpose Linseed (Linum usitatissimum L.) Genotypes Grown under Sub Temperate Conditions of Western Himalayas

Genetic analysis of linseed plant genetic resources is very important to understand gene action and combining ability for crop improvement. Eight genetically diverse lines of linseed namely Surbhi, Bhagsu, Nagarkot, T-397, Himani, Baner, JRF-1 and JRF-4 were evaluated through half diallel cross analysis under sub temperate conditions of Western Himalayas. These eight parental lines identified for seed, fibre and dual purpose trait and 28 F1 progenieswere grown in CRBD to identify potential parents and their cross combinations for yield and associated traits under variable environments. Significant level of genetic variability was observed among studied genotypes for the yield, fibre and their contributing traits. Genotype×environment (G×E) interaction was also significant except for plant height and technical height indicating a definite role of environment in the performance of genotypes. Non-additive gene action was recorded for maximum traits. Based on GCA, three genotypes viz., Baner, Nagarkot and Surbhi were recorded to be good general combiner for seed yield whereas genotypes, JRF-1 and JRF-4 were good for early maturity and fibre yield. These promising genotype harbor the genes for various traits like high seed and fibre yield, early maturity, rust and powdery mildew tolerance. On the basis of high SCA effect, four cross combinations viz., Himani×JRF-4, T-397×JRF-4, Bhagsu×Nagarkot and Surbhi×Baner were found best for seed yield while four other viz., Surbhi×T-397, Nagarkot×Himani, Surbhi×Baner and Surbhi×Bhagsu were found best for fibre yield in pooled over environments. These genotypes and cross combinations can be used in further hybridization and selection can be done for early maturity, disease tolerance, seed, fibre and dual purpose trait as per the need of linseed breeding programmes in the country.

Combining ability and heterosis to root-knot nematode resistance on seven genotypes of kenaf using full diallel cross analysis

A full diallel cross is confirmed to be able to advocate kenaf breeders to select breeding materials, such as inbred lines that produce the best combination with heterosis properties. The results of this study provided information about general combining abilities (GCA) of parents, specific combining ability (SCA), as well as heterosis values. This study aims to estimate the combining abilities and heterosis values of root-knot nematodes in kenaf originated from the full diallel cross. Semi-field research was conducted in an experimental garden located at Karangploso Balittas, from November 2018 to January 2019. The variance of GCA values was higher than SCA values for the number of root knot, reproductive factors, and number of egg mass. In contrast, the variance of GCA values was lower than SCA values for the number of second-stage juvenile (J2) and the number of egg per egg mass characters. KR4, K45, and KR15 genotypes indicated negative GCA values on all characters tested. Meanwhile, KR1, Kin2 and DS028 genotypes signified susceptibility with a positive GCA value. The crossbreeding combinations showed negative SCA values on the number of second-stage juvenile, the number of egg mass and the number of egg per egg mass characters of resistance to root-knot nematodes (M. incognita), i.e. KR6 x DS028. KR4, KR5 and KR15 genotipe was quite consistent with negative GCA and SCA values, as well as heterosis values for characters of resistance to root-knot nematodes on kenaf roots on the number of second-stage juvenile (J2), the number of egg mass and the number of egg per egg mass characters tested. Genotype of KR4 x KR5 and its reciprocal have negative heterobeltiosis values on number of second-stage juvenile, egg mass, and the number of eggs per egg mass evaluated characters

Genetic Analysis of Diallel Crosses in Wheat under Drought and Normal Irrigation Treatments

