Uman NUH | today: 11/13/2022

Influence of varietal characteristics and growing conditions of switchgrass (Panicum virgatum L.) on pollen quality

Author(s) Дрига В. В., , ,
Category The Agronomy
year 2022 issue Issue 100. Part 1
pages 75-82 index UDK 633.179: 631. 53.01:631.559
DOI 10.31395/2415-8240-2022-100-1-75-82 (Link)
Abstract Goal. The peculiarities of the formation of the quality of pollen grains - size and viability depending on the growing conditions and varietal characteristics of switchgrass were find out. Methods. Field, laboratory, mathematical and statistical. Results. The quality of pollen is determined by its size and viability. The seed germination increases with the increasing number of viable pollen. Switchgrass pollen is spherical and unpainted. On average, during the four years of vegetation (2018-2021), the size of pollen grains varied from 22.9 to 23.6 μm, depending on varietal characteristics and weather conditions in the phase of flowering and pollen formation. There is no significant difference in this indicator depending on the varietal characteristics, there was only a tendency to increase or decrease its size was found. The largest pollen sizes were in the Sunburst variety. Pollen of the Morozko variety, Cave-in-rock and Sunburst varieties was the same 23.4 μm, the smallest pollen grains were in the Alamo variety. Pollen grain sizes varied over the years, even within one variety depending on weather conditions and varietal characteristics. The smallest pollen of all varieties was in 2018 and 2019. In these years, the largest pollen of 17.3 and 18.0 μm, respectively, was formed in Morozko, and the smallest – 15.1 and 14.9 μm in Sunburst and Alamo, respectively. In the vegetation 2020–2021, the average pollen size was much larger than in 2018 and 2019 for all varieties. In 2020, the pollen sizes of Morozko and Cave-in-rock were almost the same and smaller than Sunburst and Alamo. In 2021, the largest pollen (35 μm) was formed in the Sunburst variety, the smallest size (30.9 μm) was pollen in the Morozko variety. The most aligned pollen was formed in the medium-ripe Cave-in-rock variety and was 68.3%. The least aligned pollen was formed in the Sunburst variety (54.7 %) and the medium-late Alamo variety (56.9 % alignment). The alignmenty of pollen grains of the medium-ripe Morozko variety was lower than that of the Cave-in-rock variety but greater than that of Sunburst and Alamo. Over the years of research, the alignmenty of pollen grains has also changed. Conclusions. Pollen of switchgrass is spherical in shape, not colored and not uniform in size, which depended on both genotype and vegetation conditions. On average, over the years of study, the size of pollen grains varied from 23.4 to 25.5 μm, depending on varietal characteristics and weather conditions in the phase of flowering and pollen formation. The smallest pollen sizes of all cultivars were in 2018 and 2019, and in the growing season 2020–2021, the average pollen sizes were much larger than in 2018 and 2019 for all cultivars. The influence of conditions of the year during the growing season in the phases of flowering and seed formation was 89.3 %.
Key words cultivars, viability, pollen size, ripeness group, pollen alignment
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