Hybrid Families Research Articles

Quantitative genetics and breeding strategies in hybrid populations of Pinus patula × Pinus tecunumanii

Forestry companies SAFCOL and Sappi conducted a study in South Africa to examine genetic variation and select improved material in full-sib hybrid families of Pinus patula × Pinus tecunumanii. The results from the study on clonal and seedling hybrid populations of P. patula × P. tecunumanii low-elevation subpopulations (TECL) revealed a significantly larger impact of TECL compared to P. patula. The TECL parents exhibited higher general hybridising ability (GHA) variance for volume gain and modulus of elasticity (MOE). Consequently, future hybrid crosses should focus on increasing the number of TECL parents in the breeding programme to improve these traits. In the hybrid seedling population of P. patula × P. tecunumanii high-elevation subpopulation (TECH), P. patula exerted a substantial influence on volume gain and MOE. However, the TECH parents displayed zero estimates of GHA variance for volume and a low GHA variance for MOE, relative to GHA variance among P. patula parents for MOE. Thus, this study recommends testing more P. patula parents in new intercrosses of this variety to enhance volume and MOE gain.

Genetic control of Fusarium circinatum tolerance in Pinus patula × P. tecunumanii hybrid families

The pine pitch canker fungus, Fusarium circinatum, has caused large-scale mortality of Pinus patula crops in South African nurseries and high in-field post-planting mortality. Tree breeders have identified selection and breeding of tolerant material as the likely long-term solution to this disease. In this study, the greenhouse artificial inoculation screening method was employed to investigate the genetic control of F. circinatum tolerance in a factorial mating design of Pinus patula × P. tecunumanii low elevation (PPTL) and high elevation (PPTH) hybrid families and their parental species. Results indicated that F. circinatum tolerance is under moderate genetic control (h 2 between 0.13 and 0.36) as assessed in a hybrid factorial mating design with a large number of PPTL and PPTH families. The PPTL hybrid displayed the highest level of tolerance, followed by pure P. tecunumanii LE, then the PPTH hybrid, pure P. tecunumanii HE and lastly pure P. patula. A general hybridising ability (GHA) and specific hybridising ability (SHA) analysis was also conducted to rank parent families as well as hybrid families. These breeding values can be used to identify superior families for commercial production and further breeding. A poor correlation between frost tolerance and F. circinatum tolerance was also found when compared to a previous frost tolerance study utilising the same hybrid families. The results from this study indicated that it is possible for breeders to cross selected P. patula seed parents with selected P. tecunumanii pollen parents to develop F. circinatum tolerant hybrid families for commercial production.

GENOME-WIDE ASSOCIATION STUDY OF YIELD-RELATED TRAITS IN A NESTED ASSOCIATION MAPPING POPULATION GROWN IN KAZAKHSTAN

This study evaluated 290 recombinant inbred lines (RILs) from the Nested Association Mapping (NAM) population in the UK, consisting of 24 hybrid families. All genotypes were grown in southeastern Kazakhstan (Kazakh Research Institute of Agriculture and Plant Growing, Almaty region, 2021-2022) and northern Kazakhstan (Alexandr Barayev Scientific-Production Center for Grain Farming, Akmola region, 2020). The studied traits included six yield-related characteristics: spike length (SL, cm), number of productive spikes per plant (NPS, pcs), number of kernels per spike (NKS, pcs), weight of kernels per spike (WKS, g), thousand kernel weight (TKW, g), and yield per square meter (YM2, g/m2). The significant phenotypic variability among genotypes was observed, which was suitable for the genome-wide association study of yield-related traits. Pearson's index showed positive correlations among most yield-related traits, although a negative correlation was found between NKS and TKW in southeastern, and no correlation was recorded for northern regions. Top-performing RILs, surpassing local checks, were identified for NKS, TKW, and YM2, suggesting their potential for breeding programs. The application of GWAS allowed the identification of 72 quantitative trait loci (QTLs), including 36 QTLs in the southeastern region, 16 QTLs in the northern region, and 19 in both locations. Eleven QTLs matched those reported in previous QTL mapping studies and GWAS for studied traits. The results can be used for further studies related to the adaptation and productivity of wheat in breeding projects for higher grain productivity.

