Effects of plant growth regulators on the performance of sunflower lines

Abstract

Purpose. Our purpose was is to ascertain individual responses of genotypes of sunflower lines to growth regulators and to estimate in increase in the performance, yield and seed quality.

Materials and methods. The study started in the experimental field of the Department of Genetics, Breeding and Seed Production of Kharkiv National Agrarian University named after V.V. Dokuchaiev in 2018.

Ten self-pollinated sunflower lines and 1 mutant line were used as the test material. Sterile analogues (SKh808A, SKh808A/H1002B, SKh1010A, SKh1012A, and SKh1002A), sterility fixers (Kh1010B and Kh1012B) and pollen fertility restorers (Kh06135V, Kh06134V, Kh785V and KhNAU1133V) were sown.

Fulvital Plus, Ecostim and Quadrostim plant growth regulators (PGR) were twice sprayed on sunflower plants: in the phase of 2–5 true leaves and during the flower-bud formation.

To study the PGR effects of on the sunflower lines, conventional comparative (field agricultural experiment) were used. The data were statistically processed.

Results and discussion. In 2018–2019, the PGR effects on the sunflower genotypes under investigation were shown to be extremely individual.

Among the sterile analogues, the largest gain in the yield of 0.4–0.7 t/ha was noticed in the SKh808A line, depending on the PGR, in comparison with the control. Fulvital Plus increased the yield from SKh808A/H1002B and SKh1012A by 0.3 t/ha.

In 2018, the calathidium performance in the Kh06135V line ranged from44.2 gto47.9 gvs.36.6 gin the control, depending on the PGR. In 2019, th calathidium performance ranged from30.0 gto38.5 gvs.35.2 gin the control. On average across the study years, Ecostim and Quadrostim had stable positive effects on the performance of this line.

The PGRs were found to influence the test weight and 1000-seed weight, depending on the genotype. Positive effects of all the studied regulators were noted in the SKh1002A line in 2018, however, their impact was negative in 2019, when application Quadrostim decreased the 1000-seed weight to33.8 gvs.41 gin the control, but this regulator did not affect the test weight, which was higher than the control value (227 g/L vs. 205 g/L in the control). On average, the test weight in the PGR experiments was more dependent on the year, ranging within 278 - 272 g/L (248 g/L in the control).

Conclusions. The treatment with the growth regulators was found to be the most effective for the SKh808A line. The gain in the yield ranged from 0.4 t/ha to 0.7 t/ha. depending on the growth regulator. The 1000-seed weight increased by6.7 g under the Quadrostim influence, and the test weight - by 403 g/L (379 g/L in the control) when Ecostim was applied.

Fulvital Plus and Quadrostim were the most effective growth regulators. The effect of Ecostim varied depending on the soil and climatic conditions and the line genotypes. The most effective application of the growth regulators on sterile analogues of self-pollinated sunflower lines may be due to CMS and different physiological characteristics of these lines.