Diallel Analysis Research Articles

Complete Diallel Analysis for Nematodes Resistance in some Tomato Genotypes التحلیل الدائری الکامل للمقاومة للنیماتودا فی بعض التراکیب الوراثیة لنبات الطماطم

In this study a complete diallel analysis was done under the condition of nematode infection, using four different parental genotypes of Tomato. Mean squares of the studied genotypes were significant for all studied parameters, which proves the presence of a considerable amount of genetic variation among studied genotypes. Also, GCA and SCA mean squares were highly significant for all studied traits. This means that both GCA and SCA were important in the inheritance of these traits. Likewise, reciprocal effect mean squares were found significant for all the studied traits indicating that these traits are controlled by extra-nuclear factors in addition to the nuclear factors. Also, data showed that significant SCA effects in demand direction for most crosses in some studied traits. The estimations of (σ2gi) and (σ2si) of the parental genotypes for all studied parameters indicated that the genotypes used in this study are of great importance to improve most of the studied traits. The estimation of genetic parameters and heritability for all studied traits proved the predominance of non-additive gene action in the inheritance of these traits. Results revealed that the cross (Cherry x Castle Rock) is a superior hybrid, and it could be selected in the breeding programs to resist nematode. Therefore, using this combination as started material for selection breeding program to produce resistant root-knot nematodes genotypes.

Diallelic Analysis of Tropical Maize Germplasm Response to Spontaneous Chromosomal Doubling.

Chromosome doubling is an important step in the production of maize doubled haploid (DH) lines to induce fertility in the male and female reproductive organs of haploid plants. Chromosomal doubling is routinely accomplished by treating haploid seedlings with mitosis-inhibiting chemicals. However, chromosomal doubling involves several labor-intensive steps and toxic chemicals. Spontaneous chromosomal doubling without any chemical treatments occurs at high frequency in haploids from a few maize genotypes. This study focused on elucidating the genetic components of two traits important for using spontaneous doubling in maize-breeding programs, namely, haploid male fertility (HMF) and haploid fertility (HF). In two different sets of diallel crosses, haploids were derived and assessed for HMF and HF in two environments in replicated trials. The results revealed significant genotypic variations for both traits. The general combining ability (GCA) and specific combining (SCA) were significant for both traits. Significant and positive GCA effects of up to 14% and 9% were found for HMF and HF, respectively. No significant reciprocal effects and genotype-by-environment (G×E) interactions were found for HF in both experiments, but HMF showed significant effects for both in one of the experiments. The GCA effects were more important than the SCA effects for HMF and HF across environments, implying that selection could facilitate their improvement. The high correlations between F1-hybrid performance and mid-parent values, as well as that between F1-hybrid performance and GCA effects, also supports the assumption that these traits are controlled by a few genes. SCA effects also played a role, especially when lines with low spontaneous doubling were used as parents. Overall, spontaneous doubling can be introgressed and improved in elite germplasm with selection, and it has the potential to be employed in DH pipelines.

Maternal inheritance in the efficiency of use of Azospirillum brasilense in maize

The maize crop demands high nitrogen input. However, Brazilian soils are generally deficient in this element. The use of associative bacteria, such as Azospirillum brasilense , can benefit agricultural systems that use low nitrogen levels. This study analyzes the occurrence of maternal inheritance in traits of maize genotypes for the efficiency of response to Azospirillum brasilense . For that, we used 132 treatments consisting of 66 crosses in complete diallel scheme with reciprocals. We evaluated two experiments in the same area and under the same conditions. We performed one experiment without nitrogen topdressing / with Azospirillum brasilense inoculation and another with nitrogen topdressing / without Azospirillum brasilense inoculation. These experiments took place in the second crop of 2017, in a randomized block design with two replicates. After obtaining the data, we estimated the efficien­cies for the use of Azospirillum brasilense by adapting the Fischer model. From these data, we conducted analy­sis of variance, t test, and diallel analysis, thus estimating maternal inheritance. The evaluated traits showed no maternal inheritance, being governed by nuclear genes. Most genotypes were efficient for the use of A. brasilense , for all traits.

