Cross Combinations Research Articles

Chromosomal analysis of progenies between Lilium intersectional hybrids and wild species using ND-FISH and GISH

IntroductionIntersectional hybrids in lilies possess significant breeding value, but the lack of complete lily genomes and complex genotypes pose challenges for early identification of lily hybrids. This study aimed to use intersectional hybrid cultivars as female parents and wild lilies as male parents to facilitate early identification of hybrid offsprings and enhance the efficiency and convenience of the process.MethodsWe investigated the nature of cross combinations using Non-denaturing Fluorescence In Situ Hybridization (ND-FISH) and Genomic In Situ Hybridization (GISH) techniques. Three novel oligonucleotide probes—Oligo-pTa794, Oligo-pITS and Oligo-telo—were developed for lily chromosome research.ResultsOur results demonstrated successful hybridization between wild lilies and intersectional hybrid cultivars, producing a total of 130 hybrid progenies. The combination of ND-FISH and GISH analyses effectively revealed the genomic composition of the hybrid progeny and determined the parental origin of specific chromosomes.DiscussionThis research provides significant guidance for lily breeding practices and offers a valuable reference for the application of ND-FISH and GISH techniques in interspecific hybridization breeding and molecular cytogenetic research across various plant species. The methods developed enable more precise, efficient, and convenient identification of hybrid offsprings.

Exploitation of heterosis and combining ability potential for improvement in okra (Abelmoschus esculentus L.)

Okra (Abelmoschus esculentus L. Moench) is a vital vegetable crop known for its nutritional and economic significance, especially in tropical and subtropical regions. Studying heterosis and combining ability in okra is crucial for enhancing its yield, quality, and resistance to pests and diseases. Heterosis can lead to superior offspring with enhanced traits while understanding combining ability helps in identifying the best parent combinations for breeding programs. Okra is an often cross-pollinated crop; therefore, exploiting heterosis is advantageous. The study was conducted from 2021 to 2022 at the Experimental Farm and Quality Analysis Laboratory, Department of Vegetable Science, College of Horticulture, Dr Yashwant Singh Parmar University of Horticulture and Forestry, Nauni, Solan, Himachal Pradesh, India to evaluate the heterosis and combining ability in okra to facilitate the development of high-yielding, resilient cultivars. The experimental material consisted of an F1 population of 30 crosses obtained from 10 parental lines crossed with three testers in a Line × Tester mating design, plus a standard check (Punjab-8). Estimates of heterosis (heterobeltiosis and standard heterosis) of the cross combinations UHFO-6 × Pusa Bhindi-5, UHFO-6 × Arka Anamika and UHFO-9 × Arka Anamika were high for inter-nodal distance, number of pods per plant, average pod weight, pod yield per plant, harvest duration, hundred seed weight, mucilage content, etc. Higher estimates of general combining ability (GCA) effects for pod yield per plant were observed in the parental lines UHFO-6 (123.47) and UHFO-9 (7.49). Among the cross combinations, UHFO-10 × Hisar Unnat (38.81), UHFO-2 × Pusa Bhindi-5 (38.29), UHFO-2 × Arka Anamika (17.42), and UHFO-5 × Arka Anamika (15.06) demonstrated higher estimates of specific combining ability (SCA) effects for pod yield per plant. The cross UHFO-2 × Hisar Unnat (160.00) exhibited the highest heterobeltiosis for mucilage content, while UHFO-10 × Arka Anamika (562.03) showed the highest standard heterosis for total polyphenol content. These cross combinations could produce okra with enhanced nutritional and medicinal properties. The highest GCA and SCA effects for pod yield per plant were observed in UHFO-6 (123.47) and UHFO-10 × Hisar Unnat (38.81), respectively. Identifying these parental lines and cross combinations based on their combining ability can result in the development of okra hybrids with substantially higher yields. In future, after multi-location trials, these parents and crosses can be released to replace existing okra cultivars (hybrids/varieties). Higher yielding and better quality okra cultivars can enhance the profitability for farmers, contribute to food security, and meet market demands more efficiently.

