F1 Hybrids Research Articles

Differences in the structure of inflorescences of some winter and spring rapeseed (Brassica napus L.) F1 hybrids

Differences in the structure of inflorescences of some winter and spring rapeseed (Brassica napus L.) F1 hybrids

In-vitro test of five cacao (Theobroma cacao L.) F1 hybrids to Phytophthora palmivora

Abstract Phytophthora palmivora causes black pod diseases (BPD) in cacao pods and reduces up to 25% of cacao yield. Cacao plant breeding aims to produce superior plants resistant to BPD. This research intended to confirm the pathogen through morphological characteristics and molecular identification, as well as evaluate the resistance level of five cacao F1 hybrids against P. palmivora in-vitro. The morphology of colonies was observed visually and microscopically, while sequencing analysis was performed using primer-specific pairs YPh1F/2R, followed by phylogenetic analysis. Resistance studies were using five cacao F1 hybrids: 8-7 (1), 9-7 (1), 1-11 (1), 5-1 (2), 2-8 (3), and BL 50 as the comparison variety using leaf disc methods. The research findings were Phytophthora sp. colonies on carrot medium showed faster growth than on potato dextrose agar. The microscopic observation showed the presence of pear-shaped spores. Likewise, the phylogenetic analysis confirmed that this pathogen was P. palmivora, with a high similarity of 98.78%. In the in-vitro study, two clones categorized as resistant, with clones 2-8 (3) having the lowest severity score. Other clones, including comparison varieties, have moderately resistant levels. The results are important information in assembling superior cacao clones resistant to P. palmivora.

A 7×7 diallel cross for developing high-yielding and saline-tolerant barley (Hordeum vulgare L.)

In this experiment, F1s produced from a 7 × 7 half-diallel cross along with their parents were evaluated to develop high yielding and saline-tolerant barley lines. The investigation focused on the general combining ability (GCA) of parents, specific combining ability (SCA) of offspring, genetic action, and heterosis of eight quantitative variables. Genetic analysis and potence ratio suggested that different degrees of dominance controlling the inheritance of the studied traits. Significant GCA and SCA variances suggested the presence of both additive and non-additive gene actions controlling the traits. However, a GCA:SCA ratio lower than 1 indicated the preponderance of the non-additive gene action involved in the expression of the traits. The parents P5 and P6 possess the genetic potential favorable for early and short stature in their F1s. Conversely, P2 and P4 were more likely to produce short F1s with high yield potential. Based on the mean performance, SCA, and heterobeltiosis, crosses P2 × P3, P2 × P7, P3 × P4, P4 × P5, P5 × P6, and P6 × P7 were selected as promising F1s for earliness, short stature, and high yield potential. These crosses are recommended for further breeding to obtain early-maturing and high-yielding segregants. To identify saline-tolerant F1s, screening was conducted in saline media prepared in half-strength Hoagland solution. The salinity stress involved exposing F1s to 100 mM NaCl for first 10 days, and followed by an increase to 150 mM until maturity. Among the F1s, five crosses (P1 × P2, P2 × P3, P3 × P5, P4 × P6, and P4 × P7) exhibited promising signs of saline tolerance based on a comprehensive evaluation of healthy seed set, K+/Na+ ratio, root volume, generation of reactive oxygen species (O2•− and H2O2), and activities of key antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), and glutathione reductase (GR). These crosses will undergo further evaluation in the next filial generation to confirm heritable saline tolerance.

Heterosis and combining ability for phenological yield and fiber traits of cotton (Gossypium hirsutum L.) genotypes