Seven bread wheat genotypes were crossed in a7x7half diallel scheme in 2017/2018.Parents and their 21 F1 crosses were evaluated under normal and stress conditions during 2018/2019 in two field experiments. The results of analysis of variance were significant for all studied traits. The highest mean values were detected by parents P1, P1,P2, P3,P2 and p2 for plant height, spike length, No of spikes/ plant, 1000-kernel weight, biological yield/ plant and grain yield/ plant, respectively. While, the highest mean values were recorded with crosses P3xP5 for biological yield/ plant and grain yield / plant. Mean squares for both general (GCA) and specific (SCA) combining ability estimates were highly significant for most studied traits. The ratios between GCA and SCA exceeded the unity for all studied traits, except biological yield/ plant under drought, revealing that additive and additive x additive types of gene action are more important than non-additive gene action in controlling these traits. P6 exhibited positive and significant ĝi effects for biological yield/ plant. P7 gave positive and significant combiner for spike length, No of spikes/ plant and grain yield/ plant. The highest desirable SCA effects were obtained with P1 x P6, P1 x P7, P2 x P7, P3 x P5 and P4 x P7for grain yield/ plant which exhibited significant and positive ŝij effects

Correction to: Biplot analysis of diallel crosses for yield and some of morphological traits in wheat

The original version of this article unfortunately contained a mistake

BREEDING FOR SOME QUANTITATIVE TRAITS IN COMMON WHEAT (TRITICUM AESTIVUM L) USING DIALLEL CROSSES.

A diallel cross set was carried out among six parents of common wheat without reciprocal crosses to study the inheritance of heading date, maturity date, plant height, spike length, number of spikes per plant, number of kernels per spike,1000 grain weight and grain yield per plant using Hayman approach and Jones method. The parental varieties and their possible 15 crosses were sown under two different nitrogen levels i.e.,70 kg /faddan (normal) and 35 kg/faddan (stress) using randomized complete block design with three replicates per each nitrogen level . The diallel cross analysis were carried out using the approaches proposed by Hayman (1954) and Jones (1965). Mean squares for fertilizations were found to be significant for all traits studied except days to maturity and plant height, indicating differences between the two different nitrogen fertilization levels for most characters. Genotypes, parents and the resultant crosses mean squares were found to be highly significant for most traits studied at the two different nitrogen levels and their combined data. The additive genetic variance () was found to be highly significant for all traits studied at the two different nitrogen fertilizations except number of grains per spike and grain yield per plant at the two different nitrogen levels . The dominance genetic variation and were found to be highly significant for all traits studied at the two different nitrogen fertilizations. Moreover, the estimated values of dominance components and were found to be greater in their magnitude than the corresponding additive genetic variations () for most traits under investigation. Estimates of the ratio of dominant to recessive alleles in the parents (KD / KR) were found to be more than unity for all traits studied at the two different nitrogen levels, except grain yield per plant. Moderate heritability values were detected for heading date, plant height and spike length . For the other traits, low heritability in narrow sense was detected. The additive genetic variance (a) was found to be highly significant for all characters studied at both two nitrogen fertilizer levels. The dominance genetic variation (b) was highly significant for all-characters studied at the different two nitrogen fertilizer levels. The (a) values were found to be larger in magnitude than the corresponding (b) values for most traits studied.

Gene action for quality and quantitative characters in linseed (Linum usitatissimum L.)

The present investigation had shown the genetic analysis of different agronomic characters as well as quality traits in linseed of six parents were evaluated in 2009-10, during rabi season at Students Instructional Farm, C. S. A. University of Agriculture and Technology, Kanpur, U.P., revealed the role of both additive and non-additive gene action for all ten characters through diallel cross analysis. Average degree of dominance showed the presence of partial dominance for all the characters except iodine value which showed over dominance. The proportions of positive and negative effects in the parents were asymmetrical for all the characters. The ratio of dominant and recessive alleles in parents (KD/KR), indicated the dominant alleles were more frequent than recessive alleles for the characters, number of capsules per plant, days to maturity and iodine value in F1 and days to flower in F2 generation. Characters, plant height, number of primary and secondary branches per plant, 1000-seed weight, seed yield per plant and oil content in both F1 and F2 generations showed that recessive alleles were more frequent determining the extents of genetic gain that can be made in particular direction. If the alleles present in the population are predominantly of recessive nature, the extent of genetic advance will be limited. The computed ratio of (ĥ2/Ĥ2) estimate the number of gene groups suggested the preponderance of recessive genes; however they do have dominant genes. ‘t2’ value for uniformly test for Wr, Vr interprets distribution of dominant and recessive genes among the parents by investigating the relations.

