Interline Hybrids Research Articles

Evaluation of source material for sweet maize by the main breeding characteristics

Topicality. The sweet maize grain differs from other maize subspecies in its high sugar content: the grain accumulates 2 times more mono- and disaccharides, 20 times more dextrins, and almost 2 times less starch, with a crude protein content of 10.4–14.9 %. The main direction of sweet maize breeding is to develop the high-yielding interline hybrids that are suitable for mechanized harvesting of cobs, and resistant to main diseases and pests, as well as characterized by high technological grain qualities. To effectively solve these challenges, it is necessary to know the morphological and biological characteristics and properly select the source material (self-pollinated lines). Purpose. To study of morphological and biological characteristics of sweet maize lines. Materials and methods. Visual phenological observations; laboratory-field method was used to determine morpho-biological characteristics of plants; measuring and weighing method – to determine yield and metric characteristics of plants; mathematical and statistical method - to determinate validity of results, variability of traits, correlational dependence of traits; analysis of variance; comprehensive assessment of morpho-biological and economically valuable characteristics of inbred lines. Results. According to analysis of sugar composition, the studied samples revealed a high content of monosaccharides (glucose, fructose, etc.) in the lines HOL-1 1411111, HOL-1 1411211, DKS346 114, DINAR346 141, HOL-19 and disaccharides (sucrose, lactose, maltose) in HOL-1 1411211, SVAN1212 123, HOL-19. These indicators are important in the deep processing of sweet maize for the food industry an individual product and as one of the components in the culinary products. These mono- and disaccharides are used to produce sweets, sweet or alcoholic drinks and sauces. The following DINAR346 141, HOL-1 1411511 lines had a low level of sucrose content: 3.7 and 4.6 %, respectively. Conclusions. According to the results of research on the breeding material of sweet maize, it was identified the self-pollinated families with high taste qualities (7 points), such as HOL-1 1411111, HOL-1 1411211, DKS346 114, HOL-4 1411141 and HOL-19, which will be involved to develop competitive high-yielding hybrids with a high sugar content in grain, increased taste and technological qualities in the sweet maize breeding programs in the future. Key words: sweet corn, line, sugar content, seed productivity, grain taste

Comparative study of simple interline and three-way cross maize hybrids

Domestic interline maize hybrids are predominantly three-way cross hybrids in structure, and foreign breeding and seed companies prefer simple interline hybrids. In order to improve the competitiveness of domestic breeding, it is necessary to reorient to simple hybrids, which, in turn, requires information on whether simple maize hybrids have an advantage in specific soil and climatic areas. The purpose of the current study was to conduct a comparative study of new simple interline and three-way cross maize hybrids according to grain productivity and uniformity of economically valuable traits under unstable moisture supply. The study was carried out on the experimental field of crop rotation of the laboratory for maize breeding and seed production of the FSBSI “ARC Donskoy” in 2019–2021. The objects of the study were 10 simple and 10 three-way cross new domestic maize hybrids developed by the method of complete topcrosses. The establishment of field trials, records, biometric measurements and phenological observations were conducted in accordance with the methodological recommendations for conducting field trials with maize. There has been found that productivity of simple hybrids (3.49–4.65 t/ha) turned out to be significantly larger than that of three-way cross hybrids (2.84–3.70 t/ha), the mean excess was 0.78 t/ha or 23.6 %. Simple hybrids were characterized with the best uniformity in a length of a vegetation period (V = 0.58–2.13 %), height of maize ear attachment (V = 5.0–11.3 %), plant height (V = 2.8–4.8 %), and, consequently, better harvesting adaptability. There has been found a negative mean correlation (r = –0.49...–0.69) between grain productivity and variation of traits in terms of maturation, plant height and height of maize ear attachment. There has been found no correlation between the structure of interline maize hybrids and such traits as grain harvest moisture, resistance to lodging and smut “virus”. Due to a set of traits there has been identified a new simple interline maize hybrid ‘Zernogradsky 367’.

