The effect of abiotic factors on apricot yield in the Southern Urals

The productivity of apricot plantations in the Urals is limited by the irregularity of fruiting due to poor fruit bud winter hardiness in a majority of introduced cultivars. In 1999–2016, a research project was underway at the Department of Horticulture, Southern Ural Research Institute of Horticulture and Potato Growing, aimed at studying the apricot collection accessions of diverse geographic origin under the climate conditions of the Southern Urals. Such a long-term study made it possible to identify abiotic factors affecting the yield of this crop as well as to select highly adaptive and high-yielding cultivars for the Southern Urals: ‘Prizer’ (9.4 kg/tree), ‘Snezhinsky’ (9.2 kg/tree), ‘Kichiginsky’ (9.0 kg/tree) and ‘Uralets’ (8.5 kg/tree). Among the studied genotypes there were tree forms with irregular fruiting pattern, characterized by low resistance to adverse effects of abiotic factors: ‘Khabarovsky’ (0.9 kg/tree) and ‘Michurinsky No. 22’ (0.3 kg/tree). In the environments of the Southern Urals, critical winters (continuous frosts of –40°C) considerably damage generative buds, which results in having no apricot harvest in such years. Despite the harsh winters, annual shoots of local apricot-trees tended to freeze only to a small degree. Field survey of the apricot plantations showed that generative buds of local apricot cultivars (‘Kichiginsky’, ‘Prizer’, ‘Snezhinsky’ and ‘Uralets’) could withstand frosts of –40... –43°С (2003) only if they were brief, while continuous frosts destroyed them completely (2006, 2010). In addition, a decline in harvest was observed as a result of springtime frosts and temperature fluctuations in the end of winter (1999, 2014). Despite the abundant flowering in 2001, 2015 and 2016, the yield of apricot trees was low due to the frosts during the flowering period. Productivity of apricot trees also depends on their genetic characteristics, and in particular, on the geographical origin of cultivars. The introduced cultivars ‘Khabarovsky’ and ‘Michurinsky No. 22’ yielded fruit only thrice during the entire period of research

EVALUATION OF THE APRICOT GENE POOL IN THE SOUTHERN URALS

Presented here are the results of studying the apricot gene pool at the South Ural Research Institute of Horticulture and Potato Cultivation (YUNIISK) in the context of the most important economically valuable traits. Varieties and forms of apricot have been identified for their high winter hardiness, fruit quality, and maximum adaptability to major biotic and abiotic factors of the environment -traits of great interest for further breeding work

ENVIRONMENTAL PLASTICITY OF VARIOUS PLUM CULTIVARS UNDER THE CONDITIONS OF CHELYABINSK PROVINCE

The use of adaptable fruit and berry cultivars significantly increases the environmental sustainability of horticulture. In 2014–2018, the assortment of plum in the Urals was evaluated using the parameters of productivity, environmental plasticity and stability under the conditions of Chelyabinsk Province. The analysis of environmental plasticity and stability helped to identify adaptable cultivars of Chinese plum (Prúnus salicina L.): ‘Altayskaya yubileynaya’ and ‘Uralskaya zolotistaya’. Plastic plum cultivars included cv. ‘Uralskaya zolotistaya’ (yield: 5.62 t/ha; bi = 1.10; Si2 = 25.7), ‘Uralskaya serebristaya’ (5.53 t/ha; 1.16; 21.3) and ‘Manchzhurskaya krasavitsa’ (5.53 t/ha; 1.21; 33.9); their productivity varied in accordance with changes in environmental conditions. Intensive-type cultivars with high responsiveness to the improvement of growing conditions (bi significantly higher than 1) were cvs. ‘Uvelskaya’ (5.62 t/ha; 1.46; 26.8) and ‘Krasnoselskaya’ (5.04 t/ha; 1.35; 45.7). Cv. ‘Zhemchuzhina Urala’ (4.65 t/ha; 0.05; 22.8) belongs to the cultivars with low plasticity (the bi value close to zero); it is characterized by a weak response to a change in environmental conditions. Cv. ‘Altayskaya yubileynaya’ produces the highest yield (6.16 t/ha) due to its plasticity (bi = 0.91), but has low stability (Si2 = 102.5), while cv. ‘Shershnevskaya’ secures rather high productivity (5.23 tons per hectare) due to high stability (Si2 = 32.7) and medium responsiveness to changes in environmental conditions (bi = 0.75)