Enhanced growth and yield in semi-indeterminate tomato (Solanum lycopersicum): A heterosis study under protected condition

A diallel design was employed to assess the magnitude of heterosis, aiming to improve growth and yield of semi- indeterminate tomato by identifying the desirable cross- combinations. Five semi-indeterminate tomato genotypes (VRT13, EC15127, EC362941, EC521061 and EC521069) were crossed in diallel mating fashion during rainy (kharif) season of 2020. Crosses and the parents were examined for heterosis studies under naturally ventilated polyhouse during winter (rabi) season of 2020–21. The results revealed the presence of heterotic vigour in the growth and yield characteristics of the hybrids with significant differences among the traits studied. Hybrids from crosses EC15127 × EC362941 and VRT13 × EC362941 resulted negative heterosis over mid and better parent, respectively for days to first flowering indicating their earliness for flowering. VRT13 × EC15127 and EC15127 × EC362941 noticed heterosis over better and mid parent, respectively for fruit yield. Based on overall performance, the cross combinations EC15127 × EC362941, VRT13 × EC521061, VRT13 × EC15127, VRT13 × EC362941 and EC521069 × EC362941 were performed best over their parents for growth and yield parameters. Hence, these hybrids can be exploited directly or can be used further for development of improved commercial lines

Seed traits inheritance in Fagopyrum esculentum Moench. based on image analysis method.

Common buckwheat (Fagopyrum esculentum Moench.) is one of the most important orphan crops worldwide. Various research efforts have been done to improve cultivation methods to enhance important agronomic traits such as productivity and biotic/abiotic resistance. One important aspect is the seed trait, which has not been extensively studied due to the time-consuming and tedious nature of its examination. Despite this, understanding seed traits is crucial for meeting consumer needs and optimizing crop yields. Therefore, the aim of the study is to investigate the inheritance of common buckwheat seed traits-such as shape, size, and coat color-using an image-based approach. This method allows for the analysis of a large number of seeds with a level of accuracy and precision that was previously unattainable. The results indicate that seed coat color is inherited maternally. Notably, the parameters in size had substantial increases acting like overdominance. The number of seeds that were harvested from F1s of each cross differed a lot depending on the cross combinations and pin/thrum type. In addition, seed size had large reduction in F1s from the different seed-sized parents, especially in thrum type. These may show that there could be cross barriers. The results revealed trends of maternal inheritance for seed shape and coat color in buckwheat, an area that has not been extensively studied. These findings could support buckwheat breeding efforts, helping to address market needs and food demands in the face of significant climate change.

Study on Interspecific Hybridization between Daincha (Sesbania aculeatea) and Related Species

Wide hybridization can enrich crops' genetic background and diversity by comparing different species and integrating the different parental traits. In the present study, interspecific hybridization was performed between Daincha and two related sesbania species by hand emasculation and crossing technique. A total of 460 hybrids were obtained in the Sesbania aculeata X Sesbania bispinosa cross, but no hybrids were obtained in their reverse cross, indicating the same cross combination has a large difference in the reciprocal crosses and that the hybrid has certain unidirectionality. The hybrids looked more like their Sesbania aculeata parent in stem and leaf characteristics. A total of 570 hybrids were obtained in the cross Sesbania aculeata X Sesbania rostrata, while no hybrids were obtained by reverse cross combination. The hybrid showed intermediate morphological traits when compared to their parents. Developing hybrids and segregating populations are useful genetic resources and provide interspecific hybridization to enlarge the gene pool of Daincha species.

Assessment of Combining Ability and Gene Action in F1 Generation for Quantitative and Qualitative Traits of Pigeonpea [Cajanus cajan (L). Millsp.