Intra-population variability of oil content and fatty acid composition in modern hemp cultivars

Purpose and objectives. To identify new promising material with high seed productivity, oil content and optimal fatty acid composition
 Results and discussion. It was found that the variability ranges of the oil content and seed weight increased under the influence of selections. Use of distant genotypes in hybridization contributed to the generation of high-oil lines, which later become donors of this trait. High oil content was recorded in hybrids derived from crossing cultivars and self-pollinated lines of the Central European eco-geographical type with cultivars and self-pollinated lines of the southern type. In this case, cultivar-line and line-cultivar hybrids (oil content of 36−39%), rather than inter-line ones, turned out to be the most successful results.
 Family-group selection is a basis for increasing and further stabilizing the oil content in seeds. The oil content was revealed to gradually increase during the breeding for increased oil content. It was found that the population variability of the seed oil content was from 33.99% to 46.98%.
 Continuous breeding selection gradually widens the expression range of the “oil content” trait from medium to maximum. In order to increase the practical value of cultivars via breeding techniques the seed productivity was also increased. The cultivars of different genetic origins, Hlesiia and Mykolaiychyk, as well as the cultivars of hybrid origin, Artemida and Harmoniia, were considered the most promising ones. In Mykolaichyk populations, the oil content gradually increased and stabilized at a level of 33, 35, or 37.8% without changes in the fatty acid composition of oil.
 The selections stabilized the oil content in cultivar populations. This proves the high efficiency of the developed breeding methods to create cultivars with high seed productivity and of targeted selection to increase the oil content in hemp seeds. Thus, the importance of a cultivar combining high seed yield and high oil output rises. The modern cultivars were ranked in order of decreasing oil levels in seeds as follows: Mykolaichyk, Artemida, Harmoniia, Hlesiia.
 Oil of all cultivars had an optimal ratio of omega-3 to omega 6 fatty acids of 1:3.1−1:3.9 (2016−2017). In 2018−2019, the ratio of omega-6 to omega-3 fatty acids was 4.0:1− 4.8:1. The linoleic acid content ranged from 55% to 58% and the linolenic acid content – from 12.58% to 18.23%. Mykolaichyk and Artemida were noticeable for gamma-linolenic acid. These results allow us to assert that the fatty acid composition of hemp seeds is unique and immutable during the breeding for increased oil content.
 Conclusions. We believe that the Central European type is a source and donor of high oil content, while the southern type – of a longer seed formation and, accordingly, of high oil accumulation.
 The heterosis phenomenon resulted from combining distant genotypes in one organism was observed. In this case, cultivar-line and line-cultivar hybrids, but not inter-line hybrids, turned out to be the most successful ones (oil content of 36−39%).
 The new hemp cultivars, Mykolaichyk, Artemida and Harmoniia, which combine high seed productivity with high seed oil content and unique fatty acid composition, have been created.

Комбинационная способность новых ЦМС-линий рапса озимого (Brassica napus L.) селекции ВНИИМК

Combining ability (CA) of lines is one of the main criteria of estimation of the parental components of hybrids. There are existed the different crossing schemes for estimation of a combining ability. A method of top-cross is successfully used in a breeding practice. This method was used for estimation of a range of new CMS-lines of winter rapeseed perspective in breeding of simple interline hybrids. In our research we used six sterile lines on a base of CMS Ogura and six lines-restorers of fertility (testers). We obtained 36 test-hybrids for estimation of a combining ability of the lines. Positive combination of effects of the general combining ability (GCA) and variances of the specific combining ability (SCA), stable manifested in two years, we observed in two maternal lines 39712 and 40059. Hybrids with these lines had the higher average seed yield in two years of the research. These lines can be recommended for development of practically important hybrids of winter rapeseed. It is considered the testers possessing high GCA are promising for estimation of lines CA. in our research, two lines ORK 9 and ORK 21 demonstrated the high average seed yield of test-hybrids in two years of the research and can be recommended for usage as testers.

