Мінливість кількісних ознак Hibiscus syriacus L. в умовах м. Запоріжжя

Abstract

Proper choice of assortment helps to increase the quality of green plantings. Recently, the assortment of plants is constantly expanding at the expense of introducing species. Hibiscus Syrian - a deciduous bush or a small tree up to 5-6 m high. Today, a large number of varieties of Syrian hybrid are used in landscaping, which differ in many ways. In the culture of Hibiscus, the Syrian is used for solitary and group plantings, the creation of cropped and free hedges and alleys, or as an independent single decoration of flower arrangement. The Syrian Hibiscus in Ukraine was introduced in 1811. The potential of the hybrid is not yet fully disclosed. The purpose of the study is to study the variability of the quantitative characteristics of the hybrids of two varieties Syrian Hibiscus, to assess their potential, to identify the best options for further use in landscaping and breeding work. Subsequently, it is planned to study the quantitative and qualitative characteristics of the seed generation of varieties and hybrids that have been obtained from reciprocal crossings; assessment of the decorative character of promising varieties of Syrian hybrid. Field experiments were carried out during 2015-17. As objects, 2 sorts of Syrian hybrid were used. A comparative study was conducted to evaluate the variability of quantitative characteristics. The following features were taken into account: annual growth, flower diameter, flowering intensity, morphometric parameters of seeds, weight of 1000 seed, number of seeds in a pod, laboratory similarity. The assessment of decorative was carried out on a 4-point scale. The intensity of flowering was evaluated on a 5-point scale and the number of flowers per model line was studied by the method of recording. The results obtained are statistically processed. Seasonal rhythm and plant development were studied according to the phonological observation technique. For hybridization on the mother plant, the best flowers were selected, located on the illuminated side, in the phase of painted buds were castrated, using insulating bags. The cv. Hamabo variety comes from Southeast Asia. Characterized by large flowers with pinkish-red veins on pale pink or almost white petals, each of which is decorated with a dark red spot in the center. The cv. Red Heart variety has large, spectacular white flowers with a bright red middle. The Syrian Hibiscus is characterized by deep tranquility in the autumn-winter period. Vegetation begins late, usually in late April-early May. This biological feature allows plants to avoid dipping during inverse early spring frost. And since the flowers are laid on the shoots of the current year, you can regularly observe a full blossom. The flowering period is quite long (begins at the end of June, ends in early October). At the same time, the laying and ripening of the fruits is in progress. The coefficient of variation of annual growth is very significant. It ranged from 24.4 % to 101.3 %. There is a significant variability of this feature within the range too. The evaluation of flowering in balls showed that both varieties have a good and full flowering - on plants about 75-100 % of blossoming flowers, from the full. The decorative character of the experimental plants of both varieties is estimated by us at 3 points - decorative plants during the vegetative period. This trait was stable. In the course of experimental work in 2015-2017, we carried out a reciprocal crossing of the two varieties of Syrian’s Hibiscus: direct – Hamabo × Red Heart and the reverse – Red Heart × Hamabo. Hybrid seed, like the parental form, is a renal, with a thick shell and a characteristic puffiness, dark brown. Compared to the morphometric parameters of the parent seed, the width and weight of the Red Heart × Hamabo hybrid seed are more than the Hamabo varieties, but the weight is lower compared to the ‘Red Heart’. Width and length did not differ. The annual growth rate for the cv. Red Heart and cv. Hamabo varieties for the 2015-2017 period was the same, but there was a significant variation in this trait. The cv. Red Heart varieties had a larger diameter than cv. Hamabo. Over the years, the diameter of the flowers has not changed. The intensity of flowering and decorative character of both studied varieties did not change over the years. The number of seeds in one box in both varieties of Sibian hybrid is 25 in average. The seed of cv. Red Heart is more than the width and weight. The number of viable seeds in one box and the laboratory similarity in the varieties cv. Red Heart and cv. Hamabo not different. The seeds have high crop quality. As a result of reciprocal crossings in 2015-2017, hybrid seeds were obtained from crossing Hamabo × Red Heart, and from crossing Red Heart × Hamabo – only in 2016. The width and weight of 1000 Seeds are larger in hybrids Red Heart × Hamabo compared to Hamabo × Red Heart. The number of viable seeds in the pod and laboratory similarity is high in all variants of experiments.