Purpose. To evaluate results of old garden roses varieties introduction based on the analysis of their decorative pro­perties and economic characters. Methods. Field study, comparative analysis, generalization. Results. The collection of roses at M. M. Hryshko National Botanical Garden (the city of Kyiv) was analyzed. A comparison was drawn between their gene pool and the world collection of roses. After collection screening, 22 old varieties were found at M. M. Hryshko National Botanical Garden and described. Their decorative pro­perties, economic characters and winter hardiness were eva­luated, the final result ranged from 81 to 100 points. Evalua­tion of winter hardiness that was based on the records of shoot damage degree in the field during the winter showed that in Kyiv conditions 13 cultivars were exceptionally resistant to frost, the other 9 appeared to be frost-sensitive. Conclusions. As follows from the analysis of decorative va­lues, economic characters and winter hardiness, 12 varieties of old roses such as ‘Cardinal de Richelieu’, ‘Commandant Beaurepaire’, ‘La Reine’, ‘Louise de Odier’, ‘Madame Plantier’, ‘Maiden’s Blush’, ‘Marie Baumann’, ‘Mousseuse Rouge’, ‘Persian Yellow’, ‘Poppius’, ‘Reine des Violettes’, ‘Versicolor’ were found to be perfectly suitable for landscaping.

Purpose. To evaluate results of old garden roses varieties introduction based on the analysis of their decorative pro­perties and economic characters. Methods. Field study, comparative analysis, generalization. Results. The collection of roses at M. M. Hryshko National Botanical Garden (the city of Kyiv) was analyzed. A comparison was drawn between their gene pool and the world collection of roses. After collection screening, 22 old varieties were found at M. M. Hryshko National Botanical Garden and described. Their decorative pro­perties, economic characters and winter hardiness were eva­luated, the final result ranged from 81 to 100 points. Evalua­tion of winter hardiness that was based on the records of shoot damage degree in the field during the winter showed that in Kyiv conditions 13 cultivars were exceptionally resistant to frost, the other 9 appeared to be frost-sensitive. Conclusions. As follows from the analysis of decorative va­lues, economic characters and winter hardiness, 12 varieties of old roses such as ‘Cardinal de Richelieu’, ‘Commandant Beaurepaire’, ‘La Reine’, ‘Louise de Odier’, ‘Madame Plantier’, ‘Maiden’s Blush’, ‘Marie Baumann’, ‘Mousseuse Rouge’, ‘Persian Yellow’, ‘Poppius’, ‘Reine des Violettes’, ‘Versicolor’ were found to be perfectly suitable for landscaping.

Purpose. Studying variety samples of winter triticale of various ecological and geographical origin for revealing polymorphism of the culture for its susceptibility to pathogenic complex of Fusarium head blight and defining high-yielding and resistant to diseases varieties that later can be put into the production and breeding process. Methods. Field experiments, statistical evaluation. Results. It was defined that the development of Fusarium head blight in different variety samples of winter triticale depends on the hydrothermal conditions and genotype of the host-plant. Resistance of varieties and hybrids to the disease was partial, and no immune samples were found among the analyzed ones. The following varieties proved to be tolerant to Fusarium head blight: ‘Granat’, ‘Zorro’, ‘Obrii Myronivskyi’. The positive correlation between the development of Fusarium head blight and root rot of winter triticale was found. It was determined that in the pathogenic complex of Fusarium head blight the amount of the following pathogens is increasing: Fusarium sporotrichioides, F. аvenaceum and F. poae. Conclusions. The leading varieties that combine high yields and resistance to Fusarium head blight are as follows: ‘Obrii Myronivskyi’, ‘ADM 8’, ‘Yuvileine Volynske’, ‘Yukon’, ‘Zorro’, ‘Tsekad 90’, ‘Zerniatko’, ‘Legion’ and ‘Rarytet’. These varieties should be involved in the selection process to breed the hybrids with the augmented resistance to the disease and high yields.

