Mapping the Genetic Regions Responsible for Key Phenology-Related Traits in the European Hazelnut

An increasing interest in the cultivation of (European) hazelnut (Corylus avellana) is driving a demand to breed cultivars adapted to non-conventional environments, particularly in the context of incipient climate change. Given that plant phenology is so strongly determined by genotype, a rational approach to support these breeding efforts will be to identify quantitative trait loci (QTLs) and the genes underlying the basis for adaptation. The present study was designed to map QTLs for phenology-related traits, such as the timing of both male and female flowering, dichogamy, and the period required for nuts to reach maturity. The analysis took advantage of an existing linkage map developed from a population of F1 progeny bred from the cross “Tonda Gentile delle Langhe” × “Merveille de Bollwiller,” consisting in 11 LG. A total of 42 QTL-harboring regions were identified. Overall, 71 QTLs were detected, 49 on the TGdL map and 22 on the MB map; among these, 21 were classified as major; 13 were detected in at least two of the seasons (stable-major QTL). In detail, 20 QTLs were identified as contributing to the time of male flowering, 15 to time of female flowering, 25 to dichogamy, and 11 to time of nut maturity. LG02 was found to harbor 16 QTLs, while 15 QTLs mapped to LG10 and 14 to LG03. Many of the QTLs were clustered with one another. The major cluster was located on TGdL_02 and consisted of mainly major QTLs governing all the analyzed traits. A search of the key genomic regions revealed 22 candidate genes underlying the set of traits being investigated. Many of them have been described in the literature as involved in processes related to flowering, control of dormancy, budburst, the switch from vegetative to reproductive growth, or the morphogenesis of flowers and seeds.

Female flowering lines as the basis for new highly productive F1 zucchini hybrids

Relevance. The modern marrow seed market shows the prospect of creating F1 hybrids that have the maximum return on a high-quality crop. For their successful selection, parental forms with a complex of economically valuable traits and a high combinational ability are required. The most important role is played by the female zucchini maternal lines of flowering type, which allow for hybrid seed production with free pollination and obtain high quality F1 hybrid seeds.Materials and methods. The studies were carried out at of the Krymsk EBS VIR Branch (Russia, Krasnodar Region, Krymsk) in 2019-2021. Variety testing of lines and hybrids was carried out in the open field in the fields of selective crop rotation. The plot area was 5 m2, the experiment was repeated three times.Results. The general combinative ability of parental squash lines was studied, maternal forms with a positive GCA effect on early yield (F5 409-1, F5 409-2) and on total yield (F5 409-1) were identified. A preliminary variety testing of hybrid combinations was carried out in comparison with the standards F1 Belogor and F1 Pascal. The main economically valuable traits have been studied: early maturity, early and general yield, marketability, product attractiveness. F1 hybrids of zucchini were identified, obtained on the basis of maternal forms of the female type of flowering F5 409-1, F5 409-2 in terms of yield (early above 17,7 t/ha and total above 46,7 t/ha), and marketability, more than 83,2%.Conclusions. The high productivity of F1 zucchini hybrids obtained on the basis of maternal forms of the female flowering type F5 409-1, F5 409-2 proves the promising nature of their use in breeding. As a result of two years of study, a hybrid F1 (409-1×305) was isolated, with a complex of economically valuable traits: early yield 19,6 t/ha, total yield 52,6 t/ha, marketability 84,3%, attractive appearance of fruits.