The seeds of 4 lines, 3 testers, and their 12 F1 hybrids were sown in a randomized complete block design (RCBD) with 3 replications at Botanical Garden, Department of Plant Breeding and Genetics, Sindh Agriculture University, Tandojam during Kharif 2019. F1 hybrids were raised for the estimation of heterotic effects, GCA and SCA for days to 1st squaring, days to 1st boll formation Bolls opened at 90 days after sowing, Sympodial branches plant-1, Bolls plant-1, Boll weight (g), Seed cotton yield plant-1 (g), 100-seed weight (g), Ginning outturn (%) and staple length (mm). Genotypes, parents, crosses, parent's v/s crosses, lines, testers and line × testers were significant for days to 1st squaring and days to 1st boll forming. Bolls unveiled their fissures precisely 90 days post-sowing, while parameters including sympodial branches per plant, bolls per plant, individual boll weight, seed cotton yield per plant, 100-seed weight, ginning outturn, and staple length underwent meticulous evaluation. The statistical scrutiny unveiled the insignificance of both lines and testers concerning the 90-day boll dehiscence. Similarly, the parental influence on boll weight, 100-seed weight, and staple length exhibited a lack of statistical significance. Line CRIS-134, Sindh, and tester FH-901 gave a higher mean performance for all the traits. Among the hybrids, Mehran × FH-901, Sindh-1 × CIM-602, CRIS-134 × CIM-602, CRIS-342 × Koonj, and CRIS-342 × CIM-602 gave a desirable mean performance and heterotic effect for all the traits. CRIS-342 × Koonj produced maximum SCA effects for bolls per plant. Mehran × FH-901 recorded higher SCA effects for seed cotton yield plant-1 and 100-seed weight, CRIS-342 × CIM-602 for lint percentage, and CRIS-342 × FH-901 for staple length. It is suggested that these lines and testers should be utilized in the breeding program to improve these traits.

Evaluation of Generational Implications of Metabolic Resistance Development in Malaria Mosquitoes against Permethrin Insecticides

Enzymes mediated resistance development and their activities are well documented in Anopheles gambiae vectors. However, biological consequences of such resistance development in malaria vectors are obscure. The present study aims to determine the implications of such response in An. gambiae (Kisumu) population following exposure to a concentration of Permethrin selection pressure across multiple generations. Adult Kisumu mosquitoes exposed to 0.2 µg/ CDC bottle over generations were compared with unexposed control populations by way of resistance status, cost of fitness, and correlating metabolic enzymes. Data obtained were analysed using SPSS. Analysis of Variance was employed to determine statistical differences at 95%. Fecundity rates of the mosquito population dropped progressively over generations. With increase in activity of metabolic enzymes, resistance status of the mosquito population progressed significantly (P< 0.05) over generations with 5.0 µg (18.00±0.00; 72%) at f4 generation. Mosquito resistance development is therefore a disadvantage to malaria vectors as it reduces ovipository capability, and increases longevity of immature stages (life cycle) with filial generations.

Создание во ВНИИМК несуществующей в природе озимой формы горчицы сарептской (обзор)

Breeding of a new winter form of mustard started at the V.S. Pustovoit All-Russian Research Institute of Oil Crops in 1959. This work was aimed on increasing of crop yield due to winter plant growth. Hybrids between winter rapeseed and spring mustard were used as initial material. These species cross easily and had fertile progenies. A breeding sample No. 7823 was selected in hybrid combinations; it withstands low temperatures – from minus 10 to minus 15 °C at autumn sowing. At favorable overwintering conditions, yield of this sample was 2.0–2.8 t/ha, oil content of seeds – 44–48%. During further works, the winter mustard samples No. 26205 and 25582 with yield of 3.65–4.06 t/ha were selected. However, in unfavora-ble winter conditions, the winter resistance of winter mustard was 30–40% low than of winter rapeseed. In 1968, another method to develop winter mustard was chosen: by resynthesis from the elementary species – winter turnip rape (genome AA) and black mustard (genome BB). Usage of grafting and gamma radia-tion of pollen allowed producing F1 hybrid seeds. As a result of long-term works (1971–1989), based on resynthesis hybrids, the first in the world practice variety of winter mustard Suzdalskaya was developed. It competed with winter rapeseed by seed yield and winter resistance, however, erucic acid content in seed oil was 35–37%. In 2002, the first erucic acid free (1.5%) variety of winter mustard Snezhinka was submitted for the State trial. In 2010, the absolutely erucic acid free variety of winter mustard Dzhuna was included into the State register of breeding achievements. In 2022, the variety Vyuzhanka was included into the State Register, it exceeds the variety Dzhuna by seed yield by 0.72 t/ha and has oil of high quality.