Inverse spectral problems for Dirac operators with summable matrix-valued potentials

We consider the direct and inverse spectral problems for Dirac operators on $(0,1)$ with matrix-valued potentials whose entries belong to $L_p(0,1)$, $p\in[1,\infty)$. We give a complete description of the spectral data (eigenvalues and suitably introduced norming matrices) for the operators under consideration and suggest a method for reconstructing the potential from the corresponding spectral data.Comment: 32 page

Assortment of black currant cultivars for the Southern Urals

The aim of the study was to assess black currant cultivars for yield, environmental plasticity and stability in Chelyabinsk Province. We identified adaptable black currant cvs. ‘Seyanets Druzhnoy’ (4.43 t/ha; AQ = 1.54), ‘Polar’ (3.59 t/ha; 1.38), ‘Venera’ (4.48 t/ha; 1.35), ‘Zhemchuzhina’ (4.49 t/ha; 1.34), ‘Sudarushka’ (4.43 t/ha; 1.30), ‘Bolero’ (3.42 t/ha; 1.20), ‘Gera’ (3.97 t/ha; 1.16), ‘Mortti’ (3.46 t/ha; 1.06), ‘Podarok Ilyinoy’ (3.89 t/ha; 1.03), ‘Selva’ (3.21 t/ha; 1.02) and ‘Mayak’ (3.54 t/ha; 1.01). The most interesting are intensive-type cultivars, capable of significantly increasing their productivity with the improved growing conditions. Intensive-type cultivars developed in Chelyabinsk are cvs. ‘Podarok Ilyinoy’, ‘Sudarushka’, ‘Zhemchuzhina’, ‘Gera’, ‘Mayak’ and ‘Venera’ (bi = 1.70, 1.68, 1.52, 1.46, 1.40, and 1.28, respectively).The locally developed cv. ‘Seyanets Druzhnoy’, environmentally plastic but insufficiently stable (bi = 1.17; Si2 = 6.1), exceeded in its average yield the environmentally plastic and stable cvs. ‘Selva’ (bi = 0.77; Si2 = 0.7) and ‘Mortti’ (bi = 0.93; Si2 = 1.1). Cv. ‘Bolero’ developed by the Vavilov Institute (VIR) and the Swedish cv. ‘Polar’ are neutral, i.e., they weakly respond to changes in cultivation conditions. High yields were recorded for cvs. ‘Zhemchuzhina, ‘Venera’, ‘Sudarushka’, ‘Seyanets Druzhnoy’, ‘Gera’, ‘Podarok Ilyinoy’, ‘Polar’, ‘Mayak’, ‘Mortti’ and ‘Bolero’.The yield of the following cultivars was at the average level for the experiment: ‘Rusalka’ (bi = 1.50), ‘Orloviya’ (bi = 1.56), ‘Pigmey’ (bi = 1.30), plus the yield (3.36 to 3.25 t/ha) of environmentally stable cvs. ‘Legenda’ (bi = 1.24; Si2 = 0.3), ‘Kama’ (bi = 1.00; Si2 = 0.8), and ‘Dochka’ (bi = 1.15; Si2 = 0.5). Cvs. ‘Zem Zarin’ (1.79 t/ha), ‘Chernecha’ (1.82 t/ha), ‘Zorya Galitskaya’‚ (2.18 t/ha), ‘Sibilla’ (2.37 t/ha), ‘Krasa Lvova’ (2.52 t/ha) and ‘Shakhalevskaya’ (2.84 t/ha) demonstrated yield levels significantly lower than the average

Environmental assessment of gooseberry cultivars developed in Chelyabinsk Province

