Enhanced heterozygosity from male meiotic chromosome chains is superseded by hybrid female asexuality in termites

Although males are a ubiquitous feature of animals, they have been lost repeatedly in diverse lineages. The tendency for obligate asexuality to evolve is thought to be reduced in animals whose males play a critical role beyond the contribution of gametes, for example, via care of offspring or provision of nuptial gifts. To our knowledge, the evolution of obligate asexuality in such species is unknown. In some species that undergo frequent inbreeding, males are hypothesized to play a key role in maintaining genetic heterozygosity through the possession of neo-sex chromosomes, although empirical evidence for this is lacking. Because inbreeding is a key feature of the life cycle of termites, we investigated the potential role of males in promoting heterozygosity within populations through karyotyping and genome-wide single-nucleotide polymorphism analyses of the drywood termite Glyptotermes nakajimai. We showed that males possess up to 15 out of 17 of their chromosomes as sex-linked (sex and neo-sex) chromosomes and that they maintain significantly higher levels of heterozygosity than do females. Furthermore, we showed that two obligately asexual lineages of this species—representing the only known all-female termite populations—arose independently via intraspecific hybridization between sexual lineages with differing diploid chromosome numbers. Importantly, these asexual females have markedly higher heterozygosity than their conspecific males and appear to have replaced the sexual lineages in some populations. Our results indicate that asexuality has enabled females to supplant a key role of males.

New variety of soft winter wheat Alyonushka

The article presents the main methods of creating and the results of studying a new variety of winter soft wheat Alyonushka. The variety was created at the FSBRI OP Penza Research Institute of Agriculture by the method of intraspecific hybridization of varieties with subsequent individual selection from the hybrid population F3 Kazanskaya 237 // Moshinskaya 2 / Zolushka. The characteristics of the new variety are given according to the most important economically valuable traits and properties. The new variety Alyonushka in terms of grain yield and the elements composing it, during the years of research (2015–2018), significantly exceeded the standard variety Fotinya. The average increase in grain to the standard for these years was 0.78 t / ha. The high yield of the new variety is formed due to the high mass of 1000 grains, the number and weight of grain per spike. It has high winter hardiness (88% on average), high lodging resistance (9 points) and grain quality at the level of valuable wheat. The new variety Alyonushka stably forms a completed grain (grain nature is 756-797 g / l), the content of crude protein in the grain is 14.8-16.2%, gluten is 28.2-30.2% with a gluten quality of 50-85 units. ... IDK (I-II group), baking strength of flour - 296 units, volumetric yield of bread from 100 g of flour - 780 cm3, overall assessment of bread - 4.7 points. The economic efficiency of cultivation of the Alyonushka variety in comparison with the Fotinya standard was 3780 rubles / ha. The profitability level of the new variety was 135%, which is 21% higher than that of the standard.

Molecular characteristics of S-RNase alleles as the determinant of self-incompatibility in the style of Fragaria viridis

Strawberry (Fragaria spp.) is a member of the Rosoideae subfamily in the family Rosaceae. The self-incompatibility (SI) of some diploid species is a key agronomic trait that acts as a basic pollination barrier; however, the genetic mechanism underlying SI control in strawberry remains unclear. Two candidate S-RNases (Sa- and Sb-RNase) identified in the transcriptome of the styles of the self-incompatible Fragaria viridis 42 were confirmed to be SI determinants at the S locus following genotype identification and intraspecific hybridization using selfing progenies. Whole-genome collinearity and RNase T2 family analysis revealed that only an S locus exists in Fragaria; however, none of the compatible species contained S-RNase. Although the results of interspecific hybridization experiments showed that F. viridis (SI) styles could accept pollen from F. mandshurica (self-compatible), the reciprocal cross was incompatible. Sa and Sb-RNase contain large introns, and their noncoding sequences (promotors and introns) can be transcribed into long noncoding RNAs (lncRNAs). Overall, the genus Fragaria exhibits S-RNase-based gametophytic SI, and S-RNase loss occurs at the S locus of compatible germplasms. In addition, a type of SI-independent unilateral incompatibility exists between compatible and incompatible Fragaria species. Furthermore, the large introns and neighboring lncRNAs in S-RNase in Fragaria could offer clues about S-RNase expression strategies.