Neural network empowered liquidity pricing in a two-price economy under conic finance settings

In the article at hand neural networks are used to model liquidity in financial markets, under conic finance settings, in two different contexts. That is, on the one hand this paper illustrates how the use of neural networks within a two-price economy allows to obtain accurate pricing and Greeks of financial derivatives, enhancing computational performances compared to classical approaches such as (conic) Monte Carlo. The methodology proposed for this purpose is agnostic of the underlying valuation model, and it easily adapts to all models suitable for pricing in conic financial markets. On the other hand, this article also investigates the possibility of valuing contingent claims under conic assumptions, using local stochastic volatility models, where the local volatility is approximated by means of a (combination of) neural network(s). Moreover, we also show how it is possible to generate hybrid families of distortion functions to better fit the implied liquidity of the market, as well as we introduce a conic version of the SABR model, based on the Wang transform, that still allows for analytical bid and ask pricing formulae.

Continued decline in sublethal effects of Bt toxins on Helicoverpa zea (Lepidoptera: Noctuidae) in field corn.

The majority of field corn, Zea mays L., in the southeastern United States has been genetically engineered to express insecticidal toxins produced by the soil bacterium, Bacillus thuringiensis (Bt). Field corn is the most important mid-season host for corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), which has developed resistance to all Cry toxins in Bt corn. From 2020 to 2023, corn earworm pupae were collected from early- and late-planted pyramided hybrids expressing Bt toxins and non-Bt near-isolines in North and South Carolina (16 trials). A total of 5,856 pupae were collected across all trials, with 55 and 88% more pupae collected in later-planted trials relative to early plantings in North and South Carolina, respectively. Only 20 pupae were collected from hybrids expressing Cry1F + Cry1Ab + Vip3A20 across all trials. Averaged across trials, Cry1A.105 + Cry2Ab2 hybrids reduced pupal weight by 6 and 9% in North and South Carolina, respectively, relative to the non-Bt near-isoline. Cry1F + Cry1Ab hybrids reduced pupal weight on average by 3 and 8% in North and South Carolina, respectively, relative to the non-Bt near-isoline. The impact of the Bt toxins on pupal weight varied among trials. When combined with data from 2014 to 2019 from previous studies, a significant decline in the percent reduction in pupal weight over time was found in both states and hybrid families. This study demonstrates a continued decline in the sublethal impacts of Bt toxins on corn earworm, emphasizing the importance of insect resistance management practices.

Resistance of complex interspecific cotton hybrids to wilt

<p>In the article, the results of determining the degree of tolerance to wilt disease in the wilt background of hybrid families obtained using the method of interspecies complex hybridization in the cotton plant are analyzed. In the F2–F4 generations of interspecies complex hybrids, a large-scale process of separation according to the sign of tolerance to wilt disease takes place, and among the hybrids, plants that are not damaged by wilt disease, partially damaged plants, and severely damaged plants are separated. With this in mind, it was confirmed that it is possible to isolate lines and varieties with different levels of wilt damage from complex hybrid combinations of interspecies with different genomes by purposefully conducting selection work by the breeder. A number of wilt disease-tolerant families compared to control cultivars have been isolated and are recommended for use as a starting source in genetic selection studies.<strong><em></em></strong></p>

Mapping QTLs for blight resistance and morpho-phenological traits in inter-species hybrid families of chestnut (Castanea spp.).