Biplot analysis of diallel crosses for yield and some of morphological traits in wheat

A study of combining ability for improving bread wheat yield and yield components was carried out via genotype plus genotype × environment (GGE) biplot. Six bread wheat genotypes were used to obtain F1 in a diallel cross matings at the Gachsaran Field Station, Dryland Agricultural Research Institute during 2012–2013 cropping seasons. Analysis of variance indicated significant effects of genotypes, general combining ability (GCA) and specific combining ability (SCA) for all of the studied traits. The highest values of plant height (108.15 cm), peduncle length (33.95 cm) and grain yield (265.5 g m−1) were obtained in g6 (DAMARA-6 ICW99-0427-8AP-0AP-0AP-3AP-0AP). GGE biplot analysis showed that g4 (Kouhdasht) and g6 (DAMARA-6 ICW99-0427-8AP-0AP-0AP-3AP-0AP) were as the best general combiners for days to maturity, plant height and grain yield, whereas g1 (Karim) had the highest GCA effects for spike length and thousand grain weight, and g3 (Aflak) showed the highest GCA effects in terms of peduncle length. Meanwhile, g6 showed large SCA effects for thousand grain weight and grain yield, while g4 had high SCA effects for spike length. g5 (PASTOR/2*SITTA//PBW343*2/KUKUNACMSS04Y00333S-099Y-099ZTM-099Y-099 M-3WGY-0B) had large SCA effects for peduncle length. Because of significant effects of mid-parent heterosis for grain yield, g4 × g6 was considered as the best possible cross for improvement of this trait. Based on the results of present study, GGE biplot indicated good potential for identifying suitable parents and heterotic crosses and the best hybrids according to diallel mating design.

Diallel Cross Analysis for some White Maize Inbred Lines under Two Nitrogen Levels

A half diallel cross among seven white inbred lines of maize was made in 2016 growing season. The resulted of 28 F1 crosses along with the check hybrid SC130 were evaluated under two different nitrogen levels, i.e., 90 and 120 kg N/ fed using a randomized complete block design (RCBD) with three replications at the Experimental Farm, Faculty of Agriculture, Kafrelsheikh University in 2017 growing season, to estimate general (GCA) and specific (SCA) combining ability effects and their interactions with nitrogen levels as well as identify type of gene action controlling the inheritance of the studied traits. Data were recorded on days to 50% silking, plant height, ear height, ear length, ear diameter, No. of rows/ear, No. of kernels/rowand grain yield (ard/fed). The results showed that, the mean squares due to nitrogen levels (D), genotypes (G), crosses (Cr.), G × N and Cr. × N interactions were significant for all the studied traits. General (GCA) and specific (SCA) combining ability mean squares were highly significant for all the studied traits under both and across nitrogen levels. Both GCA and SCA effects were significantly interacted with nitrogen levels for all the studied traits, except GCA × N for ear diameter. The non-additive gene action played an important role in the inheritance of all the studied traits under the two nitrogen levels and the combined data, except days to 50% silking under N1 level. The inbred lines P1 and P7 showed the best desirable GCA effects for earliness and P2 and P6 for shorter plants and lower ear placement. Whereas, P2, P3 and P4 were the best general combiners for grain yield. The crosses P1×P3, P2×P7, P3×P6, P4×P5 and P5×P7 had the best SCA effects for grain yield as well as one or more of its components under both and across nitrogen levels. The two crosses P2×P7 and P4×P5 exhibited significant and positive superiority over SC 130 under both and across nitrogen levels.