Yield and forage quality in maize (Zea mays L.) inbred lines

Objective: To analyze the genetic diversity (agronomic attributes, forage yield, and fiber content) of 100 maize inbred lines and to identify genotypes with potential for the breeding of plants with the said traits. Design/methodology/approach: One-hundred maize inbred lines were evaluated in two environments, in a 10 x 10 complete block experimental design, with two repetitions. Days to male flowering, days to female flowering, ear height, plant height, stem diameter, green forage yield, neutral detergent fiber, and acid detergent fiber data were recorded. Results: Significant differences were observed in the environmental sources of variation and genotypes for all the traits evaluated. The first four components account for 81% of the total variation observed and the first two account for 66% of the variation. The variables which have the highest absolute value and which strongly influence the dispersion of the genotypes, as well as the formation of groups, were: plant height, forage yield, and acid detergent fiber (component one) and days to female flowering and days to male flowering (component two). Consequently, the genotypes were dispersed in four groups. Study limitations/implications: It was not possible to conduct genetic diversity studies using molecular markers. Findings/conclusions: The grouping pattern of inbred lines shows the genetic diversity present; this can be an important tool in genetic improvement programs aimed at obtaining hybrids with specific characteristics.

Peculiarities in Scots pine (Pinus sylvestris L.) clones seeding on CSP (Cloning seed plantation) in western Polissya of Rivne region

The main purpose of seed orchards is to obtain regularly seeds of the highest genetic value for forest plantations. Long-term research in Ukraine and foreign experience show that there is a significant reduction in the cone yield on orchards that are over 26–28 years old even with free spacing of ramets. The aim of the study was to identify peculiarities in reproduction of Scots pine on Clonal Seed Orchards (CSO), based on comparison for performances of flowering intensity and seed production from different clones, their groups and CSO in Rivne region. The object of the study is the clonal seed orchards of Scots pine (Pinus sylvestris L.). The subject of research is the reproduction of clones on clonal seed orchards of Scots pine. The intensity of «flowering» and seeding of clones on CSO was determined by continuous list of each ramet. To assess the intensity of female «flowering», we determined the growth and the reproductive layer of the crown, the rank position of pine clones on plantations, which we divided into three groups: high, medium and weak. We analyzed the intensity of growth, «flowering» and seed production of Scots pine clones (Pinus silvestris L.) for many years on the plantations of 1977 and 1984. At CSP of 1977, the «flowering» within clones is characterized by a mixed-sexual type; on the plantation of 1984, the most clones (54.2%) were dominated by female «flowering». The rate of microstrobiles formation in clones on the younger plantation (CSP-1984) is lower than the intensity of megastrobiles formation by 4.0%, while on the older one (1977), on the contrary, the intensity of microstrobiles formation was dominant by 118.2%. The average yield of strobiles from the number of megastrobiles on the CSP of 1977 and 1984 was 70.1 and 74.3%, respectively. The close correlations were found between the number of megastrobiles and the number of strobiles (r = 0.94 and 0.84). The variation in the number of strobiles per tree over the years of observation is quite high and varied in clones of 1977 from 40.2% in 2004 to 70.7 in 2003 and averaged 52.6%; clones of 1984 ranged from 43.6% in 2004 to 78.8% in 2005 and averaged 59.3%. The number of female strobiles for the six-year period at CSP of 1977 averaged 45.8% from the number of male ones; for three years — 4.0% in clones of 1984. Their number ranged from 25.5 to 61.3% in clones of 1977; in clones of 1984 – from 16.5 to 77.5%. Depending on the clone and the weather conditions of the growing season, the ratio between the number of female and male strobiles within each clone is from 29.8 to 166.7% on CSP of 1977 and from 49.4 to 1005.4% of 1984. The correlation between the number of mega- and microstrobiles on CSP of 1977 is weak (r = 0.17), and the ones of 1984 – high (r = 0.77). No dependences were found between the preservation of megastrobiles by their number (abundance of «flowering») in clones of 1984 and the average correlation (r = 0.33) was found in clones of 1977. According to long-term data on CSP of 1977, the most productive is clone No 22. The highest yield of strobiles from the number of megastrobiles on the plantation of 1984 – in clone No 130 (88.1%), the lowest — No 121 (46.7%). Only two clones (No 22 and 97) and eight clones of 1984 (No 116, 118, 127, 129, 130, 137, 138, 139) are included into the group of clones of 1977 with abundant «flowering», harvest and high yield of strobiles). The clones that have the high and medium growth intensity, with high and medium flowering intensity, with high and medium yield of strobiles are perspective for seed plantations among the selected groups.

