Technological properties of grain and flour in bread wheat (Triticum aestivum L.) genotypes carrying two loci that determine the endosperm structure

Background.The end-use of the bread wheat grain depends on the endosperm properties determined by the alleles of the Pinaand Pinbgenes at the Halocus on chromosome 5D. The mealy (soft) endosperm is generated by the biosynthesis of puroindolines – complete proteins encoded by these genes. When milled, such grain breaks down into small starch granules covered with proteins. Mutations that disrupt the synthesis or structure of puroindolines determine the hardness and vitreousness of the grain. Earlier, we discovered a new locus for grain softness, Ha-Sp, introgressed from the diploid species Aegilops speltoidesTausch, which also determines the formation of the soft endosperm structure. By combining two active loci in one genotype, we produced a supersoft grain line (SSL). The aim of the present work was to verify the interaction of the two loci Haand HaSpin other wheat genotypes and evaluate the technological properties of grain and flour in comparison with the existing SSL line.Materials and methods.The F3–F8 hybrids from crosses of the soft-grain spring cultivars ‘Golubka’ and ‘Lutescens 62’, carriers of the Halocus, with the introgressive line 84/98w, carrier of the Ha-Splocus, were used in the work. Grain from three field seasons was studied according to milling parameters and physical properties of flour and dough.Results.At the early stages of selection (F3:4), the families with milling parameters typical of bread wheat were identified, as well as supersoft-grain families with a small flour particle size (9–10 μm) and low endosperm vitreousness (29–49%). Targeted selection made it possible to obtain lines similar to the SSL line in terms of milling performance and flour strength.Conclusion.For the first time, a set of supersoft-grain lines with special properties of grain and flour was obtained on the genetic basis of three spring cultivars. They may be in demand for a wide range of end-uses, including both food and nonfood production purposes.

Formation Characteristics of Endosperm Structures in Different Rice Genotypes

To explore the formation characteristics of endosperm structures in different rice genotypes, indica, japonica and glutinous rice cultivars were used and grown in the paddy field. The endosperm structures in the grain during the filling period were investigated. The results showed that the compactness of amyloplast arrangement was positively correlated with grain filling percentage. The endosperm structure varied with the position within a grain. At maturity, the structure was the best in the back, the intermediate in the center, and the worst in the belly of a kernel. However, the filling was better in the center than in the back and in the belly from 5 to 10 days after flowering (DAF). The endosperm structure was different among genotypes. From 5 to 25 DAF, starch accumulation was the earliest in glutinous rice, followed by indica rice and japonica rice. Gaps and pores in endosperm were closely associated with rice transparency. The starch crystallinity in endosperm was negatively correlated with amylose content. Among the three genotypes, glutinous showed the highest crystallinity, followed by japonica and indica rice. The starch crystallinity in a grain was lower on a primary branch than that on a secondary branch. Among all grains, the second grain on a primary branch showed the lowest starch crystallinity. The results indicated that the starch structure of endosperm not only differ between rice genotypes, but also varies with the location of a grain on the panicle, and that it affects the grain-filling, transparency and amylose content of rice.

Genetic analysis of sweet corn lines based on SH2 endosperm structure gene

One of the three genes of the endosperm structure is used in the selection of sweet corn; its recessive mutation sh2 activates the accumulation of sucrose in the structural complex of sugars and represses the starch synthesis. Hybrids of "super-sweet" corn have improved grain taste and slower conversion of sugars into starch. Therefore, it is important to use different genetic sources of breeding traits in the creation of a new linear material that meets the requirements of modern heterosis selection of sweet corn. The aim of the work was to study the lines of sweet corn and to identify among them new sources of selectively valuable economic features. A complex assessment of morphological characteristics and productivity of sweet corn lines was carried out. According to the results of study the main morpho-biological traits of sweet corn lines with the mutant sh2 gene, the sources of individual selection valuable peculiarities were identified. Lines SH-234 and SH-936 were marked as donors of plant growth. Lines SH-621, SH-234 and SH-936 were the best in terms of seed productivity of cobs. According to the growing season, all lines are divided into early (4 lines) and medium ripe (6 lines). The lines SH-234, SH-113 (number of grain rows) and SH-621 (number of seeds in a row) were the best in terms of productivity, and lines SH-318 and SH-936 – in terms of the cob length (14.45 cm and 13.26 cm, respectively). Only one line SH-477 had strongly wrinkled seeds. Thus, the studied sweet corn lines were characterized by high genotypic diversity; the SH-936 and SH-621 lines were the best in terms of the trait complex.