Productivity of garden strawberry and breeding possibilities to improve it

The information on the productivity trait of garden strawberry Fragaria × ananassa (Duchesne ex Weston) Duchesne ex Rozier has been summarized on the basis of literary sources. The productivity trait has a complex polygenic character. Independent inheritance of individual productivity components allows modeling their optimal combination in a new variety. The creation of highly productive varieties of strawberries is based on intraspecific hybridization. The established positive correlation between the size of berries and the yield indicates the possibility of increasing the productivity of varieties by using large-fruited forms in breeding. At present, in various zones of horticulture, researchers distinguish large-fruited varieties of domestic breeding: ‘Atlas', ‘Bereginya', ‘Vityaz', ‘Grenada', ‘Zabelinskaya', ‘Kemiya', ‘Nashe Podmoscovie', ‘Nelly', ‘Pervoklassnitsa', ‘Rusich', ‘Solnechnaya Polyanka', ‘Solovushka', ‘Festivalnaya Romashka', ‘Fruktovaya', ‘Tsaritsa', ‘Yaponka', and foreign breeding: ‘Alba', ‘Asia', ‘Elsanta', ‘Finesse', ‘Florense', ‘Vivaldi', ‘Galia', ‘Jive', ‘Joly', ‘M. Champion', ‘Merced', ‘Murano', ‘Onda', ‘Roxana', ‘Rumba', ‘Tarda Vicoda', ‘Vima Kimberly', ‘Vima Tarda', ‘Vima Rina', ‘Vima Xima'. It was noted that when using the inbreeding method, it is possible to achieve a heterotic effect on the basis of the productivity trait. The method of genetic modifications of plants is of great importance for breeding of complex quantitative traits of productivity, including yield. Expansion of the genetic base of garden strawberry by means of octoploid and polyploid forms of wild species will ensure an increase in the productivity of new varieties due to the inclusion of traits of adaptability to biotic and abiotic factors in the genotype. The use of modern research methods (screening of the metabolomic and biochemical profile, DNA certification, molecular labeling) increases the objectivity of research and the efficiency of the breeding process.

Enrichment of the triticale gene pool by intraspecific hybridization

The aim of the research was to expand the genetic diversity of winter triticale samples by intraspecific hybridization and to obtain new valuable forms for their involvement in the selection process of creating high-yielding cultivars. The research was conducted during 2013–2020 at the sites of the Department of Genetics, Plant Breeding and Biotechnology of Uman National University of Horticulture, Ministry of Education and Science of Ukraine. As initial material for hybridization was used samples of hexaploid triticale of own breeding and varieties Rozivska 6, Ladne, Khlibodar Kharkivsky, Beta, Alkid, Souvenir, Raritet; octaploid triticale samples UA0602463 and UA0601654. Hybrid offspring were analyzed for morphological and economically valuable traits, including plant height, lodging resistance, ear length, grain weight from the main ear and 1000 grains, protein and gluten content in the grain and its quality indicators, yield, etc. In the studies used a systematic method of site placement. The rooms were arranged in blocks with a plant density of 400 thousand units/ha four times. In the course of researches hybridization of hexaploid forms of triticale of different ecological and geographical origin among themselves, and also hybridization of octaploid forms with hexaploid was carried out. In F2 populations, individual-family selection of low-stem forms with high ear grain was performed. In the absence of low-stem forms in the area of F2 hybrids, ear productivity was selected, and the population was transferred to a hybridization nursery for crossing plants with donors of low-stem genes. As a result of the conducted researches 23 highly productive forms of winter triticale were obtained, in particular, two dwarf samples (h = 58 cm), four – short-stemmed (h = 60–80 cm), one – early-ripening (vegetation period 285 days), nine – with high ear productivity. Sample 63 was selected, which significantly exceeded the group standard in terms of yield (7.01 t/ha), protein content (12.2 %) and gluten of the first quality group (25.4 %).