Использование молекулярно-генетических маркеров для идентификации генов чувствительности к фотопериоду в селекционном материале сои

Soybean is one of the important oil and forage crops. It contains large amounts of oil, protein, vitamins, and other valuable nutrients. Annually, sowing area under soybean in Russia enlarges towards central and Siberian regions. However, soybean is very sensitive to photoperiod that is a key factor in regulation of soybean growth and development. The identification of gens controlling a photoperiodic sensitivity in soybeans is important for breeding of new adaptive cultivars. DNA-markers are an effective instrument for the selection of valuable genotypes from breeding germplasm. In this work, we identified gens contributing the most of decrease in soybean sensitivity to a day length. There were estimated six cultivars, five lines F6–F7, and five hybrids F1 of soybean. We used six molecular markers. Due to results, the early maturing cultivars Elana and Barguzin had the largest amount of recessive alleles; the cultivar Mamont had the largest amount of dominant alleles that characterizes it as middle maturing. The rest samples had two or three recessive alleles and belong to maturity groups from early to middle early. The analysis of hybrid combinations showed that a molecular marker for a Е3-gen is inherited co-dominantly. This allowed using it to control transferring of desired gens at crosses in progeny. Thus, the usage of the molecular-genetic markers was effective in selection by a studied trait and can be used in the breeding process.

VARIABILITY OF QUANTITATIVE PLANT CHARACTERS OF EGGPLANT COLLECTION SAMPLES

Purpose. To determine the peculiarities of the variability of the quantitative characteristics of the plant in collection samples of eggplant of different origin during different years of cultivation Methods. During 2021-2023, an eggplant collection consisting of 21 varieties and 10 F1 hybrids of various geographical origins was studied at the experimental base of the Institute of Vegetable and Melon Growing of the National Academy of Sciences. Samples were evaluated by plant height, plant width, number of shoots per plant. Field, biometric, computational and analytical research methods were used. Results. It was found that the height and width of the plant had a tendency to decrease in 2023. The average height of the collection for this year by varieties was 97.4 cm, by hybrids – 98.7 cm. The width of the plant this year was 41.3 cm on average by varieties, by hybrids – 43.4 cm. The lowest plant height was noted variety Hangqi No.1 (81.0 cm on average over the years), the highest plant height is the variety Bambina. (120.7 cm). Among the hybrids, Piatachok F1 was the shortest, Gordita F1 was the tallest (121.7 cm). The smallest plant width among the varieties was the Xingyuun variety (35.3 cm on average over the years), among the hybrids – the Farama F1 hybrid (38.7 cm). The largest plant width is in the Thai Long Green variety (51.3 cm) and in the Gordita F1 and Briska F1 hybrids (49.3 cm). The smallest number of shoots was formed in plants of the Xingyuun variety (2.7 pcs. on average over the years) and the Galchonok F1 hybrid (3.3 pcs.). The variety Luisiana Long Green (6.9 pcs.) and the Purple Dragon F1 hybrid (8.1 pcs.) had the most shoots on the plant. Almost all studied varieties and hybrids were distinguished by weak and medium variability in three characteristics. Only the Zelenenky variety showed itself to be very variable in the number of shoots (CV = 21.16). Among the varieties, the variety Tai Long Green was distinguished by the least variability in height and width of plants, and Louisiana Long Green in the number of shoots on the plant. Among the hybrids, the lowest variability of plant height and width was observed in the Izumrudny F1 hybrid, and the number of shoots per plant in Bibo F1. Thai Long Green and Daejeon Purple varieties showed the least response to the change in growing conditions by plant height, Hangqi No. 1-2 variety by plant width, and Luisiana Long Green by the number of shoots per plant. The most stable among the hybrids were Izumrudny F1 in terms of plant height and width and Bibo F1 in terms of the number of shoots. Conclusions. Thus, breeding studies allowed to determine the levels of variability of quantitative traits of the eggplant plant and to identify valuable collection samples for use in breeding programs.