Purpose. Studying variety samples of winter triticale of various ecological and geographical origin for revealing polymorphism of the culture for its susceptibility to pathogenic complex of Fusarium head blight and defining high-yielding and resistant to diseases varieties that later can be put into the production and breeding process. Methods. Field experiments, statistical evaluation. Results. It was defined that the development of Fusarium head blight in different variety samples of winter triticale depends on the hydrothermal conditions and genotype of the host-plant. Resistance of varieties and hybrids to the disease was partial, and no immune samples were found among the analyzed ones. The following varieties proved to be tolerant to Fusarium head blight: ‘Granat’, ‘Zorro’, ‘Obrii Myronivskyi’. The positive correlation between the development of Fusarium head blight and root rot of winter triticale was found. It was determined that in the pathogenic complex of Fusarium head blight the amount of the following pathogens is increasing: Fusarium sporotrichioides, F. аvenaceum and F. poae. Conclusions. The leading varieties that combine high yields and resistance to Fusarium head blight are as follows: ‘Obrii Myronivskyi’, ‘ADM 8’, ‘Yuvileine Volynske’, ‘Yukon’, ‘Zorro’, ‘Tsekad 90’, ‘Zerniatko’, ‘Legion’ and ‘Rarytet’. These varieties should be involved in the selection process to breed the hybrids with the augmented resistance to the disease and high yields.

Purpose. To investigate special aspects of accumulation of inorganic elements including heavy metals in seeds of white and black mustard to be grown for obtaining drugs. Methods. Field experiments, microwave digestion, ICP-MS and statistical analysis. Results. The content of inorganic elements including heavy metals was determined in the seeds of white and black mustard grown in Kiev Oblast. It was revealed that during the growing season plants of white mustard were able to accumulate such elements as aluminum, barium, strontium, zinc in seeds in concentrations that exceed their content in black mustard seeds, while compounds of calcium, cesium, iron, magnesium, manganese, potassium in a greater degree were accumulated in black mustard seeds. Conclusions. As legal and regulatory documents for important chemical elements don’t contain the maximum permissible limits of their content in medicinal plants, it would make sense to launch a comprehensive research with the involvement of specia­lists of relevant profiles in order to establish such a gradation. Plants of white and black mustard in Kiev Oblast have accumulated high levels of such metals as Ba, Cu, Fe, Mn, Mo, Sr, Zn that exceed the known limits of accumulation, indicating a partial contamination of soils in the region. Consequently, these plants can be used for phytoremediation of soils. Considering the fact that in the pharmaceutical practice refined mustard seed oil is used, revealed alterations of metal accumulation in seeds will not affect the quality of the final drugs. According to the research results, white and black mustard is promising for cultivation in Kiev Oblast with a view to obtain raw material that can be processed into drugs.

Purpose. To investigate special aspects of accumulation of inorganic elements including heavy metals in seeds of white and black mustard to be grown for obtaining drugs. Methods. Field experiments, microwave digestion, ICP-MS and statistical analysis. Results. The content of inorganic elements including heavy metals was determined in the seeds of white and black mustard grown in Kiev Oblast. It was revealed that during the growing season plants of white mustard were able to accumulate such elements as aluminum, barium, strontium, zinc in seeds in concentrations that exceed their content in black mustard seeds, while compounds of calcium, cesium, iron, magnesium, manganese, potassium in a greater degree were accumulated in black mustard seeds. Conclusions. As legal and regulatory documents for important chemical elements don’t contain the maximum permissible limits of their content in medicinal plants, it would make sense to launch a comprehensive research with the involvement of specia­lists of relevant profiles in order to establish such a gradation. Plants of white and black mustard in Kiev Oblast have accumulated high levels of such metals as Ba, Cu, Fe, Mn, Mo, Sr, Zn that exceed the known limits of accumulation, indicating a partial contamination of soils in the region. Consequently, these plants can be used for phytoremediation of soils. Considering the fact that in the pharmaceutical practice refined mustard seed oil is used, revealed alterations of metal accumulation in seeds will not affect the quality of the final drugs. According to the research results, white and black mustard is promising for cultivation in Kiev Oblast with a view to obtain raw material that can be processed into drugs.