ESTIMATION OF HYBRID VIGOR AND COMBINING ABILITY IN FULL DIALLEL CROSS OF MAIZE (ZEA MAYS L.)

The full diallel cross of six it inbreds line of maize in the Autumn season (2016) was carried out in the college of Agriculture, University of Anbar, alternative site Abu Ghraib Baghdad. In the spring season (2017) west of Iraq. The experiment included sowing the seeds of inbreds and hybrids resulting from crossing, which included 30 hybrid and reverse hybrids. using the design of the complete randomized design (RCBD) and three replicates. The aim of the study was to evaluate the behavior of the breeds and their hybrid and reverse axes by traditional and morphological methods. The results of the study showed the following: The genotypes differed significantly among all studied traits. The phenotypic performance of paternal strains 1 and 3 were distinct after they obtained the highest values of grain status. The superiority of these two strains was reflected in the cross-diallel (1x3) resulting from their crossing when given the highest grain yield. The results of the genetic analysis in the first method and the fixed model of the Griffing analysis indicated a greater importance for the non-additive gene in the inheritance of most of the studied traits, while the additional genetic act was more effective in inheriting the leaf area trait in the direction of reverse infarction. Most hybrid and reverse crosses gave significant values to the hybrid force in most studied traits.The results of the full diallel cross analysis indicated that the average squares of viability of the general and specific combining ability and reverse crosses were highly significant for most studied traits. This showed the importance of both the additive and non-additive function in controlling the inheritance of traits. Parents 1 and 3 showed an significant effect of their general ability in several traits, most notably the grain yield, and some of the hybrids showed desirable effect of their own union of grain status and a number of other traits. The ratio of the variation of the effect of the union to the general in the cross breed and reverse crosses was less than the correct one for all studied traits except for the paper area in the opposite direction. The percentage of inheritance was high values in the broad sense and low in the narrow concept of most of the traits studied in cross breeding and reverse.

Cytoplasmic and nuclear genetic components of membrane stability of winter wheat plants exposed to sub‐zero temperatures

AbstractWinter wheat (Triticum aestivum L.) is seeded in the autumn and harvested the following summer, and therefore, must survive multiple episodes of subfreezing temperatures throughout the winter months. Cellular membrane stability following exposure to subfreezing temperatures contributes to the ability to survive these episodes. This study investigated the inheritance of the ability to tolerate subfreezing temperatures with a seven‐parent diallel cross analysis of cellular membrane integrity as measured by electrolyte leakage after exposure to −10 or −14 °C. Significant differences in membrane stability were found among the parent lines. The inheritance of the freezing tolerance as measured by electrolyte leakage was complex and characterized by significant additive, dominant and cytoplasmic effects. General combining ability, indicative of additive genetic effects, were significant at both test temperatures, but accounted for 25.5% of the variance at the −10° C test temperature, and only 4% of the variance at the −14 °C test temperature. Specific combining ability, indicative of genetic dominance effects, were significant at both test temperatures, but accounted for only 14.6% of the variance at the −10 °C test temperature, and 38% of the variance at the −14 °C test temperature. Reciprocal (cytoplasmic) effects were significant and accounted for about 20% of the variance at both test temperatures. Cytoplasmic effects contributing to greater membrane stability were especially apparent in the cultivar Tiber when crossed to Masami, Lewjain, or Hatton. These results suggest that efforts to improve freezing tolerance are complicated by differing gene action at different test temperatures and also may benefit from identifying specific combinations of nuclear and cytoplasm sources that are most conducive to membrane stability following freezing.

SASHAYDIALL: A SAS Program for Hayman's Diallel Analysis.