The Comparative Study on Effect of Breed and Gender on Some Carcass Traits of New Zealand White and Dutch Rabbit Breeds

This study was designed to observe the effect of breed on some carcass traits of New Zealand White and Dutch rabbit breeds. In this study, 2 males and 8 female Breeder Rabbits from New Zealand White and Dutch rabbit breeds were purchased from a local farmer and allowed for breeding purposes by the ratio of 1:4 Male to Female in different cages. From the first filial generation, 80 kits were randomly selected after weaning at 21-25 days and grouped into A, B, C, and D. Groups A and C included males of New Zealand White and Dutch breeds, whereas B and D included females. Their live weight at 80 days was observed, and lastly, they were slaughtered to observe the effect of breed on carcass traits. Dutch breed males showed significantly higher (P<0.05) weaning weight, live weight, slaughter weight, carcass weight, boneless weight, bone weight and dressing percentage compared to New Zealand White males, while Dutch females also exhibited higher traits compared to New Zealand White females. The results indicated that Dutch rabbits had higher birth weight, weaning weight, live weight, slaughter weight, carcass weight, boneless weight, bone weight, and dressing percentage as compared with New Zealand White breeds.

Heterosis and Combining Ability Analysis in Tomato Using Line × Tester Model

The experiment entitled Heterosis and combining ability studies for yield and yield attributing trait in Tomato (Lycopersicon esculentum) in Bundelkhand Region was carried out during Rabi 2021-22 and 2022-23 at the Experimental, Organic Research farm Kargunwa ji, Jhansi, Department of Horticultural Sciences, Institute of Agricultural Sciences, Bundelkhand University Jhansi (Uttar Pradesh). The present experiment was design under Randomized block design with three replication with plot size - 3×3m and number of rows per plant – 5 rows per plant accommodating spacing (60×60) cm. All F1s (50) along with parents were raised in RBD in 3 replications and population size were 30 plants per treatment with standard spacing. All 17 parents (5 lines and 12 testers) were raised in separate plots along with a check grown in RBD in three replications to study the combining ability, to estimate the magnitude or percentage of heterosis in the crosses, for identification of the best F1 hybrid and correlation among different traits. Since, Line × tester analysis provides information of potential parents the hybrid line. The three best combinations for line parents viz., H-88-78-5, Kashi Aman, H-88-78-5 and their F1 hybrid viz., H-88-78-1x Kashi Chaya,VRT-67 × Kashi Chaya,H-88-78-5×VRT-50 performed significantly better amongst rest of the other treatment.

Utilisation of GMS lines for production ofheterotic bacterial wilt resistant hybrids in <i>Tagetes</i> spp.

The study was conducted using six testers, of which two (KAU M-1 and KAU M-2) were completely bacterial wilt resistant, and four genetic male sterile lines (GMS), in a line x tester model and further the F1 hybrids were evaluated in a bacterial wilt sick plot for various vegetative, floral and yield parameters along with their response to wilt incidence. Field evaluation for bacterial wilt resistance revealed that out of 24 hybrids, 13 hybrids involving KAU M-1 and KAU M-2 as testers exhibited bacterial wilt resistance. Analysis on heterosis for various characters viz., vegetative, floral, yield and total carotenoids content showed significant heterosis for many of the hybrids over mid parent, better parent and the check variety. The highest standard heterosis for yield was observed for the interspecific hybrid KU Ms-6 xx KAU M-47 (190.84%) followed by an intraspecific hybrid KAU Ms-42 x KAU M-2 (70.93%). Based on the wilt resistance and heterotic performance, these two hybrids can be suggested for commercial cultivation in wilt affected areas.

Metabolomic and transcriptomic analyses of monoterpene biosynthesis in Muscat and Neutral grape hybrids

Monoterpenes are typical aroma components of muscat grape (Vitis vinifera L.) cultivars. However, differences in the molecular mechanism of monoterpene biosynthesis between Muscat and non-Muscat grapes remain unclear. Here, comprehensive transcriptomic and metabolomic analyses of two F1 hybrids with different aroma profiles obtained from crosses between 'Muscat Hamburg' and 'Red Globe' grapes were performed to examine the unique monoterpene accumulation pattern and related candidate genes. The concentrations of most monoterpenes differed at various times, in the hybrid progeny, increasing from the pre-veraison stage to the veraison stage, followed by a decreasing trend from veraison to maturity. Within the F1 generation, the concentrations of accumulated monoterpenes were significantly higher in Muscat grapes than in neutral grapes. Furthermore, linalool, α-terpineol, and l-α-terpineol may be important odorants affecting the floral characteristics of Muscat grapes due to their high odor activity values. Transcriptional analysis identified three VvDXS (LOC100249323, LOC100268079, and LOC100247834), 1 VvHDS (LOC100257071), one VvMVK (LOC100251148), one VvHMGR (LOC100265082), and one VvGGPPS (LOC100257234) genes encoding proteins involved in the MEP and MVA pathways. Eleven TPS genes potentially involved in monoterpene regulation were also identified. Among them, VvTPS (LOC100853562) showed consistency with the accumulation of monoterpenes and had a high expression level; MYB (LOC100255488), GATA (LOC100262474), and ERF (LOC100255943, LOC100260401) were selected as candidate genes encoding transcription factors. The findings in this study provide new insights for further functional validation and investigation of genes related to monoterpene synthesis in Muscat aroma grapes.