Purpose. To study the dynamics of soft winter wheat lectin activity in caryopsis and at the early stages of ontogenesis of varieties developed by Poltava State Agrarian Academy as well as investigate varietal differences depending on dynamic pH medium. Methods. Laboratory analysis, method of hema­gglutination reaction, analytical approach, statistical evaluation. Results. A change in lectin activity was determined in samples of 14 soft winter wheat varieties in caryopsis and at the early stages of ontogenesis (on the third, seventh, tenth and twelfth day of seedlings emergence). High lectin activity was observed in samples of seven and ten days seedlings. This could be evidence of active participation of proteins in physio­logical and biochemical processes at the time of emerging wheat tillering node that can be important in forming adaptive reactions to stress. Wheat lectin activity variation for рН ranging between 4,0 and 8,0 that depended on a variety was defined for the first time. Conclusions. According to hema­gglutination ability of wheat lectins, all varieties were divided into three groups: of high ability – 4 varieties, middle – 9 varieties, low – 1 variety. Varietal variability for the investigated trait can be used in breeding programs as marker trait. In most varieties variation of hemagglutination was observed at dilutions ranging between 1:2 and 1:256. Availability of two lectin agglutination peaks in acidic and alkaline media for seedlings was fixed.

Purpose. To study the dynamics of soft winter wheat lectin activity in caryopsis and at the early stages of ontogenesis of varieties developed by Poltava State Agrarian Academy as well as investigate varietal differences depending on dynamic pH medium. Methods. Laboratory analysis, method of hema­gglutination reaction, analytical approach, statistical evaluation. Results. A change in lectin activity was determined in samples of 14 soft winter wheat varieties in caryopsis and at the early stages of ontogenesis (on the third, seventh, tenth and twelfth day of seedlings emergence). High lectin activity was observed in samples of seven and ten days seedlings. This could be evidence of active participation of proteins in physio­logical and biochemical processes at the time of emerging wheat tillering node that can be important in forming adaptive reactions to stress. Wheat lectin activity variation for рН ranging between 4,0 and 8,0 that depended on a variety was defined for the first time. Conclusions. According to hema­gglutination ability of wheat lectins, all varieties were divided into three groups: of high ability – 4 varieties, middle – 9 varieties, low – 1 variety. Varietal variability for the investigated trait can be used in breeding programs as marker trait. In most varieties variation of hemagglutination was observed at dilutions ranging between 1:2 and 1:256. Availability of two lectin agglutination peaks in acidic and alkaline media for seedlings was fixed.

Purpose. Reporting peculiarities of new forms of edible corn and prospects for their use in food production that have been created jointly by scientists from the Plant Production Institute nd. a. V. Ya. Yuryev of NAAS and Ustymiv­ka Experimental Station for Plant Production on the base of the environmentally friendly method that uses biochemical effects of natural mutations of corn grain endosperm structure. Methods. Field study, laboratory analysis, mathematical and statistical evaluation. Results. Original series of inbred lines as well as promising varieties and hyb­rids of sugar and waxy corns were obtained. Varieties and hybrids are universally usable for obtaining both fresh and canned products, characterized by good taste, provide yields of up to 10 tons per hectare of commercial products and aimed to grow in various soil and climatic conditions. Brief economic and morphological characteristics of corn varieties and hybrids created jointly by scientists from the Plant Production Institute nd. a. V. Ya. Yuryev of NAAS and Ustymivka Experimental Station for Plant Production were given. Conclusions. The use of biochemical effect of natural mutations of endosperm structure is cost-effective and environmentally friendly method for creating lines, varieties and hybrids of corn for direct consumption and processing into food products. ‘Biliavka’, ‘Nika’ varieties and ‘Binom F1’, ‘Solo F1’, ‘Twister F1’ hybrids created with the help of this method are promising for commercial use

Purpose. Reporting peculiarities of new forms of edible corn and prospects for their use in food production that have been created jointly by scientists from the Plant Production Institute nd. a. V. Ya. Yuryev of NAAS and Ustymiv­ka Experimental Station for Plant Production on the base of the environmentally friendly method that uses biochemical effects of natural mutations of corn grain endosperm structure. Methods. Field study, laboratory analysis, mathematical and statistical evaluation. Results. Original series of inbred lines as well as promising varieties and hyb­rids of sugar and waxy corns were obtained. Varieties and hybrids are universally usable for obtaining both fresh and canned products, characterized by good taste, provide yields of up to 10 tons per hectare of commercial products and aimed to grow in various soil and climatic conditions. Brief economic and morphological characteristics of corn varieties and hybrids created jointly by scientists from the Plant Production Institute nd. a. V. Ya. Yuryev of NAAS and Ustymivka Experimental Station for Plant Production were given. Conclusions. The use of biochemical effect of natural mutations of endosperm structure is cost-effective and environmentally friendly method for creating lines, varieties and hybrids of corn for direct consumption and processing into food products. ‘Biliavka’, ‘Nika’ varieties and ‘Binom F1’, ‘Solo F1’, ‘Twister F1’ hybrids created with the help of this method are promising for commercial use