Enhancing In-crop Diversity in Common Bean by Planting Cultivar Mixtures and Its Effect on Productivity

Common bean (Phaseolus vulgaris L.) is the most important food legume crop worldwide. Canadian beans, especially large seeded cultivars of Andean origin, have relatively narrow genetic diversities. Establishing crops with mixtures of cultivars instead of pure lines is a simple, cost effective way to increase genetic diversity in the field. A number of studies have demonstrated the benefits of mixture cropping over monocropping in controlling disease, increasing water use efficiency and increasing yield stability. The objective of this study was to determine the effects of increasing in-field diversity, by using mixtures of bean cultivars instead of monocultures, on productivity. The feasibility of growing bean cultivar mixtures in southern Ontario environments was confirmed with a small pilot study that was conducted with four bean cultivars and restricted number of mixtures at two locations in 2017. Mixture performance experiments were performed with seven diverse bean genotypes at two Ontario locations [Woodstock and Elora (two planting dates) research stations] as pure stands and all possible binary mixtures (planted in alternate rows or as completely random mixtures) in 2018. Conventional plot-based above ground crop data were collected. Mixing efficiencies were calculated from the yield data using a Relative yield of the mixture (RYM) index. Diallel analysis was used to identify general mixing ability of cultivars and specific mixing abilities of mixtures. Significant differences among seven bean cultivars and their mixtures were identified in all three environments for all analyzed traits. The results indicated multiple benefits of planting mixtures compared to monocultures A number of mixtures overyielded component cultivars grown in pure stands; they had higher yields, RYM index values greater than one and positive specific mixing abilities (for yield) in both types of biblends. The research has the potential to provide a theoretical basis for the use of precision agriculture tools to plant fields with mixtures instead of monocultures. It could lead to greater in-field diversity in the crop and in the above and below ground ecosystems that might provide greater buffering capacity and resiliency to the cropping system as well as increased ecosystem services.

Diallel analysis of “dedo-de-moça” pepper seeds in relation to physiological potential

ABSTRACT “Dedo-de-moça” (Capsicum baccatum var. pendulum) is one of the main chili peppers grown worldwide. However, studies on genetics and breeding of this species are rare, when compared to other Capsicum species, manly in relation to physiological seed quality traits. In this sense, this study aimed to evaluate the combining ability of “dedo-de-moça” chili pepper in relation to physiological seed quality traits, determine the gene effects involved in the expression of these traits, and identify promising hybrid combinations. Crosses among five parents (Hortivale, Horticeres, Brs Mari, UEL 110 and UEL 111) in a full diallel mating design, resulted in 20 F1 hybrids. Griffing’s diallel model was used to estimate general and specific combining ability (GCA and SCA, respectively) as well as the reciprocal effect (RE). Wide genetic variability was observed for all evaluated traits. Significant effects of GCA, SCA and RE were also verified for all traits, showing that additive, non-additive and cytoplasmic effects are involved in the genetic control of physiological seed quality. Non-additive effects were predominant for all traits, being UEL 111 (♂) × Hortivale (♀) and Hortivale (♂) × UEL 110 (♀) considered promising hybrids for obtaining more vigorous seeds with higher germination and greater longevity.

Application of dialle analysis in the study of the combination ability of corn

The article discusses the results of the use of diallelic analysis in the study of self-pollinated lines of corn. The average grain yield of self-pollinated lines (2,30 – 2,84 t/ha), as well as the average group indicators of hybrids (3,29 – 5,49 t/ha) were noted. The effects of general and variance of the specific combining ability of the lines were revealed. Ranking by grain yield allowed us to arrange the lines in the following sequence: CL 7 <MK 130 U <RSK 25 <PH26 <Yk12D2, Om 255 <MK 11 <Ch46 <Bg1266 <LV32 <RSK 7 <Yuv 19 <RSK 3 <Om232, KS 25 <Od 28. The results of the analysis of the combining ability of self-pollinated maize lines indicate a low value of the GCA effects in the lines of CL 7, Ch46 and a high effect of GCA in the lines of RSK 7, MK11, RSK 3. Significantly significant indicators of the components of dominance (H1, H2.), in absolute value exceed the values of component D, characterizing the additive effect of genes. The difference between the total average trait of all offspring (ml1) and the average parental forms (ml0) has positive values, which indicates that dominance is directed towards the parental forms with a greater severity of the trait. An analysis of the components indicates that, depending on the growing conditions, 2–7 genes or groups of genes affect the manifestation of grain yield. In 2016-2017 The paratypical component of dispersion had a significant effect on grain yield (E).