Кондитерский подсолнечник: происхождение, история введения в культуру, систематика, направления в селекции и особенности технологии возделывания (обзор)

Analyzing Russian and foreign scientific literary sources we presented data on origin, history, current state and development prospects of the confectionary sunflower. We stated main features of confectionary sunflower compared to oil form. There is described perspective initial germplasm of confectionary sunflower from the VIR collection and collections of the other scientific institutions. We consider different direction of products use, requirements to qualitative and organoleptic traits. We stated an important role of bee-pollination in formation of high seed yields. We think it is reasonable to repurpose step by step breeding works to primary development and introduction of confectionary interline hybrids. The further perfection of scientific and research works with confectionary sunflower according to climatic changes is discussed.

Genetic basis of selection of stone fruit and other agricultural plants

Methods of creation, identification on marker signs and maintenance of the valuable genotypes used at creation of new grades, pure lines, interlinear hybrids of stone fruit plants are considered. The maintenance of valuable genotypes used in the creation of new cultivars, clean lines, interline hybrids of stone fruit plants. The laying of plantations of nectarine and peach by sowing seeds directly into the garden with subsequent budding in the form of reducing the cycle of cultivation of eyepieces, the entry into the period of full fruiting of trees, as well as accelerating the introduction into production of new breeding cultivars grown by non-transplanting method. This makes it possible to create for two years of vegetation productive mother-cuttings gardens up to 500 trees of each new cultivar. Significant importance is given to modem molecular genetic and biotechnological methods, as well as classical-hybridization, individual selection, acceleration of the breeding process (use of greenhouses for growing hybrid seedlings, as well as grafting seedlings of fruit plants). In nectarine, as well as endemic to China the peach of David and the peach of the world when self-pollinating interspecific hybrids F1 in inbred offspring sometimes there are sterile individuals of plants.

THE USE OF CLASSICAL AND MODERN METHODS IN RAPESEED (BRASSICA NAPUS) BREEDING AT VNIIMK

Introduction. Rapeseed is a facultative autogamous plant; its percentage of cross-pollination is 10–50%, so rapeseed breeding engages the line and population breeding methods as well as the development of hybrids and all innovative research approaches.Material and methods. Among the main techniques used for the development of parent material and, eventually, cultivars at the Pustovoit Institute (VNIIMK) is the pedigree method (individual selection from intraspecific and interspecific hybrid populations, combined with inbreeding). Physical and chemical mutagenesis is also employed in rapeseed breeding at VNIIMK. The material with yellow-colored seed coat has been obtained by exposing rapeseed seeds to various doses of gamma rays (50, 100 and 150 kR). Seed treatment with chemical mutagens is primarily aimed at changing the fatty acid composition of oil.Results. Breeding achievements for winter and spring rapeseed, registered by VNIIMK in the State Register of Breeding Achievements of the Russian Federation over the past 15 years, are highly productive line cultivars with a seed yield of 4–5 t/ha for winter rapeseed, and 2–3 t/ha for spring rapeseed. Promising experimental interline hybrids, significantly exceeding the reference in seed yield (by 1.61–2.26 t/ha), have been developed. Yellowseeded lines, which exceed the black-seeded reference cv. ‘Tavrion’ in seed yield by 0.08–0.15 t/ha, have been selected. We developed the material with an oleic acid level of 78.9– 80.5%.

ПРОЯВЛЕНИЕ ГЕТЕРОЗИСА У МЕЖЛИНЕЙНЫХ ГИБРИДОВ РАПСА ОЗИМОГО ПО ХОЗЯЙСТВЕННО-ЦЕННЫМ ПРИЗНАКАМ

ПРОЯВЛЕНИЕ ГЕТЕРОЗИСА У МЕЖЛИНЕЙНЫХ ГИБРИДОВ РАПСА ОЗИМОГО ПО ХОЗЯЙСТВЕННО-ЦЕННЫМ ПРИЗНАКАМ

Evaluation of the resistance of the breeding material beetroot to Cercospora amid epiphytoty in greenhouses the Moscow region

