It is determined that the blossoming features of every cereal species depend on the time of the day and weather condition, also every cereal species has certain the blossoming rhythm connected with the temperature and relative humidity. This concept was discovered at the end of XIX by Gordon and Hildebrand (Sergeyeva 1989).
Investigations showed that the daily rhythm of blossoming, if even has deviations connected with weather condition, is characteristic properties of the species and reveals changes within its certain frame. Therefore daily blossoming rhythm can be used as additional determining sign in number disputable issues of cereal taxonomy (Prokudin 1977).
The results of the study of daily blossoming rhythm are of importance not only for taxonomy and also in evolution meaning.
The study of daily blossoming rhythm of polymorph cereal species showed the antecologial differences within species which reveals biological isolation within species (population, ecotype). On base of this, it was proposed that "the demarcation of daily pollination period of populations stipulates their isolations and systematic differentiations that is the beginning of sympatric speciation" (Panomaryev, Rusakova 1968, Prokudin 1977, p.13).
Then concept was studied for different species of Festuca genus by Ponomaryov (1960), Tveretinova (1969), Xudyakova (1968), Sergeyeva (1989), Musayev (1991).
The study of the time, rhythm and frequency of the blossoming was carried out by the Ponomaryev´s method (1968).
Concrete number of flower group of every previously selected species was taken under continuous observation during blossoming time of this species. The number of opened flowers is controlled in every 15-20 minutes. Temperature and humidity are measured by humid meter at the same time. The opened flowers are cut during the counting process that will not be confused with the other newly blossoming flowers.
In the research of the rhythm of blossoming of F.pratensis the first acts in the group of flowers were noted on 10-18 May (Graphic 1). First pollens were observed on 19-22 May. Maximum blossoming are observed at 7:00-8:00 am. This time an average temperature is 11-15°C and the relative humidity is around of 80%. The temp of blossoming is different. The whole blossoming of flower group takes 7-8 days. Sometimes additional blossoming around 2:00-4:00 pm is observed.
In the classification of Panomaryev F.pratensis is referred to both morning cereals and cereals twice blossoming per day due to abovementioned peculiarities.
The difference in blossoming period and daily rhythm of F.pratensis is not observed in Azerbaijan flora on various zones. But it can be noted that in East zones relatively earlier blossoming is observed.
Thus, F.pratensis species with characteristic mesophytic signs has blossoming rhythm occurring at relatively low temperature and high relative humidity. It can be shown as graphic with parameters of day time, temperature and humidity.
Graphic 1. The blossoming rhythm and frequency of F.pratensis. A) Relative humidity, B) Ambient temperature, C) Hours, D) The number of flowers
The blossoming of Festuca rupicola Heuff occurs by portion way (Graphic 2). First, several flowers are blossomed in separate brooms. Then, flower chaffs are separated and pollens are appeared.
Graphic 2. The blossoming rhythm and frequency of F.rupicola. A) Relative humidity, B) Ambient temperature, C) Hours, D) The number of flowers
About 75-90% flowers are opened in a few minutes. Then, approximately during 10 minutes the pollination is occurred.
Such a mass pollination is repeated 5-7 times in 15-20 minutes. The values of the daily blossoming rhythm for F.rupicola were tested at 220C and 64% relative humidity.
Based on analysis of daily blossoming rhythm of F.rupicola can be conclude that this species shows the acute xerophytic properties. As the blossoming of F.rupicola occurs by portion way with intervals at the day time with very high temperature and very low relative humidity, which is the important adaptation in phylogenesis.
References
- Musayev S.H. Cereals of Azerbaijan. - Baku.: Elm, 1991, 420 p.
- Ponomaryov A.N., Rusakova M.B. Circadian rhythmics of pollination and speciation of cereals. // Botanic journal, 1968, 53: 10.
- Prokudin Y.N. Cereals of Ukraine. Kiev: Naukova Dumka, 1977, 503 p.
- Segeyeva V.V. Festuca L. genus in flora of Ciscaucasia. Krasnodar: 1982, 239 p.
- Tveretinova V.V., Tarasova V.Y., Iskra T.Q. About blossoming periods and rythms of allied forms of fescue. / Scientific report, 1969, 70: 10.
- Khudyakova L.P. Observation of F.sulcata var. Valesiaca Koch blossoming. - Biographic questions of Sredneye and Nizhnee Novedye. - Saratov: 1968, 237 p.
- Godron A. De la floraisen des Graminees. Mem. De la soc. // Nation des Sc.naturelles de Cherbourg, 1873. V. 7: 92.
Библиографическая ссылка
Alaskarov M.M. BLOSSOMING TIME AND RHYTHM OF THE F.RUPICOLA AND F.PRATENSIS SPECIES // European Journal of Natural History. – 2010. – № 2. – С. 3-5;URL: https://world-science.ru/ru/article/view?id=20934 (дата обращения: 25.11.2024).