Purpose. To study the influence of fractional composition of seed material on productive properties of spring rape seeds of the ‘Magnat’ variety and ‘MVM’ (‘Gladiator’) variety sample. Methods. Field investigations, laboratory tests, statistical analysis. Results. During 2013–2014, the influence of sown seeds of different size fractions (up to 2,5 g; 2,6–3,5 g; 3,6 g and more) on the indices of productivity of spring rape varie­ties was studied. It was found that over the years of study field germination of sown fractions of seeds in ‘Magnat’ variety averaged 83.5%, in ‘MSM’ variety sample – 86.7%. During the periods of seedling emergence and harvesting, the density of spring rape crops varied depending on relevant fraction of sown seeds. In the ‘Magnat’ variety, photosynthetic potential of crops ranged from 1.1 to 1.3 million m2/ha, in ‘MSM’ variety sample – from 1.2 to 1.6 million m2/ha. Depending on the seed fractions applied, ‘Magnat’ variety crops during the gro­wing season accumulated organic biomass from 2.05 to 2.36 g/m2 per day, ‘MSM’ sample variety – from 1.83 to 2.10 g/m2 per day. Conclusions. It was established that different fractions of spring rape seeds sown in the Northern Forest-Steppe zone of Ukraine affected the indices of germinating energy and laboratory germination, crop density formation, leaf surface area and intensity of photosynthesis process (crop photosynthetic potential, net photosynthesis performance). The highest indices of productivity and yield in the ‘Magnat’ variety was ensured by large-seeded fraction (3,6 g and more), in the ‘MVM’ (‘Gladia­tor’) sample variety – by small-seeded fraction (up to 2,5 g).

Purpose. To study the influence of fractional composition of seed material on productive properties of spring rape seeds of the ‘Magnat’ variety and ‘MVM’ (‘Gladiator’) variety sample. Methods. Field investigations, laboratory tests, statistical analysis. Results. During 2013–2014, the influence of sown seeds of different size fractions (up to 2,5 g; 2,6–3,5 g; 3,6 g and more) on the indices of productivity of spring rape varie­ties was studied. It was found that over the years of study field germination of sown fractions of seeds in ‘Magnat’ variety averaged 83.5%, in ‘MSM’ variety sample – 86.7%. During the periods of seedling emergence and harvesting, the density of spring rape crops varied depending on relevant fraction of sown seeds. In the ‘Magnat’ variety, photosynthetic potential of crops ranged from 1.1 to 1.3 million m2/ha, in ‘MSM’ variety sample – from 1.2 to 1.6 million m2/ha. Depending on the seed fractions applied, ‘Magnat’ variety crops during the gro­wing season accumulated organic biomass from 2.05 to 2.36 g/m2 per day, ‘MSM’ sample variety – from 1.83 to 2.10 g/m2 per day. Conclusions. It was established that different fractions of spring rape seeds sown in the Northern Forest-Steppe zone of Ukraine affected the indices of germinating energy and laboratory germination, crop density formation, leaf surface area and intensity of photosynthesis process (crop photosynthetic potential, net photosynthesis performance). The highest indices of productivity and yield in the ‘Magnat’ variety was ensured by large-seeded fraction (3,6 g and more), in the ‘MVM’ (‘Gladia­tor’) sample variety – by small-seeded fraction (up to 2,5 g).

The creative and organizational role of academician M. M. Hryshko was analyzed in studying the gene pool of plants in Ukraine and creating collection funds of the National Botanical Garden of the National Academy of Sciences of Ukraine, which has been named after this famous scientist since 1991. Investigations on introduction, acclimatization and breeding of plants were described embracing the period from post-war years to the present day. Information was gi­ven that concerns the results of the introduction and plant breeding in the early 1950s as reported by M. M. Hryshko and recent data on species and varietal diversity of cultivated ornamental, fruit, subtropical, agricultural (including energy, feed, vegetable, spice aroma, aromatic, technical, green manure, nectariferous) plants.