To estimate combining ability and nature of gene action, twenty four pigeonpea crosses were developed from ten parents in Line × Tester fashion during Kharif 2022-23 and were evaluated in Randomized Block Design with three replications during Kharif 2023-24. The estimates of σ2gca were lower than the corresponding σ2sca for all the twelve characters studied indicating the predominance of non-additive gene action. Among the parents, the line GJP 1915 was found to be good general combiner for seed yield per plant and its yield contributing characters like plant height, number of primary branches per plant and pod length. The tester GJP 1820 was also good general combiner for seed yield per plant and its component traits like plant height, number of primary branches per plant, number of secondary branches per plant, number of pods per plant and 100-seed weight. The cross BDN 2013-41 × UPAS 120 had registered the highest sca effect for seed yield per plant. The sca effect in this cross combination was also accompanied by significant and desirable standard heterosis and high per se performance for days to maturity, reproductive phase duration, number of secondary branches per plant, number of pods per plant and number of seeds per pod and significant and desirable heterobeltiosis for days to maturity, reproductive phase duration, number of primary branches per plant, number of pods per plant and 100-seed weight. The cross GJP 1915 × BLACKTUR had registered significant and positive sca effect for seed yield per plant which was also accompanied by highest per se performance for pod length. These cross combinations can be potentially utilized in future breeding programmes for exploitation of hybrid vigour.

Estimation of Heterosis for Plant Growth, Oil Content and Yield Related Traits in Indian Mustard [Brassica juncea (L.) Czern and Coss] Using Half Diallel

Genetic investigation was carried out diallel design for heterosis analysis studies the experimental material comprised with eight parents with two checks was carried out to identify high heterotic crosses and their relationship in Indian mustard. Several hybrids exhibited heterobeltiosis and standard heterosis for seed yield per plant and other characters. The heterosis analysis revealed substantial hybrid vigor across 28 hybrid crosses, with noteworthy improvements in traits such as earlier flowering, earlier maturity, and increased seed weight. The seed yield per plant exhibited better parent heterosis ranging from -20.71% to 16.28%, with five crosses yielding more seeds than their better parents. P3 (PM-22) X P8 (RH-749) was the best cross, with a 16.28% increase. Standard heterosis ranged from -38.72% to 35.14%, with ten crosses showing significant positive heterosis. The findings from this investigation provide crucial insights into the genetic performance and breeding potential of Indian mustard genotypes. The identified parental lines and cross combinations with desirable heterosis effects offer valuable resources for breeding programs aimed at developing high-yielding and resilient mustard varieties, contributing to the advancement of agricultural practices and crop improvement. The above best parent and best crosses can be used in hybridization and heterosis breeding respectively.

Estimation of Combining Ability Effect for Hybrid Breeding in Bottle Gourd [Lagenaria siceraria (Molina) Standl.] Using Diallel Mating Design

A half diallel mating design was employed to cross eight parental lines of bottle gourd, resulting in 28 F1 hybrids (excluding reciprocals). These F1 hybrids, along with the parental lines and a commercial check (Pant Lauki-3), were evaluated during the summer of 2024 at Govind Ballabh Pant University of Agriculture and Technology, Pantnagar. The study aimed to assess the combining ability for yield and yield-related traits using a randomized complete block design with three replications. The genetic variance ratio being less than unity suggested that non-additive gene action was dominant for all the characters. The analysis indicated that none of the parents consistently exhibited good general combining ability across all traits. However, the cross combination NDBG-104 × Pusa Sandesh followed by Pant Lauki-4 × Kashi Kirti emerged as the best for most of the traits analyzed. The results suggest that it may be possible to further enhance fruit yield and earliness through hybridization and selection in transgressive segregants.

Performance of Provitamin a Maize Hybrids for Yield and Desirable Agronomic Traits

To find improved F1 hybrids for breeding procedures, the heterosis of maize hybrids must be determined. Therefore, to identify prospective hybrids for use in future provitamin A maize breeding systems, this study was carried out to evaluate the amount of standard heterosis for grain yield and related attributes. Fifteen provitamin A maize inbred lines were crossed through the diallel-II design. The resulting Eight four F1 hybrids along with four standard checks (BHQPY545, BH549, BH546, and BH547) were evaluated using RCBD (20 entries) and Alpha-Lattice Design (68 entries) with two replications during 2022/2023 main cropping season at Bako National Maize Research Center. Analysis of variance revealed significant variations for most of the traits indicating the existence of genetic variability. The Standard heterosis assessment noticed significant positive and negative heterosis for the majority of the traits investigated. Cross combinations over BHQPY 545, such as L10 × L3, L10 × L6, and L13×L12, demonstrated the largest proportion of traditional heterosis for grain yield (more than 25% yield advantage). Because BH546 and BH547 are normal maize with grain production potential, the majority of crossings yielded negative and significant results over commercial checks. The highest found heterosis for grain yield and associated factors indicated that maize genotypes' heterotic potential may be beneficial to boost yield. The findings of this study could be valuable for researchers looking to develop high-yielding provitamin A maize hybrids. As a result, possible hybrids might be recommended for commercial usage once the results have been verified by repeating the research over time and across places, as well as incorporating quality attributes analysis data.