The analysis of environmental plasticity and stability made it possible to identify adaptable gooseberry cultivars: ‘Avangard’ (CA = 1.77), ‘Vladil’ (CA = 1.58), ‘Grinchel’ (CA = 1.24), ‘Kovcheg’ (CA = 1.13) and ‘Arlekin’ (CA = 1.01). Cv. ‘Grinchel’, submitted for state trials in 2020, is an intensive-type cultivar (bi = 1.49), cvs. ‘Arlekin’ (bi = 1.03; Si2 = 4.1) and ‘Vladil’ (bi =1.03; Si2 = 1.0) are environmentally plastic and stable, while cvs. ‘Avangard’ (bi = 0.51) and ‘Kovcheg’ (bi = 0.53) belong to the neutral type. The advantages of these cultivars are their high productivity, large fruit size, dessert flavor, high winter hardiness, low thorniness, and increased resistance to American gooseberry mildew. High productivity in years with favorable and satisfactory growing conditions can be provided by the intensive-type cultivars ‘Stanichny’ (bi = 1.55) and ‘Kooperator’ (bi = 1.35) as well as the plastic but insufficiently stable cv. ‘Uralsky Izumrud’ (bi = 1.03; Si2= 5.3)

Studying steppe cherry cultivars in Chelyabinsk Province

The aim of the research was to study steppe cherry cultivars of various environmental origin in the context of their productivity, environmental plasticity and stability in the environments of Chelyabinsk Province. Evaluation of the studied set of cultivars helped to identify adaptable steppe cherries: ‘Izobilnaya’ (4.39 t/ha; KA = 1.54), ‘Shchedraya’ (4.42 t/ha; KA = 1.37), ‘Galimovka’ (3.83 t/ha; KA = 1,36), ‘Mayak’ (4.04 t/ha; KA = 1.30), ‘Ashinskaya’’ (t/ha 3.42; KA = 1.28) and ‘Mechta Zauralya’ (3.29 t/ha; KA = 1.07). The most interesting among them are intensive-type cultivars responding well to improved growing conditions, such as the steppe cherry cultivars developed at Sverdlovsk Horticultural Breeding Station: ‘Shchedraya’ (bi = 1.99), ‘Mechta Zauralya’ (1.85) and ‘Mayak’ (1.47). The Chelyabinsk cultivar ‘Galimovka’, submitted for state trials in 2018, falls under the category of environmentally plastic and stable cultivars (bi = 0.77; Si2 = 0.5), while cv. ‘Ashinskaya’ demonstrated during the tests a neutral genotype, as it poorly responded to changing environmental conditions (bi = 0.32; Si2 = 0.1). A new cultivar, ‘Vita’, with a fairly high yield (3.05 t/ha), developed at Sverdlovsk Horticultural Breeding Station, belongs to the environmentally plastic category (bi = 1.10), but its yield stability proved to be insufficient in the environments of the Southern Urals (Si2 = 2.2)

Inverse spectral problems for energy-dependent Sturm-Liouville equations

We study the inverse spectral problem of reconstructing energy-dependent Sturm-Liouville equations from their Dirichlet spectra and sequences of the norming constants. For the class of problems under consideration, we give a complete description of the corresponding spectral data, suggest a reconstruction algorithm, and establish uniqueness of reconstruction. The approach is based on connection between spectral problems for energy-dependent Sturm-Liouville equations and for Dirac operators of special form.Comment: AMS-LaTeX, 28 page

The Two-Spectra Inverse Problem for Semi-Infinite Jacobi Matrices in The Limit-Circle Case

We present a technique for reconstructing a semi-infinite Jacobi operator in the limit circle case from the spectra of two different self-adjoint extensions. Moreover, we give necessary and sufficient conditions for two real sequences to be the spectra of two different self-adjoint extensions of a Jacobi operator in the limit circle case.Comment: 26 pages. Changes in the presentation of some result

Inverse spectral problems for Sturm--Liouville operators with matrix-valued potentials

We give a complete description of the set of spectral data (eigenvalues and specially introduced norming constants) for Sturm--Liouville operators on the interval $[0,1]$ with matrix-valued potentials in the Sobolev space $W_2^{-1}$ and suggest an algorithm reconstructing the potential from the spectral data that is based on Krein's accelerant method.Comment: 39 pages, uses iopart.cls, iopams.sty and setstack.sty by IO