ГЕНЕТИЧНЕ РІЗНОМАНІТТЯ КУКУРУДЗИ І СУЧАСНІ ПІДХОДИ ДО ЙОГО СИСТЕМАТИЗАЦІЇ

The article discusses the possibilities of improving the corn grading system. It has been shown that the existing classification of maize does not provide an opportunity to systematize the modern genetic diversity of this crop, which has expanded significantly in recent times due to increasing demand for specialized forms of maize. As a result, a number of objectively existing and actively practically used valuable forms do not fit within the existing classification and consequently deprived of botanical status. The expediency of using for this purpose of the phenotypic effect of mutant genes of the endosperm structure is substantiated. Since the criteria for the distribution of maize into subspecies is determined by certain features of the physical structure of the endosperm of the grain, which are due to the specificity of its biochemical composition, the effect of mutations of endosperm o2, sh1, sh2, su1, se, su2, ae and wx on the peculiarities of the phenotype, structure of the endosperm and the structure of endo-sperm maize, namely: the content and fractional composition of the protein, the content of the basic fractions of carbohydrates, the content and fatty acid composition of the oil in biologically ripe grain was analyzed. For the study, 5 lines were used based on each mutation. Significant specific effects on these indicators other than ordinary maize and the su1 and wx mutants included in the existing maize classification and having subspecies status have been identified. An additional insertion to the corn classification system of endosperm mutants o2, sh1, sh2, su2 and ae as separate subspecies is proposed, since the totality of the morphological and biochemical characteristics of the carriers of these mutations fully complies with the requirements for the classification characteristics of this culture. The official recognition of new taxonomic groups will help to objectify the generalization of modern genetic diversity of corn and will allow reliable standardized evaluation of representatives of these groups of maize, as a raw materials for use in the feed production, food, pharmaceutical and technical branches of industry. This approach is applied for the first time and has no national or foreign analogues.

The Arrangement of Endosperm Cells and Development of Starch Granules Are Associated With the Occurrence of Grain Chalkiness in Japonica Varieties

The endosperm chalkiness in grains is one of the most important traits in rice grain qualities, and grain chalkiness directly determines grain quality and market price. Therefore, the endosperm chalkiness reduction is an important goal of breeding scientist in rice. However, little is known about the relationship of the formation of rice endosperm chalkiness and the morphological structure and development in fragrant japonica and conventional japonica varieties. In this study, we have mainly investigated the chalkiness characters such as degree of endosperm chalkiness (DEC), chalkiness rate (CR) and chalkiness area (CA) in 12 fragrant japonica varieties and 9 conventional japonica varieties. Furthermore, the endosperm structure and starch granules of rice grains were also observed with scanning electron microscope (SEM). The results indicated that the 21 varieties including the different fragrant japonica and conventional japonica varieties has a linear relationship between the DEC and the CR (P < 0.05). Among the fragrant japonica and conventional japonica varieties, the biggest difference is the CR, follow by CA and DEC. In addition, there is a certain correlation between the arrangement of endosperm cells, the distribution of starch granules and the occurrence of chalkiness characters in the different fragrant japonica and conventional japonica varieties. For the same fragrant japonica or conventional japonica variety, there is no significant difference between the starch granules from the transparent parts of chalkiness and non-chalky, while the starch granules of grains between chalky and non-chalky has obvious difference. Our results would provide important references for high quality rice breeding.