Anthecological features of Lonicera japonica Thunb. in the environments of Southern Uzbekistan

Background. Identification of spectacular ornamental perennial lianas for urban landscaping in southern cities is important for modern urban greening programs. The aim of this work was to study flowering peculiarities of Japanese honeysuckle (Lonicera japonica Thunb.).Materials and methods. The target material was honeysuckle plants growing in the environments of Southern Uzbekistan. Observations were conducted in 2019–2020 using conventional approaches.Results and conclusion. The inflorescence of L. japonica is an open dibotryoid, with flowers arranged along the lateral axes of the first order. Flowers are bisexual, zygomorphic. Blossoming of flowers in inflorescences occurs acropetally. The flowering period is almost 150–170 days (starts in April and lasts until the end of August). Dichogamy in the form of proterandry is observed in honeysuckle flowers. The male flowering phase comes the first. It starts 1.5–2.0 hours after the opening of the corolla and ends with the drying of the stamens. The corolla turns yellow 36 hours after the blooming of the flower and the stamens begin to dry out. This is the female phase. Over the next 84 hours, the pistil begins to dry out slowly, but the corolla of the flower lasts up to 96 hours. The duration of the female flowering phase is 60 hours. L. japonica is of considerable interest for vertical landscaping of urban communities. Plants remain ornamental for a long time. Studying this species as an essential oil plant is promising, since it contains a significant amount of germacrene D.

Parameter Genetik Hasil Persilangan Jagung Bersari Bebas untuk Mendapatkan Galur Berbiji Ungu

Corn (Zea mays) is a cereal crop and has become a staple food. Purple corn has more excess compared to corn in general. In addition, purple corn has high nutrient content and anthocyanin levels. This study aims to determine genetic parameters such as variability, heritability, and genetic advance of the F2 generation resulting from an open-pollinated hybridization. The research was conducted from January 2020 to June 2020 on the Research and Experimental Field of the Department of Agrotechnology, Universitas Bangka Belitung. The work used a single plant design. The lines used were derived from the results of the previous selection stage. The results showed that the phenotype variability was relatively wide on the weight character of ear cobs with cornhusk, and the cob weight without cornhusk. High heritability values are found in the characters of harvest age, age of male flowering, and age of female flowering. The value of expected genetic advance for high expectations is found in the characters of plant height, the row number of seeds, the weight of 100-seeds, and the weight of cob with cornhusk. The selection results suggest nine corn lines that can be used for the next generation selection. Keywords: corn, expected genetic advance, heritability, purple, variability

Variation of Morphological, Agronomic and Chemical Composition Traits of Local Hazelnuts Collected in Northern Spain

Hazelnut is a traditional crop in northern Spain, where it grows wild as well as being cultivated. A field collection of 41 local and 17 non-local accessions, including 15 well-known cultivars, was established at SERIDA in Villaviciosa, Spain. Here, phenotypic variation was documented for phenological and morphological traits and chemical composition. A large degree of variation for most morphological and phenological traits, except nut maturity date, was revealed. Estimates of broad-sense heritability were high (>0.75) for most of the assessed characters, except for the first male bloom date (0.65), male and female flowering periods (0.40, 0.31), kernel weight (0.69), and kernel percentage (0.33). Local accessions produced smaller nuts and kernels than well-known cultivars but with higher kernel percentage. Limited overlapping between the male and female flowering periods (dychogamy) was observed, except for ‘Forcinas 1’, ‘Forcinas 2’, and ‘Morell’. The local accessions generally exhibited significantly later male and female flowering compared with the reference cultivars. The local materials showed similar nutritional values to those reported previously for hazelnut. Moreover, the local accessions presented average values similar to the non-local accessions for total fat, ash and carbohydrate contents, as well as energy value, but their protein contents were lower. Their oils were rich in functional compounds, such as unsaturated fatty acids (average: 90.1%), tocopherols (514 mg/kg) and squalene (294.3 mg/kg). A hierarchical clustering on principal components analysis grouped the accessions and differentiated eight local accessions from the rest, including the landrace ‘Casina’. This finding provides potential new cultivars, as well as sources of desirable traits, for European hazelnut breeding programs.

