Sugar sorghum is an agricultural plant capable of generating a high content of water–soluble sugars in the juice of the stem(18–22%). Due to its biological characteristics, the cultivation of this crop opens up wide possibilities for use in variousbranches of the agro–industrial complex of arid regions of the world: it is an alternative source of raw materials in thepreparation of rich and concentrated feeds used both in the food industry and as a renewable energy source. This articlepresents the results of the selection of starting material for the breeding of new F1 hybrids and varieties with a high content ofboth monosaccharides and disaccharides in the stem juice. The analysis of sugar content involved varieties, hybrids, and lines(93 in total) bred at the Institute of RosNIISK "Rossorgo". The study identifies samples with different ratios of mono– anddisaccharides from 8,9:86,6% to 97,0:2,8%, respectively. To increase the sucrose content in the stem juice, it is proposed toinvolve the "Kapital" variety and the lines L–75, L–21, L–5, L–4 in the breeding process, in which the ratio of disaccharides is17.74–19.18%, and monosaccharides – 1.89–3.38%. With the goal of conducting breeding in the trajectory of a high content ofmonosaccharides, the Chaika variety should be used, which is characterized by 13.76% of monosaccharides and aninsignificant amount of disaccharides – 0.36% in acutely arid conditions of the year.

This article presents the results of selection work on the creation of the source material of sorghum saccuratum for use incrossings to increase the productivity and quality of the vegetative mass of hybrids in arid regions of Russia. The testconducted in 2020–2021 allowed for identifying three varieties (Flagman, Larets, Kapital) and six breeding lines (L–28/14, L–75, L–35, L–34, L–28 and L–5–1). It should be noted that these lines differ from the varieties with a higher biomassproductivity of 33.28–40.58 t/ha, and the content of crude protein and fat at the standard level is 6.60–8.69% and 1.16–1.90%,respectively. Bioenergetic assessment of the biomass of sorghum saccuratum crops showed that the identified lines were alsosuperior to the zoned varieties in collecting dry matter by 0.67–4.69 tons, gross energy output – by 12.29–83.43 GJ per 1hectare.

Many fodder crops are characterized by biological traits, and their combined cultivation and fuller use of life factors ultimately have a significant impact on the total yield, improvement of quality indicators compared with the yield of crops sown in a monoculture. Grass mixtures use solar energy, soil fertility and other biotic factors most fully, due to the placement by tiers of crops both aboveground part and root system of the constituent crops. The most productive fodder mixtures for 2021-2022 characterized by high quality aboveground biomass were identified: corn of RRDTI variety 1 with vegetable vetch Aliya variety (26.5 t/ha). Dry mass yield per hectare is significantly higher in mixture with high-protein crops than in single-species crops. Studies were carried out in the experimental field of Russian Research and Design and Technological Institute of Sorghum and Corn Rossorgo.

Abstract. During the period 2017-2018, the feed quality and productivity of three Sudan grass varieties – Endje 1, Vercors and Super Sweet, one stabilized Sudan grass population – SWT, local sweet sorghum – „Zaharna metla“ population and the sweet sorghum cultivar “Shumensko sladko” were researched in Agricultural Institute – Shumen. Green mass (t/ha), dry matter (%) and dry mass production (%) as well as basic nutritional characteristics by the two swaths of the tested cultivars in brooming phase were controlled. It was found that the sweet sorghum cultivar “Shumensko sladko” gave the highest amount of green mass – 59.5 t/ha by two swaths, and the dry mass yield was the highest from the cultivar Endje 1 – 20.8 t/ha. In terms of chemical composition, the greatest variation was demonstrated in phosphorus content (0.369-0.696%, CV=27.3%), followed by crude fat (1.28-2.39%, CV=26.8%), Ca (0.889-1.572%, CV=21.8%), crude protein (6.05-9.00%, CV=14.6%), nitrogen free extracts (42.05-51.20%, CV=7.6%), crude fiber (32.64-39.26%, CV=6.1%) and mineral substances (8.17-9.61%, CV=5.9%). It can be summarized that all hybrids provide quality hay, however the Bulgarian cultivars Endje 1 and “Shumensko sladko” showed the best nutritional value – compared to Super Sweet, Vercors, SWT and “Zaharna metla”.