Relevance.An important feature that determines the technological qualities of varieties and hybrids of beetroot is an erect, compact leaf rosette that persists until the end of the vegetation of plants. In this regard, much attention is paid to the selection of resistance to diseases affecting the leaves of plants, including Cercospora beticola Sacc. When creating resistant to Cercospora interline hybrids based on CMS, the selection of parent components plays an important role. In agroclimatic conditions of the Moscow region, Cercospora on industrial beetroot rarely reaches an economically significant threshold of harmfulness. However, in 2019, epiphytic development of Cercospora on summer first-year crops was observed in the block film greenhouse of the «Federal Scientific Vegetable Center», which allowed to assess the promising breeding material.Material and method. Phytomonitoring on beetroot plantings and sowing of the experimental production Department of the «Federal Scientific Vegetable Center» growing was carried out by methods of visual diagnostics and microscopy. Cercospora lesion in the breeding nursery was evaluated on an 11-point scale, the ranking of samples into five groups of resistance - according to the degree of disease development (R%). Analyzed: 28 sterile lines (А); 13 fertile lines of fixers (В); 25 lines of pollinators (С) and 38 hybrid F1 (АхВхС).Results. It was found that more than half of the studied lines were receptive to Cercospora. The share of relatively resistant lines was 13%. Most of them (8%) are ms - lines « obtained by pollination of CMS with mf-lines В. A close relationship (r=0.86-0.89) between the index of lesion of fixators and the degree of disease development of ms- lines was revealed, in some simple combinations a positive effect of heterosis on resistance to Cercospora relative to mf-В was noted. In the submitted sample F1 hybrids mainly observed between the nature of inheritance according to the degree of disease development (R, %), mixed effects the base line stability of pollinator mf-С (r=0,32) and a closer correlation of the stability of hybrid offspring the F1 with the resistant parent ms-line А (r=0.55). As a result of the evaluation, the most resistant to Cercospora ms- and mf-lines and derived from them hybrid F1, among which only 9% were included in the group of relatively resistant to C. beticola.

ОЦЕНКА ГИБРИДНОГО МАТЕРИАЛА НА УСТОЙЧИВОСТЬ К VERTICILLIUM DAHLIAE KLEBHAN С ПРИМЕНЕНИЕМ МАРКЕРНЫХ ФЕРМЕНТОВ ФИТОИММУНИТЕТА

The aim of the work is to assess the sustainability of breeding significant interline hybrids F 6 to V. dahlia, created in NIESSVAH as a starting material for breeding. 21 samples were selected by the NIISSVAH staff and the Institute of Bioorganic Chemistry ANRUz and transferred for the relevant biochemical analysis. In the experiment, they determined the activity of peroxidase, then they revealed its activity in seedlings of cotton seeds, and also established responsiveness to the defeat of V. dahlia. As a result of the research, the seeds of 21 different cotton hybrids were tested to study the activity of the chitin-specific peroxidase enzyme. For this purpose, seedlings of families of hybrid combinations of cotton were used in order to select a breeding material with high resistance to Verticillium. In the work on the assessment of resistance to V. dahlia, biochemical tests were used using phytoimmunity marker enzymes - chitin specific peroxidase. As a result of a biochemical study in the laboratory, it was established that the complex interlinear combination F 6 [F4-L-105 x L-108) x L-104] should be attributed to the pathogen-resistant V. dahliae among the studied samples. The family isolated from the F 6 hybrid [F 4 (L-105xL-106)xL-106] was used as a parental family when breeding a new variety of cotton C-6577, which was transferred for study to the State test from 2018.