General and Specific Combining Ability for Fruit Yield Using Diallel Population of Ridge Gourd (Luffa acutangula (Roxb.) L.)

An experiment was conducted using 7 x 7 diallel population of ridge gourd to study the general and specific combining ability (GCA and SCA) of parents and their hybrids for 17 yield traits in a randomized complete block design with three replications. Data on 17 characters were subjected to analysis of GCA and SCA variances and their effects. The GCA and SCA variance were found highly significant for all the characters except days to first female flowering. Low magnitude of σ²g/σ²s ratio was observed for all the traits other than days to first male flowering, days to first female flowering, fruit length (cm), fruit width (mm), individual fruit weight (g). On the other hand, σ²g/σ²s ratio was more than 1.0 for days to first male flowering, days to first female flowering, fruit length (cm), fruit width (mm) and individual fruit weight (g). The general combining effects (GCA) of the parents revealed that none of the parent was found to be good general combiner for all the characters. However, in the present investigation, parent P3 was observed to be one of the best general combiner as it has shown significant GCA effects in desirable direction for number of fruits per plant and fruit yield per plant. It also observed significant GCA effects for parameters related to earliness viz., days to first male flowering, node number of first female flower and days to first harvest. Similarly, parent P5 was also good general combiners for fruit length, fruit width and individual weight of fruit, parent P6 and P7 were also good general combiners for fruit length, individual weight of fruit except fruit width. The parent P2 and P4 were also good general combiners for number of fruits per plant. The estimate of SCA effects revealed that none of the crosses was consistently superior for all the characters. The highest yielding hybrid (P3 x P4) had registered the highest SCA effect for fruit yield per plant. Similarly, the cross combinations P6 x P7, P3 x P6, P3 x P7, P1 x P5, P2 x P6, P4 x P5 were observed as good specific combinations for fruit yield per plant. The hybrid P2 x P6 was good specific combiner for days to first male flowering, hybrid P3 x P4 for sex ratio followed by P4 x P5 and P5 x P7. Hybrid P1 x P4, P6 x P7, P3 x P6 and P2 x P4 were found as good specific combinations for fruit length, P4 x P6 and P3 x P4 for fruit width. The hybrids P3 x P6, P6 x P7, P3 x P4, P2 x P4 and P1 x P5 were observed as good specific combinations for individual fruit weight.

Enabling artificial intelligence‐based scenario application in new type power systems

AbstractAt present, artificial intelligence (AI) technology, as a disruptive and frontier technology, is changing people's production and lifestyle with the cross combination of other scientific fields. Under the background of Green and low‐carbon transition in energy, the construction of new type power systems (NTPS) is the future direction of the transformation and development of the power industry. AI is an important supporting technology for the digital transformation of the power industry, which can accelerate the construction of NTPS and new energy systems. This article provides the author's viewpoints on application of AI technologies in NTPS, mainly involving the development of electric power AI and the main problems it currently faced. The discussion on the bottlenecks of AI application will be focused on data and models. Some future research directions are also presented.