Chestnut blight (caused by Cryphonectria parasitica), together with Phytophthora root rot (caused by Phytophthora cinnamomi), has nearly extirpated American chestnut (Castanea dentata) from its native range. In contrast to the susceptibility of American chestnut, many Chinese chestnut (C. mollissima) genotypes are resistant to blight. In this research, we performed a series of genome-wide association studies for blight resistance originating from three unrelated Chinese chestnut trees (Mahogany, Nanking and M16) and a Quantitative Trait Locus (QTL) study on a Mahogany-derived inter-species F2 family. We evaluated trees for resistance to blight after artificial inoculation with two fungal strains and scored nine morpho-phenological traits that are the hallmarks of species differentiation between American and Chinese chestnuts. Results support a moderately complex genetic architecture for blight resistance, as 31 QTLs were found on 12 chromosomes across all studies. Additionally, although most morpho-phenological trait QTLs overlap or are adjacent to blight resistance QTLs, they tend to aggregate in a few genomic regions. Finally, comparison between QTL intervals for blight resistance and those previously published for Phytophthora root rot resistance, revealed five common disease resistance regions on chromosomes 1, 5, and 11. Our results suggest that it will be difficult, but still possible to eliminate Chinese chestnut alleles for the morpho-phenological traits while achieving relatively high blight resistance in a backcross hybrid tree. We see potential for a breeding scheme that utilizes marker-assisted selection early for relatively large effect QTLs followed by genome selection in later generations for smaller effect genomic regions.

Combining Ability of Female Channel Catfish, Ictalurus punctatus, and Male Blue Catfish, I. furcatus, for Early Growth Performance of Their Progeny

The hybrid between the female channel catfish (Ictalurus punctatus) and the male blue catfish (I. furcatus) is the best genetic type currently available for commercial catfish farming due to their superior traits. However, further genetic improvements can be achieved by selecting parents with increased combining abilities. Twenty female channel catfish and twelve male blue catfish were crossed in a partial factorial mating design, resulting in forty hybrid families. These families were evaluated for early growth in three different rearing systems, including ponds and aquaria. The early growth performance of hybrid catfish was significantly (p < 0.05) affected by the additive gene action of the female parent and the male parent. There were genotype–environment or genotype–age interactions affecting the combining abilities, both the amount and the type of genetic variation. Dam GCA was significant in all environments/ages; however, sire GCA was variable, and SCA was not significant. These findings suggest that reciprocal recurrent selection for growth could potentially improve the performance of F1 hybrid catfish.

Оценка гибридных сеянцев яблони по основным хозяйственно-биологическим признакам в Оренбургской области

Abstract. The aim is to evaluate hybrid apple seedlings according to the main economic and biological characteristics in the conditions of the Orenburg region. Methods. The studies were carried out from 2002 to 2022 in the Orenburg branch of the Federal State Budget Scientific Institution of the Federal Scientific Center for Horticulture. The objects of research were 10 hybrid families of apple trees selected by the Federal State Budget Scientific Institution of the Federal Scientific Center for Horticulture. The main observations and records on the main economic and biological characteristics were carried out according to the methodology “Program and methodology for the selection of fruit, berry and nut crops”, “Program and methodology for the study of variety of fruit, berry and nut crops”, statistical processing of experimental data was carried out by the method of two-factor analysis of variance, where A is the variety, B is the year. The scientific novelty lies in the fact that as a result of the conducted research, promising hybrid forms with a complex of economically valuable traits, with a high potential for productivity and large-fruiting in the conditions of the Orenburg region have been identified. Results. The genetic collection of the Orenburg branch of the Federal State Budgetary Scientific Institution of the Federal Scientific Center for Horticulture serves as a fundamental basis for breeding work, which makes it possible to intensify the creation of adaptive, highly productive apple varieties. It has been established that the majority of hybrid apple seedlings have high winter hardiness. Weak freezing (0.2–0.5 points) characterizes hybrids of crossbreeding combinations, such as BratChud × Simvol, Kovrovoe × Anis Sverdlovskiy. Phytosanitary monitoring carried out on the site of hybrid apple seedlings showed that over the years of the study, weather conditions did not allow the development of diseases in the apple tree. On average, fruits in the offspring were 1-1, 1-5, 1-6, 1-7, 1-8, 1-9, 1-10 (140.0 ... 150.0 g). The greatest productivity was formed by hybrids of combinations of crossing BratChud × Simvol (24.6 kg/tree), Orskoe × Prizemlennoe (24.0 kg/tree) and Arkaim × Podarok Orenburzh’yu (24.2 kg/tree).