Effects of climatic warming on spring phenology in subtropical trees: process-based modelling with experiments designed for model development

We developed process-based tree phenology models for four subtropical tree species, and for the first time for these trees, we based the model development on explicit experimental work particularly designed to address the processes being modelled. For all the four species, a model of seedling leafout was developed, and for Torreya grandis, a model for female flowering in adult trees was additionally developed. The models generally showed reasonable accuracy when tested against two sources of independent data. In scenario simulations, the models projected an advanced spring phenology under climatic warming for 2020 – 2100. For the leafout of seedlings, the advancing rates varied between 4.7 and 5.9 days per one C warming, with no major differences found between the climatic scenarios RCP4.5 and RCP8.5. For Torreya flowering, less advancing was projected, and the projected advancing per one C warming was less for RCP8.5 (0.9 days / C) than for RCP4.5 (2.3 days / C). The low advancing rates of Torreya flowering were caused by reduced chilling under the warming climate and by the particular temperature responses found for Torreya flowering. These findings highlight the need to base the model development on explicit experiments particularly designed to address the process modelled.

DROUGHT TOLERANCE IN INTERVARIETAL MAIZE HYBRIDS

ABSTRACT In the period of planting of second-season maize, there is high climatic instability with greater probability of occurrence of water deficit. This is one of the factors that most cause reduction in maize grain yield. In this context, the aim was to identify stable, irrigation-responsive and drought-tolerant maize genotypes. The experiments were conducted in Mococa / SP and Tatuí / SP, at Instituto Agronômico, in two assays, one under full irrigation conditions and the other under water stress. The experimental design was randomized blocks with 3 replicates. Male flowering, female flowering, plant height, ear height, hectoliter weight, one hundred grain weight and grain yield were evaluated. Joint analysis of variance and stability analysis were performed by the GGEBiplot method. Significant genotype and site effects were observed for all traits. Significant effects of genotype x site interaction were found for all traits except ear height and male flowering. The characteristics most affected by water deficit were male flowering, plant and ear heights and grain yield. Genotypes F2 BM709 x PopTol 2, IAC 46 x PopTol 2, F2 30K75 x PopTol 3 and F2 BM709 x PopTol 3 are considered ideotypes because of their high grain yield, phenotypic plasticity and drought tolerance.

Effects of climatic warming on spring phenology in subtropical trees: process-based modelling with experiments designed for model development

To project the effects of climatic warming on the timing of spring leafout and flowering in trees, process-based tree phenology models are often used nowadays. Unfortunately, the biological realism of the models is often compromised because the model development has often been based on various assumptions and indirect methods. We developed process-based tree phenology models for four subtropical tree species, and for the first time for these trees, we based the model development on explicit experimental work particularly designed to address the processes being modelled. For all the four species, a model of seedling leafout was developed, and for Torreya grandis, a model for female flowering in adult trees was additionally developed. The models generally showed reasonable accuracy when tested against two sources of independent data: observational phenological records and leafout data from a whole-tree chamber warming experiment. In scenario simulations, the models projected an advanced spring phenology under climatic warming for 2020 – 2100. For the leafout of seedlings, the advancing rates varied between 4.7 and 5.9 days per one °C warming, with no major differences found between the climatic scenarios RCP4.5 and RCP8.5. For Torreya flowering, less advancing was projected, and the projected advancing per one °C warming was less for RCP8.5 (0.9 days / °C) than for RCP4.5 (2.3 days / °C). The low advancing rates of Torreya flowering were caused by reduced chilling under the warming climate and by the particular temperature responses found for Torreya flowering. For instance, our results show that in Torreya flower buds, no rest break (endodormancy release) is seen at +15 °C, whereas in the seedlings of all four species, +15 °C has a clear rest-breaking effect. These findings highlight the need to base the model development on explicit experiments particularly designed to address the process being modelled.