Multi-trait multi-environment diallel analyses for maize breeding

Genetic study in maize (Zea mays) germplasm development is an important step to understand the genetic variability and complementarity between heterotic groups, as well as additive and dominance genetic effects. Thus, diallel analyses have been widely adopted with the aim of identifying the best parental lines and the best crosses. In addition, different environmental conditions make genetic selection difficult. Thus, the objectives of this study were to compare individual and joint analyses of a diallel design through a mixed model methodology for maize breeding, and to evaluate and interpret the genetic effects and their interaction with the environmental effect. Thirteen F2 hybrids were crossed in an incomplete diallel scheme. Seventy-eight inter-population hybrids, and thirteen self-pollinated parents were evaluated. Eleven traits were evaluated, and emphasis was given to the Grain Yield (GY) trait. The significance of the GY trait, specifically, varied across environments. Joint analysis, in particular, presented significance for dominance and additive by environment interaction effects. Joint analysis had the highest selective accuracies for six traits. The correlation coefficients showed similar results, with values from 0.15 to 0.50 between pairs of environments. Gains with selection, considering each environment, ranged from 9.17 to 20.66%, when five hybrids were selected. When direct gains were compared with indirect gains, combined analysis confirmed the high efficiency of selection. For selection of parents, combined analysis achieves the same results as direct selection when two parents were selected.

Diallel analysis of popcorn populations for yield, popping expansion and resistance to fall armyworm

ABSTRACT The objective of this study was to estimate the varietal and heterotic effects related to grain yield, popping expansion and resistance of popcorn against fall armyworm. Twelve open-pollinated varieties were intercrossed in a complete diallel mating scheme. The 66 experimental hybrids, together with their parents and controls Zapalote Chico, BRS 1030 and IAC 125, resulted in a total of 81 treatments, evaluated in an experiment in a 9x9 triple-square lattice design, in Maringa-PR and Araruna-PR. The data were analyzed according to the diallel model of Gardner and Eberhart (1966). The following traits were evaluated: grain yield (GR); mean plant height (PH) and insertion height of the highest ear in the stem (EI); silking (SIL); final plant density (FD) and popping expansion (PE). Variety PR 023 is indicated for intrapopulation improvement for grain yield. Regarding popping expansion, the results indicated cross SAM x UNB 2U C5 for recurrent reciprocal selection. In relation to resistance to fall armyworm, the varieties PARA 172, PA 091, PR 023, and SE 013 were selected for intrapopulation improvement. On the other hand, the crosses PARA 172 x BOZM 260, PA 091 x BOYA 462 and SAM x UNB 2U C5 can be indicated for interpopulation improvement.

Genetic characterization and divergence studies of maize (Zea maysL.) lines developed from landraces indigenous to North Eastern Hill Region (NEHR) of India

AbstractThe current study focused on characterization of the underlying genetic divergence in inbred lines developed from local landraces of North Eastern Hill Region of India – a designated Asiatic maize diversity centre – following six generations of inbreeding. Substantial genetic differentiation was indicated based on very high to moderateFstvalues for 22 of the 38 simple sequence repeat markers studied. STRUCTURE analysis partitioned the subset into two distinct and one admixture subgroup (Populations I, II and III respectively) accompanied by a significant reduction in heterozygosity. Population II was further subdivided into subpopulations Pop-M9 and Pop-T9. Nei's pairwise genetic distance and populationFstvalues indicated that Populations I and II were more divergent with neighbour joining clustering analysis clearly defining landraces originating from the states of Tripura (Population II) and Sikkim (Population I) as most divergent. Principal coordinates analysis could explain 31.26% of the variation present in the subgroups wherein Population I was more variable. Analysis of molecular variance andFstcoefficients (P< 0.001) indicated 17% population structuring with 55% variation detected for individuals within populations. These results combined with the presence of phenotypic variability in the subgroups for yield traits supported by results of a preliminary partial diallel analysis strongly suggest the existence of distinct heterotic groups. Divergence studies are crucial for exploiting heterosis, and the current study would go a long way to help establish a germplasm base for developing varieties with improved agronomic performance and surer commercial prospects no reports of which are available thus far.