Сибсовое потомство карельской березы на Заонежской лесосеменной плантации

The article reports the results of studies on the growth and development of curly birch sibs progeny (produced through controlled pollination) aged 35 and 15 years growing in the Zaonezhye forest seed orchard (sites 1 and 2, respectively) in south-eastern Karelia, Medvezhyegorsky District. The number of trees with signs of wood figure in the seed progeny of curly birch in site 1 was 67 % by the age of 20 years, and by the age of 35 years – almost 80 %. This can probably be attributed to the genetic characteristics of the parent (plus) trees on one hand and to the favorable conditions in the forest seed orchard during the first years of the sibs progeny development on the other. Four of the 36 hybrid families (selected to include forward- and backcrossing products) were used for the case study of the growth and development patterns in stands of different age. The sibs progeny of these hybrid families was dominated by high-stemmed plants, but the main trunk shape in the 15-year-old stand was one with necks and muffs, while in the 35-year-old stand – with small protuberances. The rate of height growth in the trees decreased notably with age, whereas radial (stem diameter) growth, on the contrary, accelerated. As the bark grew thicker, however, the formerly bulgy surface “smoothed down”. We have also identified specific features of the ground vegetation formed under the effect of curly birch plantations of different age (15- and 35 years old). A conclusion drawn from the study is that good results from targeted cultivation of curly birch with figured grain (e.g., for sliced veneer) can be achieved already by the age of 20–35 years. Furthermore, considering the number of trees and their origin, this forest seed orchard constitutes an essential part of the valuable gene pool of curly birch, which may turn into a source for expanded reproduction of the resources of this unique member of the European forest tree flora. For citation: Vetchinnikova L.V., Titov A.F., Kostina E.E., Zhigunov A.V. Sibs Progeny of Curly Birch at the Zaonezhye Forest Seed Orchard. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 5, pp. 9–26. (In Russ.). https://doi.org/10.37482/0536-1036-2023-5-9-26

Chineseness in Sino-Malay printing: a triptych of self-criticism

ABSTRACT From late-colonial times, Chinese-Indonesian writers began formulating competing notions of belonging and diasporic identity. Two political ideologies coexisted. The first and oldest was rooted in the ideals of the 1911 Revolution and encouraged the Indies Chinese to devote themselves to the “fatherland.” This movement attempted to resinicise those culturally hybrid Peranakan families in particular. The second group perceived the Indonesian archipelago as its home and advocated for more integration into the Indies society, often in solidarity with Indigenous people. The resulting tensions manifested themselves on the pages of vernacular publications. This article juxtaposes journalism, fiction and poetry as mutually reinforcing platforms to articulate, problematise and debate Chineseness. These genres and the slightly different messages they produced reveal evolving worldviews and a lack of consensus as key Indies Chinese experiences. Periodicals started exhibiting a greater diversity of opinions by the 1930s. A similar tendency is seen in novels and short stories in which pro-China and pro-Indies factions were often criticised in roughly equal measure. These fictionalised debates offer valuable insights into society’s faults and fissures. Fiction is relevant as it grappled with otherwise elusive social taboos, such as romantic encounters between different communities. Lastly, poetry was the genre par excellence to express frustration, aided by the rhetorical devices of sarcasm and translingual creativity. Across these genres, language proves crucial to understanding society’s conflicting expressions of Chineseness. While most of the discourse took place in vernacular Malay, acculturation through profuse borrowing from Hokkien helped to forge a discourse of identification and belonging.

Growth, survival and color segregation of F2 hybrids between selected “Haida no.1” and Orange-shell lines of the Pacific oyster