Automatic reorientation to generate short-axis myocardial PET images

BackgroundAccurately redirecting reconstructed Positron emission tomography (PET) images into short-axis (SA) images shows great significance for subsequent clinical diagnosis. We developed a system for automatic redirection and quantitative analysis of myocardial PET images.MethodsA total of 128 patients were enrolled for 18 F-FDG PET/CT myocardial metabolic images (MMIs), including 3 image classifications: without defects, with defects, and excess uptake. The automatic reorientation system includes five modules: regional division, myocardial segmentation, ellipsoid fitting, image rotation and quantitative analysis. First, the left ventricular geometry-based canny edge detection (LVG-CED) was developed and compared with the other 5 common region segmentation algorithms, the optimized partitioning was determined based on partition success rate. Then, 9 myocardial segmentation methods and 4 ellipsoid fitting methods were combined to derive 36 cross combinations for diagnostic performance in terms of Pearson correlation coefficient (PCC), Kendall correlation coefficient (KCC), Spearman correlation coefficient (SCC), and determination coefficient. Finally, the deflection angles were computed by ellipsoid fitting and the SA images were derived by affine transformation. Furthermore, the polar maps were used for quantitative analysis of SA images, and the redirection effects of 3 different image classifications were analyzed using correlation coefficients.ResultsOn the dataset, LVG-CED outperformed other methods in the regional division module with a 100% success rate. In 36 cross combinations, PSO-FCM and LLS-SVD performed the best in terms of correlation coefficient. The linear results indicate that our algorithm (LVG-CED, PSO-FCM, and LLS-SVD) has good consistency with the reference manual method. In quantitative analysis, the similarities between our method and the reference manual method were higher than 96% at 17 segments. Moreover, our method demonstrated excellent performance in all 3 image classifications.ConclusionOur algorithm system could realize accurate automatic reorientation and quantitative analysis of PET MMIs, which is also effective for images suffering from interference.

Selection of elite cross combination and genotype through genetic divergence analysis in bread wheat (Triticum aestivum L.)

Selection of elite cross combination and genotype through genetic divergence analysis in bread wheat (Triticum aestivum L.)

Inheritance of Some Traits in Crosses between Hybrid Tea Roses and Old Garden Roses.

The limited knowledge about the inheritance of traits in roses makes the efficient development of rose varieties challenging. In order to achieve breeding goals, the inheritance of traits needs to be explored. Additionally, for the inheritance of a trait like scent, which remains a mystery, it is crucial to know the success of parental traits in transmitting them to the next generation. Understanding this allows for accurate parental selection, ensuring sustainability in meeting market demand and providing convenience to breeders. The aim of this study was to assess the success of cross-combinations between scented old garden roses and hybrid tea roses used in cut roses in transferring their existing traits, with the objective of achieving scented cut roses. The evaluated traits included recurrent blooming, flower stem length, flower diameter, petal number, scent, and bud length of both parents and progenies. The inheritance of these traits was evaluated through theoretical evaluations, including calculating heterosis and heterobeltiosis and determining narrow-sense heritability. The combinations and examined traits were assessed using a hierarchical clustering heat map. The results of this study indicated that flower stem length, flower diameter, petal number, and bud length traits had a moderate degree of narrow-sense heritability, suggesting the influence of non-additive genes on these traits. This study observed a low success rate in obtaining progenies with scent in cross combinations between cut roses and old garden roses, indicating the challenges in obtaining scented genotypes. The discrepancy between the observed phenotypic rates and the expected phenotypic and genotypic rates, according to Punnett squares, suggests that the examined traits could be controlled by polygenic genes. The progenies were observed to exhibit a greater resemblance to old garden roses than hybrid tea roses and did not meet the commercial quality standards for cut flowers. The significant negative heterosis observed in 65.12% (petal number) and 99.61% (flower diameter) of the progenies provides strong evidence of resemblance to old garden roses. Considering these findings, it is recommended to consider old garden roses as parents, taking into account their suitability for other breeding objectives.

Assessment of gene action and combining ability for advancement of yield andits attributing traits in pansy (<i>Viola </i>× <i>wittrockiana </i>Gams.) through diallel mating design

Pansy is one of the most important bedding winter annual for sub-tropical climatic conditions. Twenty-eight F1 hybrids of pansy were evaluated in randomized block design with three replications, to study the combining ability for vegetative and floral characters. The analysis of variance indicated significant variability among all the genotypes for all the characters. The ratio of genetic component of variance indicated the equal importance of additive and non-additive gene action in governing the flower yield and its component traits of pansy. Estimates of general combining ability effects showed that parents Pa-64-1-5-14, Pa-62-4-12-18, Pa-63-1-7-25 and Pa-32-8-7-6 were good general combiners for most of the traits except stalk length and flower size. The specific combining ability effects showed that for yield traits the best cross combinations were Pa-64-1-5-14 × Pa-62-4-12-18, Pa-13-1-2-3 × Pa-47-1-3, Pa-11-1-3-7 × Pa- 62-4-12-18, Pa-64-1-5-14 × Pa-63-1-7-25 and Pa-11-1-3-7 × Pa-64-1-5-14. The study on gene effect of different characters indicated the predominance of non-additive gene effects for most of the characters. The gca variances was higher for branches number, flower size, days from bud initiation to flowering and flowers number than sca variances, indicating additive gene action, and progeny selection will be effective for the genetic improvement of these traits.