Наследяване на стопански ценни признаци и хетерозис при хибридни комбинации зимен ечемик

The article presents the results of the analysis of the inheritance of the main economic valuable traits of barley hybrids of the first generation using indicators of the degree of phenotypic dominance and heterosis. 6 hybrid barley combinations were evaluated according to the following characteristics: plant height (cm), productive twining, length of main spike (cm), number of grains in main spike, grain weight per spike (g), grain weight per plant (g), mass of 1000 grains (g). The research was carried out at the Institute of Agriculture-Karnobat in 2022-2023. Highly productive varieties and samples of barley, Bulgarian selection and from introduction were used as parental forms. For each investigated trait, the arithmetic mean ( x ), the error of the arithmetic mean (S %), variation coefficient (VC,%), the degree of dominance (d/a), true (HP) and hypothetical (MP) heterosis were determined. Based on the variation and inheritance in the early F1 hybrid generations, conclusions were drawn regarding the value of the cultivars used and the type of inheritance of the traits analyzed.

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.

Genome-wide association analysis of four yield-related traits using a maize (Zea mays L.) F1 population.

Increasing the yield of maize F1 hybrid is one of the most important target for breeders. However, as a result of the genetic complexity and extremely low heritability, it is very difficult to directly dissect the genetic basis and molecular mechanisms of yield, and reports on genetic analysis of F1 hybrid yield are rare. Taking F1 hybrid as the research object and dividing the yield into different affect factors, this approach may be the best strategy for clarifying the genetic mechanism of yield. Therefore, in this study, a maize F1 population consisting of 300 hybrids with 17,652 single nucleotide polymorphisms (SNPs) markers was used for genome-wide association study (GWAS) to filtrate candidate genes associated with the four yield-related traits, i.e., kernel row number (KRN), kernel number per row (KNPR), ear tip-barrenness (ETB), and hundred kernel weight (HKW). Combined with the results of previous studies and functional annotation information of candidate genes, a total of six candidate genes were identified as being associated with the four traits, which were involved in plant growth and development, protein synthesis response, phytohormone biosynthesis and signal transduction. Our results improve the understanding of the genetic basis of the four yield-related traits and may be provide a new strategy for the genetic basis of maize yield.

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.

Character Association and Path Analysis for Yield and its Attributing Traits in Urdbean Genotypes and its Triple Test Cross F1 Hybrids

This research delves into the association and path coefficient analysis between yield and its attributing traits among 111 diverse lines of urdbean. 27 lines, three testers, and Eighty-one F1 hybrids were grown in a Randomized Block Design (RBD) with three replications during Kharif 2023 at the Crop Experimental Research Farm of Chandra Shekhar Azad University of Agriculture and Technology, Kalyanpur, Kanpur (U.P.). The analysis of variance for parents (27 lines and three testers) and their 81 triple test cross hybrids indicated highly significant genotypic differences across all 12 quantitative traits under study viz., days to 50% flowering (DFF), days to 75% maturity (DM), plant height (cm) (PH), number of primary branches per plant (NPB), pods per plant (NPP), pod length (cm) (PL), seeds per pod (NSP), biological yield per plant (g) (BYPP), seed yield per plant (g) (SYPP), harvest index (%),(HI), 100-seed weight (HSW), and protein content (%) (PC). All the traits studied showed a significant positive correlation with seed yield, except for days to 50% flowering, and days to 75 % maturity at phenotypic and genotypic levels. Path analysis revealed that all the traits had high direct positive effects on seed yield except for days to 50% flowering and days to 75 % maturity at phenotypic and genotypic levels. Therefore, these traits should be the primary focus in black gram breeding programs aimed at yield improvement.