In aquatic breeding work, much attention has been paid to the performance of the F1 hybrids. However, fewer studies have been conducted on the characteristics of F2 and Fn hybrids, especially in the intraspecific hybridization of the Pacific oyster Crassostrea gigas. In this study, the two purebreds, F1 hybrid families and F2 hybrid families was developed utilizing “Haida No.1” line (HH), Orange-shell line (OO) and their reciprocal hybrids (HO and OH) of C. gigas as the parents. The growth (shell height and wet weight), survival and shell color traits of the six groups were systematically investigated. Our results demonstrated the two F1 hybrid families exhibited significantly heterosis in shell height and wet weight compared to the purebred groups, with mid-parental heterosis at 9.85–36.49% and − 16.50–50.07%, respectively. Moreover, the traits of two F2 hybrid families were gradually inferior to F1 hybrid families from 6th month. Two F2 hybrid families exhibited inbreeding depression in wet weight compared to F1 hybrid families through the whole grow-out stage, with the values from −13.13% to −7.34%. However, the growth and survival advantages were existed in F2 hybrid families compared to their two parental counterparts. Meanwhile, the survival rate of the F2 hybrid families were greater than those of the parental groups during the grow-out stage, with superiority rate of 1.55–19.59%. Furthermore, some orange-shell and purple-shell individuals were detected in the F2 hybrid families. The rates of orange-shell individuals to non-orange shell individuals and purple-shell individuals to non-purple shell individuals were both 1:3. Surprisingly, the growth traits of orange-shell and purple-shell individuals in the F2 hybrid families were significantly superior than those of their corresponding controls (Orange-shell line and wild population). Through this comprehensively comparison analysis, we confirmed that F2 hybrids of C. gigas had obvious advantages in terms of shell height, wet weight and survival rate compared to the purebred lines, and the orange and purple individuals obtained from the F2 hybrid families have great potential to be used for the development for new strains.

Profiles of Volatile Compounds from Seven New Hybrid Families Obtained by Crossings on Noir de Bourgogne Cultivar and Other Blackcurrant Varieties.

Berries of blackcurrant (Ribes nigrum L.) are popular for their strong and complex aroma and their benefits for health. In Burgundy (France), the most famous blackcurrant cultivar is the "Noir de Bourgogne". A blackcurrant breeding program was conducted to obtain new varieties, more resistant to infections and climate changes. The cultivar "Noir de Bourgogne" was crossed with seven other varieties in order to create a hybrid with good agronomic properties and organoleptic properties close to the ones of "Noir de Bourgogne". Several hybrids were created, and their aromatic profiles studied. Berries of eight cultivars, among which Noir de Bourgogne and hybrids resulting from crossings, were harvested during the summer of 2020. Volatile compounds of berries were analyzed by HS-SPME-GC-MS, and principal component analysis (PCA) was used as the most useful chemometric technique. The profiles in volatile compounds of hybrids were either different from those of the two parental varieties or close to that of varieties other than Bourgogne black. In all cases, the overall aroma strength of the hybrid did not equal that of the Noir de Bourgogne cultivar.

Gas-phase and solid-state electronic structure analysis and DFT benchmarking of HfCO.

Ab initio multi-reference configuration interaction (MRCI) and coupled cluster singles doubles and perturbative triples [CCSD(T)] levels of theory were used to study ground and excited electronic states of HfCO. We report potential energy curves, dissociation energies (De), excitation energies, harmonic vibrational frequencies, and chemical bonding patterns of HfCO. The 3Σ- ground state of HfCO has an 1σ22σ21π2 electron configuration and a ∼30 kcal mol-1 dissociation energy with respect to its lowest-energy fragments Hf(3F) + CO(X1Σ+). We further evaluated the De of its isovalent HfCX (X = S, Se, Te, Po) series and observed that they increase linearly from the lighter HfCO to the heavier HfCPo with the dipole moment of the CX ligand. The same linear relationship was observed for TiCX and ZrCX. We utilized the CCSD(T) benchmark values of De, excitation energy, and ionization energy (IE) values to evaluate density functional theory (DFT) errors with 23 exchange-correlation functionals spanning GGA, meta-GGA, global GGA hybrid, meta-GGA hybrid, range-separated hybrid, and double-hybrid functional families. The global GGA hybrid B3LYP and range-separated hybrid ωB97X performed well at representing the ground state properties of HfCO (i.e., De and IE). Finally, we extended our DFT analysis to the interaction of a CO molecule with a Hf surface and observed that the surface chemisorption energy and the gas-phase molecular dissociation energy are very similar for some DFAs but not others, suggesting moderate transferability of the benchmarks on these molecules to the solid state.