Вихід високоякісного насіння кукурудзи в залежності від густоти стояння рослин

Studied the question of the optimal density of standing plants parent forms of corn, as the self-pollinated lines and simple interline hybrids in areas that affect hybridization yields and their seed productivity. The research was conducted during 2014-2017 in the Right-bank Forest-steppe of Ukraine in the LLC Agrofirma Kolos of the Skvyra district of the Kyiv region. Field experiments included options for studying the effectiveness of the plant density of parental forms of corn: simple hybrids, Rist SV, Rushnik SV, Richka S (75, 85 and 95 thousand / ha), self-pollinated lines UR 9 zS, UR 331 SV, UR 12 zS 85, 95 and 105 thousand hectares). According to research results, the density of plant standing significantly influences the formation of individual productivity of parent forms (hybrids) of corn. It was established that the highest values of the mass index of 1000 grains were all formed by the density of stems of 75 000 / ha. Increasing the density resulted in a reduction in the mass of 1000 grains. The analysis of the results shows that there is a connection not only between the moisture content of the grain and the density of the seed, but also the morphological characteristics of the hybrids of corn. It was noted that when the density of sowing increased, the moisture content of corn grain was naturally elevated. The lowest percentage of moisture was low in grain with a density of 75 000 / ha, and the most humid one was a density of 95 000 / ha. It has been established that the recommended plant densities contribute to the formation of higher yields, low harvesting moisture and increased yield of conditioned seeds. Key words: corn, sowing norms, parental forms, self-pollinated lines, hybrids, seed productivity, seed moisture, weight of 1000 grains, yield of conditioned seeds, climatic conditions. Conclusions: As a result of studies found: - optimum standing thick which makes it possible to get the highest yield of certified seed of hybrids for Rist SV and Rushnyk SV, density is 75 thousand / ha; - for hybrid Richka S, self-pollinated lines UR 9 zS and UR 12 zS- 85 thousand / ha; - for self-winded line UR 331 SV - 95 thousand / ha; To obtain high yields of corn seeds, the above hybrids and self-pollinated lines should be grown at the recommended standing density.

Epistatic interaction of resistance genes to acaricides in interline hybrids of two-spotted spider mite

Disruptive selection in inbred propagation is carried out to obtain sensitive and resistant strains of two-spotted spider mite Tetranychus urticae Koch. to malathion, bifenthrin, abamectin, and bromopropylate. Mites resistant to malathion are crossed with resistant mites of the other lines obtained. Females of interlinear hybrids are compared in terms of mortality rates with mites from homozygous lines showing resistance to any of these insectoacaricides. The testing is carried out family-wise by the diagnostic concentrations of the toxicants. The mortality of interlinear hybrids in all variants of crosses was double that in homozygous mites with a resistance gene only to the active insectoacaricide. The results obtained suggest that the interaction of resistance genes in interlinear hybrids of spider mites to insectoacaricides of different chemical classes occurs according to the epistatic type. The resistance gene to the active toxicant is hypostatic.

Physiological mechanism epistatic interaction of resistance genes to acaricides of various chemical classes in the interline hybrids of two-spotted spider mite

Summary: Background. The presence in interline hybrids two-spotted spider mite Tetranychus urticae Koch two genes determining resistance to acaricides of various chemical classes significantly increases their sensitivity to the action of each these toxicants.
 Materials and methods. The resistant and susceptible to malathion, bifenthrin and abamectin inbred lines of spider mite by disruptive selection cycles were obtained. The toxicological tests were performed by diagnostic concentrations of acaricides. The protein marker gene of resistance to malathion was determined by poliacrylamide disc-electrophoresis.
 Results. The epistatic interaction of resistance genes to different acaricides is not manifestation at the stages of transcription and translation of genetic information.
 Conclusion. The epistatic effect of another gene on the resistance gene to the current acaricide is a different consequence of metabolism processes encoded by each gene at the stage of phenotypic regulation.

Expression and inheritance of breeding characters in variety×line, line×variety and interline F1 hemp hybrids of different eco-geographical types