Combining Ability and Gene Action Analysis for Seed Yield and Component Traits in F2 Generation of Vigna mungo L. Hepper by using Griffing Approach

Background: Urdbean (2n=2x=22), also known as blackgram is an important short duration legume crop belonging to family Fabaceae, widely cultivated in Asia. Urdbean occupies an important position among pulses owing to its high seed protein (25-26%), carbohydrates (60%), fat (15%), minerals, amino acids and vitamins. Owing to its low water requirement, it is also suitable for rainfed conditions. It adapts well to various cropping systems owing to its ability to fix atmospheric nitrogen in symbiosis with soil bacteria, rapid growth and early maturity. Half diallel analysis was adopted in present study to gather information on gca (general combining abilities) and sca (specific combining abilities) of 6 diverse parents and simultaneously estimating various types of gene effects involved in the expression of seed yield and related attributes in urdbean. Methods: The F1’s were developed during 2017 in 9 x 9 half diallel fashion by Sharma et al. 2019 and these F1’s were evaluated. Significant crosses on the basis of gene action and combining ability were selected for further advancement. The experimental material comprised of the six parents and 15 F2’s of a 6 x 6 half diallel cross among six cultivars of urdbean (four are purelines viz., Palampur-93, HPBU-111, DU-1 and KU-553 and rest of the two are advanced and indigenous lines viz., Him Mash-1 and IC-281994). The F2’s along with the parental genotypes were grown in a Randomized block Design (RBD) with three replications at Experimental Farm of the Department of Crop Improvement, COA, CSK HPKV Palampur (H.P.) during Kharif, 2018. Results: The cross combination, Him Mash-1× HPBU-111, was identified the best for high seed yield on the basis of sca. The specific crosses, Palampur-93 × IC-281994, Palampur-93 × KU-553 were good specific combiners for most of the traits viz., plant height, branches per plant, pods per plant, biological yield per plant, seed yield per plant, harvest index, 100-seed weight and crude protein content.

Combining Ability and Heterosis in Diallel Analysis of Maize (Zea mays L.) Lines

A sound breeding program for maize improvement is very important to meet the demands of the growing population. Therefore, combining ability and heterosis were studied in a 4 x 4 full diallel cross in maize for growth attributes, yield and its contributing traits. Randomized Complete Block Design (RCBD) with four replicates was used to study the general combining ability of parents, specific combining ability of F1s (including reciprocals) and heterosis of the F1s over commercial check variety on selected agronomic characters. Genotype was highly significant for all the traits studied. The combining abilities (GCA and SCA) and reciprocal mean squares were highly significant for most studied characters. The ratio of GCA/SCA was not less than unity for studied traits excepted for days to anthesis and ear height. The results indicated that the additive genetic effects were more important and played major role in studied traits. Thus, results revealed GCA effects for the parental lines (PL). Where ‘PL2’ was excellent combiner for number of tassels and cob circumference and ‘PL3’ was good combiner for days to silking and grain yield (t.h-1). While ‘PL4’ for short height. Majority of the F1s from the GCA effects showed high SCA effects. This F1 (PL2 x PL3) performed best amongst. However, several reciprocals were not desirable. Heterosis estimation was carried out using a commercial check, Oba super II. When commercial check was used, the percent heterosis especially on grain yield varied from -8.89 to 22.62%. Among the twelve F1s, nine of the crosses exhibited significant positive heterosis for grain yield (t.h-1). Those F1s that showed significant positive and/or negative desirable traits for SCA effects and significant positive heterosis could be used for varietal development in maize breeding. And conservation of those parents that exhibited high GCA effects be considered as well.

Heterosis studies using Diallel analysis in bread wheat (Triticum aestivum L.)