Formation of yield elements in composite hybrid families of cotton

A report on the execution of the 2019–2021 strategic plans and their control was presented at the ICAC international organization's annual report conference on October 1, 2020. Also, it was reported that the output capacity of these businesses and factories plummeted by 75% in nations like Vietnam, Bangladesh, and India. The global climate change, the emergence of new races of disease-causing agents and the numerous damages caused by harmful insects indicates the need to create new varieties of cotton that are resistant to adverse factors. The use of the O-3406, O-3407, O-3398, O-3411 and O-2757 families and the created T-3377, T-3378, T-3379 lines based on composite hybridization to achieve positive results in the process of creating especially productive varieties. efficiency is highlighted. The obtained results were subjected to statistical analysis according to the Dospekhov method. The results showed that from the families obtained on the basis of double hybridization, O-31 (F4 Tashkent-6 x Bukhara-6) had a relatively high result, which was 24.8 units. In the rest of the families in this block, it was noted that the indicator according to the sign was from 22.8 units to 24.10 units.

Approximation by Operators for the Sheffer–Appell Polynomials

In this paper, we introduce a generalization of the Kantrovich–Stancu-type Szasz operator asymmetry with hybrid families of special polynomials. Additionally, we construct certain positive linear operators together with the Sheffer–Appell polynomial sequences and then obtain the properties of convergence and the order of convergence, which is symmetric to these operators. For applications, we consider certain explicit examples including mixed-type special polynomials.

Rapid evolution of hybrid breakdown following recent divergence with gene flow in Senecio species on Mount Etna, Sicily

How do nascent species evolve reproductive isolation during speciation with on-going gene flow? How do hybrid lineages become stabilised hybrid species? While commonly used genomic approaches provide an indirect way to identify species incompatibility factors, synthetic hybrids generated from interspecific crosses allow direct pinpointing of phenotypic traits involved in incompatibilities and the traits that are potentially adaptive in hybrid species. Here we report the analysis of phenotypic variation and hybrid breakdown in crosses between closely-related Senecio aethnensis and S. chrysanthemifolius, and their homoploid hybrid species, S. squalidus. The two former species represent a likely case of recent (<200 ky) speciation with gene flow driven by adaptation to contrasting conditions of high- and low-elevations on Mount Etna, Sicily. As these species form viable and fertile hybrids, it remains unclear whether they have started to evolve reproductive incompatibility. Our analysis represents the first study of phenotypic variation and hybrid breakdown involving multiple Senecio hybrid families. It revealed wide range of variation in multiple traits, including the traits previously unrecorded in synthetic hybrids. Leaf shape, highly distinct between S. aethnensis and S. chrysanthemifolius, was extremely variable in F2 hybrids, but more consistent in S. squalidus. Our study demonstrates that interspecific incompatibilities can evolve rapidly despite on-going gene flow between the species. Further work is necessary to understand the genetic bases of these incompatibilities and their role in speciation with gene flow.

Селекционные испытания факториальных гибридов Populus tremula L. в ювенильном возрасте

The aspen is known for its rapid growth, unpretentiousness to growing conditions, valuable timber and some other useful properties. The largest areas on the Eurasian continent are occupied by Populus tremula L. Unfortunately, it is susceptible to heart rot Fomes igniarius Fr., which is a significant drawback. Considering this drawback many scientists had carried out selection of rot-resistant stands and individual aspen trees in natural forests, and later proceeded to artificial hybridization. Besides different crossing options, factorial hybridization, in which several females are crossed with several males, is of interest. The resulting hybrids provide an opportunity to determine the best parental individuals or their pairs. Factorial hybridization of P. tremula in Russia was first carried out in the Central Chernozem region in 2015–2016 within the framework of international cooperation with the Institute of Forest Genetics of the Johann Heinrich von Thünen-Institute (Germany) under the MARussiA project. The purpose of the work was to carry out hybridization, create a field experiment on variety testing of the resulting hybrids and observe them to identify the best hybrids and parents. The hybrids were tested at experimental field sites in the Voronezh and Lipetsk regions. This paper presents the results of field testing at the Latnoye variety test plot in the Semiluky district of the Voronezh region (51°42’ N, 38°56’ E; total area – 2,160 m2). Survival of plants of different hybrid families in the 4-year field experiment ranged from 67 to 100 %; on average, it was 88 %. The average height of plants at this age in individual families varied from 349±38.7 to 510±30.0 cm, being on average 419 cm in the experiment. The average diameter at breast height (1.3 m) was 3.4 cm with fluctuations by families from 2.4 to 4.6 cm. The average size of species cylinders of aspen hybrids by families was 3.5 dm3 with fluctuations from 1.7 to 7.7 dm3. The general and specific combining abilities of the parental forms had been preliminarily found. The results have been compared with the results obtained in other countries. Performed laboratory and field experiments on hybridization of P. tremula L. in the Central Chernozem region will allow to determine the best parental forms and select a number of economically valuable hybrids.