The relevance of creating hemp hybrids using self-pollinated lines and detecting heterotic effect in them was caused by a need for essentially new initial material of the crop, as well as for expanding its genetic basis and accelerating breeding process of creating varieties through obtaining homogeneous and stable populations as early as in the early stages. The aim and tasks of the study. The goal and objectives of the research was (i) to detect the level of expression and the features of heritability (namely coefficients of dominance hp) for the major breeding characters in variety×line, line×variety and interline F 1 hemp hybrids; (ii) to prove the possibility of creating hybrids using self-pollinated lines expressing heterotic effect, which contain no cannabinoids and are stably monoecious. Material and methods. Reciprocal crossing of varieties and self-pollinated lines have been carried out as follows: Hlukhivski 58 and Hlesiia, Hlesiia and Zolotoniski 15 resulted in 12 variety×line, line×variety and interline hybrids. F 1 hybrids have been assessed against the growing space of 30 by 5 cm according to their morphological, technological characteristics and seed productivity. Factors of dominance (hp) were determined by the formula (G.M. Beil and R.E. Atkins 1965). Results and discussion. The characteristics under study in majority of F 1 hybrids have been inherited according to the super dominance type and showed variability within families of a crossing variation. Among the crosses within the Central-Russian eco-geographical type, the most valuable appeared to be interline hybrids, and within the Central-Russian and Southern type – variety×line and line×variety hybrids. When crossing distant genotypes it is advisable to use a variety of Central-Russian eco-geographical type and a self-pollinated line of the South type. Conclusions. Proved is a possibility of creating variety×line, line×variety and interline hemp hybrids expressing heterotic effect, which contain no cannabinoids and are stably monoecious in order to expand the genetic basis of initial breeding material.

Comportamiento de híbridos intra e inter poblaciones entre líneas endocrinadas e implicaciones de estados resultados en el desarrollo de híbridos de maíz

During the development of hybrids, non-related progenitors of opposite heterotic pattern were used. When heterotic patterns of different germplasm are not well defined, or the heterotic response among existing materials is low, it is possible to develop inter-line hybrids with some materials. The objective of this study was to determine the yield of intra and inter-population hybrids developed from lines from Pool-19 and Pool-20 (Dialelo 1); lines from Pob.32, 25 and Pool-23 (Dialelo 2); lines from Pool-24 and Pob.24 (Dialelo 3); and lines from Pob.21, Pool-23 y Pob.32 (Dialelo 4), evaluated in México, Central America and Africa. Intra and interpopulation hybrids were also evaluated in experiments involving crosses of white tropicallines to testers from Populations 21, 32, 25 and Pool-24. Interpopulation hybrids outyielded intrapopulation hybrids from 8.0 to 15.6%. In the line x tester experiments, the interpopulation hybrids also outyielded intrapopulation hybrids. In the four dialells, the best intrapopulation hybrids yielded from 92.2 to 118.6% in relation to the best control. This indicates the possibility to obtain high yielding intrapopulation hybrids. Similar results were obtained from the line x tester experiments.

Epistatic interaction of resistance genes to acaricides in interline hybrids of two-spotted spider mite

Background. Study of the genetic bases of pesticide resistance of arthropods for sustainable rational pest control is important. Materials and methods. The disruptive selection cycles were conducted with inbred arrhenotokous reproduction of two-spotted spider mites Tetranychus urticae Koch. The resistant and susceptible lines of two-spotted spider mites to malathion, bifenthrin, abamectin and bromopropylate were obtained. The tests were performed by diagnostic concentrations of toxicants. Results. The resistant spider mites to malathion were crossed with resistant spider mites to bifenthrin, abamectin and bromopropylate. Mortality of interline hybrids in all variants of crosses were 2 times higher than mortality of spider mites with the gene resistance only to the current toxicant. Conclusion. The interaction of resistance genes to various toxic compounds in interline hybrids of spider mites is the type of epistasis. The resistance gene to the current pesticide in heterogeneous spider mites is hypostatic.

Genetic control over characteristic of 1000 seeds weight in hybrids of sugar beet and combining ability of crossbreeding components

The article shows experimental data of interline hybrids of sugar beet on the basis of weight of 1000 seeds, genetic determination of characteristic based on the method of Hayman and topcrossed polytested crossbreeding is established, their comparison is made. It also highlights valuable hybrid combinations and valuable for combining pollinating lines used in the breeding to enhance properties of sowing seeds.