The present study was carried out for the estimation of heterosis and heterobeltosis in bread wheat during the year 2017-18. A diallel set of 9 x 9 was prepared by crossing nine genotypes in all possible combinations excluding reciprocals. Parents and their F1 generations were planted in RBD (randomized block design) with three replications. The observations were recorded on five randomly selected plants in parents and F1s for thirteen traits. Analysis of variances showed that significant variation is present among all the genotypes for all studied traits. The mean sums of squares due to parents as well as crosses were found highly significant for all thirteen traits, indicating the existence of substantial variation for all the traits among the genotypes as well as crosses. No any cross combination was found that exhibit significant heterosis for all the traits in the present investigation. Cross combinations namely, HD3059 × Raj3765, HD2967 ×WH1184, HD2967 × Raj3765, HD3059 × WH1184 and HD3059 × WH283 were found most promising for the grain yield per plant by showing high per se performance and heterosis over better parent. These crosses could be extensively used for developing superior segregates and better pure lines for different breeding programmes.

Assessment of combining ability and standard heterosis through diallel analysis in sesame (Sesamum indicum L.)

Sesame is a drought tolerant oilseed crop with highest oleic acid content, which is yet to be explored for its hybrid vigour. With the view of producing elite hybrids, combining ability in sesame was studied among five sesame genotypes through diallel analysis. A set of 20 F1’s and their parents were evaluated at Plant Breeding Farm, Faculty of Agriculture, Annamalai University in RBD design with three replications. For this study, estimation of combining ability of seed yield traits viz., the number of days to 50% flowering, plant height, the number of branches per plant, the number of capsules per plant, capsule length, the number of seeds per capsule, 1000 seed weight and seed yield per plant were recorded from five randomly selected plants in each replication. Among the parents, TMV 5 and TMV 3 were adjudged as superior for seed yield per plant and most of the characters. Among the hybrids, TMV 3/TMV 5 and TMV 3/VRI (SV) 2 were identified as best performers since these hybrids had desirable per se performance for all the eight characters studied followed by TMV 3/TMV 6 and TMV 6/TMV 3 for seven characters including seed yield per plant. The combining ability variance revealed the preponderance of additive gene action for all the characters studied. Based on sca effects, the hybrid VRI (SV) 2/TMV 3 was considered as the best performing hybrid followed by TMV 3/TMV 5 and TMV 3/TMV 6, which could be further utilized in hybrid development in sesame. Considering standard heterosis, hybrids, TMV 3/TMV 5, TMV 3/TMV 6, TMV 5/TMV 3 and TMV 6/TMV 3 found to be the better performing. Comparing per se, sca and standard heterosis VRI (SV) 2/TMV 3 observed to be the best along with the hybrids TMV 3/TMV 5 and TMV 3/TMV 6 as the better hybrids.

Hayman’s diallel analysis for yield and attributing traits in sesame (Sesamum indicum L.)

Eight sesame (Sesamum indicum L.) genotypes were crossed in a half diallel mating fashion. The analysis of variance for combining ability revealed that the mean sum of squares are due to the general combining ability were highly significant for all the traits. The t2 test specified the fulfillment of assumptions required under diallel analysis for all the traits studied except the number of effective branches per plant, capsule length (cm) and harvest index (%). The component D measures the additive effects of genes. It was significant for all the traits except seed yield per plant and harvest index. The components H1 and H2 were significant for all the traits except days to maturity revealing the importance of fixable and non-fixable component. Greater values of H1 than H2 and the ratio of H2/4H1 (< 0.25) confirmed the unbalanced distribution of gene at the loci in the parents’ implying dominance for all the traits. It was also confirmed by greater than one value of KD/KR components for all the traits which suggested the higher frequency of dominant genes than recessive genes in the parents. The component F was significant for days to flowering, days to maturity, capsule length, oil content and leaf area per plant. The graphical analysis showed the regression line intercepted Wr axis below the origin indicating over dominance for plant height, the number of seed per capsule, oil content and leaf area per plant. The regression line intercepted the positive side of Wr axis for days to maturity which implies the presence of partial dominance.