Different methods of diallel crossing are commonly used in plant breeding. The diallel cross analysis method proposed by Hayman is particularly useful because it provides information, among others, on additive and dominance effects of genes, average degree of dominance, proportion of dominance, direction of dominance, distribution of genes, maternal and reciprocal effects, number of groups of genes that control a trait and exhibit dominance, ratio of dominant to recessive alleles in all the parents, and broad-sense and narrow-sense heritability. In this paper, we fully describe a SAS-based software SASHAYDIALL for performing a complete diallel cross analysis based on Hayman’s model with or without reciprocals. We demonstrate the use of SASHAYDIALL with two data sets; one is a published diallel cross data set with reciprocals in cabbage (Brassica oleracea L.), and the second is a data set from a multilocation diallel cross trial in maize (Zea mays L.) without reciprocals. With SASHAYDIALL, diallel experiments conducted in single sites can be analyzed to estimate various genetic parameters, and this analysis is extended over locations or environments to assess genetic effect × environment interaction. SASHAYDIALL is user-friendly software that provides detailed genetic information from diallel crosses involving any number of parents and locations.

Genetic architecture of some agronomic traits as deciphered from diallel cross analysis of Plantago ovata Forsk

From a collection of 105 genetic stocks of Plantago sp., a 7 × 7 diallel analysis was conducted for the estimation of gene action in seven parents in Plantago ovata. Using Hayman's Graphical (Wr – Vr graphs) model we analyzed the gene action for fourteen agronomic traits. The traits – days to 50% flowering, plant height, branches per plant, panicles per plant, peduncle length, panicle length, panicle weight per plot, days to maturity, seed yield per plot, inflorescence husk yield per plot, husk yield per plot and 100 seed weight exhibited overdominance whereas, leaf area and swelling factor exhibited partial dominance. The pattern of distribution of the seven parents along the regression line deciphered the absence of recessive genes in most of the traits.

Performance and Analysis of F2 Diallel Cross among Six Faba Bean Genotypes under Orobanche Infested Soil at Giza Research Station, Egypt

Performance and Analysis of F2 Diallel Cross among Six Faba Bean Genotypes under Orobanche Infested Soil at Giza Research Station, Egypt

APTITUD COMBINATORIA GENERAL Y ESPECÍFICA EN LA CALIDAD DE SEMILLA DE LÍNEAS S3 DE MAÍZ

El análisis de cruzas dialélicas es una herramienta útil para determinar el efecto genético en estudios de calidad de semilla de maíz (Zea mays L.). El objetivo de esta investigación fue determinar los componentes genéticos de aptitud combinatoria general (ACG), aptitud combinatoria específica (ACE) y efectos recíprocos (ER) involucrados en la expresión de la calidad de semilla y vigor de plántula de líneas S3 y sus cruzas directas y recíprocas. Las cruzas F1 y sus progenitores se sometieron a pruebas analíticas de calidad física como biomasa de semilla y calidad fisiológica mediante germinación estándar, velocidad de germinación y vigor por envejecimiento acelerado. Adicionalmente, se desarrolló un ensayo en arena como sustrato para registrar la emergencia y altura de plántulas, biomasa seca del vástago, índice de vigor I e índice de vigor II. Se utilizó un diseño experimental de bloques completos al azar con tres repeticiones en laboratorio y con dos repeticiones en la evaluación en cama de arena. Se encontraron diferencias estadísticas significativas entre genotipos en la calidad de la semilla y el vigor de la plántula. Situación semejante ocurrió para los efectos de ACG, ACE y ER en ambos grupos de características evaluadas, con predominio de ACG sobre ACE. Los efectos recíprocos significativos indican la importancia de seleccionar apropiadamente el progenitor femenino para favorecer la calidad de la semilla y el vigor de la plántula. En las cruzas con heterosis alta en estos rasgos participó cuando menos una línea de alta ACG y los efectos de ACE fueron altos y positivos. Las líneas de maíz TNM-5 y TNM-4 mostraron alta ACG y alta ACE en combinaciones específicas superiores, por lo que podrían ser empleadas primero en programas de mejoramiento genético por selección para incrementar la frecuencia genética aditiva en la calidad de semilla y vigor de plántula y posteriormente usarse en programas de hibridación.