Growth and survival for genetically improved lines of Eastern oysters ( Crassostrea virginica) and interline hybrids in Maine, USA

The production of cultured Eastern oysters ( Crassostrea virginica) in the northern New England states and Canadian Maritime Provinces is hampered by a short growing season, relatively cold water temperatures, and outbreaks of Roseovarius Oyster Disease (ROD). A breeding program at the University of Maine has produced the University of Maine Flowers Select (UMFS) line by selecting for oysters with improved cold water growth performance and resistance to ROD. We conducted two grow-out trials comparing the survival, size, and yield for the UMFS line to two other genetically improved lines of Eastern oysters to assess the suitability of this line outside of the Damariscotta River, where it was developed. In the first trial, oysters were deployed in August just prior to when ROD outbreaks typically occur in Maine among small, seed oysters. We observed substantial differences in yield in this field trial, particularly at study sites located on the Damariscotta River. These differences were due to variation in line-specific survival. The second field trial was deployed in June when ROD has less of an impact on seed oysters. Mortality in this second trial was lower than in the first trial and there was a corresponding higher dependence of line-specific yield on variation in growth. However, there was no line which consistently grew better and had higher yield at all sites. Based on our results, we suggest that breeding programs for Eastern oysters may benefit from focusing on the additive nature of survival variation among lines and placing less emphasis on the relatively subtle variation in line-specific growth.

Genetic studies of self-fertility in rye (Secale cereale L.). 2. The search for isozyme marker genes linked to self-incompatibility loci

The segregation of several isozyme marker genes has been studied in F2 inbred families from hybrids between self-sterile and five self-fertile inbred lines (nos. 2, 3, 4, 5, and 8) as well as from interline hybrids. Self-pollination of F1 hybrids between self-sterile forms and lines 5 and 8 gave an F2 segregation ratio of 1 heterozygote:1 homozygote for the gene Prx7 (chromosome 1R) against the allele from the line. This is interpreted as a result of tight linkage of the Prx7 gene with the S1 gene in chromosome 1R (recombination at a level of 0-1%). The self-pollination of such hybrids with lines 2,3 and 4 gave normal segregation for the Prx7 gene (1:2:1). This means that these lines carry a self-fertility allele which is not on chromosome 1R. Interline hybrids 5×2, 5×3 and 5×4 had self-fertility alleles for the two S genes and in inbred F2 progenies gave the expected deviating segregation for the Prx7 gene in a ratio of 2:3:1. The segregation of interline hybrid 5×8 was normal, 1:2:1, as expected. Highly-deviating segregation in an inbred F2 family of a hybrid with line 5 has also been obtained for another gene from chromosome 1R - Pgi2 (recombination with the S1 locus of 16.7%). By using the same method it has been estimated that line 4 has a self-fertility allele of the S2 locus from chromosome 2R and that the genes β-Glu and Est4/11 are linked with it (recombination 16.7% and 17.5-20% respectively). Lines 2 and 3 have a self-fertility allele of the S5 locus from chromosome 5R which is linked with the Est5-7 gene complex (recombination at a level of 28.8-36.0%).

Genetic studies of self-fertility in rye (Secale cereale L.). 1. The identification of genotypes of self-fertile lines for the Sf alleles of self-incompatibility genes

Segregation for self-fertility has been studied in progenies from the crosses of self-sterile (SS) plants with interline hybrids obtained by a diallel scheme of pollinations between seven self-fertile (SF) lines (nos. 2-8) and with F1 (SS plant x SF line) hybrids. All the offspring families from the SS plant x F1 (SS plant x SF line) crosses demonstrated a 1SF∶1SS segregation. The crosses of SS plants with some interline hybrids gave only self-fertile plants, whereas the crosses with other interline hybrids gave a segregation of 3SF:1SS expected in the case of digenic segregation. The data obtained permitted us to identify three different S loci (S1, S2, S5) and to estimate the genotypes of self-fertile lines for their Sf alleles: lines 5, 6, 7 and 8 are S1f/S1f S2n/S2n S5m/S5m, line 4 is S1n/S1n S2f/S2f S5m/S5m, and lines 2 and 3 are S1n/S1n S2m/S2m S5f/S5f(Sn, Sm designate active alleles of the incompatibility genes). The identification of the particular S gene which is presented by the Sf allele in each line has been made on the basis of our data concerning the linkage of the Sf mutation with isozyme markers of particular rye chromosomes, which is reported in an accompanying paper.