The creative and organizational role of academician M. M. Hryshko was analyzed in studying the gene pool of plants in Ukraine and creating collection funds of the National Botanical Garden of the National Academy of Sciences of Ukraine, which has been named after this famous scientist since 1991. Investigations on introduction, acclimatization and breeding of plants were described embracing the period from post-war years to the present day. Information was gi­ven that concerns the results of the introduction and plant breeding in the early 1950s as reported by M. M. Hryshko and recent data on species and varietal diversity of cultivated ornamental, fruit, subtropical, agricultural (including energy, feed, vegetable, spice aroma, aromatic, technical, green manure, nectariferous) plants.

Purpose. To analyze thecollection of hybrid tea roses for the countries of origin, flower color, years of breeding. To select best modern cultivars for use in landscaping basing on evaluation of ornamental properties and economic characters. Methods. Field study, comparative analysis, generalization. Results. The collection of roses at M. M. Hryshko National Botanical Garden (the city of Kyiv) has been analyzed. After screening the collection, 141 hybrid tea rose varieties have been revealed. The collection of hybrid tea roses varieties has been analyzed for the countries of origin, flower color, years of breeding. Modern varieties (bred after 2000) has been described and their decorative value, economic characters has been estimated. Conclusion. The analysis of the collection of hybrid tea roses showed that most of them are varieties with red and pink flowers bred in 1961–2000 in countries of Western Europe. Evaluation of modern varieties for ornamental properties and economic characters allowed the authors to recommend 10 hybrid tea varieties for use in landscaping, namely: ‘Akvarel Rose Park’, ‘Alain Souchon’, ‘Aphrodite’, ‘Chippendale’, ‘Edith Piaf’, ‘Laetitia Casta’, ‘Line Renaud’, ‘My Girl’, ‘Pullman Orient Express’, ‘Terracotta’.

Purpose. To analyze thecollection of hybrid tea roses for the countries of origin, flower color, years of breeding. To select best modern cultivars for use in landscaping basing on evaluation of ornamental properties and economic characters. Methods. Field study, comparative analysis, generalization. Results. The collection of roses at M. M. Hryshko National Botanical Garden (the city of Kyiv) has been analyzed. After screening the collection, 141 hybrid tea rose varieties have been revealed. The collection of hybrid tea roses varieties has been analyzed for the countries of origin, flower color, years of breeding. Modern varieties (bred after 2000) has been described and their decorative value, economic characters has been estimated. Conclusion. The analysis of the collection of hybrid tea roses showed that most of them are varieties with red and pink flowers bred in 1961–2000 in countries of Western Europe. Evaluation of modern varieties for ornamental properties and economic characters allowed the authors to recommend 10 hybrid tea varieties for use in landscaping, namely: ‘Akvarel Rose Park’, ‘Alain Souchon’, ‘Aphrodite’, ‘Chippendale’, ‘Edith Piaf’, ‘Laetitia Casta’, ‘Line Renaud’, ‘My Girl’, ‘Pullman Orient Express’, ‘Terracotta’.

Purpose. Reviewing the literature on modern technologies of genetic modification of crop genomes. Results. The current state of genetically modified plants creation is analyzed. The information on cis-, intra- and subgenic plants and their comparison with transgenic crops is given. Examples of cis- and intragenesis application for improving characteristics of crops are provided. Such state-of-the-art technology of crop genome modification as genome editing is considered. Conclusions. Technologies for producing cis-, intra-, subgenic plants are rapidly developing and resulting in crops of the 21st century that can solve the problem of food provision for a constantly growing world population with the least contrary to the public interest.

Purpose. Reviewing the literature on modern technologies of genetic modification of crop genomes. Results. The current state of genetically modified plants creation is analyzed. The information on cis-, intra- and subgenic plants and their comparison with transgenic crops is given. Examples of cis- and intragenesis application for improving characteristics of crops are provided. Such state-of-the-art technology of crop genome modification as genome editing is considered. Conclusions. Technologies for producing cis-, intra-, subgenic plants are rapidly developing and resulting in crops of the 21st century that can solve the problem of food provision for a constantly growing world population with the least contrary to the public interest.

