Inheritance of economically important traits in common vetch hybrids (F 1 )

. The paper presents the results of a study on the true heterosis and the degree of dominance/ depression of traits (the number of pods and seeds per plant, plant height) in F 1 common vetch hybrids. The highest phenotypic dominance and true heterosis of the pod (H tr. =151.5 %, h p =8.7) and seed number (H tr. =111.7 %, h p =6.7) per plant were observed in hybrid accession 13 (Mestnaya x VIR 217). Our correlation analysis revealed a strong direct correlation between seed productivity per plant and the number of seeds (r=0.93) and pods per plant (r=0.92), as well as between the number of seeds and the number of pods per plant (r=0.98).


Introduction
The production of animal products is closely linked to the availability of highly nutritious forages.Leguminous crops play an important role in forage production as sources of proteins [1][2][3].Common vetch Vicia sativa is one of the most valuable forage legumes used for creating highly productive grass seed mixes aimed for the harvest of herbage, haylage, hay, and grain [4][5][6].The conditions of Primorsky kray allow farmers to harvest up to 10 t/ha of herbage and 2 t/ha of common vetch seeds [7].However, there is a need to create new high-yielding varieties of common vetch.
Work on the breeding of new Vicia sativa varieties is carried out all around the world [8][9][10].The main goal of breeders is to obtain accessions that are able to provide high yet stable yield under local conditions.
Our research goal was to evaluate F1 common vetch hybrids for economically important traits.
The research objectives were:  To determine the effect of heterosis and the degree of dominance in F 1 hybrid accessions based on the structural analysis. To establish correlation between the economically important traits of common vetch.

Materials and methods
The breeding nursery of the first generation (F 1 ) was organized in the fields of FSBSI "FSC of Agricultural Biotechnology of the Far East" in the steppe zone of Primorsky kray.
The region is characterized by monsoon climate.The positive accumulated temperature (above 10 о С) over the growing period of 2022 was 2778 о С; the total precipitation over the same period was 657.8 mm.
The conditions were perhumid (the hydro-thermal coefficient of Selyaninov (HTC) = 2.37).The plough layer was 22-25 cm; the content of humus was 3.65±0.51%;the рН of salt extraction was 5.2±0.1; the content of exchangeable potassium was 59±11 mg/kg of soil; the content of mobile phosphorus was 59±10 mg/kg of soil; the content of nitrogen was 60±8 mg/kg of soil.
Common vetch was sown in the last ten days of April.The seeds were harvested at the soft dough stage when the pods began to turn brown.
The setup of the experiment, calculations and phenological observations were performed according to "the Methodology for Studying Collections of Leguminous Crops" (N.I.Miroshnichenko, R.B. Demina, L.V., Moken', 1968) and the methodology for "Common Vetch Breeding" (S.I.Rep'ev, 1991).
The parameters of true heterosis and depression were calculated according to D.S. Omarov (1975).The degree of dominance of traits in the studied hybrids was calculated using the formula of G.L. Brubaker (1966).
The degree of dominance was determined by the formula [(1)]: Where h p -the degree of dominance or depression; F 1 -the arithmetic mean of a trait; M p -the average of a trait in both parents; P max -the average in the parent with the most developed trait.

Results and Discussion
The research resulted in the selection of hybrid accessions that significantly exceeded the parental forms in terms of the number of pods and seeds per plant and seed productivity per plant.
The correlation analysis revealed a weak positive correlation between the number of seeds per plant and the plant height (r=0.01), a weak inverse correlation between the number of pods per plant and the plant height (r=-0.01),and between the seed productivity and the plant height (r=-0.07).It was established that the seed productivity per plant was strongly correlated with the number of pods per plant (r=0.92) and the number of seeds per plant (r=0.93)(Figures 1 and 2).

Conclusions
The conducted research resulted in the selection of common vetch hybrid accessions with high (above 50 %) true heterosis (H tr. ) of the following traits:  The number of pods per plant: accessions 6 (Omichka x VIR 217), 8 (Nemchinovskaya yubileinaya x Omichka), 9 and 10 (Nemchinovskaya yubileinaya x Lugovskaya 85), and 13 (Mestnaya The highest phenotypic dominance and heterosis of the number of pods and seeds per plant were observed in hybrid accession 13 (Mestnaya x VIR 217).
The performed correlation analysis revealed a strong direct correlation between the seed productivity of common vetch and the number of pods and seeds per plant (r=0.92-0.98).Hybrid accessions 6 (Omichka x VIR 217), 8 (Nemchinovskaya yubileinaya x Omichka), 10 (Nemchinovskaya yubileinaya x Lugovskaya 85), 13 (Mestnaya x VIR 217) generate considerable interest as sources of high seed productivity under the conditions of Primorsky kray.

,Figure. 1 .
Figure. 1. Seed productivity per plant among F1 common vetch hybrids depending on the number of pods per plant.

Figure. 2 .
Figure. 2. Seed productivity per plant among F1 common vetch hybrids depending on the number of seeds per plant.

Table 1 .
Some biometric parameters of F 1 common vetch accessions.

Table 2 .
The degree of dominance and heterosis in F 1 common vetch accessions.