ALTERNARIA LEAF SPOT DISEASE ON Rosa canina L. IN BOTANICAL GARDEN IN TASHKENT

ABSTRACT

In this article, information is provided about the damage by pathogenic organisms to one of the medicinal plants - sweetbrier. The plants mentioned in the article are considered medicinal and are spread in hilly, low-mountainous and mountainous regions. As a result of diseases, the amount of vitamins in plants, the yield and the number of species are being reduced dramatically. In the paragraphs below the results of studying the distribution, development, damage and biological characteristics of the disease-causing fungus of the disease and measures to combat it in species stored in the collection of the Tashkent Botanical Garden are presented. The information obtained from the results of these studies serves as the primary source for protecting plants from spotting disease, obtaining high yields, and creating large-scale artificial plantations.

АННОТАЦИЯ

В данной статье были даны сведения о повреждении патогенными организмами одного из лекарственных растений шиповник. Упомянутые в статье растения считаются лекарственными и распространены в холмистых, низкогорных и горных районах. В результате болезней резко снижается количество витаминов в растениях, урожайность и количество видов. Представлены результаты изучения распространения, развития, повреждения и биологических особенностей гриба-возбудителя заболевания и меры борьбы с ним у видов, хранящихся в коллекции Ташкентского ботанического сада. Информация, полученная по результатам этих исследований, служит первоисточником для защиты растений от пятнистости, получения высоких урожаев, создания масштабных искусственных насаждений.

Keywords: Rosa L., Rosaceae, Rosales, Rosa canina L., Ascorbic acid, Pleosporaceae, Alternaria, Alternaria alternata (Fr.) Keissl. 1912.

Ключевые словa: Rosa L., Rosaceae, Rosales, Rosa canina L, Aскорбиновая кислота, Pleosporaceae, Alternaria, Alternaria alternata (Fr.) Keissl. 1912.

Introduction. Rose hip (Rosa L.) Family Rosaceae, Order Rosales it is the richest in vitamin C, it is a bushy plant that ripens in September and October. There are 135 species distributed throughout the world [1].

Rose hipis a medicinal plant included in the national pharmacopoeias of the CIS countries as a vitamin plant, its fruits are valuable raw materials for the pharmaceutical industry. Fruit seeds contain vitamin E. Rose hipfruits have been used in folk medicine since ancient times. A tincture made from its fruits is used to treat pulmonary tuberculosis, inflammation of the liver, gall bladder, intestines, kidneys, and bladder. Also, a decoction prepared on the basis of the fruit of the rose hipis consumed as a blood-stopping and antipyretic agent. Not only the flowers and fruits of Rose hipare medicinal, but also the decoction prepared on the basis of its leaves is useful for gastrointestinal diseases [2].

The Rose hip family are naturally widespread in Uzbekistan's Tashkent, Jizzakh, Samarkand regions, Fergana Valley, Kashkadarya and Surkhandarya regions, as well as lower and middle mountain regions. In Uzbekistan, 17 types of rose hip are distributed [2].

There are 10-12 thousand types of medicinal plants in the world. Chemical, pharmacological and medicinal properties of more than 1000 plant species have been investigated [7].

There are 577 species of medicinal plants in Uzbekistan. About 4,500 species of tall plants are naturally distributed on the territory of Uzbekistan, and about 1,200 of them have medicinal properties. Currently, 112 types of medicinal plants are allowed to be used in official medicine in our Republic, and 80% of them are naturally growing plants [2].

The purpose of the study. Today, due to the influence of various pathogenic organisms, the medicinal properties of the Rose hip plant are declining, and the number of species is disappearing. it is very important to prevent species from dying and fight against diseases. the article describes the identification of the species composition of the pathogenic microorganism that causes spotting disease and the use of measures to combat it.

Research methods. Between may and october 2021, Herbarium samples of Rosa canina L. which is one species of rose hip were collected during the field research conducted in Tashkent Botanical Garden under the name of M. Rusanov. In the preparation of herbarium specimens, V.L. Volkov, A.A. Lakotko (2013) methods were used [4].

Infected plants were photographed using a Canon EOS 750D digital camera. Examination of herbarium samples collected from diseased plant parts was carried out in the laboratory of mycology and algology of the Institute of Botany of the Academy of Sciences of the Republic of Uzbekistan. Wet chamber method was used to separate micromycetes inside the tissue [5].

The N-300V (HDCE-XN) microscope was used to examine the structure of fungi and their morphological features. In determining the species composition of the fungus, available identifier information [6] and website was use [8].

Research results. During autumn of 2022, rosae growing in the urban area of in Botanical garden in Tashkent presented many spots that looked like disease symptoms. Both leaf surfaces presented large necrotic lesions, of a brown-to-black colour that increased their size, became irregular and eventually coalesced resulting in withering, extensive drying and shedding of leaves.

Pieces of Infected leaf tissue were surface sterilized with 1 % NaOCl solution for 1 min and plated on potato dextrose agar (PDA) that were incubated at 27 - 28 °C for 7 days under a 12 h light photoperiod. 7 days of incubation, white fungal colonies developed which initially turned to green olivaceous colour and later as the turned to black. Conidiophores were short, septate, branched or unbranched, and had a brown appearance (Fig.1).

Figure 1. Infected leaves

A sample of the infected plant was examined, as a result Alternaria alternata which causes the diseased is identified on the leaves type of fungus was identified and then a pure culture of this type of fungus was extracted.

Structure of the fungus. Hyphae are colorless, olive or brown, conidia are long, often branched chain-shaped, curved, oval or elliptic neck, often short, conical, septa up to 8. Size 20.0 - 63.0 х 9.0 - 18.0 microns (Fig. 2).

a                                               b                                  c

Figure 2. Alternaria alternata pure fungus culture (а) and microscopic appearance of conidia (b,c)

The division Ascomycota, class Dothideomycetes, order Pleosporales , family Pleosporaceae, genus Alternaria, species Alternaria alternata (Fr.) related to Keissl species. Fungi are usually stored in the dead parts of plants (dried branches, stems and leaves), as a result of which the leaves get into a damaged shape, in severely affected cases it causes leaf shedding and derailment of the physiological processes of the plant. It was observed that the infected stem first turns brown and with time turns dark brown and black and becomes more brittle. Humid and hot air temperature is very favorable for the spread of the pathogen.

Taking measures to combat diseases. To eliminate the sources of infection treatment with 3 % Bordeaux liquid during the dormant period of the plant, and during the growing season 1 % of the lequid is effective. The application of Talento 72% s.pd.v during the vegetative period of the plant against the fungus Alternaria alternata which was determined during the research, is considered to be effective.

References:

1. Berdiev E. T. Rose hip is a treasure of natural vitamins. "Tashkent" 2018. 12-26 р.
2. Tokhtayev B.Yo., Mahkamov T.Kh., Tolaganov A.A. Medicinal and nutritious plants instructions on the organization of plantations and preparation of raw materials. – Tashkent, 2015. 137 p.
3. Khojaev. Sh.T. Methodological guidelines for testing insecticides, acaricides, biologically active substances and fungicides. 2 - edition, Tashkent, 2004.
4. Methods of collection of biologic material and preparation of biopreparatov. V.L. Volkov, A.A. Lakotko 2013.-14 p. Naumov N.A. Methods of mycological and phytopathological research. - L: Selkhozgiz. 1937. - 272 p.
5. Pidoplichko N.P. Fungi parasites of cultivated plants. In 3 volumes - Kyiv, "Naukova Dumka", 1977. Vol.1. pp. 96-127.
6. https://www.agro.uz/ru/11-045361557.
7. http://www.indexfungorum.org/names/names.