English

In the kernels of wheat, a macro molecule called phytic acid acts as an inhibitor of nutrients. Phytic acid in high concentration is undesirable as it hinders the absoption of other molecules. Regression analysis, the model of additive-dominance and Hotelling&rsquo;s t2 test were adequate for biological yield, grains spike-1 and phytic acid, while partially adequate results were found for grain yield and 1000-grain weight. Greater values of H1 and H2 than D for biological yield, grain yield, 1000-grain weight, grains spike-1, and phytic acid concentration indicated that these traits were under the control of non-additive gene action. Same results were also confirmed by average degree of dominance. Estimates of heritability for broad and narrow sense varied greatly for the traits of biological yield (0.89, 0.10), grain yield (0.98, 0.13), 1000-grain weight (0.68, 0.25) grains spike-1 (0.680, 05), and phytic acid concentration (0.86, 0.01). Phytic acid concentration ranged from 0.56 to 3.43% among F1 crosses while for parental genotypes the range was 1.06 to 3.67%. Some of the F1 hybrids like Ps-2005 &times; Ghaznavi (0.56%), AUP-4006 &times; Ps-2004 (0.74%), Janbaz &times; Ps-2004 (0.89%) and Janbaz &times; Ps-2005 (1.01%), indicated the lowest concentration of phytic acid. This research confirms that F1 hybrids with low phytic acid concentration could yield desirable segregants. &nbsp; Key words: Bread wheat, phytic acid, biological yield, grain yield, diallel analysis, inheritance, heritability.

The Genetics of Encephalization in Eight Inbred Mouse Strains and their F1 Crosses

Increased relative brain size (encephalization) is an important feature of primate and human evolution that has been associated with increased intelligence. Although the heritability of brain size is known to be high, the extent to which different genetic factor types (e.g., additive genotype, maternal genotype, sex, nonadditive genetic interactions) contribute to measured brain size and encephalization are not as well understood. Endocast measures from a large normative sample of genetically diverse mouse lines were estimated to quantify 1) how increased encephalization impacts neurocranial shape and 2) the contribution of various genetic factors towards determining encephalization. Digital endocasts were estimated for 1182 mice representing the eight Collaborative Cross mouse inbred founder lines and 62 reciprocal F1 crosses. Endocasts were estimated by applying a single atlas image endocast segmentation to micro‐computed tomography (μCT) images of each specimen’s skull, based on the nonlinear volumetric image registration of each μCT to the representative atlas image. This method was validated by comparison of automatically extracted endocasts to endocasts that were manually segmented (using Endex software) for a large subset of the specimens. Measures of endocast volume, length, width, and height represent different aspects of endocast size. Ratios of volume over cranial base length (IRE) and volume over body weight (V2W) represent encephalization relative to cranial size and body size, respectively. Diallel analysis (BayesDiallel in R) was used to estimate the genetic influence of multiple additive and nonadditive genetic factors on each measure. The total heritability of each size and encephalization measure is between 0.82 and 0.87, with additive founder strain genotype effects accounting for the vast majority of this heritability. There are also significant inbreeding, sex, maternal genotype, and founder strain cross‐specific effects. The additive effects of founder genotypes were more pronounced for V2W than for IRE, with some of the strains showing opposite directions of effect between these encephalization measures. Care must be taken in the measure of overall size used to estimate encephalization. While inbred mice tend to have smaller overall size, they tend to have a higher encephalization, likely because the impact of inbreeding on brain volume is not as severe as the impact on skull size or body weight. In addition to the strength of genotypic effects, we quantified the influence of increased encephalization on overall cranial vault shape. As encephalization increases, endocasts display more substantial increases in cranial vault height than either length or width. Variation in the mouse cranial base size appears limited, while the shape of later ossifying vault bones strongly covaries with relative brain size. These results support the conclusion that encephalization is highly heritable and indicate which types of genetic factors contribute most strongly. Additionally, relatively large mouse brains are accommodated primarily through variation in cranial vault height, leading to a round cranial vault shape that is analogous to globular vault of modern humans.Support or Funding InformationFinancial support provided by Stony Brook University Startup Funds to CJP

Genetics of fruit yield and its component characters in okra (Abelmoschus esculentus (L.) Moench)

A full diallel cross involving seven okra genotypes was used to study the inheritance of fruit yield and its component characters in okra. Data from the F1 generation and parents were analyzed using Hayman (1954) method of diallel analysis. The estimates of D were significant for all the traits studied. The values of H1 and H2, as well as H2/4H1, indicated that there were unequal frequencies of the alleles at all the loci. An excess of dominant alleles was involved in five out of the eleven traits of interest. The mean degree of dominance was more than unity for all the traits studied, including fruit yield per plant. The narrow sense heritability estimates were higher for four out of the 11 traits studied. In the presence of overdominance for yield, the best recurrent scheme to develop hybrids will be reciprocal recurrent selection.