Maternal effects, reciprocal differences and combining ability study for yield and its component traits in maize (Zea mays L.) through modified diallel analysis.

Combining ability status of the inbred lines is crucial information for hybrid breeding program. Diallel or line × tester mating designs are frequently used to evaluate the combining ability. In the current study a modified diallel model was used, wherein the Griffing's combining ability effects were further partitioned to understand the effects due to maternal and reciprocal. To do this, eight parental lines of maize were crossed in full diallel method and the generated hybrids along with parents were phenotyped. The field data on the quantitative traits was analyzed using both Griffing's and the modified model to determine how well the parents' and the F1 hybrids combined. For each of the traits, a sizable reciprocal and maternal variance was observed. The number of kernel rows per cob variable had a ratio of additive variance to dominance variance greater than one. All other traits including grain yield had a ratio close to zero, suggesting that non-additive gene action was primarily responsible for the genetic control of most of the traits. The narrow sense heritability was low to moderate for majority of the variables, except for number of kernel rows per cob. With the help of the improved model, it was possible to choose superior parents and cross-parent pairings with accuracy. Based on the modified general combining ability effects and maternal effects, the parental line P5 was recognized as a potential female parent and P7 as a good male parent for grain yield and yield-attributing characteristics. The cross combination of P8×P1 had the highest specific combining ability effect on grain yield. P5×P6 cross had the highest reciprocal effect. The correlation analysis implies that the Griffing's general combining ability effects and specific combining ability effects were found to be less efficient in predicting F1 performance as compared to the modified model.

Estimation of Phenotypic and Genotypic Correlation Analysis in F3 Populations of Bread Wheat Genotypes

Wheat is one of the most important crops all over the world in terms of yield, production, consumption, cultivation, and adoptability. Wheat genotypes exhibiting different yield associated traits which influence each other in many ways. Therefor genotypic and phenotypic correlations are the breeder’s utmost priority to know about the inter-relationship between two or more traits which may be either directly influencing each other in a positive direction or indirectly swaying each other in a negative direction in breeding programs. To find out phenotypic and genotypic correlations among different productive traits, this study was designed at the research area of The Department of Plant Breeding and Genetics, The University of Agriculture, Peshawar, during 2022-23. The experiment was carried out by using 27 wheat genotypes comprising of nine parents and 18 F3 populations evaluated in RCB design with three replications. Overall the study exhibited that kernel yield plant-1, which is one of the most yield contributing trait, was significantly correlated with thousand-kernel weights, tillers plant-1and biomass yield, along some other yield contributing traits. The parental genotype, Janbaz, and cross combinations Watan × AUP-5008, Pirsabak-2005 × AUP-5008, Saleem-2000 × Janbaz and Watan × Tatara were the most promising genotypes for most of quantitative traits and; hence are recommended to be evaluated in further breeding schemes. Both phenotypic and genotypic correlation study exhibited that kernel yield spike-1 was significant and positively associated with plant height, tillers plant-1, thousand-kernel weight and biomass yield. Based on correlations, yield, and production the parental genotype, Janbaz, and F3 combinations Watan × AUP-5008, Pirsabak-2005 × AUP-5008, Saleem-2000 × Janbaz and Watan × Tatara were the most promising genotypes for most of the quantitative traits, which can be incorporated in further breeding program.

ASSESSMENT OF COMBINING ABILITY FOR YIELD AND YIELD RELATED TRAITS IN SPRING WHEAT (TRITICUM AESTIVUM L.)