The main purpose of cluster analysis is to divide the set of objects under study characterized by a set of features into groups(clusters) that are homogeneous in the appropriate sense. A positive feature of cluster analysis is the ability to compress a largeamount of information, systematize it, build a scientifically based classification, identify the internal relationship between theunits of the population under study. The aim of the article is to identify promising samples of sorghum × drummondii accordingto the main economic characteristics based on cluster analysis for further use in breeding for heterosis in the conditions of SaratovOblast. Grouping of samples allows for examining the composition of each cluster as fairly identical source material in terms ofthe severity of the indicators. During the period from 2015 to 2017, 32 samples of sorghum × drummondii were evaluatedaccording to 12 economically valuable characteristics, which were subjected to statistical processing. At the 22nd iteration stepwith a Euclidean distance of 14.4, the samples were grouped into 10 clusters. Cluster differences were observed to be significant,except for the "1,000 Seed Weight" feature. The study distinguished clusters 1 and 5 based on the intensity of the initial growth.The second cluster is characterized by the number of differences in the parameters of the largest leaf, the width of the flag leaf,and grain yield. Clusters 3 and 4 did not differ significantly in most features. In the 6th cluster, differences were noted accordingto the following indicators: "the extension of the panicle leg", "height at maturity", "inflorescence length" and "length of the flagleaf". The 7th cluster revealed differences in the width of the flag leaf, the width of the inflorescence, and grain yield. The 8thcluster distinguished itself by the parameters of the flag leaf and the yield of green biomass. In the 9th cluster, differences wererevealed on the basis of: "height at maturity" and the parameters of "inflorescence", "largest leaf". The last cluster wasdistinguished by the greatest number of differences in the parameters of the largest leaf (in length 8 and 6 in width), grain yieldand green biomass, the extension of the panicle leg. The results obtained are used in the selection of components of crosses inthe selection of grass sorghum hybrids.

叶片是植物最主要的光合作用器官,是水稻的源器官。其生长、发育和衰老的分子机理的研究对水稻经济产量和生物产量具有重要的意义。2006年我单位在参加农业部实践8号卫星航天育种工程的空间辐射诱变籼稻（Oryza sativa L.indica）泸恢H103中得到一叶片早衰突变体。初步研究结果表明,该早衰叶突变体表现的特点是：抽穗期前心叶抽出时,先前抽出的倒4叶片就开始变黄衰老,抽穗初期时先前抽出的倒3叶表现衰老,抽穗后期先前抽出的倒2叶表现衰老,灌浆期剑叶表现衰老,完全成熟时剑叶完全衰老死亡。利用该突变体分别与其野生型泸恢H103、R527、R602杂交,获得F1及其衍生的F2群体,对早衰叶突变体进行遗传分析。遗传分析表明由一隐性核基因psl2控制。本研究为最终定位和克隆目标基因奠定了基础。[著者文摘] | Plant leaf is the most important organ for photosynthesis, and it is the source organs of rice. The research on growth, development and molecular mechanism of aging have great significance to the economic and biological yield of rice. We obtained senescence mutant from leaves of the rice Luhui-H103 （Oryza sativa L. indica） after space radiation mutagenesis in the 8th unit of satellite space breeding projects of the ministry of agriculture in 2006. The preliminary findings showed that the representative features of senescence leaves mutant were follow： the four leaves from root which were putting out previously began to turn yellow and aging when the centre leaf put out before heading stage; In the initial stage of heading, the three leaves from root were aging; The two leaves from root were aging at the later stage of heading; Flag leaf was senescent in pustulation period, and the flag leaves were senescent completely and dead when the spikes were full maturity. The mutants were crossed with their wild-type Luhui-H103, R527 and R602, respectively, obtained the F1 and F2 groups, and using them for genetic analysis of premature aging leaf mutants. Genetic analysis showed that the mutant was controlled by a recessive nuclear gene psl2. This research laid the foundation for the final mapping and cloning of the target gene.[著者文摘]

[Objective] The study aimed at investigating the effects of different geographic sites, soil chemical characteristics and nitrogen application levels on nitrogen accumulation and distribution in different organs and utilization efficiency for mid-season hybrid rice. [Method] By using mid-season rice varieties II-you 7 and Yuxiangyou203 as the experimental materials, field experiment was conducted at seven ecological sites in four provinces or cities in Southwestern China in 2009. A total of four nitrogen application levels were set as follows: by using 75 kg/hm2 of P2O5 and 75 kg/hm2 of K2O as the base fertilizer, extra 0, 90, 150 and 210 kg/hm2 of nitrogen fertilizer (in which, base fertilizer, base-tillering fertilizer and base-earing fertilizer respectively accounted for 60%, 20% and 20%.) was applied, respectively. In the split-plot design, fertilizer was considered as the main factor while rice variety was taken as the secondary factor. A total of eight treatments were set with three replications. [Result] Highly significant differences of grain yield were found among seven locations, two varieties, four nitrogen application levels, interactions of site variety and site nitrogen application level, but the interaction of variety nitrogen application level had no significant influence on rice yield. There were highly significant effects of site, varieties and nitrogen application level on dry matter production, nitrogen content, nitrogen utilization efficiency. Highly significant negative correlations between uptake efficiency and utilization efficiency for nitrogen were found; and multiple stepwise regression analysis showed that nitrogen uptake-utilization efficiency were significantly influenced by different ecological sites, chemical quality of soil and the levels of nitrogen application. [Conclusion] The research will provide theoretical and practical basis for the highly efficient application of nitrogen in mid-season hybrid rice cultivation.