Variation and correlation between the parameters of the bulbs of the Oriental hyacinth and the amount of precipitation

Okach Mariya Aleksandrovna ORCID: 0000-0001-7147-1676 Educational master, Botanical Garden-Institute, Volga State University of Technology 424300, Russia, respublika Marii El, g. Ioshkar-Ola, ul. Mira, 2b OkachMA@volgatech.net Other publications by this author

The range of the oriental hyacinth (Hyacinthus orientalis L.) is confined to the mountainous regions of Southwestern Asia, Syria, Lebanon, Israel, the Mediterranean coast of Iran, and the northeastern part of tropical Africa ^[1]. Two subspecies of oriental hyacinth grow in the southern part of Anatolia (Turkey): H. orientalis subsp. orientalis and H. orientalis subsp. chionophyllus, the latter subspecies is endemic to Turkey ^{[2, 3, 4, 5]}. The climate of these places is characterized by hot, dry summers and mild, rainy winters. Precipitation is usually 400-600 mm per year, with a minimum in the summer season, when there is a drought; permanent snow cover is not formed. The average monthly air temperature in summer is 20-25 °C, in winter 5-12 °C ^[6]. A short period of favorable living conditions in the dry Mediterranean subtropical climate, with long periods of drought, contributed to the formation of the life form of the bulbous geophyte in the hyacinth of the East (according to the classification of X. Raunkier). Geophytes are characterized by the ability to completely move from the air to the ground under adverse conditions ^[7]. The renewal buds of the oriental hyacinth are located in a modified shoot - bulb. The bottom of the bulb is a strongly shortened stem, and the scales are overgrown leaf sheaths ^[8]. Two types of adventitious roots are formed at the bottom of the bulb: suction and contractile. Contractile roots are long fleshy roots with a high sugar content in the cortical parenchyma, with rapid consumption of sugars, the root length decreases longitudinally ^[9] and the bulb is drawn into the soil to an optimal depth. The contractile roots of the oriental hyacinth are formed in late spring, before the beginning of an unfavorable summer period. Oriental hyacinth, despite growing in a warm subtropical climate, belongs to cold-resistant ephemeroids, which allows it to successfully undergo primary introduction in the temperate continental climate of the Republic of Mari El. The natural way of reproduction of varietal hyacinths is vegetative. Depending on the variety, the number of daughter bulbs formed in the nest ranges from 1-5 bulbs. According to the literature, the productivity of bulbs, under favorable conditions of overwintering, is influenced by such factors as air temperature and the amount of precipitation during the active growing season. These factors directly affect the intensity of photosynthesis and the accumulation of nutrients in the bulbs ^[10]. The identification of links between these indicators will allow us to assess the degree of acclimatization of this culture to the conditions of introduction.

According to the modern classification, the oriental hyacinth belongs to the Asparagus family ^[11]. The first mention of the cultivation of hyacinth in Turkey as a beautifully flowering ornamental plant dates back to the XV century. From the XVI- XVII century to the present, the Netherlands has become a commercial center for the production of planting material and a breeding center for oriental hyacinth ^[12]. The modern assortment of oriental hyacinth varieties makes it possible to successfully use it in urban landscaping.

The purpose of this work is to study the effect of precipitation on the productivity of the Oriental hyacinth in the conditions of the Republic of Mari El.

Objects and methods of research. The object of the study was a collection of hyacinth varieties from the Eastern Botanical Garden-Institute of the State Technical University, Yoshkar-Ola. To study the biometric indicators of bulbs and their productivity, 10 varieties of oriental hyacinth with a simple and double flower shape were selected from the collection (Table 1). All varieties grew in the same edaphic conditions. The reconciliation of the names of varieties and their distribution by garden groups was carried out according to the data of the Royal Horticultural Society ^[13] and the Royal General Association of Growers of Bulbous Plants ^[14]

Table 1

Characteristics of Oriental hyacinth varieties

The territory of the Republic of Mari El belongs to a temperate continental climate, with long cold winters, dry spring, warm summers, wet and cold autumn. Average monthly air temperature in summer +18 - +20 °C, in winter -18 - -19 °C. The average annual precipitation is 580 mm, the amount of precipitation during the active vegetation period is 268 mm, Figure 1 shows the amount of precipitation in the vegetative period 2012-2015 ^{[15, 16, 17]}.

Fig. 1 - The amount of precipitation (from the norm) in the growing season 2012-2015

The work was carried out in the period from 2012 to 2015. Hyacinths were planted at the end of September. The distance between the bulbs in the row was 15 cm, between the rows 20 cm. The bulbs were dug out after the leaves died off. During the work, biometric parameters such as the diameter and height of the bulb, as well as the number of bulbs in one nest, were taken into account. The level of individual variability was determined by G.N. Zaitsev ^[18], the share of the factor's influence on the level of variability of the trait was determined by N.A. Plokhinsky ^[19]. The field materials were processed using descriptive statistics and analysis of variance using the Microsoft Excel application program at a 95 percent reliability level.

Presentation of the results.

The analysis of correlation coefficients and variations of biometric and quantitative indicators of hyacinth varieties are presented in Table 2. The table shows that there are strong and medium direct correlations between the bulb diameter and its height, with the exception of the varieties ‘Woodstok’ and ‘Splendid Cornelia’, with simple purple flowers (r=0.30). The presence of these connections indicates the uniformity of the deposition of spare nutrients in the bulb during the growing season. The individual variability of varieties by the average diameter of the daughter bulbs in the nest is included in the variation rate, with the exception of varieties: ‘Lady Derby’, ‘Splendid Cornelia’, ‘Madame Sophie’, ‘Isabelle’. In the group of varieties with simple flowers, there are also strong and medium direct correlations between the diameter of the bulbs and the number of daughter bulbs formed, with the exception of the 'Woodstok' variety. In the group of varieties with double flowers, these correlations are weak. The analysis of the correlation between the amount of precipitation (during the growing season) and the reproduction coefficient revealed medium and strong feedbacks. The coefficient of variation of varieties by the number of daughter bulbs in the nest exceeds the rate of variation, the exception is the variety ‘Eros'. The results obtained indicate the degree of acclimatization of this plant to the conditions of introduction.

Table 2

Correlation coefficients and variations of biometric and quantitative indicators of Oriental hyacinth varieties.

The analysis of variance revealed the dependence of the reproduction coefficient on the amount of precipitation during the growing season (Table 3). The share of the influence of these indicators on each other is in the range of 66.7% - 73.7%.

Table 3.

Dispersion analysis of the effect of precipitation on the reproduction coefficient

Hyacinth of the East

Note: F is the Fisher criterion, p<0,05;

Conclusions:

1. The level of individual variability in bulb diameter in most varieties is included in the variation rate, which indicates the suitability of environmental factors for this parameter.

2. The number of daughter bulbs in the nest is characterized by a high level of variability and depends on environmental conditions.

2. The reproduction rate of hyacinth varieties is strongly influenced by such an environmental factor as the amount of precipitation during the growing season (66.7% - 73.7%).