Grain yield and other related characters were studied in 18 F1 generations along with nine parents (six lines and three testers) which were evaluated for combining ability with three replications in a randomized complete block design (RCBD). The results indicated that among various lines, line 9479 was identified as a good general combiner for the traits, viz., spike length, spikelet’s per spike, and 1000-grain weight, whereas, Line 9486 appeared as a good general combiner for the characters, flag leaf area, plant height, peduncle length, number of tillers per plant and 1000-grain weight. Line 9515 for flag leaf area, plant height, and spike length. Line 9519 for the number of tillers per plant, grain yield per plant, and plant height; line 9520 for peduncle length, number of tillers per plant, grains per spike, grain yield per plant and 9521 was identified as good general combiner for the characters spike length, spikelet’s per spike, number of grains per spike and spike density. Tester Punjab-11 emerged as a good general combiner for the traits; peduncle length, plant height, flag leaf area, and number of tillers per plant, whereas, Tester Ass-11 appeared as a good combiner for the spike length, peduncle length, 1000-grain weight, and flag leaf area. Tester Chakwal-50 identified a good general combiner for the number of tillers per plant, plant height, grains per spike, spikelets per spike, grain yield per plant, 1000-grain weight, and spike density. Out of 18 cross combinations, seven crosses viz. 9479 × Aas-11, 9486 × Aas-11, 9515 × Aas-11, 9519 × Chakwal-50, 9520 × Punjab-11, 9521 × Punjab-11, and 9521 × Aas-11 emerged with significant positive SCA effects for grain yield per plant. Thus, these crosses can be exploited for grain yield per plant by using biparental mating system.

Genetic bias in repeated evolution of pigment loss in cave populations of the Asellus aquaticus species complex.

Similar phenotypes can evolve repeatedly under the same evolutionary pressures. A compelling example is the evolution of pigment loss and eye loss in cave-dwelling animals. While specific genomic regions or genes associated with these phenotypes have been identified in model species, it remains uncertain whether a bias towards particular genetic mechanisms exists. An isopod crustacean, Asellus aquaticus, is an ideal model organism to investigate this phenomenon. It inhabits surface freshwaters throughout Europe but has colonized groundwater on multiple independent occasions and evolved several cave populations with distinct ecomorphology. Previous studies have demonstrated that three different cave populations utilized common genetic regions, potentially the same genes, in the evolution of pigment and eye loss. Expanding on this, we conducted analysis on two additional cave populations, distinct either phylogenetically or biogeographically from those previously examined. We generated F2 hybrids from cave × surface crosses and tested phenotype-genotype associations, as well as conducted complementation tests by crossing individuals from different cave populations. Our findings revealed that pigment loss and orange eye pigment in additional cave populations were associated with the same genomic regions as observed in the three previously tested cave populations. Moreover, the lack of complementation across all cross combinations suggests that the same gene likely drives pigment loss. These results substantiate a genetic bias in the recurrent evolution of pigment loss in this model system. Future investigations should focus on the cause behind this bias, possibly arising from allele recruitment from ancestral surface populations' genetic variation or advantageous allele effects via pleiotropy.

Microsatellite marker-assisted backcross breeding for improvement of wheat salt tolerance using Kharchia 65

BackgroundSalinity is a significant abiotic stress that affects plants from germination through all growth stages. This study was aimed to determine the morpho-physiological and genetic variations in BC1F2, BC2F1 and F3 generations resulting from the cross combination WH1105 × Kharchia 65.ResultsA significant reduction in germination percentage was observed under salt stress in BC1F2 and F3 seeds. Correlation, heritability in the broad sense, phenotypic coefficient of variability (PCV) and genotypic coefficient of variability (GCV) were measured for all traits. The presence of both Nax1 and Nax2 loci was confirmed in twenty-nine plants using the marker-assisted selection technique. Genetic relationships among the populations were assessed using twenty-four polymorphic SSR markers.ConclusionCluster analysis along with two and three-dimensional PCA scaling (Principal Component Analysis) revealed the distinct nature of WH 1105 and Kharchia 65. Six plants closer to the recurrent parent (WH1105) selected through this study can serve as valuable genetic material for salt-tolerant wheat improvement programs.