Combining ability of biomass sorghum in different crop years and sites for bioenergy generation

AbstractBiomass sorghum [Sorghum bicolor (L.) Moench] is considered as a raw material of great potential for bioenergy generation. The objective of this study was to estimate the combining ability of biomass sorghum of A and R lines, carrying the bmr‐6 allele, evaluating different crop years and site effect, aiming at the bioenergetic potential for the production of second‐generation ethanol. Four male‐sterile lines (A), and 10 fertility restorative lines (R) were used, obtaining 40 hybrids bmr and sensitive to the photoperiod. From the F1 seeds, four experiments were conducted in different crop years and sites. The data were submitted to individual diallel analysis according to IV model proposed by Griffing (1956), adapted for partial diallel design by Geraldi and Miranda Filho (1988). Promising lines were identified to breeding line groups A and R, aiming to obtain new lines breeding to obtain superior hybrids. The crop year and site effects were significant for most traits. The use of partial diallel analysis is promising for the biomass sorghum breeding program and A and R lines with potential bioenergetic were identified for the production of second‐generation ethanol.

Combining ability of carrot genitors for root yield traits and leaf blight tolerance

The market demand for uniformity and productivity of commercial carrot roots has prioritized hybrid materials over open-pollinated varieties. In this sense, the objective of this work was to estimate the combining ability of carrot genitors for root productivity and resistance to leaf scorch. The experiments were conducted in Gama, DF, in the agricultural years 2012/13 and 2013/14. We evaluated 33 carrot hybrids, originated from crosses between three male-sterile populations, with 11 male-fertile S2 lines, all the genitors being of tropical origin. At 90 days after sowing, the severity of the leaf blight disease was estimated in the plots. At 100 days after sowing, harvesting was performed and root yield characters were evaluated. Analysis of variance and partial diallel analysis were performed for each year and jointly for both years. It was found that additive and non-additive genes are important in the manifestation of root yield and leaf blight resistance traits in carrot hybrids. The male-sterile parents with higher overall combining ability for root productivity are strains LM-649 and LM-650 and, among the male-fertile, strain LM-555-2-2. The best hybrids for root yield and leaf blight resistance are LM-649 × LM-555-11-1, LM-650 × LM-555-7-1 and LM-650 × LM-554-8-1.

Diallel Analysis of some Quantitative Traits in Eight Inbred Lines of Maize and Gge Biplot Analysis for Elite Hybrids

An 8x8 half diallel analysis were performed at two planting dates to study the importance of types of combining ability (GCA and SCA) and its interaction with environment in F1 of maize. Planting dates (D), crosses (Cr), GCA, SCA, CrxD, GCAxD, SCAxD were significant for all traits. GCA/SCA exceeded the unity for most traits. Non-additive seemed to be more prevalent for plant, ear heights and grain yield plant-1. P8 gave significant positive () effects for all studied traits. High SCA effects were exhibited by the crosses P1xP7, P1xP8, P2xP5, P3xP4, P3xP8, P4xP7, P4xP8 and P5xP6 for grain yield plant-1 across planting dates. Superiority of P2xP5 and P3xP8 over SC Hytech 2031 reached 13.84 and 6.16%, respectively. However, useful heterotic effects relative to SC 128 mean value were 21.14 and 10.22%, for the aforementioned crosses, respectively. P1xP8, P4xP8 and P5xP6 gave positive insignificant out-yielded than check hybrids. The five superior hybrids P2xP5 (G1), P3xP8 (G2), P5xP6 (G3), P1xP8 (G4) and P4xP8 (G5) along with SC10 (G6), SC 128 (G7) and SC Hytech 2031(G8) were evaluated in 2019 season at various environments using RCBD with 3 replicates to identify environments and suitable adapted maize hybrids. Stable genotypes are ranked descending for means of grain yield as follows: G1 > G8> G2> G7. G1, G8, and G2 were above average stability while genotypes G7 showed below average stability. Thus, G1 (P2xP5) and G2 (P3xP8) are promising crosses, and it's recommended to register as new varieties with high productivity and stability across environments.