On the processes of sympatric speciation in the group of «yellow» wagtails in the Middle Volga region

This article discusses the mechanisms of sympatric speciation in the group of species of «yellow» wagtails based on hybridization. Interspecific and intraspecific hybridization can be attributed to the genetic mechanisms of divergence of populations of «yellow» wagtails. The existence of hybridization between the subspecies of the white-eared yellow wagtail M. flava beema and the yellow-fronted wagtail M. lutea leads to the emergence and further accumulation in the population of individuals with a light-colored head to varying degrees, the so-called «gray-headed» individuals. Intraspecific hybridization of subspecies forms of the yellow wagtail M. flava — nominative M. f. flava and white-eared M. f. beema leads to constantly occurring genotypic splits, which support intraspecific polymorphism of populations and provide the basis for further genetic divergence of these subspecies and species. The form of "gray-headed" hybrids is characterized by maximum genetic distances (1306.67–1375.67), which may correspond to the species rank. The modern polytypic complex of M. flava (in the narrow sense, a series of species and subspecies of only M. flava) probably formed in historical time on the basis of fan hybridization between the original forms of M. f. flava and M. lutea. Thus, the factors of genetic differentiation and divergence, along with ecological and geographical isolation, play a leading role in the formation of the spatio-temporal and genetic structure of the genus Motacilla. Currently, there is an active process of genetic divergence and separation of subspecies and species forms of «yellow» wagtails under conditions of wide sympatry within a single polytypic complex based on intraspecific and interspecific hybridization in the European part of Russia.

Intraspecific Hybridization Of Normal Pigmented And Albino Clarias Gariepinus From Yola And Katsina under Hatchery Condition

The study examined the reproductive indices of albino and normal pigmented Clarias gariepinus fish from Katsina (KT) and Yola (YY), carried out under hatchery condition. The experiment compared the fecundity, testes, milt volume, percentage fertilization and hatchability of albino (AA) and normal pigmented (NN) Clarias gariepinus from Katsina (KT) and Yola (YY). Normal pigmented C. gariepinus from Katsina (KT) had the highest number of eggs (229,240), followed by YY (127,250) and the least was recorded in the Albino (AA) (124,750). The weights and lengths of the left and right lobes as well as the volumes of the milt were quantified . However, KT had the highest weight and length of the right testis (18g and 5.7cm respectively) while AA had the highest weight, length of the left testis and milt volume (30g, 11cm and 8.4ml respectively). The least length and weight of the testes was observed in YY. Meanwhile, KT and YY had milt volumes of 4.0ml and 4.7ml, respectively. The highest percentage fertilization and hatchability were recorded in KT × KT (98.7% and 98.5% respectively) among the purebred, while KT × AA had the highest percentage fertilization and hatchability (98.4% and 97.3% respectively) in the reciprocal hybrids. The percentage fertilization and hatchability among the genetic crosses showed significant differences (p<0.05). The results deduced the essentiality of fish hybridization. Furthermore, crossing of broodstocks from different regions have showcased the contingency of acquiring fish seed of improved reproductive potentials in the reciprocal hybrids in the aspects of fecundity, fertilization, hatchability rate, testis quality and faster growth. Keywords: Albino, Fecundity, Intra-specific Hybridization, Normal pigmented, Testis

Global insights into homoeolog gene expression in upland cotton under intraspecific hybridization

Background: Hybridization is useful to enhance yield potential of agronomic crops in the world. Cotton has genome doubling due to alloteraploidy process and hybridization process in coordinate with duplicated genome can produce more yield and adaptability. Therefore, expression of homoeolog gene pairs between hybrids and inbred parents are vital to characterize genetic source of heterosis in cotton.Results: Investigation results of homoeolog gene pairs between two contrasting hybrids and their respective inbred parents identified 36853 homoeolog genes in hybrids. It was observed both high and low hybrids had similar trends in homoeolog gene expression patterns in each tissue under study. An average of 96% of homoeolog genes had no biased expression and their expressions were derived from the equal contribution of both parents. Besides, very few homoeolog genes (An average of 1%) showed no biased or novel expression in both hybrids. The functional analysis described secondary metabolic pathways had a majority of novel biased homoeolog genes in hybrids. Conclusions: These results contribute preliminary knowledge about how hybridization affects expression patterns of homoeolog gene pairs in upland cotton hybrids. Our study also highlights the functional genomics of metabolic genes to explore the genetic mechanism of heterosis in cotton.