Purpose. The analysis of allelic status of such key genes of carotenogenesis as gene of lycopene-ε-cyclase (lcyε) and gene of β-carotene hydroxylase (crtRB1) for DNA-markers in domestic maize lines and their hybrids. Methods. DNA isolation, PCR, gel electrophoresis. Results. Allelic status of key genes of carotenogenesis was investigated in eight maize inbred lines and their single crosses. Molecular genetic polymorphism in the studied sample of maize lines and hyb­rids has been detected in gene of β-carotene hydroxylase for marker crtRB1-3’TE. For this gene, codominant character of inheritance of alleles of parental lines in single crosses was confirmed. For markers of gene of lycopene-ε-cyclase lcyε-3’INDL and lcyε-SNP216, polymorphism in the group of investigated lines and hybrids has not been identified, genotypes included only one variant of alleles for each marker. For lines ‘DK253ZSZM’, ‘DK633/266zS,zM’, ‘DK366zS,zM’ and hybrids ‘DK296S×DK253ZSZM’, ‘DK272S×DK633/266zS,zM’ and ‘DK231S×DK366zS,zM’, the decrease of the activi­ty of β-carotene hydroxylase owing to the mutation of gene crtRB1 under the influence of transposone element at the 3’-end, the inhibition of β-carotene transition into β-cryptoxanthin can be expected, that allows to predict β-carotene accumulation in grain. Conclusions. The study of allelic status of carotenegenesis gene of lycopene-ε-cyclase in maize showed no polymorphism for markers lcyε-3’INDL and lcyε-SNP216 in eight inbred lines and their single crosses, along with this, for marker lcyε-3’INDL in genomes of all studied samples the allele was identified to be favorable for the accumulation of β-carotene. For marker crtRB1-3’TE of gene of β-carotene hydroxylase, the studied breeding material was polymorphic. Allele of crtRB1 being favorable for the accumulation of β-carotene was identified in lines ‘DK253ZSZM’, ‘DK633/266zS,zM’, ‘DK366zS,zM’ and hybrids ‘DK296S×DK253ZSZM’, ‘DK272S×DK633/266zS,zM’ and ‘DK231S×DK366zS,zM’. Single crosses inherit maternal and paternal alleles of gene of β-carotene hydroxylase codominantly.

Purpose. The analysis of allelic status of such key genes of carotenogenesis as gene of lycopene-ε-cyclase (lcyε) and gene of β-carotene hydroxylase (crtRB1) for DNA-markers in domestic maize lines and their hybrids. Methods. DNA isolation, PCR, gel electrophoresis. Results. Allelic status of key genes of carotenogenesis was investigated in eight maize inbred lines and their single crosses. Molecular genetic polymorphism in the studied sample of maize lines and hyb­rids has been detected in gene of β-carotene hydroxylase for marker crtRB1-3’TE. For this gene, codominant character of inheritance of alleles of parental lines in single crosses was confirmed. For markers of gene of lycopene-ε-cyclase lcyε-3’INDL and lcyε-SNP216, polymorphism in the group of investigated lines and hybrids has not been identified, genotypes included only one variant of alleles for each marker. For lines ‘DK253ZSZM’, ‘DK633/266zS,zM’, ‘DK366zS,zM’ and hybrids ‘DK296S×DK253ZSZM’, ‘DK272S×DK633/266zS,zM’ and ‘DK231S×DK366zS,zM’, the decrease of the activi­ty of β-carotene hydroxylase owing to the mutation of gene crtRB1 under the influence of transposone element at the 3’-end, the inhibition of β-carotene transition into β-cryptoxanthin can be expected, that allows to predict β-carotene accumulation in grain. Conclusions. The study of allelic status of carotenegenesis gene of lycopene-ε-cyclase in maize showed no polymorphism for markers lcyε-3’INDL and lcyε-SNP216 in eight inbred lines and their single crosses, along with this, for marker lcyε-3’INDL in genomes of all studied samples the allele was identified to be favorable for the accumulation of β-carotene. For marker crtRB1-3’TE of gene of β-carotene hydroxylase, the studied breeding material was polymorphic. Allele of crtRB1 being favorable for the accumulation of β-carotene was identified in lines ‘DK253ZSZM’, ‘DK633/266zS,zM’, ‘DK366zS,zM’ and hybrids ‘DK296S×DK253ZSZM’, ‘DK272S×DK633/266zS,zM’ and ‘DK231S×DK366zS,zM’. Single crosses inherit maternal and paternal alleles of gene of β-carotene hydroxylase codominantly.