Estimation of breeding value of blackcurrant genotypes for growth vigour, plant habit and their susceptibility to fungal diseases.

The study was conducted in 2012–2014 at the Experimental Orchard of the National Institute of Horticultural Research in Skierniewice, central Poland. The aim of the research was to assess the breeding value, based on the general combining abilities (GCA), specific combining abilities (SCA) and reciprocal (RE) effects, of six dessert parental forms of blackcurrant for plant growth vigour, plant habit and resistance to fungal diseases: Podosphaera mors-uvae (causal agent of powdery mildew of currant), Drepanopeziza ribis (leaf anthracnose) and Cronartium ribicola (white pine blister rust). The plant material consisted of seedlings of F1 generation obtained by crossing of six blackcurrant genotypes: ‘Bona’, ‘Ceres’, clone D13B/11, ‘Sofiivska’, ‘Vernisazh’ and ‘Big Ben’ in a diallel design according to Griffing’s Method III.It was shown that the cultivars ‘Big Ben’, ‘Sofiivska’ and ‘Vernisazh’ had significantly positive GCA effects for growth vigour and resistance of plants to powdery mildew, whereas ‘Ceres’ – for plant habit, which indicated their high breeding value for these traits. The significantly positive SCA values were estimated for the hybrid family: ‘Big Ben’ × ‘Ceres’ for low susceptibility of plants to powdery mildew and anthracnose. Statistically significant effects for reciprocal crosses (RE) were obtained only for few hybrid families.

Long-term evaluation of intra- and inter-provenance hybrids of loblolly pine in the Piedmont region of the southeastern United States

Long-term response of two intra- and two inter-provenance populations of loblolly pine (Pinus taeda L.) were evaluated in the Piedmont region of the southeastern United States. In total, 82 polycross families of the Atlantic Coastal (C) and Piedmont (P) provenances (C×C, P×P) and their hybrids (C×P, P×C) were field tested for growth, sawtimber potential, and survival through age 19 years. The Coastal pure (C×C) families were the tallest, and the hybrid populations (C×P, P×C) were intermediate for height. The four populations did not differ for diameter at breast height. The hybrid C×P population, followed by the C×C population, showed significantly higher stand volumes per hectare. These two populations maintained higher survival and stand density compared to the Piedmont pure populations. Sawtimber potential was significantly higher in the Piedmont pure families at the coldest study sites, presumably due to defect in the C×C and C×P from cold damage. No significant genotype-by-environment interactions were detected for any traits. The genetic gain for height, stand volume, and survival was considerable in the C×C and C×P over the Piedmont source, suggesting potential for benefiting from the faster growth of the Coastal material in the Piedmont region. The performance of the Coastal intra- and inter-provenance populations was marginally affected by the minimum winter temperatures (MWT). These results indicate that the Coastal and the hybrid families can be planted in the Piedmont region with MWT’s of −13 °C or greater and where the difference in MWT between the origin of the Coastal parents and the test sites was not extreme (e.g., the difference did not exceed 2.8 °C). These MWT limits encompass the southern Piedmont of North Carolina (<35.615 °N) and the Piedmont of South Carolina, Georgia, and Alabama.