Isolation and evaluation of novel male sterile and self‐incompatible mutant lines of mungbean (Vigna radiata L.)

AbstractHeterosis has long been harnessed in crop production, and while crop fertility lays the groundwork for leveraging heterosis, there remains a dearth of comprehensive data regarding genic male sterility in mungbean. Mungbean (Vigna radiata (L.) Wilczek), being a self‐pollinating crop, exhibits significant hybrid vigour in F1 hybrid seed yield, suggesting the potential for developing hybrid varieties to propel mungbean yield beyond existing plateaus. A new male sterile mutant was induced, isolated, stabilized and evaluated, via gamma irradiation at a rate of 600 Gy, identified in the M3 generation of the GM 4 accession. A uniform male sterile line was crossbred with the wild‐type parental plant to explore the inheritance pattern of male sterility. Pollen sterility was validated through the acetocarmine test, while stigma viability was ascertained using the hydrogen peroxide. While all F1 plants displayed fertile flowers, the F2 generation showed a clear 3:1 segregation ratio for fertile to male sterile plants, indicating the control of male sterility by a single recessive gene, mms. Also, a novel existence of a truncated stigma nestled within the anther column inhibits the effective reception of pollen during anthesis, offering potential in reducing emasculation time by a slight cut on the flower bud and enhancing cross pollination during hybrid seed production. The isolation of these two mutants is poised to significantly advance the global mungbean hybrid breeding programme.

Expansion of learning capacity elicited by interspecific hybridization.

Learned behavior, a fundamental adaptive trait in fluctuating environments, is shaped by species-specific constraints. This phenomenon is evident in songbirds, which acquire their species-specific songs through vocal learning. To explore the neurogenetic mechanisms underlying species-specific song learning, we generated F1 hybrid songbirds by crossing Taeniopygia guttata with Aidemosyne modesta. These F1 hybrids demonstrate expanded learning capacities, adeptly mimicking songs from both parental species and other heterospecific songs more extensively than their parental counterparts. Despite the conserved size of brain regions and neuron numbers in the neural circuits for song learning and production, single-cell transcriptomics reveals distinctive transcriptional characteristics in the F1 hybrids, especially in vocal-motor projection neurons. These neurons exhibit enrichment for nonadditively expressed genes, particularly those related to ion channel activity and cell adhesion, which are associated with the degree of song learning among F1 individuals. Our findings provide insights into the emergence of altered learning capabilities through hybridization, linked to cell type-specific transcriptional changes.

Introgression of an All-Stage and Broad-Spectrum Powdery Mildew Resistance Gene Pm3VS from Dasypyrum villosum Chromosome 3V into Wheat.

Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is a serious disease that threatens wheat production globally. It is imperative to explore novel resistance genes to control this disease by developing and planting resistant varieties. Here, we identified a wheat-Dasypyrum villosum 3V (3D) disomic substitution line, NAU3815 (2n = 42), with a high level of powdery mildew resistance at both the seedling and adult-plant stages. Subsequently, NAU3815 was used to generate recombination between chromosomes 3V and 3D. Through genomic in situ hybridization (GISH), fluorescence in situ hybridization (FISH), and 3VS- and 3VL-specific markers analysis, four introgression lines were developed from the selfing progenies of 3V and 3D double monosomic line NAU3816, which was derived from the F1 hybrids of NAU3815/NAU0686. There were t3VS (3D) ditelosomic substitution line NAU3817, t3VL (3D) ditelosomic substitution line NAU3818, homozygous T3DL·3VS translocation line NAU3819, and homozygous T3DS·3VL translocation line NAU3820. Powdery mildew tests of these lines confirmed the presence of an all-stage and broad-spectrum powdery mildew resistance gene, Pm3VS, located on chromosome arm 3VS. When compared with the recurrent parent NAU0686 plants, the T3DL·3VS translocation line NAU3819 showed no obvious negative effect on yield-related traits. However, the introduction of the T3DL·3VS translocated chromosome had a strong effect on reducing the flag-leaf length. Consequently, the T3DL·3VS translocation line NAU3819 provides a new germplasm in breeding for both resistance and plant architecture.